S. H. Phillips

No-Tillage Agriculture

The no-tillage cropping system, a combination of ancient and modern agricultural practices, has been rapidly increasing in use. By the year 2000, as much as 65 percent of the acreage of crops grown in the United States may be grown by the no-tillage practice. Soil erosion, the major source of pollutants in rural streams, is virtually eliminated when no-tillage agriculture is practiced. The no-tillage system reduces the energy input into corn and soybean production by 7 and 18 percent, respectively, when compared to the conventional tillage system of moldboard plowing followed by disking. In addition, crop yields are as high as or higher than those obtained with traditional tillage practices on large areas of agricultural land.

No-Tillage in the Tropics

In the tropical regions of the world there exists a wide range of differences in climate, vegetation and soil resources. The so-called tropical zone comprises about one-third of the land surface of the earth. It is difficult to clearly define the tropics, and for convenience is often given a latitudinal definition, which includes the zone between Tropic of Capricorn and Tropic of Cancer or latitudes of 23.5° N and S (Kalpage, 1974). Another definition of the tropics (Sanchez, 1976) is that part of the world where the mean monthly temperature variation is 5°C or less between the average of the three warmest and three coldest months. Located within this tropical zone are many of the developing nations that face food supply problems (U.S. President’s Science Advisory Council, 1967) because food production technology has lagged behind population growth.

Other Pests in No-Tillage and Their Control

Innate doubts associated with any major change of accepted cultural practices tend to surface during the early years of adoption. This is especially true when research data and grower experience are lacking or at best limited. Major concerns in the 1960s were raised relative to mulch buildup and the anticipated potential increase in severity of insect infestations and disease problems. Many of the recommendations on pest control were based on deep coverage of crop residues by plowing and clean cultivation. No-tillage reversed this concept and the idea of leaving mulch and crop residues on the soil surface appeared to present an ominous situation. In addition, germinating and growing plants to be desiccated with herbicides were present in the field and could also serve as host plants for pests.