Compost Improvement
4.11 - Compost improvement
Rebecca Rashev, University of Guelph, Canada
Suggested citation for this chapter.
Rashev, R. (2022) Compost improvement. In Farmpedia, The Encyclopedia for Small Scale Farmers. Editor, M.N. Raizada, University of Guelph, Canada. farmpedia.org
Background
Soil fertility in crops is a constant problem and one of the main factors limiting crop production in subsistence farms globally (Becx et al., 2012). With the increased prevalence of cattle and livestock in some regions (for example, in the northern regions of Ghana) that heavily rely on agriculture but are constant victims to the sub-tropical climate, collection and redistribution of animal manure can become a solution to restoring crop fertility (Becx et al., 2012; Thapa, 1996). While the direct application of animal manure aids in fertilizing soils, it is essential to compost it alongside other organic wastes to create more efficient fertilizer in larger amounts (Tanner, Holden, Winugroho, Owen and Gill, 1995; Paudel and Thapa, 2004; Sotamenou and Laurent, 2013; Wondimagegn, 2014; Harris, 2002; Amisi and Doohan, 2010; Tilman, Cassman, Matson, Naylor and Polasky, 2002; and Quamruzzaman, 2006). Composting is the biological process of decomposing organic wastes in which bacteria, fungi and other microorganisms break down organic materials into stable, usable organic substances called compost (Bernal, Alburquerque and Moral, 2009). Compost has nutritional and disease-suppressant benefits that restore organic matter to soil, increase the water holding capacity of soil, and act as a storehouse for nutrients.
Description of Practice
Collecting ingredients: livestock, crop and household residue. Only organic materials should be used as composting ingredients, including crop, livestock and household residues (Harris, 2002; FAO, 2015). More specifically: (1) leftover crop residues from harvests or garden plants (mulch or dead coverage from crop waste/cultivated fallow), chopped branches, tree and shrub leaves, forages and dried grass; (2) household organic waste from the kitchen such as fruit and vegetables, damaged/expired food, crushed egg shells, coffee and tea waste, dried fruit and nut shells, fruit peels, as well as napkins, tissues, hair or animal shear; (3) livestock manures and even livestock urine. If a family does not own livestock, local villages usually have waste piles from which they could collect manure (Harris, 2002; FAO, 2015).
Creating the compost pile. Compost techniques can be divided into closed and open systems (FAO, 2015; FAO, 2003). Open systems are carried out outdoors, whether in piles above ground or in dug-up pits below ground. Closed systems are carried out in holding units, such as plastic drums or containers made from bricks or wooden panels. The size (specifically height) of the compost pile directly affects moisture, oxygen content and temperature (which determine the rate of decomposition of organic material); therefore it is recommended that compost (whether in open or closed systems) should be 1.5-2 m high and 1.5-3 m wide (FAO, 2015). This, along with downsizing and shredding of raw materials prior to composting, ensures high porosity and proper aeration when turning and mixing the compost pile, so that microorganisms responsible for decomposition of organic materials can flourish uniformly (FAO, 2003). The initial layout of the compost pile should be similar to that of lasagna, with alternating layers of manure and crop/household residue, with a bottom layer of stone to allow for water drainage. This design provides a proper ratio between plant matter and manure and avoids the risk of leaching nutrients from compost into the soil (FAO, 2003).
Monitoring compost. Once the system has been created with initial layering, compost should be left outside over a span of a few weeks to a couple of months (Tanner et al., 1995). During the first few days of decomposing, temperatures should increase in the compost pile, where the peak temperature destroys micro-organisms that are human or plant pathogens, as well as weed seeds (FAO, 2003). During the process of composting, one should perform frequent clump tests to determine the moisture content of the compost: if material is too dry and crumbles away in one's fist, one should add more water, urine or manure to the compost; if the material is too wet and one can see excess water squeezed out in the fist, one should modify the compost by adding more dry matter, such as dried grass or legume forages (FAO, 2003).
For optimal results, compost should be ventilated by mixing frequently (FAO, 2003; FAO, 2015). This increases aeration and oxygen exposure, which aids in the process of decomposition of organic matter. Aeration also removes excessive heat, water vapour and gasses trapped in the compost pile. When mixing, one should also test the moisture content of the compost as well as its temperature in comparison to the ambient (outside) temperature (FAO, 2003; FAO, 2015).
While the process varies from weeks to months, the final product of the compost can be characterized by the pile being uniform, dark brown to black in colour, having a pleasant smell of earth, and particles being reduced in size with a consistent, soil-like texture (FAO, 2003; FAO, 2015). It is vital for compost to complete all stages of decomposition and sterilization in order to be viable as a source of fertilizer without the possibility of spreading weeds or pathogens onto crops (Amisi and Doohan, 2010).
Benefits
Biophysical Benefits. Compost offers many benefits with respect to improving the physical and biological properties of soil. Having higher nutrient content, compost can be used to restore nutrients in soils that are needed to produce higher crop yields (Thapa, 1996; Tanner et al., 1995; Harris, 2002). Use of compost can stimulate soil fauna and increase the water holding capacity in drought-prone soils in semiarid climates, which is a major biophysical constraint of subsistence farmers (Becx et al., 2012), and can also reduce runoff and soil loss in areas such as Burkina Faso (Baptista et al., 2015). Compost has disease-suppressant properties, especially for young plants not yet predisposed to infection, and can be used as a replacement for fungicides (which are not always readily available to subsistence farmers) (Ndiaye et al., 2010).
Economic Benefits. Increasing the use of organic matter that is accessible from home will decrease a farmer's reliance on purchasing commercial fertilizers. The money saved by buying less fertilizer could be used to put children (especially daughters) in school, or to afford better tools that will make weeding or planting easier, and will decrease the labour and time requirements of farming in the long term (Wondimagegn, 2014). Once subsistence farmers have incorporated these techniques in compost use and management and have begun to produce higher yielding crops, increased production could be the push for subsistence farmers to transition towards entrepreneurial farming, and being able to produce more for markets. With the ability to create a profit, these farmers will now be exposed to the possibility of investing in inputs and new technologies, which will eventually increase overall productivity (Becx et al., 2012).
Labour and Time Requirements
Lack of knowledge is perhaps the main contributing constraint for subsistence farmers moving towards compost use, with extensive labour as second and lack of transport as third, with farmers stating that "soil is not yet that bad to do so much work" (Becx et al., 2012; Akalu et al., 2016). Composting results in work pertaining to maintaining the compost as well as the need to manually collect, mix, monitor, and apply the final product to fields (Paudel and Thapa, 2004; Schroeder, 1985; Sotamenou and Laurent, 2013; and Quamruzzaman, 2006). If some supplies are required that are not present on hand (e.g. if the family does not keep livestock on the farm), transportation and time would be needed to acquire those materials (Harris, 2002).
Picture Based Lesson to Train Farmers
South Asian version (pictures only, text for you to insert) — lesson 5.11
East/South Asian version (pictures only, text for you to insert) — lesson 5.11
Sub-Saharan Africa/Caribbean version (pictures only, text for you to insert) — lesson 5.11
Latin America version (pictures only, text for you to insert) — lesson 5.11
North Africa and Middle East version (pictures only, text for you to insert) — lesson 4.10
Source: MN Raizada and LJ Smith (2016) A Picture Book of Best Practices for Subsistence Farmers. eBook, University of Guelph Sustainable Agriculture Kit (SAK) Project, June 2016, Guelph, Canada.
Helpful Hints and Further Reading
It is important to take into account that the nutrient balance in soils varies across regions and that areas adjacent to one another could be deficient in different nutrients (Smaling et al., 1997). In areas such as Northern Ghana, soils are coarse with low organic matter content, poor structure and fertility, with the two most commonly deficient nutrients being nitrogen (N) and phosphorus (P). In order to help replenish these deficiencies, farmers can add residue from crops that are high in the nutrients needed (e.g. crop residue from legumes, such as cowpea, soybeans and groundnut, which are high in N) to compost in order to re-supply the soil and fertilize crops such as corn, which take up large amounts of N from the soil (Eghball, 2002).
Further information about composting is available in:
FAO's Farmer's Compost Handbook (2015): Link
FAO's On-farm Composting Methods (2003): Link
GardenAfrica's training film, "Black Gold: The Secrets of Compost": Link (gives a step-by-step explanation of how to create a compost pile, specific to subsistence farmers in African regions)
FAO's "Composting: Let's Give the Soil Something Back": Link (focuses on the impact of food wastage on soil sustainability and how to reduce one's food waste footprint)
FAO's "Impact of Compost Use on Crop Yields in Tigray, Ethiopia" by Sue Edwards, Arefayne Asmelash, Hailu Araya and Tewolde Berhan Gebre Egziabher: Link
FAO's "Waste Management Opportunities for Rural Communities – Composting as an Effective Waste Management Strategy for Farm Households and Others": Link
FAO's "How to Make and Use Compost" by Sue Edwards and Hailu Araya: Link
References
1. Akalu, T., de Graaff, J., Ritsema, C., & Kassie, M. (2016). Farmers' perceptions about the influence of land quality, land fragmentation and tenure systems on sustainable land management in the North Western Ethiopian Highlands. Land Degradation & Development, 27(4), 884-898.
2. Amisi, K. J., & Doohan, D. (2010). Redroot pigweed (Amaranthus retroflexus) seedling emergence and growth in soils amended with composted dairy cattle manure and fresh dairy cattle manure under greenhouse conditions. Weed Technology, 24(1), 71-75.
3. Baptista, I., Ritsema, C., Querido, A., Ferreira, A., & Geissen, V. (2015). Improving rainwater-use in Cabo Verde drylands by reducing runoff and erosion. Geoderma, 237-238, 283-297.
4. Becx, G., Mol, G., Eenhoorn, J., van der Kamp, J., & van Vliet, J. (2012). Perceptions on reducing constraints for smallholder entrepreneurship in Africa: the case of soil fertility in Northern Ghana. Current Opinion in Environmental Sustainability, 5(5), 489-496.
5. Bernal, M., Alburquerque, J., & Moral, R. (2009). Composting of animal manures and chemical criteria for compost maturity assessment. A review. Bioresource Technology, 100(22), 5333-5453.
6. Eghball, B. (2002). Soil properties as influenced by phosphorus- and nitrogen-based manure and compost application. Agronomy Journal, 94(1), 128-135.
7. Harris, F. (2002). Management of manure in farming systems in semi-arid West Africa. Experimental Agriculture, 38(2), 131-148.
8. Ndiaye, M., Termorshuizen, A., & van Bruggen, A. (2010). Effects of compost amendment and the biocontrol agent Clonostachys rosea on development of charcoal rot (Macrophomina phaseolina) on cowpea. Journal of Plant Pathology, 92(1), 173-180.
9. Paudel, S. G., & Thapa, G. B. (2004). Impact of social, institutional and ecological factors on land management practices in mountain watersheds of Nepal. Applied Geography, 24, 35-55.
10. Quamruzzaman, M. (2006). Improving plant nutrient management for better farmer livelihoods, food security and environmental sustainability. Link
11. Schroeder, R. (1985). Himalayan Subsistence Systems: Indigenous Agriculture in Rural Nepal. Mountain Research and Development, 5(1), 31-44.
12. Smaling, E., Nandwa, S., & Janssen, B. (1997). Replenishing soil fertility in Africa: Soil fertility in Africa is at stake. Soil Science Society of America and American Society of Agronomy, 47-61.
13. Sotamenou, J., & Laurent, P. (2013). Sustainable urban agriculture and the adoption of composts in Cameroon. International Journal of Agricultural Sustainability, 11(3), 282-295.
14. Tanner, J.C., Holden, S. J., Winugroho, M., Owen, E., & Gill, M. (1995). Feeding livestock for compost production: A strategy for sustainable upland agriculture on Java. Livestock and Sustainable Nutrient Cycling in Mixed Farming Systems of Sub-Saharan Africa, 2, 115-128.
15. Thapa, G. B. (1996). Land use, land management and environment in a subsistence mountain economy in Nepal. Agriculture, Ecosystems and Environment, 57, 57-71.
16. Tilman, D., Cassman, K. G., Matson, P. A., Naylor, R., & Polasky, S. (2002). Agricultural sustainability and intensive production practices. Nature, 419, 671-677.
17. Wondimagegn, M. (2014). Crop mix and resource use pattern under risk: Case of smallholder farmers in Eastern Highlands of Ethiopia. International Journal of Agriculture and Crop Sciences, 5(5), 251-261.