Crop rotation has increased in the south in the last 10 years due to the changing tides of the ever changing grain price. With the increase in corn acres across the south, as well as the increase in irrigation, we have seen a steady increase in yields.
There are many studies showing yield increases of 10 to 15 percent in soybeans and corn when rotation is utilized. Rotations also help with a reduction in nematodes, weeds and diseases. Northern Leaf Blight is a good example of a disease that has increased over the last several years, and can be reduced by rotating corn and soybeans. Understanding the relationship between nitrogen N and crop rotation is very important when making N management decisions. There are several benefits to using crop rotation, including improved nutrient cycling, soil tilth, and soil physical properties; and enhanced weed control.
Crop rotation also may influence the rate of N mineralization or the conversion of organic N to mineral N by modifying soil moisture, soil temperature, pH, plant residue, and tillage practices. The incremental increase in N use over the past five decades, due to emphasis on maximizing yield, has led to a subsequent increase in N in the soil profile of some agricultural fields. Therefore, the influence of agricultural practices on water quality has prompted studies to develop best management practices to optimize the use of fertilizer N and reduce N loss to surface and groundwater.
Crop rotation can play a major role in minimizing the potential risk of nitrate leaching to surface and groundwater by enhancing soil N availability, reducing the amount of N fertilizer applied, and minimizing the potential risk of N leaching. Research on the impact of long-term crop rotation on soil N availability shows that planting alfalfa, corn, oat, and soybean significantly increased the mineralized net N in soil compared with planting continuous corn.
Rotation involving crops with higher crop residue can reduce surface crusting and water runoff, thereby improving soil moisture content for the succeeding crop. Cover crops that are legumes will have the same benefits of weed, insect and disease control, as well as improve fertility of soil by nitrogen fixation. Cover crops will also act as a barrier to reduce wind and water erosion. Yields are higher when a crop different than the preceding crop is grown. Research has shown that, even with the same fertility levels, significant positive yield differences can be achieved through rotation.
Some of the crops in a rotation have the potential to generate income through recreational use. Crops like grain sorghum, sunflower and brown-top millet are some options to attract birds for hunting. Crop rotations can be two, three, four or more years. Having a longer crop rotation interval is better than a short crop rotation interval.
Having the same double-crop year in and year out will not be beneficial if the same crops are grown in the same season every year; this is not considered to be crop rotation.
But double cropping can be integrated into a crop rotation if the current management plan has the same single crop every year. Canola, corn, alfalfa, sesame, soybeans, cotton, sunflower, chickpeas, forage sorghum, grain sorghum, pear millet and teff are some of the crops that can be employed in a crop rotation in the Southern Great Plains.
Some of the crop rotations can include a cover crop or a fallow period when no crop is grown. Crop rotation is not a one-size-fits-all formula.
Farmers and Ranchers in Action including support from Soybean and other Checkoff programs. Farmers and Ranchers Alliance. All rights reserved.
Author: Mark Moore. Rotate, then rotate again. Good soil structure starts at the roots. Crop rotations can benefit other soil conservation methods. Wheat is an excellent crop to add to a diverse crop rotation system. Get Involved. Sustainable Stories.
0コメント