Life and thoughts from a small-scale organic farm . . . and its farmers

This is a blog that explores ideas around the growing of food and community at Glen Valley Organic Farm.

Monday, June 20, 2011

Animals, Agriculture, Fertility and What We Eat

What if your vegetables came from animals? If you're eating organically, this isn't too far off the mark.

It occurs to me regularly that our system of organic farming involves a significant amount of compost that, of course, comes from various livestock operations. In order to grow, we need soil fertility. Keeping our soil healthy and rich requires nutrients.

As required under organic guidelines, we use compost made of manure from organic livestock. The vast majority of our compost comes from off-farm operations, including chicken, goat, duck, turkey and mushroom sources. In addition to this, potting soil mixes often use blood meal and bone meal and fish fertilizer is used on transplants to keep plants alive when planting is delayed.

As a result, the veggies you eat from organic farms, depend on livestock operations in a fairly direct manner. I often wonder how this sits with our customers, particularly those who are vegan or vegetarian for a variety of reasons related to animal treatment. I've wanted to discuss this issue for some time.

The need for fertility
All systems of agriculture rely on the use of some inputs of nutrients and organic matter for the sake of fertility. When we grow and harvest a crop, we are removing plant matter from the fields. With it, we remove organic matter and nutrients that went into the plants' growth.

Animal manure is an obvious source of fertility to be added back into the soil. It is rich in nutrients, organic matter and, in an agricultural context, it is readily available.

Through the process of composting, bacteria breaks down matter and brings the temperature of the compost pile to a temperature that kills pathogenic bacteria. The compost is turned regularly to ensure all parts of the pile reach this temperature.

Alternatives to animal compost
There are alternative fertility sources for agriculture. The most widely used in our current system of agriculture is chemical fertilizer.

The macro nutrients required for growing are manufactured or mined from various chemical components. Nitrogen is produced, in the form of ammonia, from the air using natural gas (nitrogen comprises 78% of the air we breath). The process is comparable to the manner by which lightening fixes nitrogen (fields become quite lush in the days after an electric storm).

Phosphorus is made through a process that uses sulfur, coal and rock phosphate. Potassium is mined in the form of potash and then granulated.

These processes are, obviously, energy intensive, using non-renewable resources. Moreover, this form of agriculture focuses on feeding the plants, not the soil. It does not add organic matter back into the soil and, over time, leaves soil lifeless -- organisms cannot live in soil without nutrients and organic matter.

An alternate form of building soil is through the use of cover crops (green manures). Legumes such as peas and clovers have a symbiotic relationship with bacteria that grow on their roots and fix nitrogen. By turning these crops back into the soil, this nitrogen becomes available to a future crop.

By growing grain crops, organic matter is returned to the soil and there is evidence that these cover crops can help break disease and pest cycles in vegetable production. Grain crops do not fix nitrogen, although they provide a variety of other benefits, including weed control, water and soil conservation and the maintenance of soil microbial activity.

A limitation of cover crops is that they would require a significant portion of land being taken out of production at any given point in time in order to build the soil. And, ultimately, these crops will not build all of the nutrients required for production.

We use cover crops over the winter to help prevent soil erosion as well as throughout the growing season to build soil, control weeds and maintain nutrients in the soil. They are an important part of our agricultural practices.

Finally, there is an option of using human waste -- although not an option for organic growers, where the use of human waste is prohibited by organic standards. But sewage sludge is used in some conventional systems. This has challenges, ranging from the concentration of certain metals (like copper and lead) to the transfer of pathogens if the waste has not been treated properly.

There are a variety of innovative uses of human waste (as in biosolids -- that sounds better, doesn't it?) and this is an issue that needs further discussion. Simply stated, in our current system we take one of the most concentrated sources of nutrients and dump them into waterways where aquatic life is threatened by the resulting algae blooms. We are throwing away a source of nutrients that we cannot reclaim later.

The role of livestock
Given the above limitations, livestock remain an important component of organic production systems. Indeed, livestock waste is used in a variety of organic and conventional systems in a variety of manner -- some more sustainable than others.

But it also remains a fact that in our society we eat a tremendous amount of meat. It seems problematic to me that our over-consumption of meat (and its impacts in the form of resource allocation, greenhouse gas production, etc.) should form the backbone of a "sustainable" food system. Nonetheless, I think animal husbandry is a crucial part of sustainable agriculture.

In our current systems, we have more animal waste than can be used in agricultural systems. Animal waste leaches into our aquifers in the Lower Mainland (contaminating our water supplies) and runs off into rivers, lakes and oceans, causing algae growth and dead zones as algae decomposes and robs the water of oxygen.

There must be a balance.

A New Urban Diet?
This has lead me to think of cultural solutions, including the reduction of meat consumption. This isn't new, but it is contentious. From my perspective, those who spend most of their days in offices do not need the high calorie food provided by our dairy, egg and meat agriculture in the quantities available.

A sustainable urban diet might use fewer animal products. A vegetarian diet might be more appropriate for most people, most of the time.

The animal products we enjoy (milk, cheese, butter, eggs, meat) might be better celebrated in connection with their rural origins.

For example, cheese was traditionally a means of preserving milk for the months when animals finished their lactation cycle. Cheese could be eaten in the off season as well as transported to more distant markets for some additional income. It was not a daily staple for anyone other than the rural dwellers who made the product.

Easy to say for someone who farms? Perhaps, but a new urban diet has to take into account that staple foods must come from lower on the food chain if we are to achieve anything resembling a sustainable food system.

What this means for farmers is that they need to produce less livestock and animal products. It also means producing livestock based on what inputs can be produced at a closer distance; at the moment, all of our feed is brought in from the prairies and overseas and, in conventional systems, uses chemical fertilizers to grow and then fossil fuels for transport.

In the end, we need a better understanding of how much livestock production is needed to produce an equitable and sufficient diet for the population. This may involve re-scaling agriculture; we have an increasingly number of studies showing the higher productivity of small-scale, organic production. The urban farming movement will play a significant role in this discussion as well.

Otherwise, until we see a repopulation of rural areas in the form of small farms, we must rethink our menu and means of producing our food.

Animals, Veganism and Agriculture
In the end, I think livestock is a crucial component of sustainable agriculture. But this animal husbandry must be done an smaller scales (i.e. no 500 hog feed operations or 20,000 layer hen barns) and in coordination with the many other crop production systems that can make use of compost.

In this light, I think a close relationship with animals that respects them as living beings, but also as part of a nutrient cycle is important. I don't anthropomorphize livestock, but I do recognize that as living beings they feel pain and have a quality of life that must be measured and nurtured.

The animals we raise on our farm provide some food for us on the farm (milk and meat from the goats, eggs and eventually stewing hens from our chickens), but also provide some of the nutrients we need to grow our crops.

We rely on animal compost as a part of our farm's fertility plan. I respect that various choices people make about their food. When discussing agriculture with others I often think that we arrive at the same point (e.g. vegetarianism) but for different reasons (e.g. compassion for animals vs. environmental concern).

There is usually a lot of overlap in the ideas that inform our choices. And in that spirit, I'm curious to hear your thoughts on this topic. Please feel free to share your ideas and comments in the comments section below.


  1. Chris, one again, you've hit the nail on the head. Although I don't eat meat myself, I'm totally reliant on manure to grow food and I can't see how we can replace that manure with anything that's cost effective and isn't shipped in from thousands of kilometers. Yes, there is a role for green manures but still, they don't replace everything. Thanks for starting the conversation.

  2. You've really clearly outlined the contentious points and I can't really disagree with any of your conclusions. From an ecological perspective, as close to a closed system (nutrient cycle) as possible would be ideal, and that would include human waste as well as animal waste. Biodiverse production systems would also go a long way to replenishing and recycling needed nutrients. I struggle with the idea of not having livestock in certain areas; where I am from, on the prairies, the natural ecosystem is made for grazers, and people are here too and need to eat whether that's ecologically appropriate or not...

  3. I've been thinking about the place of vegetarianism in a sustainable food system a lot lately so thanks for summing it up! Long live the small-scale, organic, bio diverse farm. Keep up the great work.