整合分析施氮与水分输入梯度对中国北方玉米产量、氮肥生产力及水分利用效率的影响

Meta-analysis of the effects of nitrogen and water input gradients on maize yield,nitrogen fertilizer productivity,and water use efficiency in northern China

为获得不同环境和气候条件下水分、氮素、其他环境因子以及农艺措施对玉米(Zea mays)产量、氮肥生产力(NP)和水分利用效率(WUE)影响的整体表现,本研究基于35篇有关施氮和水分输入梯度对玉米产量、NP和WUE影响的文献,利用整合分析方法(Meta-analysis),探究了影响中国北方玉米产量、NP和WUE的相关因素,定量分析各影响因子与玉米产量、NP和WUE之间的关系。研究结果表明:玉米产量平均值为9.19 t·hm^(−2),NP和WUE的平均值分别为55.66 kg·kg^(−1)和1.83 kg·m^(−3)。水氮因子对玉米产量表现出显著的互作效应,相较对照,水分输入和施氮分别使玉米整体增产13.43%(P<0.01)和10.69%(P<0.01)。随着输入量增加,水氮因子逐渐成为NP和WUE增加的主要限制因子。回归分析中,水氮因子、土壤有机碳(SOC)、播种密度(PD)和速效钾(AK)对玉米产量的影响表现为正效应,年平均温度(MAT)表现为负效应。在结构方程模型(SEM)中,SOC与玉米产量存在较强正相关性,其标准化路径系数为0.73。综上所述,我国北方的玉米水分利用效率和氮肥生产力还有很大的提升空间,在优化水肥措施的基础上可以从土壤养分入手,提高土壤的SOC和AK水平,同时也可以适当增加播种密度,从多个方面入手,更大程度地实现玉米高产与节水环保共赢。

This study was conducted to determine the overall performance of the effects of water,nitrogen,other environmental factors,and agronomic measures on maize(Zea mays)yield,nitrogen productivity(NP),and water use efficiency(WUE)under different environmental and climatic conditions.This study is based on 35 studies on the effects of nitrogen application and water input gradients on maize yield,NP,and WUE,using meta-analysis to explore the relevant factors affecting maize yield,NP,and WUE in northern China,and to quantitatively analyze the relationship between each influencing factor and maize yield,NP,and WUE.The results showed that the average maize yield was 9.19 t·ha^(−1),and the average of NP and WUE were 55.66 kg·kg^(−1) and 1.83 kg·m^(−3),respectively.Water and nitrogen had a significant interaction effect on maize yield.Compared with the control,water input and nitrogen application increased the overall maize yield by 13.43%(P<0.01)and 10.69%(P<0.01),respectively.As the input volume increased,water and nitrogen gradually became the main limiting factors for the increase in NP and WUE.In the regression analysis,the effects of water and nitrogen factors,soil organic carbon(SOC),planting density(PD),and available potassium(AK)on maize yield were positive,while that of the mean annual temperature(MAT)was negative.In the structural equation model(SEM),there was a strong positive correlation between SOC and maize yield,and its standardized path coefficient was 0.73.In summary,there is still room for improvement in the water use efficiency and nitrogen productivity of maize in northern China.Based on optimizing water and fertilizer measures,appropriate soil nutrient inputs could increase SOC and AK levels in the soil.Simultaneously,planting density can be increased appropriately,to achieve a win-win situation between high maize yield,water-use efficiency,and environmental protection.