有机肥等氮替代化肥对春玉米生长、产量和水肥利用效率的影响

Effects of Organic Manure and Other Nitrogen Substitutes on Spring Maize Growth,Yield,and Water and Fertilizer Utilization Efficiency

[目的]为探究不同施氮量下有机肥等氮替代化肥对陕北旱区春玉米生长、产量和水肥利用效率的影响。[方法]采用多元回归分析和三维拟合模型,以期建立陕北地区春玉米种植最佳氮肥管理模式。设置3个施氮水平(N1、N2、N3分别为240,180,120 kg/hm^(2))和5个有机肥等氮替代比例(R0、R12.5、R^(2)5、R37.5、R50分别为100%化肥氮、12.5%有机肥氮+87.5%化肥氮、25%有机肥氮+75%化肥氮、37.5%有机肥氮+62.5%化肥氮、50%有机肥氮+50%化肥氮),共15个处理。在春玉米主要生育期测定春玉米生长、产量及产量构成要素,计算生育期耗水量(ET)、水分利用效率(WUE)、氮肥偏生产力(NPFP)及经济效益。[结果]Logistic函数对春玉米干物质累积量具有较高的拟合度,R 12.5处理可推迟干物质快速积累期的起点、终点和最大值出现的时间,N2处理可提升干物质累积量的日最大增长速率。施氮量和替代比例对春玉米干物质累积量、产量及构成要素、ET、NPFP和经济效益有显著影响(p<0.05),两者交互作用对穗长、穗粗、ET的影响显著(p<0.05)。N2处理的平均干物质累积量、产量、ET、净收入分别比N1和N3处理提高5.58%和15.80%,4.25%和16.76%,4.96%和3.41%,8.76%和29.42%。有机替代比例为12.5%~37.5%的处理可显著提升干物质累积量、产量及构成要素、ET、WUE、NPFP、净收入、产投比。随着施氮量增加,WUE上升,而NPFP降低。处理N2R^(2)5的干物质累积量、ET最高,处理N2R37.5的产量、净收入、产投比最高。春玉米产量与干物质累积量、ET、WUE、净收入、产投比呈显著正相关。[结论]综合分析得到,在施氮量和替代比例区间分别为190~210 kg/hm^(2)和17%~29%时,可使春玉米干物质累积量、产量、WUE、NPFP、净收入同时优化。

[Objective]This study was aimed to investigate the effects of organic manure replacing chemical fertilizer with equal nitrogen under different nitrogen application rates on the growth,yield and water-fertilizer use efficiency of spring maize in the dry zone of northern Shaanxi.[Methods]Multiple regression analysis and three-dimensional fitting models were used to establishing an optimal nitrogen management model for spring maize cultivation in northern Shaanxi.In this experiment,three nitrogen application levels(240,180,120 kg/hm^(2)for N1,N2,N3,respectively)and five organic manure replacing chemical fertilizer with equal nitrogen ratios(R0,R12.5,R^(2)5,R37.5,R50 for 100%chemical fertilizer nitrogen,12.5%organic fertilizer nitrogen+87.5%chemical fertilizer nitrogen,25%organic fertilizer nitrogen+75%chemical fertilizer nitrogen,37.5%organic fertilizer nitrogen+62.5%chemical fertilizer nitrogen,50%organic fertilizer nitrogen+50%chemical fertilizer nitrogen,respectively),a total of 15 treatments.During the main reproductive period of spring maize,spring maize growth and yield and yield components were measured,and water consumption(ET),water use efficiency(WUE),nitrogen fertilizer partial productivity(NPFP)and economic benefits were calculated.[Results]The Logistic function had a high fit for dry matter accumulation in spring maize,the R12.5 treatment delayed the start,the end and the appearance of the maximum value of the period of rapid dry matter accumulation,and the N2 treatment enhanced the maximum daily growth rate of dry matter accumulation.Nitrogen application and replacement ratio significantly affected dry matter accumulation,yield and components,ET,NPFP and economic efficiency of spring maize(p<0.05),and the interaction significantly affected ear length,ear coarse,and ET(p<0.05).The average dry matter accumulation,yield,ET,and net income of N2 treatment were higher than those of the N1 and N3 treatment 5.58%and 15.80%,4.25%and 16.76%,4.96%and 3.41%,8.76%and 29.42%,respectively.R12.5%~R37.5%treatment significantly enhanced dry matter accumulation,yield and components,ET,WUE,NPFP,net income and input/output.WUE continued to increase with increasing N application,while NPFP continued to decrease.Treatment N2R^(2)5 had the highest dry matter accumulation and ET,and treatment N2R37.5 had the highest yield,net income,and input/output.Spring maize yield was significantly and positively correlated with dry matter accumulation,ET,WUE,net income and input/output.[Conclusion]The comprehensive analysis obtained showed that dry matter accumulation,yield,WUE,NPFP,and net income of spring maize could be optimized simultaneously at the N application and replacement ratio intervals of 190~210 kg/hm^(2)and 17%~29%,respectively.