USC Dana and David Dornsife College of Letters, Arts & Sciences > Blog

February 27, 2012

Which Came First: Soil Conservation or Sustainable Agriculture?

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.

Sources:

www.fao.org/ag/agl/agll/soilbiod/docs/CGRFA_SoilBiodSustAg.doc

http://www.fao.org/ag/agl/agll/soilbiod/default.stm

http://www.europeanlandowners.org/files/pdf/soil_bio_and_ag_009.pdf

Wonho Jung and Christopher Miranda are undergraduates in the USC Dornsife College of Letters, Arts and Sciences.

September 25, 2011

Sustainable Agriculture: the new face of agriculture in America

Agriculture is an important multi-billion dollar industry in the United States that plays an important economic and social role. In recent years, the concept of sustainable agriculture has emerged out of the increasing concern for long-term farm productivity and the effect of agricultural practices on the environment. Sustainable agriculture is an alternative approach to agriculture that incorporates integrated farming systems to produce environmental goods while protecting resources and enhancing future environmental quality. The key to creating sustainable agriculture is improving and maintaining soil biodiversity, but this cannot be done until the economic and social issues related to farming are addressed.

Soil biodiversity is a central component of sustainable agriculture since without it the availability of arable soil would decrease, therefore making soil management techniques crucial in sustainable farming. Soil is the home for a myriad of organisms, bacteria, fungi, and microbes, which all play key roles in soil quality and health, in turn affecting agriculture. The function of these soil biota are “central to the decomposition processes and nutrient cycling” and therefore “affect plant growth and productivity, as well as the release of pollutants in the environment.” Soil biodiversity is key in sustainable agriculture’s goal of producing adequate amounts of nutritious food while maintaining environmental quality and conserving natural resources.

Sustainable farming is extremely intertwined with three variables: environment, economy, and society. Environmental factors sustainable farmers must take into account are biodiversity, recycling of nutrients, waste, and avoidance of pollution, to name a few. Although most attention is usually places on the environmental facet of sustainable agriculture, the economic and social influences play increasingly crucial roles in its success. Economically, concerns of profitability, especially compared to other farms, and maintenance agricultural raw materials are important for farmers to take into consideration. The social dimension includes the “retention of an optimum level of farm population, the maintenance of an acceptable quality of farm life, and the equitable distribution of material benefits from economic growth.” The struggle for many sustainable farms is that environmental, economic, and social factors do not always coincide and therefore priority must be given to certain interests over others. For example, sustainable agriculture techniques such as crop rotation, conservation tillage, cover cropping, nutrient management, and multicrop farming can become costly and do not necessarily yield the biggest profit margin. Conversely, due to competition from other farms, sustainable or not, in order to stay in business farms must have a maximum output of crops.

Organic farming is a type of sustainable farming that prohibits the use of synthetic products, including fertilizers and pesticides, and stresses maintaining soil productivity and quality. In 1995, the National Organic Standards Board defined it as “an ecological production management system that promotes and enhances biodiversity, biological cycles and soil biological activity.” Since organic farms do not use unnatural pesticides and fertilizers, they tend to rely more on natural nutrient cycles than do conventional farms. These types of farms must be creative in the ways they replace chemical fertilizers and frequently practice crop rotation, maturing, cultivation, and mineral fertilizers. Since many of these practices are more time consuming and costly than traditional chemical fertilizers, organic farms rely on higher prices for their produce in order to ensure profitability. By increasing their prices, organic farmers do not have to choose between being environmentally sustainable and making an economic profit.

Due to the increasing global population rate and more demand on agricultural resources, sustainable agriculture is becoming more important and necessary, however it is crucial to remember the role of soil biodiversity in its success and how economic and social factors play an important role in its effectiveness and implementation.

About the authors: Ariana Verdu and Lily Phillips are working towards their bachelor degrees in the USC Dornsife College of Letters, Arts and Sciences.