Chapters 4.8
4.8 - Adding organic nutrients to home gardens
Rebecca Clayton, University of Guelph, Canada
Suggested citation for this chapter.
Clayton,R. (2022) Adding organic nutrients to home gardens. In Farmpedia, The Encyclopedia for Small Scale Farmers. Editor, M.N. Raizada, University of Guelph, Canada. http://www.farmpedia.org
Background
There are numerous advantages associated with adding organic nutrients to the home gardens of subsistence farmers in the developing world; including soil sustainability, environmental quality, and increased yield. These organic nutrients can include collecting kitchen scraps to make compost and using human urine (especially at night).
There are many existing practices of adding organic nutrients to home gardens that are practiced around the world and worth acknowledging. For example, there are people living in the Himalayas in Nepal who use forest litter for bedding material for livestock, and later when it has been enriched with urine and manure, they spread it across fields for extra nutrients (Giri and Katzensteiner, 2013). The Ngwa people in southeastern Nigeria commonly use a pit to collect waste, and after covering it for several months, they dig it up and use the rich hummus soil in their agricultural area (Izugbara and Umoh, 2004). Additionally, there are reports from populations in India, China, Cuba, Philippines, and Ethiopia that deserve further research and development (Misra and Roy, N.D; Edwards et al., 2007). Therefore, it is important to keep in mind that practices pertaining to organic nutrient addition to home gardens are widespread and unique, and must be implemented according to what is most appropriate for the particular context.
Benefits
There are a number of benefits associated with adding organic nutrients to home gardens and smaller plots of farmland. Organic ingredients added to soil help improve soil health and structure, particularly sandy soils, increasing their workability and allowing the soil to hold moisture better (Pleasant, 2012; Román, 2015). Organic addition also helps to regulate soil moisture, reduce water loss through evaporation, and lower the risk of erosion (Román, 2015). These qualities are invaluable to the long-term sustainability of soil. Not only do the organic nutrients benefit the physical properties of the soil, but they add chemical nutrients that assist with increasing yields, such as nitrogen, potassium, and phosphorous (amongst others) (Román, 2015; Lynch, 2014). Another advantage of organic fertilizer is that it reduces pollution of the soil, water, and air, when compared to synthetic fertilizers (Schwarz and Bonhotal, 2011). Finally, an advantage of organic nutrients is that they work to increase yields without costing farmers money. Organic fertilizers can be made using household waste, human waste, and cooking waste. Though synthetic fertilizers can be advantageous to farmers, they are often unavailable in very remote regions of developing countries. Additionally, they can be expensive and farmers may be unclear about how to apply them. When farmers know how to add inexpensive and easily accessible organic nutrients to their gardens and fields themselves, they become more self-reliant.
Table 1: The following table provides some examples of compost inputs and their macronutrient contents
*Oilcakes are crop residues following the extraction of oil from oilseeds
Instructions
This section will outline two different methods of adding organic nutrients to gardens and fields previously mentioned: compost, and urine. Composting: Composting is more intensive than using urine, but high quality compost can be created through a variety of inputs and combinations; it is about balancing the green and brown inputs. This means that farmers in Bolivia, Sudan and Laos alike can use whatever compost ingredients they may have at their disposal and can be successful. Green feedstocks (compost ingredients) are nitrogen-wet materials, including food scraps, manure, and green trimmings. (Schwarz and Bonhotal, 2011). By contrast, brown feedstocks are carbon-dry materials, such as straw, woodchips, brown leaves, and soiled paper (Schwarz and Bonhotal, 2011). First, kitchen scraps must be collected from the household (although meat and dairy products should be excluded as they are not ideal for home composting) (Schwarz and Bonhotal, 2011). It would be helpful to have a location outside or a container to place the kitchen scraps. The second step is to collect scraps such as leaves, brush, and weeds. Third, a place must be chosen to mix the compost and allow it to decompose. This space must be large enough for a large quantity of compost, since the pile must retain its own heat in order to decompose faster (minimum size of one cubic yard). The temperature also should be considered when selecting a spot; in cool climates the compost should sit in the sun to allow it to receive the maximum amount of heat possible, while in warmer climates it should be in the shade so as not to dry out (Schwarz and Bonhotal, 2011). The next step is to mix the compost, which is done by layering the browns and greens, starting with a layer of brown feedstocks and followed by greens in a well on top. Another layer of browns should be added, followed by greens, and so on. These steps of layering should be continued until all the ingredients have been used, all while keeping the greens towards the middle, so that only the browns are visible (Schwarz and Bonhotal, 2011). Turning the pile with a pitchfork or shovel, as well as adding water can help to speed up the decomposition process (Schwarz and Bonhotal, 2011). The compost takes about six months to a year to transform, and then can be added to the soil to enable crop production (Schwarz and Bonhotal, 2011).
Human Urine: A second strategy for organic nutrients, one that is very simple, is for the residents of the farm to urinate on the fields. Urine contains high levels of nitrogen, phosphorous and potassium, and is free and usually wasted (Richert et al., 2010). It can be added to fields by collecting it in jerry cans directly or in composting toilets. If collected and stored, it should be done so in a sealed container in order to avoid ammonia emissions (Richert et al., 2010). Otherwise, people can urinate directly onto the soil (ideally at night). It is important that urine be added directly (and only) to the soil for two reasons: first, nutrients are most needed at the beginning of the growing period (before crops are covering the soil) and second, it should not be added within a month of the harvest of crops that are eaten raw, for sanitary reasons (Richert et al., 2010). Commonly, people dilute urine with water, reducing the risk of applying too much urine, which can make it toxic to crops. It can diluted from anywhere between 1:1 to 1:15 ratios of urine to water, but most commonly it is diluted about 1:3 (Richert et al., 2010). Some studies have found very high success rates with urine as fertilizer, doubling financial returns when compared to mineral fertilizer, and increasing the amount of macronutrients in the soil (AdeOluwa and Cofie, 2012).
Common Problems and Critical Analysis
Each of these methods has its drawbacks, particularly space and time. Mixing compost requires considerable labour and patience, as well as a large amount of space. For all three inputs, the smells may attract unwanted pests or animals, and diseases can spread through urine in some parts of the world (Richert et al., 2010). Pathogens and diseases such as Salmonella, Shigella and E. coli can be spread through manures, as well as Clostridium perfringens, Cryptosporidum parvum, Bacillus cereus and Listeria monocytogenes which can be found in compost (Román, 2015). Some other risks include heavy metal content, which if they are found in great concentrations, can be damaging to human health (Román, 2015). Therefore caution must be taken while engaging in these composting activities. Furthermore, it is important not to discount the ease and immediate benefits of commercial fertilizers, and both organic and synthetic fertilizers can be integrated. Synthetic fertilizers are beneficial to be used along with organic nutrients, since compost generally has low concentrations of iron, copper, and zinc (He et al., 2001). Soil quality and compost ingredients are important factors that contribute to whether the compost will be effective; testing the soil remains important.
Cost Analysis
These solutions are very low cost, with the only tools required being a shovel or pitchfork for turning compost and a jerry can for urine storage. However, if farmers do not own sufficient livestock then manure must be purchased, which can be expensive.
Picture Based Lesson to Train Farmers
Further Reading
Here are some reports for further understanding on each of these organic fertilizing practices: Composting:
http://cwmi.css.cornell.edu/compostingathome.pdf
http://www.fao.org/3/a-i3388e.pdf
http://www.fao.org/docrep/014/i2230e/i2230e14.pdf
Urine:
http://www.ecosanres.org/pdf_files/ESR2010-1-PracticalGuidanceOnTheUseOfUrineInCropProduction.pdf
References
1.Adeniyan, O.N. et al. “Comparative study of different organic manures and NPK fertilizer for improvement of soil chemical properties and dry matter yield of maize in two different soils.” Journal of Soil Science and Environmental Management 2.1 (2011) : 9-13. Web.
2.AdeOluwa, O.O. and O. Cofie. “Urine as an alternative fertilizer in agriculture: Effects in amaranths (Amaranthus caudatus) production.” Renewable Agriculture and Food Systems, 27.4 (2012) : 287-294. Web.(2016).
3.Edwards, Sue and Hailu Araya. “How to Make and Use Compost.” Climate Change and Food Systems Resilience in Sub-Saharan Africa Food and Agriculture Organization of the United Nations (2011) : 380-436. Web.
4.Edwards, Sue et al. “Impact of Compost Use on Crop Yields in Tigray, Ethiopia.” Natural Resources Management and Environment Department, Food and Agriculture Organization of the United Nations (2007) : 1-55. Web.
5.Giri, Anjana and Klaus Katzensteiner. “Carbon and Nitrogen Flow in the Traditional Land Use System of the Himalaya Region, Nepal.” Mountain Research Development 33.4 (2013) : 381-390. Web.
6.Halberg, N. et al. “Global Development in Organic Agriculture: Challenges and Prospects.” Danish Research Centre for Organic Food and Farming. CABI Publishing (2006) : 1-392. Web.
7.He, Zheni et al. “Plant Nutrition Benefits of Phosphorus, Potassium, Calcium, Magnesium, and Micronutrients from Compost Utilization.” Compost Utilization in Horticultural Cropping Systems (2001) : 307-320. Web.
8.Izugbara, C. Otutubikey and J.O. Umoh. “Indigenous Waste Management Practices Among the Ngwa of Southeastern Nigeria: Some Lessons and Policy Implications.” The Environmentalist 24 (2004) : 87-92. Web.
9.Lynch, Derek H. “Sustaining Soil Organic Carbon, Soil Quality, and Soil Health in Organic Field Crop Management Systems.” Managing Energy, Nutrients and Pests in Organic Field Crops, Edited by Ralph C. Martin and Rod MacRae, CRC Press (2014) : 107-131. Web.
10.MacRae, Rod et al. “Introduction.” Managing Energy, Nutrients and Pests in Organic Field Crops, Edited by Ralph C. Martin and Rod MacRae, CRC Press (2014) : 1-6. Web.
11.Misra, R.V. and R.N. Roy. “On-Farm Composting Methods.” Food and Agriculture Organization of the United Nations (N.D.) : 1-26. Web.
12.Paungfoo-Lonhienne, Chanyarat et al. “Past, present and future of organic nutrients.” Plant Soil 359 (2012) : 1-18. Web.Web.
13.Pleasant, Barbara. “How to Make Compost.” Mother Earth News 254 (2012) : 52-58. Web.
14.Richert, Anna et al. “Practical Guidance on the Use of Urine in Crop Production.” EcoSansRes Series. Stockholm Environmental Institute (2010) : 1-69. Web.
15.Román, Pilar, María M. Martínez and Alberto Pantoja. “Farmer’s Compost Handbook: Experiences in Latin America.” Regional Office for Latin America and the Caribbean. Food and Agriculture Organization of the United Nations (2015) : 1-112. Web.
16.Roy, R.N. et al. “Plant nutrition for food security: A guide for integrated management.” FAO Fertilizer and Plant Nutrition Bulletin. Food and Agriculture Organization of the United Nations (2006) : 1-348. Web.
17.Schwarz, Mary and Jean Bonhotal. “Composting at Home – The Green and Brown Alternative”. Cornell Waste Management Institute. Department of Crop and Soil Sciences, Cornell Cooperative Extension (2011) : 1-12. Web.