Relationships between field management, soil compaction, and crop productivity.

In southern Iran, intensive tillage operations and residue removal increased soil compaction, which reduces soil porosity, crop development, and yield. While conservation farming combined with crop residue retention showed encouraging results. A 2-year field experiment (2016–2017) was conducted to evaluate the effect of tillage methods (conventional tillage, CT; reduced tillage, RT; and no tillage, NT) on soil properties as well as crop yield of wheat and corn grown with or without crop residue removal, using a split-plot design with three replications near Shiraz, Iran. Results showed NT had higher soil bulk density (BD) at 0–10 cm soil depth (up to 1.32 Mg m−3), thereby lower cumulative water infiltration (less than 10 cm/150 min). The lowest soil organic carbon was obtained under CT with residue removal (less than 1%), while RT and NT either showed similar effects or RT was superior over NT. Reduced tillage produced higher yield of wheat and corn, which were 9190 and 14,996 kg ha−1, respectively. Our research has shown that replacing RT with CT and/or NT can greatly optimize crop yield, reduce soil compaction, and improve water infiltration under wheat-corn rotation, but it is based on the short-term results and evaluation of long-term experiment is highly recommended. [ABSTRACT FROM AUTHOR]