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Integrating soil conservation practices and glyphosate‐resistant crops: impacts on soil
Author(s) -
Locke Martin A,
Zablotowicz Robert M,
Reddy Krish
Publication year - 2008
Publication title -
pest management science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.296
H-Index - 125
eISSN - 1526-4998
pISSN - 1526-498X
DOI - 10.1002/ps.1549
Subject(s) - glyphosate , agronomy , cover crop , tillage , crop , crop rotation , soil conservation , environmental science , biology , agriculture , ecology
Abstract BACKGROUND: Conservation practices often associated with glyphosate‐resistant crops, e.g. limited tillage and crop cover, improve soil conditions, but only limited research has evaluated their effects on soil in combination with glyphosate‐resistant crops. It is assumed that conservation practices have similar benefits to soil whether or not glyphosate‐resistant crops are used. This paper reviews the impact on soil of conservation practices and glyphosate‐resistant crops, and presents data from a Mississippi field trial comparing glyphosate‐resistant and non‐glyphosate‐resistant maize ( Zea mays L.) and cotton ( Gossypium hirsutum L.) under limited tillage management. RESULTS: Results from the reduced‐tillage study indicate differences in soil biological and chemical properties owing to glyphosate‐resistant crops. Under continuous glyphosate‐resistant maize, soils maintained greater soil organic carbon and nitrogen as compared with continuous non‐glyphosate‐resistant maize, but no differences were measured in continuous cotton or in cotton rotated with maize. Soil microbial community structure based on total fatty acid methyl ester analysis indicated a significant effect of glyphosate‐resistant crop following 5 years of continuous glyphosate‐resistant crop as compared with the non‐glyphosate‐resistant crop system. Results from this study, as well as the literature review, indicate differences attributable to the interaction of conservation practices and glyphosate‐resistant crop, but many are transient and benign for the soil ecosystem. CONCLUSIONS: Glyphosate use may result in minor effects on soil biological/chemical properties. However, enhanced organic carbon and plant residues in surface soils under conservation practices may buffer potential effects of glyphosate. Long‐term field research established under various cropping systems and ecological regions is needed for critical assessment of glyphosate‐resistant crop and conservation practice interactions. Published in 2008 by John Wiley & Sons, Ltd.