Author
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Anderson, Randal |
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Submitted to: Journal of Sustainable Agriculture
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 3/1/2004 Publication Date: 6/1/2005 Citation: Anderson, R.L. 2005. Improving sustainability of cropping systems in the central great plains. Journal of Sustainable Agriculture. 26(1):97-114. Interpretive Summary: Rotations are changing in the semiarid Central Great Plains because of no-till systems and crop residue management. Producers now grow a diversity of crops in addition to winter wheat and fallow. A long-term cropping systems study was started at Akron, Colorado in 1990 to evaluate rotations comprised of different crops. After 10 years, we examined trends associated with soil structure, nutrient cycling, and pest management as affected by rotations. Arranging crops in a cycle of four, with two winter annual crops followed by two summer annual crops (fallow serves in either life cycle category), improved soil structure, nutrient cycling, and pest management. Fallow was developed to help producers adjust to variable precipitation in this semiarid climate; they would like to eliminate fallow, as it is detrimental to the health of the soil. Thus, we also suggest options for developing rotations with continuous cropping. Soil in the Central Great Plains were severely damaged during the Dust Bowl era, but producers can repair this damage with continuous cropping and no-till. Also, growing a range of crops in conjunction with residue management and no-till may help producers adjust to variable precipitation and minimize financial risks of crop production. Technical Abstract: Rotations are changing in the semiarid Central Great Plains because of no-till systems and crop residue management. Producers now grow corn (Zea mays L.), proso millet (Panicum miliaceum L.), sunflower (Helianthus annuus L.), or sorghum [Sorghum bicolor (L.) Moench] in sequence with winter wheat (Triticum aestivum L.) and fallow. A long-term cropping systems study was started at Akron, Colorado in 1990 to evaluate rotations comprised of a diversity of crops, with the goal of developing rotations that minimize frequency of fallow. After 10 years, we examined ecological trends associated with soil structure, nutrient cycling, and pest management as affected by rotations. Soil structure and nutrient cycling improved with continuous cropping, whereas arranging winter and summer annual crops in a cycle-of-four improved pest maangement. Producers are seeking rotations that not only are economical, but also improve soil quality; they view fallow and tillage as detriments to long-term sustainability. Therefore, we also suggest options for developing rotations with continuous cropping, based on insight gained from the Akron study. Soils in the Central Great Plains were severely damaged during the Dust Bowl era; producers seek to repair this damage with continuous cropping and no-till. But, a concern with continuous cropping is yield variability and financial risk, which producers previously managed with fallow. Crop diversity and sequencing in conjunction with residue management and no-till may provide advantages that minimize need for fallow in risk management. |
