Watch this video for directions on a fun and easy experiment you can do to teach youth about soil particle sizes. For online lessons on this topic and more visit the Iowa State Extension Moodle Courses here (link to https://moodle.extension.iastate.edu/) and look under 4-H courses.
Leaving crop residue on the soil surface improves nutrient cycling and, ultimately, soil quality that will increase and sustain soil productivity. Through conservation practices that include balanced residue management and soil fertility, environmental quality can be substantially enhanced. By retaining crop residue on the soil surface, soil organic carbon (SOC) and nutrient-holding capacity are increased while protecting the soil from wind and water erosion.
The benefits of healthy soil in sustaining crop production are most evident when growing conditions are less than ideal. Healthy soils increase the capacity of crops to withstand weather variability, including short term extreme precipitation events and intra-seasonal drought. The extreme drought in 2012 resulted in variable yield reduction to corn and soybean production in Iowa with the worst impact on fields with conventional tillage systems (i.e., chisel plow, deep ripping, etc.).
Clarke McGrath, extension field agronomist, discusses the severe soil erosion in southwest Iowa.
Spring rains come with unexpected quantities and force, causing significant amounts of soil erosion to unprotected cropland. Spring is the most critical time for soil erosion because of degraded crop residue, tillage in preparation for planting and lack of crop canopy.
Soil erosion problems are not only limited to water erosion in Iowa, although it is the dominant one due to high rainfall events and their significant impacts on sediment transport to lakes and streams in the state. However, wind erosion at this time of the year can be very significant and contribute to serious topsoil loss given the high winds experienced in the state during recent weeks. Soil loss by wind erosion may not be physically noticeable on the field, but it can be significant in terms of its effects on air, soil, and water quality over time.
Spring rains come with unexpected quantities and force, causing significant amounts of soil erosion to unprotected cropland. Spring is the most critical time for soil erosion because of degraded crop residue, tillage in preparation for planting, and lack of crop canopy. Residue cover is not only good for preventing soil erosion, but it will cut down sediment transport to water bodies and contribute to the improvement of water quality.
Spring rains can come hard and fast as we experienced last week, causing substantial soil erosion when soils are most vulnerable because of degraded crop residue cover, soil preparation by tillage, and no crop canopy. The soil profiles in most of Iowa are now filled to capacity with water. The profiles are at or near saturation. Therefore, the intensity and amount of rain we received have exceeded the soil capacity to filter water and minimize surface runoff even in fields with the most adequate conservation practices.
When it comes to soil erosion and surface runoff from agriculture land, tillage and row-crop management attract a lot of attention. However, most Iowa land currently in pasture is unsuitable for crop production because of steep slopes. These slopes make pasture even more vulnerable to water erosion. Mismanaged pasture can contribute substantially to water quality degradation due to soil erosion and sediment transport to nearby water bodies.
