黄土高原春玉米氮肥生产力对不同耕作措施的响应:Meta分析

Response of nitrogen fertilizer productivity of spring maize on the Loess Plateau to different tillage measures:a meta-analysis

为明确黄土高原不同耕作措施(覆盖种植、秸秆还田、深松耕和免耕)对春玉米氮肥偏生产力(PFP_(N))的影响,探究不同耕作措施下驱动春玉米PFP_(N)变化的因素,本研究采用Meta分析、回归分析和随机森林相结合的方法,以传统耕作措施(裸地种植、无秸秆还田和犁耕)为对照,分析了春玉米PFP_(N)在不同耕作措施下的变化特征。结果表明:与传统耕作措施相比,覆盖、秸秆还田和深松耕分别使春玉米PFP_(N)提高38.8%、10.3%和8.4%,而免耕对春玉米PFP_(N)无显著影响。随机森林模型表明:在覆盖和秸秆还田措施下,年均降雨量和生育期降雨量是影响春玉米PFP_(N)的两个重要因素;在深松耕措施下,年均降雨量和持续时间是影响春玉米PFP_(N)的两个重要因素。亚组与回归分析表明:在年均降雨量≤400 mm、生育期降雨量≤300 mm或年均温度<7℃的区域,覆盖可以使春玉米PFP_(N)提高77.7%~99.5%,且覆盖措施对春玉米PFP_(N)的提高效果与年均降雨量、生育期降雨量和年均温度呈负相关;在年均降雨量400~500 mm或生育期降雨量300~400 mm的条件下,秸秆还田使春玉米PFP_(N)提高10.2%~16.3%;在年均降雨量400~500 mm,深松耕试验持续时间<3 a时,春玉米PFP_(N)可提高14.1%~14.6%。因此,依据区域和气候特征,采用适宜的耕作措施可以进一步提高春玉米PFP_(N),促进旱区作物可持续生产目标的实现。本研究可为提高黄土高原春玉米PFP_(N)以及制定区域可持续发展的农业生产策略提供参考。

This study aimed to clarify the effects of different tillage measures,including mulch planting,straw returning,subsoiling,and no-tillage,on the partial productivity of nitrogen fertilizer(PFP_(N))of spring maize in the Loess Plateau and explore the factors driving the change in PFP_(N)under different tillage measures.Meta-analysis,regression analysis,and random forest analysis were per-formed.Compared with traditional tillage measures(such as,bare land planting,straw-free returning,and plowing),mulching,straw returning,and subsoiling tillage increased PFP_(N)by 38.8%,10.3%,and 8.4%,respectively,whereas no-tillage had no significant ef-fect on spring maize PFP_(N).The random forest model showed that the average annual rainfall and growing season rainfall were two re-latively important factors affecting the PFP_(N)of spring maize under mulching and straw returning,and that the average annual rainfall and test duration were important factors under subsoiling.Subgrouping and regression analysis showed that in the areas where the av-erage annual rainfall was≤400 mm,growing season rainfall was≤300 mm or average annual temperature was<7℃,mulching in-creased the spring maize PFP_(N)by 77.7%-99.5%,and PFP_(N)was negatively correlated with average annual rainfall,growing season rainfall,and average annual temperature.In areas where the average annual rainfall was 400-500 mm or the growing season rainfall was 300-400 mm,straw return could increase PFP_(N)by 10.2%-16.3%.When the average annual rainfall was 400-500 mm and the duration of the subsoiling experiment was less than 3 years,the PFP_(N)was increased by 14.1%to 14.6%.Therefore,according to the regional and climatic characteristics,adopting appropriate tillage measures can further improve the PFP_(N)of spring maize and pro-mote the realization of the goal of sustainable crop production in arid areas.This study provides a reference for improving the PFP_(N)of spring maize in the Loess Plateau and formulating agricultural production strategies for regional sustainable development.