Tillage practices do not affect winter wheat grain yield trend

Abstract

Tillage is an integral part of the crop production system and is one of the crucial management decisions producers make to enhance soil health and crop productivity. However, its contribution to winter wheat (Triticum aestivum L.) grain yield over time requires further investigation in dryland cropping systems. The objective of the study was to evaluate the influence of tillage practices on the rate at which winter wheat grain yield changes over time. A long-term tillage experiment established as a winter wheat–fallow in 1970 was used to address the research objective. The tillage treatments included moldboard plow (MP), stubble mulch (SM), and no-till (NT) and were assigned to three blocks arranged as a randomized complete block design. The rate at which grain yield changed over time was studied using data from 1972 to 2010. The rate at which grain yield changed between 1972 and 2010 was not significantly different from zero for all the tillage practices with grain yield decreasing by approximately 10 kg ha⁻¹ year⁻¹. The slopes associated with each of these tillage practices did not differ from each other, suggesting that tillage practices did not affect the rate at which grain yield changed over time. In dryland cropping systems without nutrient application, yield trends may remain similar among tillage practices, and the long-term decline in soil fertility or quality possibly decelerates organic crop producers from harnessing the full benefits of improved genotypes.