施氮量和机插密度对钵苗机插杂交籼稻C两优华占产量和氮素利用效率的影响

Effects of nitrogen application rate and planting density on yield and nitrogen use efficiency of indica hybrid rice C Liangyouhuazhan with bowl mechanical-transplanting method

【目的】探明施氮量和机插密度对钵苗机插水稻氮素利用率及产量的影响,为在钵苗机插水稻生产中选择适宜的施氮量和机插密度提供理论依据。【方法】在大田试验条件下,采用裂区设计,设3种机插密度水平(21.65万、16.84万和12.63万穴/ha)和4种施氮量水平(0、75、150和225 kg/ha),测定不同机插密度和施氮量下钵苗机插水稻的产量及其构成、干物质积累量、主要生育时期各器官氮积累量,并计算氮素利用率。【结果】随施氮量的增加,百千克籽粒需氮量呈逐渐上升趋势,而氮肥吸收利用率、氮肥生理利用率、氮肥偏生产力、氮素籽粒生产效率及氮素干物质生产效率均呈下降趋势,产量呈先升高后降低的变化趋势。随机插密度的降低,氮肥农学利用率、氮肥生理利用率、氮肥偏生产力、氮素籽粒生产效率及氮素干物质生产效率均呈降低趋势,产量也呈先升高后降低的变化趋势。施氮量和机插密度互作对成穗率、有效穗数、每穗总粒数、氮肥吸收利用率、氮肥农学利用率、氮肥生理利用率、氮肥偏生产力、氮素籽粒生产效率和氮素干物质生产效率的影响达极显著水平(P<0.01),但对产量无显著影响(P>0.05)。【结论】在贵州喀斯特地貌地区实施钵苗机插水稻的适宜机插密度和氮肥施用量分别为16.84万穴/ha和150 kg/ha,水稻产量为9208.83 kg/ha。回归分析结果表明,获得最高产量的施氮量和机插密度分别为145.63 kg/ha和18.18万穴/ha,水稻产量为9024.771 kg/ha。

【Objective】The aim of this experiment was to ascertain the effects of different nitrogen(N)rate and densities on rice yield and N use efficiency in indica hybrid rice with bowl mechanical-transplanting,and provide theoretical basis for selecting suitable N application rate and planting density in bowl mechanical-transplanting rice production.【Method】Under the field experiment conditions,three density levels(216,500 hole/ha,168,400 hole/ha and 126,300 hole/ha)and four N rate levels(0,75,150 and 225 kg/ha)were set up using split panel design.The yield and yield components of rice with bowl mechanical-transplanting method under different densities and N application rates,dry matter accumulation,N accumulation in various organs during main growth period,and N use efficiency were measured and calculated.【Result】With the increase of N application rate,the N requirement for 100 kg grains(NRG)showed an upward trend,while the fertilizer-N recovery efficiency(FRE),fertilizer-N physiological efficiency(FPE),partial factor productivity of applied N(PFP),N grain production efficiency(NGPE),N dry matter production efficiency(NDMPE)showed opposite trend,yield increased first and then decreased.With the decrease of planting density,FRE,FPE,PFP,NGPE and NDMPE showed a decreasing trend,but yield increased first and then decreased.N application rate and density interaction had influence on rate of productive tillers,effective panicles,total grains per spike and FRE,FPE,PFP,NGPE,NDMPE,the impact reached extremely significant level(P<0.01),and had no significant effect on yield(P>0.05).【Conclusion】Appropriate planting density and N fertilizer application for indica hybrid rice with bowl mechanical-transplanting method in karst areas in Guizhou were 168,400 hole/ha and 150.00 kg/ha respectively,rice yield is 9208.83 kg/ha.The results of regression analysis shows that the N rate and density of the highest yield are 145.63 kg/ha and 181,800 hole/ha respectively,and the rice yield is 9024.771 kg/ha.