How do dual-mulching and DA-6 with manganese affect root growth, hydrothermal resource utilization by promoting photosynthesis of maize in semiarid regions?
摘要
In dryland agricultural ecosystems, achieving sustainable crop production is crucial. The new plant growth regulator (DA-6) has become an important technical guarantee for enhancing plant photosynthetic capacity and promoting plant growth. The combined effects of dual-mulching (plastic film mulch on ridge and straw mulch on furrow) with foliar spray of DA-6 with manganese G1 = DA-6 1 mL L-1 + 0.08 g L-1 manganese; G2 = DA-6 2 mL L-1 + 0.08 g L-1 manganese; G3 = DA-6 3 mL L-1 + 0.08 g L-1 manganese under optimizing N management, low N: 85 kg ha-1; high N: 250 kg ha-1on soil hydrothermal properties, root growth, and maize production remain unclear. The results showed that, at all maize growth stages, the RLG2 considerably maintained soil water storage and regulated soil temperature, with a substantial impact on yields. From the jointing to the flowering stage, the RLG3 treatment reduced ETMC and ETI, whereas from the flowering to the maturity stage, the RHG2 treatment improved these two indicators, thereby helping to resolve the contradiction in maize soil water demands. The lodging rate of maize under RHG2 treatment decreased by 44.7%, and the grain yield was improved by 49.0% compared with CK. Furthermore, RHG1 and RHG2 significantly increased the contents of hemicellulose, cellulose, and lignin. The Pn rate in the RHG2 treatment increased and the chlorophyll ab content at 70 DAP. In addition, RHG2 significantly increased NupE (7.5%), NfP (4.4%), NUE (10.4%), NHI (0.1%) and economic benefits (25809 CNY ha-1) in comparison with RLG2 treatment, which aimed to improve crop productivity with a suitable N nutrition status. Overall, RHG2 can improve soil water and temperature conditions, promote root growth, and increase yields. It improves the utilization efficiency of water and temperature resources and supports sustainable agriculture in semi-arid regions.