Many of the farming practices that were used 50 plus years ago are now considered conservation practices. Longer crop rotations that included 4 – 5 different crops provided additional biodiversity above and below ground, which provided a longer period that the soil was protected by a living plant. Roots in the ground all year round is now considered one of the principles for improving soil health. Cover crops were used to help improve the soil and today growers are interseeding into an existing crop.
Farmers a half century ago where dealing with smaller farms and more diversity. Field sizes were much smaller than they are today, had different crops growing in them at different times of the year, and most farms had livestock in the operation. When a storm event occurred and water ran off from farm fields, the water flowed over several different land uses before entering the creek or stream. Today fields are much larger in size and crop rotations include fewer crops, allowing the surface water and runoff to travel faster, causing more erosion and less filtration.
In 2015 the Illinois Nutrient Loss Reduction Strategy (ILNLRS) was developed with a focus on the loss of nutrients from point and non-point sources. The Illinois science assessment that is part of the strategy tells us that approximately 48% of the total phosphorus and 82% of the total nitrogen being lost is from non-point agriculture sources. Unlike soil erosion, nutrient loss is something we don’t recognize as occurring because we can’t physically see it happening. The water coming from a tile line looks the same whether it has 5, 10 or 20 ppm of nitrates leaving the crop field and the soil that is eroding looks the same with both high and low concentrations of phosphorus.
Ephemeral gully, sheet and rill erosion is something we can physically see occurring in the field and conservation practices are used to decrease and prevent this. When we build structures to control ephemeral gully formation we recognize the problem is no longer present and can correlate the conservation practice to the elimination of the concern. When we plant cover crops to reduce the level of nitrates leaving the tile system, we don’t physically see the amount being reduced in the tile outlets. Through research on practices like cover crops we know their effectiveness in reducing nitrogen and phosphorus loss from agricultural fields.
Today the focus is still on the elimination of soil erosion, but also on improving water quality. Conservation practices that are part of a Soil Health Management system start with no-till/strip-till, cover crops and nutrient management. These practices not only reduce soil erosion but also improve water quality and soil health.
These practices do require an additional level of management and must be done on an annual basis to be effective. They’re also complementary and improve the efficiency of traditional conservation practices like terraces, grassed waterways, Water and Sediment Control Basins (WASCOBS), and other structural practices. As often as possible, conservation practices should be stacked and used in combination with one another for the best results at reducing soil erosion and improving water quality.
We must use the information available to us today to help increase our adoption of conservation practices that will improve our soil. We can all do better by the soil no matter what type of farming we are doing or what crops we are raising. The adoption of conservation practices will result in healthier soil, less soil erosion and improved downstream water quality.