Effects of conservation tillage on wheat growth duration and grain yield in the North China Plain

摘要

ABSTRACT Low wheat grain yield under conservation tillage has been reported, and growth duration could determine the yield. Thus, an 11-year field experiment was conducted to assess the relationship between growth duration and grain yield under different tillage and residue managements. Four treatments were investigated: no-till with residue removal (NT0), conventional tillage with residue removal (CT0), no-till with residue retention (NTR, conservation tillage), and conventional tillage with residue incorporation (CTR). Beginning at 20 days after anthesis (DAA), NTR significantly increased physiological activities, indicating that NTR had a longer growth duration. NTR significantly prolonged growth duration by 2–3 days compared with the other treatments attributed to delayed emergence of seedlings caused by higher soil compaction and moisture under NTR. The CT0 had the highest grain yield on the standard harvest date used in the local area (36 DAA). Whereas the plants in NTR reached physiological maturity (39 DAA), the grain yield in NTR was significantly increased by 7.8–8.8 compared with yield at 36 DAA, and no significant difference was observed between NTR and CT0 due to the increased thousand kernel weight of NTR. Thus, it is practicable for harvesting at physiological maturity in NTR to obtain higher grain yield.