What Matters? Organic Matter
In Biodynamic farming systems, soil is at the heart of the process, providing the living, dynamic substrate from which terrestrial plants and animals derive materials for growth. Biodynamic farmers embrace the philosophy of giving more to the soil than is taken from it, through the application of the preparations, composting, cover cropping, and diverse crop rotations to increase soil organic matter and the diversity and abundance of soil microbes. Investing in our soil is an act of faith in the future, an acknowledgement of the essential value of this finite resource, and an awareness of the massive impact that human civilization has had on our soil over the millennia.
The Biodynamic Farm Standard was recently updated to include the requirement of maintaining and ideally increasing soil carbon levels (i.e., humus) over time, and a protocol for measuring soil carbon is in development. To quote from the introduction to the Standard:
“Because the underlying theme of the Biodynamic Farm Standard is to generate inputs out of the life of the farm system itself rather than importing them from outside, the heart of a Biodynamic farm’s fertility system is the sequestering and recycling of carbon. Crop rotation and integration of animal agriculture also assist in reducing petrochemical inputs compared to conventional agricultural practices. These factors, in addition to Biodynamic farming’s focus on improving soil health, water quality and biodiversity, combine to make it one the highest paradigms of sustainable, regenerative agriculture. Demeter’s vision is to heal the planet through agriculture.”
There are numerous benefits to the farm itself, and the planet as a whole, of increasing all forms of organic matter in the soil. Adding a protocol for measuring this important variable of soil health will demonstrate the effectiveness of Biodynamic practices over time, in addition to improving the health of our farms and foods.
What is organic matter? According to the USDA Natural Resource Conservation Service, Organic matter is the fraction of the soil that includes approximately 5% of living organisms, 10% plant residues, 33-50% decomposing material (the active fraction) and 33-50% stable material (humus) by weight. The active fraction may readily change depending on soil management (tillage, cover crops, etc), and its decomposition can contribute to nutrient release for crops. Humus is stable organic material that has been converted by microorganisms through decomposition and acts as a reservoir for nutrients, increases the water holding capacity of the soil, improves soil structure, facilitates cation exchange, and provides energy for living soil organisms. The living microbial biomass within the soil includes the microorganisms responsible for decomposition of plant residues and active organic matter.
As farmers, if we seek to increase the levels of stable soil organic matter, we can add compost, cover crops, animal manure, and crop residues. Incorporating perennial grass and legume sods into crop rotations can also improve organic matter levels through reduction in erosion and decomposition of the root mass.
We can additionally choose management strategies such as conservation tillage practices, avoiding soil compaction, and establishing leguminous cover crops, which enhance organic matter accumulation by providing the nitrogen needed for decomposition of new plant or animal materials.
In return for proactive management that increases organic matter levels in the soil, we are rewarded with a myriad of benefits, including:
> Improved Biological Function, as we feed and increase soil microbe populations
Abundant nutrients available to plants
> Improved soil structure
> Enhanced water holding capacity, resulting in resilience in times of drought
> Erosion control, keeping topsoil in place and our waterways clear of sediment
> Acting as a CO2 reservoir, absorbing atmospheric carbon and mitigating the effects of Climate Change.
Through Biodynamic practices, farmers are protecting the soil, water, wildlife, and climate, all while producing nutritious foods.
“The soil is the great connector of lives, the source and destination of all. It is the healer and restorer and resurrector, by which disease passes into health, age into youth, death into life. Without proper care for it we can have no community, because without proper care for it we can have no life.” --- Wendell Berry in The Unsettling of America
