February 27, 2012
Agriculture requires fertile soils and is therefore dependent on a high level of soil biodiversity. However, agriculture itself has a major influence on biodiversity. For sustainable farming, a farmer should manage his soil’s health, ensuring that the soil will support crops for years to come. The FoodandAgricultureOrganization has historically encouraged scientists and farmers to share research and experiences for the benefit of agricultural development programs and farmers. As soil is fundamental to agriculture, it is also fundamental to human health and food security. It is important that we conserve soil biodiversity and the manage soil for the value of its ecosystem services.
One common agricultural practice, the use of fertilizer, is advantageous to the soil biota. For example, mineral fertilizers can increase the abundance of nematodes. However, because soil biodiversity is very sensitive to the changes in soil pH and the concentration pore water salts, using fertilizer might decrease the soil biodiversity. It is important to use the appropriate amount of fertilizer to avoid damage to the soil organisms.
Pesticides are also commonly used, and can affect soil biota. Soil organisms can be exposed to applied pesticides, so it’s important that the pesticides don’t harm the soil organisms. Testing has led to the development of regulations to ensure that when used properly, pesticides will not cause unacceptable harm to the soil organisms. When planning for fertilizer and pesticide use, a farmer can work towards improving soil biodiversity. By using an appropriate amount of fertilizer and pesticides, the farmer can stimulate plant and soil organism growth while decreasing the risk towards soil organisms.
The farmer can use several physical techniques to manage his soil. The first is planting his crops. By providing plant cover for the soil, the farmer protects his soil and the organisms with in his soil from wind or water erosion. Further, cultivation of row crops such as sugar beet, maize, potato and vegetables provides only partial soil coverage and protection, leaving the land vulnerable to erosion. Large field areas are often devoid of any morphological structures, such as hedges, that could potentially mitigate erosion from wind or water. The farmer might also reduce or even stop tilling the fields. Intense mechanical soil treatment that disturbs the soil pore system is a common cause of erosion. Reduction may improve soil structure, increasing water capacity, and decreasing erosion. The consequence of the erosion is usually the loss of humus and nutrients from the upper soil, leading to reduced fertility.
As such, agricultural practices and following natural processes can have tremendous influences on soil and soil biodiversity. To maintain adequate food supply, and reach sustainable agriculture, conservation of soil is the most important factor in today’s agriculture business. Farmers can conserve soil biodiversity by using contemporary agricultural techniques that cause fewer disturbances to the soil than traditional techniques. Although soil analysis may be an extra cost to production, the benefits would outweigh the cost. With analysis and proper planning, the farmer will be able to enjoy his soil for a lifetime. Through effective soil management, the farmer can avoid stripping the land of nutrients.
As the world’s population grows and its food needs increase, we must work to relieve population pressure on food supply. Soil biodiversity is the key factor for sustainable agriculture, and thus the practices to conserve soil biodiversity are important. As the soil biodiversity and agriculture are the basis of human food supply, we need to take action to preserve our soils.
Wonho Jung and Christopher Miranda are undergraduates in the USC Dornsife College of Letters, Arts and Sciences.