Agri Kultuur January/ February 2015 | Page 42

ARTICLE BY MARCELLOUS LE ROUX Photo: www.thegeorgetowndish.com Department of Agronomy (Faculty of AgriSciences) University of Stellenbosch “Soil is a living ecosystem, and is a farmer's most precious asset. A farmer's productive capacity is directly related to the health of his or her soil.” Howard Warren Buffett S ince contemporary agriculture emanates from the Industrial Revolution, it shares goals of maximizing productivity, economic return and efficiency. It is recognized that the most pivotal component of farming systems is the soil itself and agronomic practices are innately linked to the presence or absence of soil organisms. The nature of the underlying organic matter (also referred to as humus) and mineral components are not the sole drivers of the composition of the soil biota component. On the contrary, the latter is also strongly influenced by environmental variables such as temperature, pH and moisture. Numbers Photo: www.pro-environmental-organics.com and types of soil organisms, especially microorganisms that are the most abundant constituents of the soil biota, are in a constant state of fluctuation and are greatly influenced by agricultural activities such as tillage and cropping practices. Consequently, agricultural production combines practices and management suites that enhance crop water- and nutrient acquisition, and that minimize or completely eliminate weeds and crop diseases. However, production efficiencies of most of the current agroecosystems are precariously poor and widespread negative impacts have been reported, including soil erosion, loss of wetlands, deforesta- tion, pollution of ground and surface waters caused by herbicides, insecticides, and fungicides, as well as eutrophication of estuaries caused by off-farm movement of excess nutrients. It is apparent that the natural soil balance, which hinges on biological, physical and chemical components, has been compromised over the years with efforts of soil restoration mainly being concentrated on the latter two of these aforementioned aspects. The presence and activities of beneficial microorganisms in conventional agricultural systems have been neglected in favor of non-sustainable inputs of energy,