The definition for a conservation tillage system is:
A bundle of complementary best management practices that are implemented in a crop production system, in conjunction with other conservation practices, to enhance environmental stewardship, farm profitability and agricultural sustainability.
The best management practices used in conservation tillage systems achieve little to no soil disturbance; promote crop rotations; provide permanent soil coverage; increase residues on the soil surface; reduce use of inputs; improve soil quality; and control traffic [8]. Conservation tillage systems affect nearly every aspect of crop production, including crop rotations, planting, equipment performance, and fertilizer practices, as well as pest management and incidence through reductions in tillage and presence of crop residues [24]. Derpsch [8] recognizes that these types of systems can be developed from a “basket” of alternative conservation practices. The farmer chooses the practices that are best for the local conditions.
Conservation tillage systems are designed to enhance environmental stewardship, farm profitability and agricultural sustainability. Each of these concepts is addressed individually to emphasize their importance in the above definition.
Environmental Stewardship
Farmers who adopt conservation tillage systems are acting as environmental stewards by enhancing ecosystem services on and off agricultural lands. Ecosystem services are both direct and indirect. Direct services include the production of food, livestock feed, biofuel feedstocks and fiber for textiles. Indirect services include maintaining soil fertility and increasing the efficiency of nutrient cycling (cycling and filtration services); crop pollination (translocation services); carbon sequestration and water conservation (stabilizing services); and recreation or aesthetic values (life-fulfilling services) [5]. An important indirect ecosystem service provided by conservation tillage systems is the maintenance and protection of the land, and the services it provides for future generations.
Intensive agricultural practices such as inversion tillage can degrade indirect ecosystem services by reducing soil productivity, increasing soil erosion and degrading soil quality. This can contribute to eutrophication of water bodies, increased nutrient and pesticide runoff, higher rates of soil erosion, and a need for increased inputs such as fertilizer, water and energy as soil productivity declines [32]. In contrast, properly managed conservation tillage systems enhance ecosystem services, improving farm profitability and sustainability. These benefits are further highlighted in chapters 2 and 3 of this book. Other chapters highlight the benefits of alternative conservation practices.
Farm Profitability
Economics plays a significant role in the management of conservation tillage systems. Many factors contribute to farmers’ conservation decision-making, including agricultural payment programs such as conservation programs; market conditions, for example crop prices, marketing options and the emerging biofuels market; market and production risk such as volatile commodity prices and weather; the cost of conservation practices; and management style. Economic factors are discussed in considerable detail in Chapter 15.
Conservation tillage systems tend to require a higher degree of management. The farmer needs to know how different conservation practices will interact to affect crop production and economics as well as soil and water conservation. Farmers also need to consider limiting factors such as low precipitation, high evapotranspiration and increased potential for soil erosion when making management decisions [10, 29]. Chapters 4–14 provide specific management guidelines for different conservation practices that make up conservation tillage systems. Chapters 17–20 provide management considerations for different areas of the Southeast. The management guidance provided is to help ensure the economic viability of these systems.
Agricultural Sustainability
Sustainability has many different connotations. A broad definition of sustainability for conservation tillage systems is production systems: that meet current and future societal needs for food and fiber, ecosystem services, and healthy lives, and that do so by maximizing the net benefit to society when all costs and benefits of the practice [and system] are considered [32]. Thus, agricultural sustainability pertains to the whole of society, not just the farmer.
What does this mean at the farm level? Sustainability on the farm encompasses (1) protection and long-term maintenance of soil and water resources, which includes using practices that reduce soil erosion, enhance soil quality and improve water use efficiency; and (2) enhancement of economic opportunities and growth by improving cash crop yields, lowering costs of production, reducing risk, improving crop profitability and improving overall economic management [24]. By being good stewards of the land, farmers are improving social welfare and are being socially responsible. Other actions farmers can take to improve sustainability include taking part in discussions concerning conservation and policy at the local, regional and national level; taking advantage of conservation-program benefits to improve on-farm conservation; and interacting with other farmers through conservation alliances, farm groups and conferences.