enhancing soil biological activity and net primary productivity through no-tillage, wheat residues, and corn-bean intercropping

Conservation management practices play a crucial role in enhancing soil microbial activity, which, in turn, drives improvements in net primary productivity (nppc) and facilitates efficient carbon allocation. this study presents an innovative approach to examining the synergistic effects of tillage systems, varying wheat residue levels, and corn-bean intercropping patterns on soil biological activity and nppc. the study was conducted as a carefully designed field experiment, utilizing a split-split plot arrangement within a randomized complete block design (rcbd) with three replications, at the agricultural research, education and extension organization in shahrekord during 2017-2018 growing season. the experiment included three tillage systems (conventional, minimum, and no-tillage) as the main plots, four levels of crop residue (0%, 30%, 60%, and 90% of the straw yield of wheat) as the subplots, and five intercropping patterns (corn monoculture, bean monoculture, and corn-bean ratios of 2:2, 3:1, and 1:3) as the sub-subplots. the results indicated that the highest soil microbial respiration was observed in the no-tillage system combined with 60% wheat residues and a corn-bean intercropping ratio of 2:2. soil microbial biomass carbon increased significantly under the no-tillage system with 90% wheat residues and the same intercropping ratio of 2:2. the carbon allocation coefficient in seeds, straw, roots, and extra-root structures increased under no-tillage compared to conventional tillage by 10.09%, 11.84%, 52.18%, and 62.67% for corn, and by 12.68%, 7.85%, 35.71%, and 34.92% for beans, respectively. corn exhibited higher nppc and allocated more carbon to its aerial organs than beans. this study demonstrates that the combination of no-tillage systems and wheat residue management in diverse intercropping patterns not only synergistically enhances soil microbial activity and nppc but also promotes soil health and supports sustainable agricultural productivity.