Agriculture and Environment: Corn (Maize)

Better Management Practices: Adopt Conservation Tillage

Many BMPs save producers time and money. Conservation tillage saves on fuel, labour, and depreciation of farm equipment while improving soil structure and fertility (USDA 1995).

Producers reduce mechanical cultivation, and the savings are substantial. A farm of 400 hectares saves 450 person-hours per year, more than U.S.$800 for machinery use and wear and tear, and U.S. $3,250 in fuel savings per year (CTIC 1997).

Producers seem to be interested in switching to conservation tillage or no-till production if they do not have huge existing capital investments in machinery and if their land tends to be erodible.

Recent research regarding the impacts of conservation tillage suggests that it can have a significant positive impact on soil biodiversity while reducing erosion and increasing water retention in soil. Studies indicate that it increases earthworm population 2-3 times above those in conventional fields, bringing the associated benefits of improved water infiltration, better crop rooting, and increased soil fertility (Scardena 196).

One of the key remaining questions about conservation tillage is: What are its overall impacts regarding herbicide use? One form, no-till, substitutes herbicide use for mechanical cultivation to prepare fields for planting and to control weeds.

BMPs are not found only in high-input forms of agriculture in developed countries. In the humid tropics, corn is cultivated on steep slopes and more marginal area in the Andes, Belize, and mountainous areas of Mexico. Use of conservation tillage methods there is reducing impacts and increasing producers' yields and income.

In Belize, for example, producers are now planting native nitrogen-fixing legumes simultaneously with corn. These plants overtake the corn after it is harvested, protecting the soil from exposure, reducing erosion, fixing nitrogen, and actually reseeding themselves for the next season's crop.