Tillage practices affect soil porosity and surface roughness, which in turn affect rates of runoff, evaporation, and infiltration. As a general rule, any tillage practice that reduces leaching will help reduce the risk of groundwater contamination. Selecting and adopting correct tillage practices is important to both groundwater and surface water quality. The aim is to reduce runoff while simultaneously maximizing the water-holding capacity of the soil to reduce leaching. Reducing leaching may lead to an increase in runoff when rainfall is high and the soil is shallow or has a low water infiltration rate.
Planting strategies can also influence the types and number of pests and pest control options.
For example, planting crops in narrow rows can enhance weed control. The denser canopy protects soil from exposure to rain and suppresses growth of late-germinating weeds through shading and competition. Thus, less herbicide may be needed to control weeds. Conclusion Agricultural activities can lead to contamination of groundwater, mainly with nitrate and pesticides. The potential for groundwater contamination at a given location depends on site characteristics, characteristics of individual pollutants, and agronomic and management factors.