Agronomy Library > Event & Field Reports

Estimating the Value of Crop Residue
Author: Murray Hartman
Date Created: March 07, 2002
Last Reviewed: February 22, 2007

Maintaining crop residues offers many benefits including reduced erosion risk, increased soil organic matter, plant nutrient recycling and improved soil moisture conservation. However, selling straw may be an option for some areas in some years. 

Estimating the value of straw is complex. The past approach based primarily on nutrient content is too simplistic. In different areas and situations, crop residues can have vastly different values. For example, in erosion-prone areas, the value of straw for erosion protection is several times the fertilizer value of the straw's nutrients. Also, many topics, such as the allopathic nature of residues, are not well understood. Thus, the net value of residues remains elusive. 

Some of the key considerations in deciding whether to retain straw on a field are: 

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If the risk of wind or water erosion is moderate to severe, do not remove straw. 

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On thick Black soils with a low risk of erosion, straw removal once in a three  or four-year rotation is an option, preferably after a crop that produces high amounts of residue

Chaff removal is an option in many areas because chaff does not have much erosion control benefit and is a source of weed seeds. 

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For low organic matter soils, retaining crop residues is very important to maintain sufficient soil organic matter. For soils with high levels of organic matter, the annual addition of straw may not always be critical. 

Adequate fertilizer or use of zero tillage is often as important as straw retention for building soil organic matter levels. 

Crop residues are very important for soil moisture conservation. Do not remove straw in drought-prone areas. 

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Crop residues contain economically significant amounts of micronutrients. However, the actual nutrient contents vary greatly. Test samples for an accurate assessment. 

When retaining a crop residue cover, spreading the residues uniformly across the field is essential to avoid or reduce such problems as equipment plugging, poor seed germination, nutrient tie-up and infestations of diseases, weeds or insects. 
 
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