Tuesday, November 14, 2006 - 3:00 PM
190-3
Residue and Nutrient Management Under Reduced Tillage Systems.
Soil tillage is one of the oldest methods known to mine organic nutrient reserves for enhancing crop production. However, conventional tillage (CT) leads to a rapid reduction in soil organic matter and soil structure and when practiced inappropriately, results in increased erosion and loss of nutrients. A form of conservation tillage, no-tillage (NT), is one of the truly revolutionary agricultural practices developed in the past 50 years and has become an important option in many countries of the world for sustaining economic food production and environmental quality. Numerous observations have indicated significant differences exist between NT and CT soils. No-tillage has greater potential to limit nutrient (especially N) pollution to water supplies because it results in slower N mineralization and greater N retention due to more efficient cycling. We must better define and understand the differences between tillage management systems in how N forms are distributed in soil and how cycling and timing of plant-available N can lead to optimum N uptake and crop yields under NT conditions. Dr. Martens published a comprehensive review, in 2001, on N cycling under different soil management systems with emphasis on reduced tillage and no-tillage. This review, along with additional publications by Dr. Martens and other more recent work, will serve as the basis for a presentation on current knowledge, and limitations of that knowledge, on NT residue and nutrient management. Dr. Martens was a strong proponent of NT and stated, "The numerous benefits of NT over CT should result in NT rapidly being implemented in all of the major agricultural areas in the Untied States". This has not occurred and Dr. Marten's goal was to improve our understanding of factors that affect N availability under NT so that farmers adopt NT, instead of abandoning the practice, for production of crops.
Recorded presentationBack to S03 Soil Biology & Biochemistry
Back to The ASA-CSSA-SSSA International Annual Meetings (November 12-16, 2006)