What Can Be Done?
Runoff Mitigation
One potential way to reduce the amount of agricultural runoff is by collecting and removing the contaminants in the runoff before it can enter the watershed. The advantage of this solution is that farmers do not need to change their growing practices or chemical usage. Despite seeming like it would require a fairly complicated system to remove the contaminants in field runoff, there are several simple solutions.
A simple but effective filter is a plastic tank filled with sand, rocks, topsoil, and wood chips. The simple design means that it is both low maintenance and low cost. Using this design, a research team achieved an 80% reduction in Nitrogen in the runoff, along with reductions in Phosphorus deposits and other contaminants.
This system allows a farm to reduce the amount of chemicals in its runoff without changing any of their established farming practices. This allows the farms to keep the same level of productivity while reducing the level of Agricultural pollution they create. The downside is that each field would need to be retrofitted with collection systems and filters to remove the contaminants. This would be an expensive undertaking for most farmers, both because the cost in acquiring the equipment and the time when the fields are being modified with collection systems and not growing food.
Changing Agricultural Practices
Another method to reduce agricultural runoff is to change the way crops are grown. One way to reduce runoff without changing the layout or profitability of the fields is to avoid tilling the field before planting. This increases the amount of nutrients in the field to begin with, and helps reduce soil erosion. Both of these reduce the amount of runoff coming from a field. The downside of this is that it increases the number of weeds in a field and requires stronger planting equipment than if a field was tilled before planting.
Another obvious way to reduce runoff is Crop Rotation. This practice is already widely used on many farms. Since each crop uses different amounts of different nutrients, by rotating them out, one can reduce the amount of nutrients that need to be replaced by fertilizers. Since there is less need for fertilizers, less fertilizers are applied to the field, which means less enters the watershed.
Finally, the most obvious way to reduce agricultural pollution is to reduce the amount of chemicals applied to a field. The less are applied, the less runoff there is. Naturally, the downside of this is the fields do not get the chemicals that can increase their yield, which means less profit for the farmer, and less food produced.
Performance of Nitrogen-Removing Bioretention Systems for Control of Agricultural Runoff
Environmental and economic implications of various conservative agricultural practices in the Upper Little Miami River basin.
