Research Progress in Agricultural Tillage: Ray Allmaras' Legacy.

Research progress in agricultural tillage: Ray Allmaras’ legacy

 By D.C. Reicosky

  ¹ Collaborator, USDA-Agricultural Research Service, North Central Soil Conservation Research Laboratory, 803 Iowa Avenue, Morris, MN 56267; Phone: +1-320-589-3411 x 144; Fax: +1-320-589-3787; e-mail: don.reicosky@ars.usda.gov
 Abstract

 The management of crop residues and soil organic carbon  is of primary importance in maintaining soil fertility and productivity and for minimizing agriculture’s impact on the environment.  Conservation agriculture  aims to conserve, improve and make more efficient use of natural resources through integrated management of available soil, water and biological resources combined with external inputs.  Conservation agriculture through less intensive tillage contributes to global environmental conservation. This work briefly reviews research on new tillage technology, crop residue management, tillage-induced carbon losses and environmental benefits of soil carbon to highlight the contributions of Ray Allmaras, one of the early leaders who researched tillage and crop residue management. His early work showed the critical importance of uniformly spreading straw and chaff to minimize allelopathic effects on subsequent crops.  The establishment of Tillage Management Regions (TMR) across the US brought together common soil properties that focused on reduced-tillage intensity. These TMRs did not follow state boundaries, but instead used geographical classification with common climate, topography, soils, land-use practices to solve conservation problems.    Further work showed potential for adopting conservation tillage on U.S. croplands. As a result, soil organic carbon sequestration emphasized carbon dynamics in corn-soybean sequences with corn-residue transformation into root and soil carbon as related to nitrogen, tillage, and stover management.  Extension of Ray Allmaras' legacy requires transforming conservation agriculture through less intensive tillage to no till/zero till/direct seeding that contributes to better carbon management and global environmental conservation for sustainable agricultural production. Continued research is needed to provide less soil disturbance and better crop residue management for our global food security.