Discussion
Correlation analysis showed that (i) maize yield was significantly and positively correlated with S-SC, S-CL, S-UE, SOC, and TN. (ii) S-SC was significantly and positively correlated with TN, SOC, and MBC. (iii) TN was significantly and positively correlated with S-UE, and SOC was significantly and positively correlated with S-SC. It has been concluded that straw return coupled with subsoiling and rotary tillage is an appropriate approach to enrich soil nutrients, enzyme activities, and maize yield.
Methods
Therefore an experiment was conducted a split plot design during 2018-2022. They were comprised of traditional planting with no straw return and straw return, accompanied by four different tillage methods: control (no tillage), rotary tillage (25 cm tillage depth), subsoiling (35 cm tillage depth), and subsoiling plus rotary tillage (35 + 25 cm tillage depth).
Results
Results showed that subsoiling along with rotary tillage enhanced soil total nitrogen (TN) by 9.0%, soil organic carbon (SOC) 7.5%, soil microbial biomass carbon (MBC) 6.8%, soil catalase (S-CAT) 9.6%, soil urease (S-UE) 4.1%, soil cellulase (S-CL) 14.5%, soil sucrase (S-SC) 10.8% and maize yield 3.0% compared to no tillage.