Sustainable Agriculture – An Overview
3 September, 2014
D.W. Lobb P.Ag.(Hon)
Sustainable agriculture requires the protection of soil from irreversible alternate use and the care of soil in a way that maintains or improves its capacity to grow crops without compromising the surrounding environment.
Thoughtful land planning and rigid protection of cropland are necessary for agriculture to meet new production demands. Sustainable land management or soil care must begin with measures to control soil erosion by tillage, water and wind. But much more is needed.
We have learned through experience and scientific discovery that support and care of soil biota gives soil its capacity to produce, regenerate and be physically stable. Because most biota are damaged or destroyed by soil disturbance, tillage must be minimized or eliminated if sustainability is to be achieved. Furthermore, precise soil moisture management is critical to soil biota survival, crop root development, nutrient retrieval and water availability. A healthy balance of air and moisture must be achieved through combinations of drainage, irrigation and crop residue management. Soil biota populations can be fed and organic matter levels can be increased with the use of cover crops and careful choice of crop types and rotations. All of this is critical to soil health and crop production efficiency. While we know that our scientific understanding of soil health and the soil ecosystem is not complete, we do know that they are complex and must be protected and nurtured in sustainable agriculture.
On our more fragile soil and where soil improvement is attempted, deep-rooted perennial forage crops provide significant benefit. By processing forages through ruminant livestock, food can be produced as meat or milk. Forages and ruminants are the key to extending food production to fragile soil in a sustainable way. The development and use of more perennial crops would result in less soil disturbance and lead to more sustainable production.
To be truly sustainable, society must accommodate the recycling of human, livestock and food-processing waste back to the land where production occurs so nutrient and organic matter levels can be maintained. To achieve this, large concentrations of human and livestock populations must be discouraged. All nutrients, regardless of source must be used responsibly and efficiently because supply is limited. Furthermore, nutrient lost to an off-site fate brings unnecessary agricultural cost and environmental concern.
Farm business models that endure must be built around sustainable soil management because all agricultural production begins with the soil. Benefits can be realized in many ways as healthy soils produce more stable yields and the productive potential of the soil improves.
History has proven that social and economic stability are predicated by agricultural sustainability. As low-input, tillage-based agriculture has evolved during the past 10,000 years, man has repeatedly destroyed the soil around him and then moved on. Moving on is no longer an option. Intensive, health-focused soil management must be the new frontier for agriculture as it meets a rapidly growing demand for food on a declining land base. "Intensive" is the only alternative to agricultural exploitation of fragile and Natural Heritage lands. We must now carefully implement the very high levels of science and management required to ensure that "intensive" agriculture is sustainable.