Composting for the Market Farmer – Does it Make Sense?
Composition and Structure of the Soil Profile
Let’s discuss some of the essential aspects related to composting for the market farmer. One of the core tenets behind vegetable crop production is the absorption of water and nutrients through crop roots. The breakdown of the science behind maximizing crop nutrient and water absorption relies heavily on soil profile structure. Outside of farm practices, when plants dry up and decompose, they return essential nutrients and minerals back to the soil. But in farm systems, the nutrients originating from soil are harvested and sold. Consequently, over time this depletes the plants productive potential. Composting is the guided breakdown and decay of raw organic material into a stable resource available to soil organisms and plants.
Start with Simple Soil Testing Kits
The productive capacity of soils is highly variable, sometimes even within the same ¼ acre. So, it is especially important before planning or starting a fertilization regimen to get an in-depth understanding on your soil needs. Do this through simple soil testing kits or collection methods and send them to a lab. Generally, the first nutrients to deplete are those that represent the plants primary composition (Nitrogen, Phosphorus, and Potassium). Micronutrients and certain minerals also play a role in healthy plant productivity. By establishing healthy, biologically active, and accessible soil profile this becomes less of a concern. Composting for the market farmer provides not only a new abundance of nutrients and minerals but also improves the top soil profiles and water retention properties.
Benefits of Farm Waste for Greater Plant Productivity
This blog series will help make clear the benefits of using farm waste (e.g. animal excretions, plant materials, etc.) as an essential part of building your soil profile for greater plant productivity. Here I am covering the introduction to why composting is an essential part of any small farm. Composting should be seen as an alternative to synthetic fertilizers to avoid cost, leeching, runoff, and hauling excess waste materials from your farm. Composting also directly benefits the soil microbiome which not only unlocks a greater potential for plant-soil interactions but also helps provide a resilience against disease and pests.
The focus of this series is on thermophilic aerobic digestion, specifically for mixed-use farms as this is the most efficient, easiest, and most cost effective strategy for fertilizing your fields. Let us begin with the standard definition of compost from USDA NOP guidelines and apply the timelines of using raw manure on fields as our instructions for applying composted manure to stay within regulations and to keep consumer safety as the top priority. In the second and third installment of this three part series on composting will then walk through each individual step in order to demonstrate feasibility and variance of strategies.
National Organic Program Final Rule Guidelines for Compost and Manure for Organic
Operations Definition of Compost (205.2)
- An initial C:N ratio of between 25:1 and 40:1
- Maintained at a temperature of between 131 and 151 degrees F for 3 days using an in-vessel or static aerated pile system;
- Temperature maintained between 131 degrees F and 170 degrees F for 15 days using a windrow composting system, during which period the materials must be turned a minimum of 5 times
Use of Animal Manure (205.203)
Raw animal manure must be composted unless it is:
- Applied to land used for a crop not intended for human consumption;
- Incorporated into the soil not less than 120 days prior to the harvest of a product whose edible portion has direct contact with the soil surface or soil particles, or;
- Incorporated into the soil not less than 90 days prior to the harvest of a product whose edible portions does not have direct contact with the soil surface or soil particles.
Now that you have the reasons for starting a compost system and the basic regulations that we will follow, I would like to note that compost without manure is a lengthy and more strenuous process to get a quality end product. The secondary benefit of composting manure is the amount of strain it takes away from any given environment of jumpstarting the process of decomposing animal effluents, especially if they are in large quantity. Another note for those who might believe composting to be old fashioned and not in-line with 21st century best practices, the European Commission issued a report this year titled A sustainable Bioeconomy for Europe: strengthening the connection between economy, society and the environment which advocated strongly for the multifaceted uses of composting to turn harmful waste into a beneficial byproduct.
If you want to read into more depth on the methods and best practices in starting your own composting system, you can look for my next two posts on the follow up topics of:
- An Overview of Decomposition Ratios and Materials: What materials are easiest and cheapest to source and make up a perfect 30:1 Carbon to Nitrogen ratio so nutrients and minerals dont mineralize or leach?
- A Guide to Different Composting Systems: What system works best for different environments/climates/ land use allocations? What are some of the end uses for a compost product?
James Robert Sears Wirth was born and raised in an agriculturally rich area of Northern Utah in the United States. During his undergraduate degree in Sustainable Agriculture Systems degree at Utah State University James worked as a Sustainable Food Specialist. Because of his educational emphasis, he has experience on all sides of modern and traditional agricultural production. James has worked in production systems from planning and inspections on a greenhouse, to invasive pest and beneficial insect monitoring.
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Markham, B. The Mini Farming Handbook. Skyhorse Publishing. 2014. Print.