Agriculture and Environment: Wheat

Introduction

The FAO has developed a qualitative assessment of the environmental impacts of various commodities (Runge 1994). This assessment includes wheat in a more general category of grains. One of the main environmental impacts of grains such as wheat is the destruction of natural habitat due to field enlargement or creating new fields following the abandonment of degraded areas.

Array of environmental problems
This in turn causes the displacement of indigenous species and biodiversity loss, due especially to the promotion of high-yielding varieties. Other major environmental problems are soil erosion, soil degradation, and water use and pollution. The increasing use of manufactured fertilisers and pesticides and creation of dust from dry milling also cause environmental problems.

Looking at the positives
Despite these problems, wheat has a fairly positive role because much of it is planted in the late fall, winter, or very early spring depending on the location and the variety. Due to its "off-season" nature it provides ground cover and reduces soil erosion. It requires less fertiliser and pesticides per hectare than many other crops (but often more per ton produced), and most wheat is not irrigated.

Agrochemicals, doing the harm again
A broad range of pesticides is used on wheat including herbicides, soil fumigants, insecticides, and fungicides. While the quantities used per hectare are not large, because wheat is grown on so much land the total quantities of chemicals used are quite large. More importantly, these chemicals end up in runoff and freshwater systems if soil is not protected from erosion and if there is insufficient organic matter and mulch to bind and hold them.