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soil science

Organic Stories: Covert Farms, Oliver, BC

in 2019/Climate Change/Crop Production/Current Issue/Fall 2019/Grow Organic/Land Stewardship/Organic Community/Organic Stories/Water Management
Covert Family Farm - Portrait proud family vintners in vineyard

Fighting Drought through Complex Ecosystems

By Emma Holmes

Irecently had the pleasure of visiting Covert Farms Family Estate in Oliver, where Gene Covert, a third-generation farmer, gave me a tour of his family’s 650 acre organic farm, vineyard, and winery. Gene’s grandpa George Covert bought the desert-like piece of land back in 1959, and although some laughed, thinking the land would not be suitable for agriculture, he, his son, and eventually grandson, Gene, have built the farm into a robust, flourishing, certified organic farm that embraces biodynamic, permaculture, and regenerative farming methods.

Gene studied ecosystem complexity as a Physical Geography student at UBC and has carried this learning through to his farming career, approaching it with a high level of curiosity for the natural world and experimentation. His wife, Shelly Covert, a holistic nutritionist, has been co-managing the family farm and in 2010 they were awarded the Outsanding Young Farmer Award BC/Yukon. Gene and Shelley are deeply connected to their land: “The relationships of our land are complex and most have yet to be discovered. As we learn more we find interest, intrigue, and humility.”

Like many places in BC, Oliver is expected to face increasing warmer and drier conditions. Already a drought prone desert, it is more important than ever to find ways to slow the water down, trap it at the surface, give it time to infiltrate, and store it in the soil.

The secret to storing more water lies in soil organic matter. Soil organic matter holds, on average, 10 times more water than its weight. A 1 percent increase in soil organic matter helps soil hold approximately 20,000 gallons more water per acre.1

The Covert’s guiding philosophy is that “only by creating and fostering complexity can we hope to grow food with complex and persistent flavours. Flavours are the ultimate expression of the mineralization brought about by healthy soil microbial ecosystems.” To increase the organic matter content of his sandy soil, Gene took inspiration from organic and regenerative farmers in other agricultural sectors and began experimenting with cover crop cocktails, reduced tillage, and integrating livestock into his system.

Cover crop cocktails. Credit: Covert Farms

Cover Crop Cocktails

Cover crop cocktails are mixtures of three or more cover crop species that allow producers to diversify the number of benefits and management goals they can meet using cover crops. Farmers like Gabe Brown are leading the way and driving the excitement around cover crop cocktails, and research is following suit, with universities starting research programs such as Penn’s State Cover Crop Cocktail for Organic Systems lab.2

To help him in meeting the right mix for his system, Gene uses the Smartmix calculator, made by farmers for farmers3. He has found that seven or more species affords the most drought tolerance. He uses a combination of warm and cool season grasses, lentils, and brassicas. Some of the species in his blend include guargum, a drought tolerant N-fixing bean, radish to break up soil at lower depths, and mustards as a cutworm control.

Gene plants Morton lentils right under the vine to fix N and suppress downy brome. This type of lentil was developed by Washington State University for fall planting in minimum tillage systems. Crop establishment is in the fall and early spring, which is when evapo-transpiration demand is minimal, thus improving water-use efficiency.

The diverse benefits of his cover crop include N fixation, increase in soil organic matter, weed control, pest control, and increased system resilience in a changing climate.

Gene Covert. Credit: Covert Farms

Low-Till

Frequent tillage can negatively impact soil organic matter levels and water-holding capacity. Regular tillage over a long-time period can have a severe negative impact on soil quality, structure, and biological health.

The challenge for organic systems is that tillage is often used for weed control, seedbed preparation, soil aeration, turning in cover crops, and incorporating soil amendment. Thus, new management strategies need to be adopted in place of tillage. Cover cropping, roller crimping, rotational grazing, mowing, mulching, steaming, flaming, and horticulture vinegars are cultural weed control practices that can be used in organic systems as an alternative to tillage. The most successful organic systems embrace and build on the complexity of their system, and utilize several solutions for best results.

Gene used to cultivate five to six times a year, mostly for weed control, but now cultivates just once a year to incorporate cover crop seeds under the vines. Instead of regular tilling to control weeds, he uses cover crops that will compete with weeds but that won’t devigorate the crop and that can be controlled through non-tillage management strategies like roller crimping and rotational grazing. For cover crop seeds between the rows, he uses a no-till seeder.

Intensive Rotational Grazing

Integrated grazing sheep or cattle in vineyards is not a new concept, but it became much less common since the rise in modern fertilizers. It has been increasingly gaining steam in recent years due to the myriad benefits it provides. The animals act as cover crop terminators, lawn mowers, and weed eaters while also improving the overall soil fertility and biological health4. The appropriate presence of animals increases soil organic matter, and some on-farm demonstration research out of Australia showed significant reductions in irrigation use, reduced reliance on machinery, fuels, and fertilizers, and increased soil organic matter.5

Incorporating livestock into a horticultural system adds a completely new management challenge and thus level of complexity. It comes with the risk of compaction and over grazing if not managed properly. The key is to move herds frequently, controlling their access to different sections and never letting them stay too long in one area. As well, the grazing window needs to be limited to after harvest and before bud-break to prevent damage to the cash crop

Grapevines and mountains. Credit: Covert Farms

Increased Resiliency

Since experimenting with and adopting these management practices, Gene has found his cost of inputs has dropped and he has noticed a significant increase in soil organic matter and reduced irrigation requirements. Based on his success so far, he has a goal of eventually dryland farming. No small feat on a sandy, gravelly, glacio-fluvial soil in a desert climate facing increasing droughty conditions!

On-Farm Demonstration Research

A farmer’s experience and observations are critical in problem solving and the development of new management practices. Increasing farmer-led on-farm research is fundamental to improving the resiliency of producers in the face of ongoing climate change impacts, such as drought and unpredictable precipitation.

Farmer-led on-farm research compliments and builds experience by allowing a farmer to use a small portion of their land to test and identify ways to better manage their resources in order to achieve any farming goal they have, including climate adaptation strategies such as increasing soil organic matter to reduce irrigation requirements. The beauty of on-farm demonstration research is that it is farmer directed, it can be carried out independently, and it uses the resources a typical farmer would have on hand.

If you’re inspired by an idea, or a practice you have seen used in another agricultural system and are interested in conducting your own field trials, I highly recommend the BC Forage Council Guide to On-Farm Demonstration Research: How to Plan, Prepare, and Conduct Your Own On-Farm Trials.6 It is an accessible guide that covers the foundations of planning and conducting research, allowing you to achieve the best results. While it was created for the forage industry, the guide covers the basics of research and is applicable to farmers in any sector.

My highest gratitude and praise for the farmers who are finding the overlaps at the edges of agricultural models, where one becomes another—and leading the way into the new fertile and diverse opportunities for sustainable food production in a changing climate.

Thank you to Gene Covert and Lisa Wambold for their knowledge, passion, and insights.


Emma Holmes has a BSc in Sustainable Agriculture and an MSc in Soil Science, both from UBC. She farmed on Orcas Island and Salt Spring Island and is now the Organics Industry Specialist at the BC Ministry of Agriculture. She can be reached at: Emma.Holmes@gov.bc.ca

References and Resources:

1. Bryant, Lara. Organic Matter Can Improve Your Soil’s Water Holding Capacity. nrdc.org/experts/lara-bryant/organic-matter-can-improve-your-soils-water-holding-capacity
2. agsci.psu.edu/organic/research-and-extension/cover-crop-cocktails/project-summary
3. greencoverseed.com
4. Niles, M.T., Garrett, R., and Walsh, D. (2018). Ecological and economic benefits of integrating sheep into viticulture production. Agronomy and Sustainable Development. 38(1). link.springer.com/article/10.1007%2Fs13593-017-0478-y
5. Mulville, Kelly. Holistic Approach to Vineyard Grazing. grazingvineyards.blogspot.com
6. BC Forage Council. (2017). A Guide to On-Farm Demonstration Research. Farmwest.com. farmwest.com/node/1623

Adapting at Fraser Common Farm Cooperative

in 2019/Climate Change/Crop Production/Current Issue/Fall 2019/Grow Organic/Land Stewardship/Livestock/Organic Community/Pest Management/Seeds/Soil/Tools & Techniques/Water Management

Photos and text by Michael Marrapese

In 2018 Fraser Common Farm Co-operative—home of Glorious Organics—undertook a year long on-farm research project to explore how small farms could adapt to climate change. Seeing the changes in seasonal rainfall, climate predictions by Environment Canada, and new ground water regulations from the provincial government, the cooperative could see that water availability would eventually become a significant limiting factor in farming operations. 

The discussions about adaptation were complex and multi-factored. Every operation on the farm is connected to something else and many systems interconnect in differing ways throughout the season. Changing practices can be difficult, time consuming, and sometimes risky. 

During the year-long project, funded by Vancity, Co-op members worked to evaluate farming practices and areas of opportunity and weakness in farm management. The project generated several feasible solutions to decrease the demand on groundwater, buffer water demand, harvest rain water, and use irrigation water more efficiently. Some solutions were fairly straightforward and easy to implement. Others required more expertise, better data, and further capital.

Mark Cormier: Improving Water Practices

Mark Cormier explains how Glorious Organics uses edible, nitrogen fixing peas, and Fava beans for cover crops. He’s moved away from overhead spray irrigation to drip tape for the bulk of Glorious Organics’ field crops. He puts drip tape under black plastic row mulch. The plastic mulch significantly increases water retention and suppresses weeds. After the first crop comes off the field he rolls up the plastic and plants salad greens in the same row without tilling. Glorious Organics plans to double the size of the artificial pond and and dredge out a smaller natural spring basin to provide more water for the longer, drier summers the region is experiencing. Cormier notes that this year they are selling a lot of plums, a crop that they don’t water at all. 

Mark Cormier with Fava bean cover crop.
Mark with black plastic mulch and drip tape irrigation.
Plums in the upper orchard
Artificial pond and solar powered pumping station.

David Catzel: Developing Diversity

Catzel has several plant breeding and selection projects on the go to develop populations of productive, flavourful, and marketable crops. Preserving and expanding bio-diversity on the farm is vital for long-term sustainability. With his multi-year Kale breeding project, David has been seeking to develop a denticulated white kale and in the process has seen other useful characteristics, like frost-hardiness, develop in his breeding program. He’s currently crossing varieties of watermelon in order to develop a short-season, highly productive variety. His development of seed crops has also become a significant income source. He estimates his recent batch of Winter White Kale seed alone will net $1,500 in sales. As the Co-operative diversifies its product line to include more fruit and berries, organic orchard management practices have become increasingly important. Catzel has been instrumental in incorporating sheep into orchard management. A critical component of pest management is to keep the orchards clean and to remove any fruit on the ground to reduce insect pest populations. The sheep eat a lot of the fallen fruit and keep the grass and weeds in check making it easier to keep the orchards clean. 

David Catzel and the Kale Breeding Project.
David Catzel crossing Watermelon varieties.
David Catzel with his Winter White Kale seed crop.
David tending sheep.

Barry Cole: Gathering Insect Data

With the arrival of the spotted wing drosophila fruit fly, Fraser Common Farm was facing a management crisis. There seemed to be little organic growers could do to combat the pest, which destroys fruit before is is ripe. Infestations of Coddling Moth and Apple Maggot were making it difficult to offer fruit for sale. Barry Cole set about to gather meaningful data to help understand pest life cycles and vectors of attack. He’s set up a variety of traps and tapes and monitors them regularly to determine when pests are most active and which trees they prefer. The “Bait Apples” attract a large number of Apple Coddling Moths. The yellow sticky tapes help determine which species are present at various times in the season. Since many of the fruit trees are more than 20 years old, he also monitors and records tree productivity and fruit quality to better determine which trees should be kept and which should be replaced. 

The fake apple trap.
Identifying active pests.
Inspecting Early Harvest.
Barry Cole inspecting walnuts for pests.

Michael Marrapese is the IT and Communications Manager at FarmFolk CityFolk. He lives and works at Fraser Common Farm Cooperative, one of BC’s longest running cooperative farms, and is an avid photographer, singer, and cook.

Feature image: David Catzel’s watermelon varieties.

Clockwise from left: ; the fake apple trap; identifying active pests; Barry Cole inspects walnutd for pests; Mark Cormier with fava bean cover crop; plums in the upper orchard; David Catzel with his White Winter Kale seed crop. Credit: Michael Marrapese. 

Biodynamic Farm Story: Putting the Dynamic in Biodynamic

in 2019/Crop Production/Current Issue/Fall 2019/Grow Organic/Land Stewardship/Soil/Tools & Techniques

Anna Helmer

I used to write a small weekly column for the local paper, telling stories about the farm each week. I kept it going through the busy times and the not busy times. I hardly remember how I managed to write the required 600 coherent words during those intensely busy summer weeks. Maybe they weren’t coherent. Likely not, now that I think about it. Maybe coherence was not a goal. If you can’t do it, don’t make it a goal, I always say.

Those winter columns, though. I remember writing those. They were the ones where I had done precious little farm work during the week and now had to write about it. They were a challenge to compose. At least in the summer weeks there was lots of material. However, I did learn how to make 600 entertaining words out of, say, a flat tire and a quiet market.

I am feeling reminiscent of those lazy days of winter and cobbling together something interesting about scant farming activities because I have agreed to do another installment of Biodynamic Farm Story, but I really haven’t done much Biodynamic stuff lately.

The blame for this lies entirely with the farm. In addition to non-descript regular farm work, each tractor has broken down several times, we’ve poured new concrete, built a new shed, and started attending our local market about six weeks earlier than ever before. The events have very much taken precedence over Biodynamic activities. The original Biodynamic lectures don’t seem to specifically address what to do when this happens.

Those lectures contain a fair amount about the importance of talking with other farmers about Biodynamic methods, however. I gather Steiner, the lecturer, understood that much of his content was untested in real farm-world situations. There is also acknowledgement that every single farm, being its own entity consisting of its own unique people, soil, and environment, will have to find its own way.

(Cosmic) Hightland Cow. Credit: Nilfanion (CC)

I think that’s the story this time: how does it work to be a Biodynamic farm (or farmer!) when events overtake intentions? This is about how we can’t seem to follow the Biodynamic calendar very well, and how in actual fact, we seem to forget all about being Biodynamic when the fur starts flying on a busy farm season. Perhaps this is when the “dynamic” part comes into play.

I would like to think that the work we do in the shoulder seasons—creating composts, using the preparations, planning planting around propitious dates in the calendar—all contribute to the strength of the farm now, when it is being fully taxed. I suppose it possibly might be so.

Theoretically, what would a biodynamically active farmer not like me be doing right now on the farm? I would have two things on the list: compost management and Biodynamic Preparation 508.

Priority one: turn the cow manure pile and bung in more Biodynamic preparations, purchased in a set from the Josephine Porter Institute—nettle, yarrow, dandelion, oak bark, chamomile and valerian. They are intended to not only stimulate the biological breakdown of the material into humus and whatnot, but also to create a source of energy for the farm. How cool is that?

I came across a metaphor for the Biodynamic compost heap several years ago, the source regretfully forgotten, the actual meaning mangled: Cosmic Cow. Consider the cow that can transform the energy of the sun (via green grass) turning it into precious manure that may be used to grow our eating plants. It is a remarkable feat that is accomplished in a complex digestive system. Even more remarkable, the function carries on despite the animal eating all kinds of garbage along with the lovely grass. And through thick and thin, the animal maintains a more or less even disposition, emanating a particular energy that is quite powerful, in its own way.

So the Cosmic Cow Biodynamic Compost heap can do the same sort of thing. Its digestive system is powered up to produce the desired dirt, and the whole thing is solidly grounded to be able to broadcast the infinite energy of the universe to the farm.

If I had some time, and if the loader tractor hadn’t developed a leak in the axle and the right seal had been sent from the source of seals and if it therefore had a wheel, I totally would have done that job by now. Pretty certain it is high on Dad’s list too. The wheel will eventually go back on, surely. Meanwhile, the pile sits patiently in the field, the essential activity continuing despite neglect.

I am also looking into the preparation called 508. It uses horsetail in either a tea form (very easy to make) or a more complicated distillation. There has been a lot of rain, heat, and wind lately and fungal issues may arise. The 508 may help cope with that. Plus, it is all the rage right now in Biodynamics and I am nothing if not keen to fit in.

If there is one weed we have plenty of in the potatoes this year, it is horsetail. Do I go to the effort of picking it, boiling it up and spraying it around? So far, I do not.

A look into my farm notes for the past couple of months reveals at least a passing nod to the Biodynamic Calendar. I have noted when something I did was done because it was a good day to do it according to the position of the moon and the planets. It still means nothing to me, but I think the plants get it, so that’s good. For example, the carrots were done right. As that field also had a good helping of BD 500 both last fall and this spring, I could expect one of our best crops ever. I don’t, however. Biodynamics is a method, not a guarantee.

Unlike chemical fertilizers. They are more of a guarantee. It is very plain to see the appeal of popping in a wee bit of N, P, and K at planting time. Conventional farmers in Pemberton who planted potatoes weeks later than us are pleased that theirs came into flower right at the same time and achieved row cover well ahead. It’s just a fact of science.

A fact that means nothing to me. Today when I walked through our potato field, I would have needed a machete to get through the White Rose and Fingerlings. As an aside, did you know that potato flowers smell delicious?

I boast like this because I think Biodynamic farming can be a difficult sell to…well…most farmers. Let’s face it. The positive results are heavily anecdotal. I must add my own.


Anna Helmer farms with her family and friends in the Pemberton Valley and could have submitted the picture that featured a lot of weeds but instead chose the one that did not.

Feature image: Tractor wheel in a beautifully weed-free potato crop. Credit: Anna Helmer

Soil Health & Cover Crops

in 2019/Climate Change/Crop Production/Grow Organic/Land Stewardship/Seeds/Soil/Spring 2019

A Recipe for Success in Achieving Long Term Soil Conservation

Saikat Kumar Basu

Why Care for our Soils?

Soil is an important constituent of both agriculture and forestry; unfortunately, it is taken for granted most of the time. It is a cheap, easily accessible or available global resource for which we have often forgotten to take the necessary care. We have used it non-judiciously without proper planning and vision for the future.

The concept of soil health has always been there since the dawn of human civilization—but only quite recently have we started to better understand, appreciate, and care for our soils as part of sustainable agriculture. We as humans have possibly matured over time and realized that our exploitative and non-judicious use of our soil resources can limit our long-term agricultural productivity and jeopardize successful crop production.

Unless we are serious enough to take good care of one of our most abundant yet highly sensitive natural resources of this planet, the soils, we ourselves will be solely to blame for the degradation of our soils—thanks to the self-destructive approaches we’ve used to achieve very short-term objectives of making easy profits without thinking deeply about the long-term consequences.

Soil health today has emerged as an important aspect of proper soil management as a component of sustainable agriculture to help in quality crop production without depleting or damaging soil quality and helping in proper soil conservation at the same time (Fig. 1).

What Impacts Soil Health?

Several factors impact soil health, among the most important being over application of fertilizers and pesticides. The soil represents a dynamic ecosystem and an intricate playground of delicate physics, chemistry, geology, and biology. Any chemical application on the soil therefore has some positive or negative impact on the soil quality by interfering with the physicochemical and biogeological processes associated with soil formation. These changes include shifting the soil pH due to various anthropogenic activities that slowly impact the soil quality. Drastic reduction in pH makes soil acidic, while rapid increase in pH leads to alkalinity or salinity; both conditions make the soil unsuitable for a long time for quality crop production. Furthermore, increased emphasis on monoculture associated with our modern industrial agriculture year after year depletes the soil of essential macro and micro nutrients necessary for maintaining optimal soil health (Fig. 2).

Fig 2. Increased emphasis on crop monoculture is detrimental to long term soil health.

Over application of synthetic chemical fertilizers and various pesticides to secure crop production adds too much pressure on our soil, impacting not only the physicochemical and geological processes active in the soil, but also negatively impacting the soil macro and micro flora and fauna devastatingly over a long period of time. Several beneficial microbes like soil bacteria, Cyanobacteria, soil fungi, soil borne insects, spring tails (Collembola), earthworms, and other critters essential for maintaining soil health suffer population collapse due to non-judicious over application of synthetic fertilizers and pesticides.

Many such chemical residues remain in the soil for prolonged period and often percolate deep into the soil, reaching the groundwater table or adjacent surface fresh water resources via surface run off, with long term negative impacts on both soil and water. Often the beneficial soil macro and micro flora and fauna are altered or replaced by harmful species that prove detrimental to soil health and significantly impact crop production and forest ecology. Random unplanned crop rotations and fallow harm our soil more than we actually realize; making them susceptible to weed and pest infestations (Fig. 3), loss of precious top soil and lower crop production due to poor soil health.

Fig 3. Untended soil is subjected to weed infestation that interferes with quality crop production.

Best Management Practices (BMPs) for Promoting Sustainable Soil Health

To maintain optimal soil health for long term success in achieving quality crop production we need to take necessary steps and plan carefully. This takes needs patience, and deeper understanding, as well as painstaking observations to implement good soil health practices on cropland.

Regular soil tests are important to ensure that we are aware of the excesses as well as depletion of necessary macro and micro nutrients in the soil. We also need to look into the topography of the crop field, the low and high spots in the field, the areas impacted by acidification and salinity issues, detailed history of fertilizer and pesticide applications over the years and the successive crops grown. Any past issues associated with the soil should be recorded for future reference. The nature of pest and weed infestations should be recorded to identify any specific patterns with respect to local pest and weed populations. Such detailed record keeping together with advanced GPS- and GIS-generated high-quality images of the field over the years will provide a farmer or crop producer or a professional agronomist ample reference to make judicious decisions to secure comprehensive soil health strategy and crop management for the future.

Based on the above information, we need to adopt a specific crop rotation plan to ensure that the soil is not exhausted of essential soil nutrients. Application of fertilizers and pesticides should follow manufacturer’s guidelines stringently to avoid over application (Fig 4).

Fig 4. It is important to keep track of weed and pest species impacting crop production in a particular field for making judicious decisions regarding appropriate chemical applications at the appropriate stage and dosage following manufacturer’s instructions.

It is also important to note if soil compaction is causing a problem for the field. If this is an issue, then highly mechanized farming activities and movements of heavy vehicles need to be restricted to a specific easily accessible area to reduce negative impacts of soil compaction on the field.

Intercropping could be practised depending upon the farming need and also to use the soil resources judiciously. This can enhance crop production and add crop diversity to the field important for maintaining soil health.

Role of Cover Crops in Promoting Long-Term Soil Health and Soil Conservation

Cover crops are an important aspect for maintaining general soil health if used with scientific outlook and proper planning. Several cover crops choices are available. Annual and perennial legumes, various clovers and sweet clovers, bird’s-foot trefoil, hairy vetch, common vetch, cicer milkvetch, sainfoin (Fig. 5), fenugreek, fava beans, soybeans, field pea or forage pea, cowpea, chickpea, green pea, black pea, different species of beans, oil crops such as annual and perennial sunflower, safflower, flax, forage canola, different mustard species (Fig. 6), brassicas such as forage rape, turnips, collards, radish, forage crops such as tef grass, Sudan grass, sorghum, sorghum x Sudan grass hybrids, corn, cereals such as winter rye, wheat and triticale, different millets, such as Proso millet, Japanese millet, German millet, red millet, special or novelty crops such as hemp (Fig 7) , chicory, plantain, phacelia, buckwheat, and quinoa are only a handful of choices to mention from a big basket of abundant crop species currently available across Canada.

Fig 5. Mustard cover crop in full bloom.
Fig 6. Perennial forage legume sainfoin is an excellent cover crop that can be successfully used in crop rotation cycles. Sainfoin is also exceptional for pollinators, attracting bees and other insects in large numbers.
Fig 7. Hemp is a new speciality crop for Canada and has been generating serious interest among farmers for agronomic productions. Hemp has been found to attract diverse species of insect pollinators too.

Several grass species such as orchard grass, tall fescue, short fescue, meadow fescue, creeping fescue, chewing fescue, festulolium, timothy, annual and perennial rye grass, Italian rye grass, and various other forage and native species are being used in specific legume-grass mix, in highly planned and organized crop rotations or in soil reclamation and pollinator mixes for attracting insect pollinators to the crop fields and in checking soil erosion effectively.

Cover crops should be selected based on the agro-climatic zone and soil zones of the region and used in planned rotations. Species or different appropriate cover crop mixes are to be selected based on the long-term objective of the crop production. For example, cover crop mixes used as pollinator mixes could not only be planted in the field during a fallow; but can also be used in agronomically unsuitable areas, along field perimeter, under the centre pivot stand, hard to access areas of the farm, shelter belts or adjacent to water bodies or low spots in the field too.

Forage cover crops could be used where the field is partly subjected to animal foraging or grazing or ranching. Similarly, oil crops, pharmaceutical or neutraceutical crops, or specialty or novelty cover crops could be used in crop rotations with major food or industrial crops grown in the particular field in a specific agro-climatic region.

Fig 8 Cover crops rotations can be an effective long term solution for managing optimal soil health with long term positive impacts on soil quality and soil conservation.

Cover crops not only play an important role in crop rotation cycle; but, also help in retaining soil temperature and moisture as well as protect top soil from erosive forces like wind and water. The presence of live roots in the soil and a rich diversity of crops stimulate the growth and population dynamics of important soil mega and micro fauna and flora for sustaining long term soil health, soil quality and soil conservation. Cover crops help in balancing the use of essential soil macro and micro nutrients in the soil, as well as promoting better aeration, hydration, nitrogen fixation, and recycling of essential crop minerals, assisting bumper production of food or cash crops due to improvement in soil quality for successive high-quality crop production.

It is important for all of us to understand and appreciate that soil is a non-renewable resource and needs special care and attention. Unless we are careful to use this special resource so deeply associated with our agricultural and forestry operations judiciously, we may be slowly jeopardizing crop productivity—and our common future—in the not so distant future.

Proper planning and scientific soil management practices can play a vital role in keeping our soil productive as well as healthy. Use of crop rotations and cover crops are some of the important approaches towards long-term soil health, soil conservation, and crop productivity. We need to learn more about our local soil resources for our future food security and incorporate more soil friendly practices to prolong the life and quality of our soil.


Saikat Kumar Basu has a Masters in Plant Sciences and Agricultural Studies. He loves writing, traveling, and photography during his leisure and is passionate about nature and conservation
Acknowledgement: Performance Seed, Lethbridge, AB

Featured Image: Fig 1. Scientific management of soil health contributes towards long term high quality crop production as well as soil conservation. Image Credit: All photos by Saikat Kumar Basu

Ask an Expert: Soil Testing

in 2019/Ask an Expert/Crop Production/Grow Organic/Land Stewardship/Soil/Spring 2019

Tools for your Nutrient Management Toolkit

Amy Norgaard, Dru Yates, & Emma Holmes

Every year farmers align countless variables to produce healthy crops that make it to market. Crop planning. Bed prep. Transplanting. Irrigation. Weed management. Pest management. Harvest. Storage and transport. Typically, there is a sweet spot in terms of either quantity or timing for each of these, and there are indicators or measures to stay in that ideal range. For example, the weather forecast and local temperatures highlight best times for transplanting, thermometers track temperatures in storage facilities, and in-field insect traps help monitor pest pressures. Nutrient management is another one of these farm management components that we can stack in our favour—and soil sampling is an essential tool to make informed decisions in this area.

The main reason for soil sampling in agriculture is to assess soil fertility and related properties like pH and texture. Results not only inform management practices for the current season but can also act as a report card for past decisions. Just like we can feel or measure the soil to make irrigation decisions, we can use soil tests to provide us with a snapshot of fertility status and amend accordingly. Being able to apply the right nutrients in the right quantities is just another opportunity to add another piece to the puzzle on the way to our yield, quality, and/or productivity goals.

Best Practices for Taking a Soil Sample

When collecting soil for analysis, the goal is to obtain a sample that is representative of the area you are interested in. Since soil properties vary across fields, there are several steps to ensuring the most reasonable average possible.

1. Take several sub-samples from your area of interest and mix them together to get a composite sample:

  • If your garden plot is small (100 – 200 sq. ft), take 4 – 5 samples.
  • If your garden is larger (500 – 10,000 sq. ft.), take 9 – ­ 10 samples.
  • If you are measuring a larger area (i.e. 1 – 25 acres) and that area is relatively uniform in cropping and management history, take about 15 – 30 samples to make your composite sample.
  • If your sample area is larger than 25 acres, try to arrange your sampling areas so that a single composite sample does not represent more than 25 acres.

2. Avoid spots that look different from the rest, or that have been managed differently. For example:

  • Wet spots in an otherwise well drained field.
  • Areas where plants are growing exceptionally well, or exceptionally poorly compared to the rest of the field.
  • Greenhouses that are left covered over winter.
  • If you are curious about an area that is different from the rest, sample it separately.

3. Make sure each sub-sample is the same volume and is taken to the same rooting depth (usually 6 inches for most nutrient tests).

4. Collect samples randomly from the entire field area. A soil probe is the ideal tool as it is fast and ensures consistency among depth and volume of samples, but if you don’t have one readily available, a trowel or garden spade works well. You will also need a bucket and plastic bags. It helps to pre-label the bags with the sample name using a sharpie so that samples don’t get mixed up! Clean any equipment that comes into contact with the sample (eg. shovel and bucket) with clean potable water and dilute soap.

5. Start collecting samples from the sampling area and add into the bucket. Remove any bits of vegetation, pebbles, or fauna with a gloved hand. Once you have all your sub-samples for your area in a bucket, mix them together and take a ½ cup of soil and put into the prelabeled ziplock bag.

6. Repeat for other samples, making sure to clean your tools between sites.

For more details on taking a soil sample, please refer to this factsheet, which can be accessed by searching for ‘Soil Sampling for Nutrient Management’ on the BC Ministry of Agriculture website

Due to inherent variability in analytical methods, two labs can provide different values for the same nutrient of interest because labs use different extraction methods and equipment. Even when using the same method there is lab to lab variability. Therefore, it is important to use the same lab consistently to monitor trends over time. It is also important to take into consideration the methods used when analyzing the results.

On Testing Compost and Amendments (It’s a Good Idea)

Composts are commonly used in organic agriculture as a source of organic matter and plant nutrients. However, these amendments vary widely in their composition depending on many factors, such as feed-stock, composting process, and storage conditions. These not only affect the initial nutrient content, but also influence nutrient loss prior to spreading, as well as the soil nutrient dynamics (release and availability to crops) when the amendment is spread in the field. Therefore, testing a compost pile shortly before spreading gives us the best snapshot of its composition and represents another tool in our toolkit when making site-specific nutrient management decisions in systems using these products.

Composts can be tested for a variety of properties, including both macro- and micro-nutrient content, carbon to nitrogen ratio (C:N), pH, electrical conductivity (EC), organic matter content, etc. Together, these provide an overall picture of compost quality and can help predict the subsequent effects on soil quality and nutrient supply to crops. The specific parameters to test for depend on the goals for using the product, and any specific concerns or goals. For example, farms that already have salinity issues may want to test potential soil amendment sources for EC as an indicator of salt content to avoid exacerbating this pre-existing situation.

From a broad nutrient management perspective, testing for C:N, nitrogen (N), and phosphorous (P) are valuable first steps in balancing these nutrients, as compost products are often used to supply all or at least part of the N and P needs in organic farming systems. Additionally, these nutrients are important to consider because they are not only needed in significant quantities, but are also environmentally damaging when lost to surrounding ecosystems. In general, applying compost to target crop N requirements results in the over-application of P, and over time we see excess P levels in soils where this management practice is common (Sullivan & Poon, 2012). This highlights the advantage of implementing soil and compost testing, where we can not only monitor our soil P levels over time, but also be aware of the quantity we are applying by testing our amendments.

Finally, while N and P are two important plant macronutrients, compost provides a variety of other plant nutrients that can be important considerations, depending on the crop we are amending, soil test values, and any other farm-specific considerations. Implementing compost testing as a tool to be more informed about the properties of these amendments allows for more specific, targeted use and more efficient, environmentally-friendly farming systems overall.

How to Calculate Amendment Needs

While compost and soil tests answer the question “What’s there?”, there are still a few steps to go from these values to a target amendment application rate in the field. This can often be the most intimidating element and involves a few calculations. However, there are several online or downloadable calculators and resources for this process. The two nutrient calculators listed below are good starting points, and are accompanied by several resource pages and/or documents to get oriented to how they work. The BC Ministry of Agriculture’s Nutrient Management Calculator allows you to pick your lab when inputting your values, and will assist you in choosing the right rate and nutrient source for your crops.

Amendment Calculators:
Organic Cover Crop and Fertilizer Calculator (OSU Extension)
BC Ministry of Agriculture Nutrient Management Calculator

Additional Nutrient Management Resources:
Fertilizing with Manure and Other Organic Amendments (PNW)
Nutrient Management for Sustainable Vegetable Cropping Systems in Western Oregon (OSU)

Soil Fertility in Organic Systems – A guide for gardeners and small acreage farmers (PNW)

Post-harvest Nitrate Testing

The post-harvest nitrate test (PHNT) is a soil test performed in the late-summer to early-fall to evaluate nitrogen (N) management, and is another soil test to add to your nutrient management toolkit. This test measures the amount of nitrate-N remaining in the soil following harvest, and represents the plant-available N that was not used by the crop during the growing season.

Nitrate is highly mobile within the soil system and so is highly susceptible to leaching during winter months. For example, in coastal BC, effectively all soil nitrate is assumed to be lost from the root zone (in absence of an established cover crop) due to high winter rainfall. As such, it is:
1. common for spring nitrate-N soil test values to be minimally informative, and
2. important to manage soil N in ways that keep PHNT values low.

The PHNT is often referred to as a “report card” assessment of N management as it is used in retrospect—an evaluation of the impacts of nutrient management decisions that were made for the previous season. It provides a way for growers to assess and adjust their N management, to both get the most effective use out of the fertilizer inputs they are paying for, and to reduce environmental impacts of excess nitrates entering waterways.

Rating General Interpretation PHNT (kg/ha)

0-30 cm

Low Continue present N management < 50
Medium Adjust N management to improve plant uptake efficiency 50-99
High Reduce N inputs, implement strategy to reduce N leaching (e.g. cover crop) 100-199
Very High >200

Table 1. Post-Harvest Nitrate Test (PHNT) ratings developed for corn and grass in the B.C. Lower Mainland (taken from Kowalenko et al. 2007).

To take a sample for PHNT, follow the general instructions for a taking a soil sample (see above in ‘Best Practices for Taking a Soil Sample’), plus the following modifications. Note that PHNT sampling protocols are somewhat crop and region specific. The following are generalized tips:

Timing: the general guideline is to sample after harvest, and before cover crop seeding, soil amending, and significant rainfall. For example, sampling before 125mm cumulative rainfall in south coastal BC on fine to medium textured soils is ideal.

Depth: sample to a minimum of 30cm. This is deeper than standard nutrient sampling recommendations.

Adjust for volume: take the nitrate-N value that you get from the soil lab and multiply by depth (0.3m), multiply by the bulk density of the soil (kg/m^3), and divide by 100 to get PHNT value in kg/ha. Soil bulk density will vary by soil type, and farm-specific values can be attained by paying for a bulk density test at a soil lab. The finer the texture, the denser the soil – many commonly used book-values fall between 1150 to 1300 kg/m^3.

For certain forage crops in coastal BC, such as silage corn and grass, target PHNT values have been developed to indicate whether N inputs should be managed differently in the following season. Under these rating systems (Table 1), higher ratings mean lower N-use efficiency and greater risk for leaching loss of nitrate-N.

The typical, potential reasons for inefficient N-uptake are:

  • N applications were in excess of total crop needs;
  • N was not applied at the optimal time(s) for crop uptake; or,
  • N was not applied where it was accessible to plant roots, or that other growing conditions (e.g. moisture, temperature, other nutrients) were limiting to crop uptake of N.

Relative differences in PHNT values are a useful tool in N management decisions, regardless of crop-specific target PHNT values. If you can identify a field or crop with high PHNT relative to your other fields, this is something to note, adjust nutrient management, and evaluate how that impacts your PHNT values the following season. This PHNT approach to N testing will provide much more insight into your N management than the N values you will receive from your spring soil tests. To address the need for more PHNT information in other field vegetable crops besides silage corn and grass, work is ongoing in BC to better understand PHNT testing and its implications.

Further detail on taking samples and interpreting PHNT values is available through the OSU Extension Catalog, search ‘Post-Harvest Soil Nitrate Testing’.

Assistance can also be found by contacting your Organics Specialist, Emma Holmes (Emma.Holmes@gov.bc.ca) at the BC Ministry of Agriculture.

Soil Labs 

AGAT Laboratories
120 – 8600 Glenlyon Parkway, Burnaby, BC V5J 0B6
Phone: (778) 452-4000

Exova (formerly Bodycote/Norwest)
#104, 19575 – 55A Avenue, Surrey, BC V3S 8P8
Phone: (604) 514-3322 Fax: (604) 514-3323
Toll free: (800) 889-1433

Maxxam Analytics (formerly Cantest Ltd.)
4606 Canada Way, Burnaby BC V5G 1K5
Phone: 604-734-7276 Toll-free: 1 (800) 665-8566
Email : info@maxxamanalytics.com

Ministry of Environment Analytical Laboratory
4300 North Road
PO BOX 9536 Stn Prov Govt Victoria, BC
Phone: 250-952-4134
Email: NRlab@gov.bc.ca

MB Laboratories Ltd.
By Courier: 4 – 2062 West Henry Ave, Sidney BC V8L 5Y1
By Mail: PO Box 2103, Sidney BC V8L 3S6
Phone: (250) 656-1334
Email: mblabs@pacificcoast.net

Pacific Soil Analysis Inc.
5 – 11720 Voyageur Way, Richmond BC V6X 3G9
Phone: (604) 273-8226
Email: cedora19@telus.net

Plant Science Lab (affiliated with TerraLink Horticulture Inc.)
464 Riverside Road, Abbotsford, BC V2S 7M1
Phone: (604) 864-9044 x1602
Email: pwarren@terralink-horticulture.com


Amy Norgaard: Amy has a BSc in Agroecology and is now working on a MSc in Soil Science in the Sustainable Agricultural Landscapes lab at UBC. She has worked on several small-scale organic farms and is an Articling Agrologist with the BCIA. Her research is focused on nutrient management on organic vegetable farms. She can be reached at: amynorgaard@alumni.ubc.ca

Dru Yates: Dru has a M.Sc. in Soil Science from UBC, is an Articling Agrologist with the BCIA, and currently works as a consultant with E.S. Cropconsult Ltd. Her work includes providing integrated pest management (IPM) services to vegetable and blueberry growers throughout the Fraser Valley, as well as performing sampling and local research trials related to nutrient management. She can be reached at: dru@escrop.com

Emma Holmes: Emma Holmes has a B.Sc. in Sustainable Agriculture and a M.Sc. in Soil Science, both from UBC. She farmed on Orcas Island and Salt Spring Island and is now the Organics Industry Specialist at the BC Ministry of Agriculture. She can be reached at: Emma.Holmes@gov.bc.ca

References

Kowalenko, C.G., Schmidt, O., and Hughes-Games, G. (2007). Fraser Valley Soil Nutrient Study 2005. A Survey Of The Nitrogen, Phosphorus And Potassium Contents Of Lower Fraser Valley Agricultural Soils In Relation To Environmental And Agronomic Concerns.

Sullivan, C. S., & Poon, D. (2012). Fraser Valley Soil Nutrient Survey 2012.

Feature Image: Amy Norgaard sampling soil. Credit: Teresa Porter

Healthy Soils Yield Resilient Operations

in 2019/Climate Change/Crop Production/Grow Organic/Land Stewardship/Livestock/Soil/Spring 2019/Tools & Techniques/Water Management

Three case studies examine soil management practices in the face of climate change

By Rachel Penner, BC Agriculture & Food Climate Action Initiative

Improving soil health is one way producers can increase the resilience of their operations in the face of climate change. The BC Agriculture & Food Climate Action Initiative (CAI) has supported multiple projects, with funding from the provincial and federal governments, evaluating practices to maintain or improve soil health. Case studies in three regions of the province offer some practical takeaways for farmers looking to adapt to changes in climate.

Okanagan: Adding Compost and Reducing Irrigation

Climate change is expected to increase average temperatures and lengthen the growing season in BC’s Interior, enabling cherry producers to expand production northward and grow crops at higher elevations. However, expanding production may be limited by challenges with managing soil pathogens and by water availability.

A three-year research project focusing on cherry production in the Okanagan resulted in two key findings: 

  • adding compost to old and new orchards helped maintain soil health
  • reducing post-harvest irrigation by 25% did not impact fruit yield or quality

Gayle Krahn, the horticulture manager at Coral Beach Farms, participated in the project. “It’s through these trials that growers gain the confidence needed to invest in mulches,” says Krahn. “As well, the results from the deficit irrigation studies gave us a good handle on how much water we need in our orchards. Climate change could affect our water supply, so we need to be mindful of our water usage while ensuring we can continue to grow healthy crops.”

Louise Nelson with the Biology department at UBC Okanagan led the three-year experiment. Researchers monitored the effects of compost and mulch applications, comparing results with controls in two new and one established orchard, and assessed the impacts of post-harvest deficit-irrigation.

The study, completed in 2018, revealed that adding compost to cherry orchards had the following impacts on the soil:

  • increased soil organic matter, total carbon and nitrogen, other mineral nutrients and pH
  • increased percentages of nitrogen, phosphorus and potassium in leaves after two years
  • increased fruit firmness and stem pull
  • tended to increase total nematode abundance in soil
  • tended to decrease plant parasitic nematodes in plant roots and soil
  • decreased colonization of roots by arbuscular mycorrhizal fungi

“I would definitely recommend that growers invest in compost as it helps build soil structure, reduce moisture loss and keep soils cool during summer heat,” says Krahn. “The result is increased root growth and a healthier tree, which equates to growing quality fruit.”

The study also found that a 25% reduction in post-harvest irrigation had no impact on fruit yield and quality, stem water potential, tree growth, or leaf mineral content, giving producers greater assurance that they can safely decrease water usage in their cherry orchards post-harvest.

Delta: Using and Maintaining Tile Drains

Climate projections indicate that winter rainfall will increase and extreme rainfall events will double in frequency by the 2050s in BC’s Fraser River delta. This increase in moisture could prevent farmers from getting onto waterlogged fields, either to plant or to harvest, and could also increase soil erosion, nutrient runoff, and damage to crops.

However, effective spacing and maintenance of tile drains can increase the ability of producers to work their fields.

A project in Delta, completed in July 2017, evaluated practices for improving on-farm drainage management as a way to adapt to wetter spring and fall conditions. The project, led by three researchers in the Faculty of Land & Food Systems at UBC in collaboration with the Delta Farmers’ Institute, the Delta Farmland & Wildlife Trust and local farmers, set up demonstration sites on two fields and monitored practices across a total of 30 fields in multiple locations.

The results of the two-year project indicated the following:

  • Using tile drains in vegetable crop fields increased workable days by 8% and by 14% when pumps where also used. (The impact was negligible for blueberry fields.)
  • Drain tiles spaced at 15 feet allowed soil to dry faster in the spring than drain tiles spaced at 30 feet.
  • Cleaning tile drains resulted in 12 extra workable days per year at a cleaning cost of $10/additional workable day/acre.

Central Interior: Practising Management-intensive Grazing

Management-intensive grazing, a practice that involves planned grazing and rest periods for pastures, is a context-dependent practice that can vary from one rancher and pasture location to the next, making it difficult to test the impact it has on soil.

A four-year project in BC’s Central Interior, completed in spring 2017, compared grazing practices and used traditional soil sampling methods, plant community composition and remote sensing to measure soil carbon. Results confirmed that management-intensive grazing increased soil carbon, which has important implications for soil health.

“What got me interested in grazing-management practices was the enthusiasm of the ranching community,” says Lauchlan Fraser, a professor at Thompson Rivers University who led the project. “I wanted to see if some of the claims that were being made held up.”

The data showed that, for intensively managed pastures, total carbon was 28% greater and organic carbon was 13% greater when compared to extensively managed pastures. It is widely agreed that this stored carbon is linked to soil health, and a fact sheet for the study stated that: “Benefits associated with greater soil carbon include soil moisture retention, erosion control and species biodiversity.”

These outcomes were experienced by the producers who participated in the study. All the ranchers reported that they saw improved soil moisture retention, which would help them cope better in a drought year. They also thought the practice would work as a tool to control invasive species and improve plant and animal diversity, both important contributors to resilient grazing systems.

“It would be worthwhile to follow up with doing the research required to test how biodiversity and soil moisture are influenced,” says Fraser.

While carbon sequestration is primarily associated with climate change mitigation, the project’s final report found additional implications for climate change adaptation: “Flexibility of electric fencing, and actively managing cattle on a daily basis, was identified to be an adaptation strategy, since a rancher is able to adapt his or her practices based on conditions which vary from one year to the next,” says Fraser.

Project Funding and Detailed Reports

For all three of the projects, funding was provided by the Governments of Canada and British Columbia through the Canadian Agricultural Program as part of the Farm Adaptation Innovator Program delivered by CAI.

Complete project results and fact sheets can be found on the CAI website at:

bcagclimateaction.ca


Rachel Penner is the Communications Specialist for the BC Agriculture & Food Climate Action Initiative. She grew up on a grain farm in southwestern Manitoba, received her journalism diploma in Alberta and spent time as a writer and editor in Saskatchewan. She now resides in Victoria, BC, where she works and volunteers as a communications designer and strategist.

Feature photo: Farm field in Delta, BC. Photo credit: CAI – Emrys Miller

Footnotes from the Field: Intergenerational Soil Stewardship

in Fall 2018/Footnotes from the Field/Grow Organic/Land Stewardship/Organic Standards/Tools & Techniques
Onions by Moss Dance at Birds and Beans

Intergenerational Soil Stewardship: Our Only Hope?

Marjorie Harris BSc, IOIA V.O. P.Ag

Soil, specifically topsoil, is the foundation of life on this earth. Earth is the only planet with healthy fertile soil on it that we know of yet, in the whole of the universe. Fertile soil is a little-understood mixture of biology and geology whose potential only exists in the topsoil layer. The topsoil layer is composed of the topsoil itself and organic matter in various stages of mineralization and humus production. Degradation and erosion of the topsoil depletes soil fertility, restricting plant growth, vitality, and micronutrient content. Hence, it becomes imperative for one to reach out to a website, and take aid of professionals in combating the problem of soil erosion.

The theme for this month’s BC Organic Grower is: “Bioregionalism: building place based economies.” Agricultural philosopher Wendell Berry suggests that an agrarian economy is based on local adaptation of economic activity to the capacity of the land to sustain such activity.

This is a challenging idea because history shows us that farming as practised in the past and the present always causes topsoil degradation. Through the ages, soil degradation, or erosion, has steered the fate and course of human civilizations and ultimately caused the demise of those civilizations. This story has repeated itself throughout the world and in the history of every type of farming. In the words of Sir Winston Churchill, “Those who fail to learn from history are doomed to repeat it.” No greater historical comment can be made for agriculture: learn or be doomed. All farming societies exhausted their topsoils within 800 to 1700 years.

The Canadian Organic Standards speak to soil conservation and soil fertility specifically in the following sections:
The general principles of organic production in Annex 1:
1. Protect the environment, minimize soil degradation and erosion, decrease pollution, optimize biological productivity, and promote a sound state of health.
2. Maintain long-term soil fertility by optimizing conditions for biological activity within the soil.

Clause 5.4.3 Tillage and cultivation practices shall maintain or improve the physical, chemical and biological condition of soil, and minimize damage to the structure and tilth of soil, and soil erosion.

Principle of Health

Organic agriculture should sustain and enhance the health of soil, plants, animals, humans and the planet as one and indivisible.

We have run out of new lands to discover on planet Earth. In 1995, Dr. David Pimental of Cornell University calculated that we had already lost 30% of the arable land we were farming to soil erosion. With the advent of chemical and mechanical agriculture the soil erosion problem has increased a hundred-fold in areas. As an example, in the past 150 years, one-half the fertile topsoil of Iowa has been lost to erosion.

Topsoil is a strategic and underappreciated resource. Soil can be conserved, made, and lost and it is the balance of these factors that determines the soils fertility. How we manage the soil resource in our generation will affect generations to come. As long as soil erosion continues to exceed soil production, it is only a matter of time before agriculture fails to support Earths humanity.

What Can We Learn from the Trials and Errors of Our Ancestors?

Çatalhöyük, Anatolia (modern Turkey) was home to a Neolithic farming civilization that lasted around a thousand years starting about 7500 BC. Scientists have studied skeletal remains which have provided a highly informative record of human health. From the skeletal health record they have been able to divide this civilization into three distinct health time periods: Early, Middle and Late. During the Middle period the civilization reached its peak in population and health, and then as soil fertility was depleted the human skeletal health parameters demonstrated decline. By the end of the Late period 52% of human births resulted in infant mortality before the age of two months. Similar skeletal health studies have been conducted on the remains of other farming civilizations globally with outcome of human health declining in parallel with topsoil and soil fertility depletion, supporting the assumption that human health is interdependent on topsoil retention and soil fertility.

Dr. David R. Montgomery succinctly identifies the problem and a potential solution in his book Dirt: The Erosion of Civilizations: “Sustaining our collective well being requires prioritizing society’s long term interest in soil stewardship; it is an issue of fundamental importance to our civilization. We simply cannot afford to view agriculture as just another business because the economic benefits of soil conservation can be harvested only after decades of stewardship, and the cost of soil abuse is borne by all.”

What Does a New Sustainable Agriculture Ethic Require from Us?

In Dr. David Montgomery’s more recent publication “Growing a Revolution: Bringing Our Soil Back to Life,” he outlines solutions to soil conservation and topsoil rebuilding techniques he has witnessed applied in the field around the world. He identifies the main culprit of soil erosion in agriculture as the invention of the plow. The plow breaks the soil structure and exposes the underground community of biota to the surface. “The plow is the villain that set the seeds for soil degradation. Only deserts have bare earth and Nature tends to clothe herself in plants.”

Another challenge is that during one generation a farmer can seldom see the effects of topsoil erosion unless a dramatic natural weather event sweeps the soil away. During day to day farming it is difficult to ascertain the minimal yet additive effects of traditional tillage techniques. Fallow land tillage is a traditional technique that leads to desertification and needs to be abandoned and replaced with topsoil preserving methods. Topsoil conservation and rebuilding requires the focused consciousness of Intergenerational Soil Stewardship to guide agricultural sustainability.

Soil is in a Symbiotic Living Relationship with Plants

When plants are actively photosynthesizing they release 30% to 40% of the sugars, carbon compounds, and proteins they manufacture through their roots into the root rhizosphere. The root exudes these nutrients to feed the underground community of fungi and microbes in exchange for micronutrients from fungi and microbial metabolites that act as growth stimulators and plant health promoters.

When plants are fed synthetic N, P, K they grow big on top of the ground but do not invest in growing a big root system and do not deliver as much nutritious root exudates to feed the underground microbial and fungi communities. As a result the plant does not reap the benefits of vitality factors and micronutrients. The plants overall health is less and the plant tissue has demonstratively less micronutrient content to pass on up the food chain. Micronutrient studies demonstrate that under conventional agriculture the plants have lost between 25% to 50% of their micronutrient content in the past 50 years.

The solution to successful topsoil building Dr. Montgomery observed while touring farms around the world required three things to happen at once: no till planting techniques, cover cropping, and adding organic matter to the soil. Dr. Montgomery has coined the method Conservation Agriculture and the methods can be applied in both conventional and organic farms—because when it comes to soil conservation and restoration, everybody needs to get on board.

Principles of Conservation Agriculture:

1. Minimal or no disturbance/direct planting of seeds (e.g., no till)
2. Permanent ground cover: retain crop residues and include cover crop in rotations
3. Diverse crop rotations: to maintain soil fertility and break up pathogen carryover
4. Livestock assisting in topsoil building: mimic bison grazing, move cattle in a tight herd to intensive graze (high disturbance), and move frequently to produce low frequency grazing.

Benefits of Conservation Agriculture, after a short transition period of 2 to 3 years to allow soil organic matter to build fertility:

1. Comparable or increased yields
2. Greatly reduced fossil fuel and pesticide use
3. Increased soil carbon and crop resilience
4. Higher farmer profits

“This is not a question of low tech organic versus GMO & agro-tech….this is about ‘how to apply an understanding of soil ecology to the applied problem of increasing and sustaining crop yields in a post-oil environment’.”

“Agriculture has experienced several revolutions in historical times: the yeoman’s revolution based on relearning Roman soil husbandry and the agrochemical and green revolutions based on fertilizer and agrotechnology. Today, the growing adoption of no-till and organic methods is fostering a modern agrarian revolution based on soil conservation. Whereas past agricultural revolutions focused on increasing crop yields, the ongoing one needs to sustain them to ensure the continuity of our modern global civilization. The philosophical basis of the new agriculture lies in treating soil as a locally adapted biological system rather than a chemical system.”

Intergenerational Soil Stewardship: Society on a global scale based on an agrarian economy adapted to its bioregion dedicated to topsoil conservation and restoration and the development of soil fertility.


Marjorie Harris is an organophyte, agrologist, consultant, and verification officer in BC. She offers organic nutrient consulting and verification services supporting natural systems.

References:
1. Montgomery, D. (2007). Dirt: The Erosion of Civilizations. University of California Press. Montgomery, D. (2017). Growing a Revolution: Bringing Our Soil Back to Life. W. W. Norton & Company.
3. Pimental, D., Burgess, M. (2013). Soil Erosion Threatens Food Production. Agriculture, 3(3), 443-463; doi: 10.3390/agriculture3030443
4. Montgomery, D. (2014). Soil erosion and agricultural sustainability. PNAS. 104 (33) 13268-13272; https://doi.org/10.1073/pnas.0611508104

Ask an Expert: Fostering Resilient Soil Ecosystems

in 2018/Ask an Expert/Crop Production/Spring 2018

Emma Holmes, Organics Specialist, BC Ministry of Agriculture

Studies examining soil microbes are showing huge potential to improve growing practices. A number of soil microorganisms have abilities to increase soil fertility, aid in nutrient and water uptake by the root system, and protect crops against pests and disease.

Soil Bio-fertilizers

If you grow legumes, you are likely already familiar with Rhizobia, the family of soil bacteria that form symbiotic relationships with legumes to convert atmospheric nitrogen to a form of nitrogen that is plant available. Producers have been inoculating their legume seeds with rhizobium since the ‘50s and it is estimated that 70 million tonnes of N are fixed annually by Rhizobia (Zahran, 1999). There are significant potential gains to be had from reducing dependence on nitrogenous fertilizers by increasing biological nitrogen fixation including reduced input costs, pollution prevention, and improved yield and crop quantity (Kelly et al., 2016).

But it is not just legume crops that see big returns in partnering with soil organisms. Farmers around the world are using bio-fertilizers to cut back on expensive fertilizers, build their soil quality, and better protect their waterways and aquifers.

There are six main types of biofertilizers:

Symbiotic Nitrogen Fixers (e.g. Rhizobium) form nodules on the roots of legumes and can fix 50-200 kgs N/ha in one crop season.

Asymbiotic Free Nitrogen Fixers (e.g. Azobacter) live in the soil and fix significant levels of nitrogen without the direct interaction of other organisms.

Associative Symbiotic Nitrogen Fixers (e.g. Azospirillum) form close relationships with grasses and can fix 20-40 kgs N/ha.

Phosphate solubilizing bacteria (e.g. Fusarium) convert non available inorganic phosphorus into a plant available form.

Algae biofertilizers (e.g. Cyanobacteria) can provide plants with growth promoting substances (ex. Vitamin B 12) and fix 20-30 Kgs N/ha.

Mycorrhizal fungi refers to the symbiotic association between plant roots and soil fungus that enhances plant soil and nutrient uptake.

Growers in the Fraser Valley have reported that using a bio-fertilizer has allowed them to reduce their N fertilizer application by as much as 30-40% while seeing similar yields and higher product quality. The bio-fertilizer is called TwinN, a freeze dried microbial product that contains a group of asymbiotic free nitrogen fixing bacteria called diazotrophs. Along with N fixation, the diazotophs in TwinN have also been shown to increase root growth and root hair density and decrease root infection. It is thought that the colonization of the plant with beneficial bacteria protects the host plant from harmful bacteria (similar to the use of probiotics to promote human health).

Soil FoodWeb

Dr. Elaine Ingham, a soil microbiologist who previously worked with at Oregon State University and the Rodale Institute, is now the president of Soil FoodWeb. She has dedicated her career to help producers grow crops better by directly observing and promoting life in the soil.

Soil FoodWeb features comprehensive guides and online courses on making compost tea and analyzing soil samples using a microscope. Commercial growers using the Soil FoodWeb management programs report substantial savings in crop production input costs, reduced water usage, and increases in yield and quality.

Korean Natural Farming (KNF)

Koran Natural Farming looks very holistically at the entire farm system, including the people in it, and uses inputs that are generally close at hand and relatively inexpensive. Unlike bio-fertilizers, which involve bringing in microbes from another region or lab, KNF focuses on fostering beneficial Indigenous Micro-Organisms (IMO) within the ecosystem in which the crops are grown.

For more information, check out this link to a video on KNF Indigenous Micro-Organisms: https://vimeo.com/35078856

RootShoot in Vancouver provides 2-day workshops on KNF that includes a detailed explanation of the actual making of inputs including indigenous microorganisms, fermented plant juice, fish amino acid, and lactic acid bacteria.

Measuring Soil Diversity

The Plant Health Laboratory in Abbotsford can conduct a nematode assessment for $16-$32 (depending on turn around time). Nematodes are used as biological indicators of soil health because the number and types present in a soil reflect changes in the microbes they consume, and the soil’s physical and chemical environment.

Independent Soil FoodWeb consultants can analyze bacteria, nematodes, protozoa, and fungi using microscopes.

Managing for Soil Diversity

As the complexity of the food web increases, productivity of the soil tends to increase. Strategies for supporting robust soil biology include:

  • Supply organic matter, which acts as a home and food source for soil microbes. Composts and manures can also provide an input of beneficial soil microbes.
  • Leave crop residue to break down in place. Surface residue encourages decomposers and increases food web complexity.
  • Plant winter cover crops to act as a food source for bacteria in a time when food is otherwise scarce.
  • Create a diverse landscape that supports diverse niches of life.
  • Reduce tillage, which can disrupt sensitive organisms such as fungi. Over the long-term, tillage can deplete soil organic matter and thus reduce soil activity and complexity.
  • Minimize the use of fertilizers and pesticides. Even organic products can reduce the populations of fungi, nematodes, protozoa, and bacteria.
  • Minimize fallow periods, which can result in starvation for many creatures in the soil food web.
  • Minimize compaction and improve drainage to support aerobic microbial populations.
  • Cultivate beneficial indigenous micro-organisms
  • Apply compost teas and/or bio-fertilizers.

Emma Holmes has a B.SC in Sustainable Agriculture and M.Sc in Soil Science, both from UBC. She farmed on Orcas Island and Salt Spring Island and is now the Organics Industry Specialist at the BC Ministry of Agriculture.

Emma.Holmes@gov.bc.ca

References:

Kelly,  et al., (2016). Symbiotic Nitrogen Fixation and the Challenges to its Extension to Nonlegumes. Applied and Environmental Microbiology, 82(13). Retrieved from: http://aem.asm.org/content/82/13/3698.full

Zahran, H.H. (1999). Rhizobium-Legume Symbioses and Nitrogen Fixation under Severe Conditions and in an Arid Climate. Microbiology and Molecular Biology Reviews, 63(4). Retrieved from: https://www.ncbi.nlm.ih.gov/pmc/articles/PMC98982/

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