Tillage and stubble management: on-going research in USA
1991
Papendick, R.I. (Washington State Univ., Pullman (USA). USDA/ARS) | Parr, J.F. (USDA/ARS, Beltsville (USA)) | Meyer, R.E. (U.S. Dept. of State, Washington D.C. (USA). SandT/AGR, USAID)
There is a considerable emphasis on conservation tillage research in the US in response to growing concern over soil erosion and its adverse effects on productivity and environmental quality. Conservation tillage can reduce erosion by 50 or more and at the same time conserve water which has significantly increased crop yields and reduced farming risks in the dryland areas. US farmers are now applying conservation tillage practices to about one-third of the nation's croplands. Approaches to conservation systems receiving more emphasis include no-till fallow, increased cropping intensity for more soil cover, no-till into cover or sod crops, and ridge-till. Adaptive research on tillage methods include slot mulching, paraplowing, and basin pitting. Studies of fertilizer placement with conservation planting show generally that banding the fertilizer near the seed row of crops is superior to broadcasting or banding some distance away from the row. A new combination seed-fertilizer drill opener termed "cross-slot" has been developed that is capable of efficiently operating over a wide range of conservation tillage conditions. Yields with the cross-slot opener were comparable or superior to those with standard double disc or hoe-type openers. Conservation tillage alone as used with many conventional cropping systems will probably not change the current status of nitrate leaching and thus, the potential for groundwater contamination. The status with pesticide contamination of water is less certain and no clear cut distinction between conventional and conservation tillage yet exists
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