对比分析了氮肥习惯施用（FN）、氮肥习惯施用配合秸秆还田（FNS）、氮肥高量施用配合秸秆还田（HNS）、氮肥后肥前移施用（RN）、氮肥后肥前移施用配合秸秆还田（RNS）5种不同耕作措施对玉米农田土壤水分、碳氮、酶活性、微生物生物量及玉米籽粒产量的影响，并通过相关分析和通径分析进一步揭示土壤理化性质和生物学性质变化规律及其耦合效应，明确秸秆还田玉米地不同氮肥运筹方式下土壤水、碳、氮演变特征。结果表明：与不还田处理相比，秸秆还田处理可显著提高0~100 cm土层土壤水分含量，且秸秆还田与全膜垄沟栽培结合后（FNS、HNS、RNS），二者的协同效应较单一地膜覆盖（FN、RN）增强了土壤纳雨增墒能力，为秸秆的正常腐解提供了适宜的水热环境；秸秆还田下不同氮肥运筹处理较对照FN处理均可显著提高土壤有机碳和全氮含量，其中以RNS和HNS处理提升效果最显著，土壤过氧化氢酶、脲酶、蔗糖酶和碱性磷酸酶活性以及微生物生物量碳、氮含量明显增加，表现为0~20 cm土层大于20~40 cm土层，FN处理和RN处理无显著性差异；土壤微生物生物量碳、氮含量与土壤酶活性和土壤有机碳、全氮含量呈显著或极显著正相关关系，且土壤微生物生物量碳、氮对土壤有机碳、蔗糖酶、全氮和过氧化氢酶变化较敏感，对土壤性质变化具有一定指示作用。在产量方面，秸秆还田处理FNS、HNS、RNS较对照FN处理分别提高5.30%、10.93%、11.41%，且氮肥的常量投入即可获得较高的氮肥偏生产力。综合土壤因子、玉米产量和氮素利用率来看，秸秆还田条件下可通过调整氮肥的后肥前移来平衡土壤碳氮收支，实现节本增产增效，同时提高氮肥利用率，其是内蒙古黄土高原地区一种节氮、稳产、增效的秸秆还田技术模式。
In this paper, five different tillage measures were designed, including conventional use of N fertilizer (FN), FN combined with corn straw returning (FNS), high application rate of N fertilizer combined with corn straw returning (HNS), reducing topdressing N fertilizer to basal (RN), reducing topdressing N fertilizer to basal combined with corn straw returning (RNS). Correlation analysis and path analysis were used to further disclose the changes and coupling effects of soil physiochemical and biological properties. Compared with no straw returning (FN, RN), straw returning (FNS, HNS, RNS) significantly increased soil water content of 0-100 cm soil, and the synergistic effect of straw returning and full film ridge cultivation (FNS, HNS, RNS) was stronger than that of single plastic film mulching (FN, RN), which provided more suitable hydrothermal environment for the normal decomposition of straw. Compared with FN, treatments with straw returning significantly increased the contents of soil organic matter and total nitrogen, and the effects of RNS and HNS were the most significant. The activities of catalase, urease, sucrase and alkaline phosphatase as well as microbial biomass carbon and nitrogen in soil increased significantly, the activities of catalase, urease, sucrase and alkaline phosphatase were higher in 0-20 cm soil than in 20-40 cm soil, and there was no significant difference between FN, RN and RNS treatments. Soil microbial biomass carbon and nitrogen were significantly or extremely significantly positively correlated with soil enzyme activities and soil carbon and nitrogen, and soil microbial biomass carbon and nitrogen were sensitive to the changes of soil organic matter, sucrase, total nitrogen and catalase, which could indicate the changes in soil properties. Compared with FN, corn yields of FNS, HNS and RNS increased by 5.30%, 10.93% and 11.41%, respectively, and the higher partial productivity of N fertilizer could be obtained with the conventional input of N fertilizer. In conclusion, some topdressing N fertilizer used as basal fertilizer with straw returning can balance soil carbon and nitrogen budget, save cost, increase yield and nitrogen use efficiency, thus, it is a feasible technology model for straw returning in the Loess Plateau of Inner Mongolia.
高日平,赵沛义,韩云飞,刘小月,杜二小,高宇,任永峰,李焕春,张鹏.秸秆还田与氮肥运筹对土壤水碳氮耦合及作物产量的影响[J].土壤,2021,53(5):952-960. GAO Riping, ZHAO Peiyi, HAN Yunfei, LIU Xiaoyue, DU Erxiao, GAO Yu, REN Yongfeng, LI Huanchun, ZHANG Peng. Effects of Straw Returning and Nitrogen Application on Soil Water, Carbon and Nitrogen Coupling and Crop Yield[J]. Soils,2021,53(5):952-960复制