栽培方式对水稻氮素吸收利用与分配特性影响的研究

Studies on influence of cultivation patterns on characteristics of nitrogen utilization and distribution in rice

2006和2007年,在桶栽条件下,以早稻(三系籼型杂交稻金优253)为试材,应用15N示踪技术研究了稻草还田免耕、免耕、稻草还田常耕、常耕4种栽培方式对水稻氮素吸收利用与分配特性的影响。结果表明,1)水稻植株吸收的氮肥数量及其在体内的分配与土壤耕作方式密切相关;免耕提高了水稻对肥料氮的吸收比率及在子粒和根中的分配比率,但降低了在叶和茎中的分配比率。2)免耕水稻产量和氮素吸收总量与常耕水稻差异不显著,但免耕水稻吸收的氮素中来源于肥料的比例比常耕水稻的大;免耕水稻的氮肥回收效率高于常耕水稻,但氮素的稻谷生产效率差异不明显。3)稻草还田对氮肥的吸收利用有显著的影响。免耕条件下,稻草还田降低了基肥和分蘖肥氮素的积累量,增加了穗肥氮素积累量,氮肥总积累量呈下降趋势;常耕条件下,稻草还田提高了各个时期的肥料氮素积累量,氮肥的总积累量增加显著。4)稻草还田提高了免耕水稻和常耕水稻产量,2007年其差异达显著水平。免耕条件下稻草还田降低了氮素的回收效率,但常耕条件下稻草还田提高了氮肥的回收效率。

Pot experiments were conducted to evaluate the influence of no tillage with straw incorporation on characteristics of nitrogen utilization and distribution in rice using 15N tracer techniques in the early seasons of 2006 and 2007. The test plant was Jinyou 253.Four treatments,no tillage-straw incorporation（NT-S）,no tillage（NT）,conventional tillage-straw incorporation（CT-S）,conventional tillage（CT） were designed.The results showed that： 1） Nitrogen fertilizer uptake and distribution in rice plants were influenced by soil tillage practices.NT increased the ratio of nitrogen fertilizer uptake in grain and root,and decreased the distribution in leaves and stem.2） Lower grain yield was observed under NT compared to CT,but the difference was not significant.The difference of total nitrogen uptake in rice plants was not significant under different tillage practices,but higher proportion of nitrogen uptake from fertilizer and nitrogen recovery efficiency were found under NT compare to CT.3） Straw incorporation had a significant effect on nitrogen fertilizer utilization.Under NT-S decreased the accumulate of nitrogen uptaken from basal and tillering fertilizer,however,increased nitrogen uptake of fertilizer at earring.Under CT-S increased accumulate of nitrogen fertilizer of each stage of the growing period,consequently,increased the total nitrogen fertilizer absorption significantly.4） Straw incorporation increased rice grain yield under both tillage practices,but decreased nitrogen fertilizer recovery efficiency under no tillage.