A farmer does not want to use fertilizers in his soil. how can he increase the fertility of the soil in a cost-efficient way?
Using Wastewater for Irrigation: As urban areas grow in developing countries, residents and governments are struggling to find ways to properly dispose sewage and waste water. The United Nations Food and Agriculture Organization notes that wastewater contains most of the essential elements of fertilizer in the proper amounts. Effective treatment and application of wastewater could dually contribute to healthier urban areas and provide vital, organic fertilizer to rural areas.
Wastewater Irrigation in Action: Using effluent wastewater as an agricultural fertilizer could be an easy way for farmers, especially in cities, to fertilize their crops; but it can be risky. As Pay Drechsel wrote inState of the World 2011, “In Ghana and surrounding areas, polluted stream water is often used to irrigate vegetable crops. The problem is that the water often contains biological and chemical substances that are harmful to human health.” The Bill and Melinda Gates Foundation, however,recently announced aprogram that may make this a more practical option for farmers. The Foundation will be spending US$42 million in sanitation grants over the next few years to “reinvent the toilet.” The hope is that this money will help build better human waste infrastructure in urban areas, promote improved sanitation, and effectively capture the wastewater for use in energy and fertilizer.
Reintegrating Livestock: As many as one billion people around the world “rely on farm animals for their livelihoods,” according to researchers from the International Livestock Research Institute. But animals are not only important for their egg and meat production, but also because they can be integrated into larger agricultural systems. Animal manure can be an effective – and inexpensive – way to boost the health of organic topsoil.
Livestock Integration in Action:International organizations are beginning to recognize the potential and value of these integrated farming systems. The African Wildlife Foundation’s Heartland program and the multinational TerrAfrica project are both promoting sustainable land and water management practices in drought-prone areas of the continent. In Botswana, the Mokolodi Nature Reserve is both a wildlife preserve and an educational center, sending staff to teach local farmers sustainable ecoagriculture and integrated livestock farming techniques.
Preventing Nitrogen Leaching (Inhibitors): Nitrogen is essential to healthy soil. Chemical fertilizers and nitrogen-fixing plants, such as legumes, can help provide nitrogen to soils. Yet, nitrogen, like water, follows a cycle that includes leaching or escaping from the ground as a gas. Poor land management, erosion, overfertilization, and chemical runoff can all contribute to nitrogen depletion, which will leave the land dry and unusable. To combat nitrogen loss, soil scientists have been experimenting with chemical inhibitors that will keep vital nutrients in the ground longer.