Composting

Composting is an important agricultural practice of returning nutrients to agricultural soils. It is also a method for both maintaining and improving soil health and fertility in agricultural fields. Composting has specific goals and a relatively concise set of practices, and many international monographs and journal articles advocate its adoption for soil and farm health. By focusing on composting's goals and practices, this article outlines the role and rationale of composting in ecoagricultural regimes.

Turning consumer food waste into compost for organic agricultural soils is one way in which food consumption can go green

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There are two ways humans have added necessary nutrients to agricultural fields over human history. One is the method developed during World War II in which chemicals used in weaponry were applied to agricultural fields and were found to help boost agricultural productivity, speed up plant growth, increase yields, and reduce the need for various agricultural inputs, especially labor and compost. The result of this method of adding chemicals to agricultural fields, coupled with the development of high-yielding hybrid seeds, increased inputs of pesticides and herbicides, increasing the commercialization and consolidation of farming under national and international trade regimes that help subsidize such chemical-based farming, as well as the ascendant popularity of this farming method and the research and teaching of this method in agricultural land grant universities throughout the world, has come to be known as the “Green Revolution.” The Green Revolution is coming under increasing criticism from eco-agriculture advocates because of this dependence on fossil fuels and the deleterious effect these chemicals have on soil health.

[Page 61]The other way humans have added necessary nutrients to agricultural fields is by composting. Composting is the process of combining organic items that are rich in carbon, such as animal manure or dried leaves, with organic items that are rich in nitrogen, such as grass and food waste, into humus. One practice of composting is to make sure there is a correct ratio between these “brown” and “green” components; the ratio that is traditionally sought is a chemical ratio of 30 parts carbon to 1 part nitrogen. These organic matters are transformed in a compost pile by the presence of microorganisms, especially bacteria, which use enzymes to chemically break down the organic matter. Invertebrates then help to physically break down the compost.

The method of creating compost entails gathering the organic matter into a large enough pile or bin and adding water; after this, heat from the sun and naturally occurring oxygen mix with the pile, and the process of decomposition begins. It is important for the compost pile to achieve a high enough temperature—over 100 degrees Fahrenheit—for seeds and harmful bacteria and blights to be successfully killed and broken down; otherwise, they are spread back onto agricultural fields. If the compost pile becomes warmer than 140 degrees Fahrenheit, then the beneficial bacteria and organisms in the compost can be killed and the compost loses its life and health-giving properties. Finding a successful mix and ratio of carbon/nitrogen and maintaining a proper temperature and moistness level must be learned. Thus, making compost is part art form and part agricultural practice.

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