摘要
于2002-2005年,在湖南长沙采用连续定位试验,研究了早稻施氮对连作晚稻产量、氮肥利用率、土壤有效氮含量的影响。试验设早稻施氮/晚稻不施氮、早稻施氮/晚稻施氮、早稻不施氮/晚稻不施氮、早稻不施氮/晚稻施氮4个处理。结果表明,在连续4年早季施氮的条件下,连作晚稻施氮处理的平均产量为6.45 t/hm^2,地上部干物质重12.13 t/hm^2,氮素吸收量183.6 kg/hm^2,分别比连作晚稻不施氮处理增加28.4%、35.1%和103.5%,均达到显著水平;在连续4年早季不施氮的条件下,连作晚稻施氮处理的平均产量为6.61 t/hm^2,地上部干物质重12.14 t/hm^2,氮素吸收量165.6 kg/hm^2,分别比不施氮处理增加33.4%、37.6%和95.6%,均亦达到显著水平。连作晚稻在早季不施氮和早季施氮两种情况下氮肥利用率不同,前者的氮肥生理利用率显著高于后者,增幅为37.8%,两者的氮肥农学利用效率、吸收利用率差异不显著,但前者4年氮肥农学利用效率平均值比后者高18.1%,吸收利用率低6.8个百分点。早晚两季均不施氮小区土壤碱解氮含量均明显低于其他施氮小区,但没有出现随试验年度加长而连续下降的趋势;当早稻或晚稻其中有一季施用了氮肥,或者两季均施用了氮肥的小区,土壤碱解氮含量差异不显著。说明连作晚稻产量主要受当季施氮量的影响,而受早季施氮量的影响较小;早季不施氮小区的连作晚稻氮肥的农学利用效率、生理利用率比早季施氮小区高;在一定程度上降低稻田氮肥用量不会导致土壤背景氮含量的下降。
To explore the effects of fertilizer-N application for early cropping rice on rice yield, nitrogen use efficiency and soil nitrogen content in late cropping rice. Long-term experiment with different N treatments in double rice cropping system was conducted on the farm of Hunan agricultural university by using random block design with 4 replications from 2002 to 2005. There were four N treatments： N fertilizer applied in early season but not in late season （ENL0） , N fertilizer applied in both early and late seasons （ENLN）, no N fertilizer applied in either early or late seasons （E0L0）, and N fertilizer applied in late season but not in early season （E0LN） . The results showed that when N fertilizer was applied for both early and late rice, the average yield, dry matter production and N uptake of late rice reached 6.45 t/ha, 12.13 t/ha and 183.6 kg/ha, respectively, which were 28.0% ly. The average grain yield, dry matter production and N , 35.1% and 103.5% higher than those of ENLo, respectiveuptake of the E0LN treatment reached 6.61 t/ha, 12.14 t/ha and 165.6 kg/ha, respectively, which were 33.4%, 37.6% and 95.6% higher than those of E0L0 treatment, respectively. The agronomic efficiency, physiological efficiency and partial factor productivity of fertilizer N of E0LN increased by 18.1%, 37.8% and 2.7 %, respectively, but the recovery efficiency decreased by 6.8 %, compared with those of ENLN. The alkali-hydrolyzed soil N content in plots without N fertilizer in either early or late season rice was significantly lower than that in plots with N fertilizer in either season, but did not decrease continuously over years. No significant dif- ference of the soil N content was observed among treatments receiving N application in one or both seasons. The results indicated that the grain yield of double late rice was significantly affected by N fertilizer applied in late season but not by that in early season. The agronomic efficiency, physiological efficiency of N fertilizer in late cropping rice was higher without N fertilizer in early season than those with N fertilizer in early season. To some extend, reduce N fertilizer rate would not significantly reduce soil indigenous N content.
出处
《植物营养与肥料学报》
CAS
CSCD
北大核心
2007年第5期772-780,共9页
Journal of Plant Nutrition and Fertilizers
基金
国家农业部"948"重大项目-作物养分资源管理体系的建立(2003-Z53)
国际水稻所合作项目资助
关键词
施氮
水稻
产量
干物质生产
氮肥利用率
土壤背景氮
nitrogen application
rice
yield
dry matter production
nitrogen fertilizer use efficiency
indigenous nitrogen of soils
