|Powell, J - CONSULTANT, MADISON, WI|
Submitted to: Meeting Abstract
Publication Type: Proceedings
Publication Acceptance Date: April 22, 1996
Publication Date: N/A
Technical Abstract: Crop residues perform various functions in semi-arid farming systems. When left in fields after grain harvest, they enhance soil and water conservation, nutrient cycling and subsequent crop yield. Crop residues are also used for various other purposes, such as livestock feed, fuel and construction material. Although retaining crop residues on soil surfaces has numerous beneficial effects, their other uses preclude total crop residue return. This papers examines the key roles of crop residues in semi-arid farming systems and suggests alternatives to crop residues for soil amendments. The retention of even limited amounts of surface residues can conserve soil organic matter and nutrient levels, decrease water runoff and increase infiltration, decrease evaporation, and control weeds. There are various soil management and related practices that allow crop residues to be removed without adversely affecting the soil environment. These include the introduction of appropriate, improved crop genotypes that produce both sufficient grain and residues of good quality; the partial rather than total removal of crop residues through selective crop residue harvest/return practices; provision and strategic use of chemical fertilizer and animal manure; substituting forages for crop residues; use of clean or reduced tillage; use of structural and support practices that complement tillage; and application of surface soil-amending materials. Not all practices are adaptable to all conditions, but one or more practices should be suitable for sustaining land productivity under most conditions where crop residues are limited or used to other purposes.