不同土壤背景下秸秆还田量对水稻产量构成及氮吸收利用的影响

Effects of straw returning amounts on rice yield components and N uptake of different soil background

以辽宁省新审定的北方粳稻(辽粳2501)为材料,在总施氮量为N 200 kg/hm~2、基-蘖-穗氮肥比例50-30-20条件下,采用盆栽试验,研究不同土壤类型(砂质荒漠土、壤质滨海盐土、粘质棕壤土)及秸秆还田量(0、30%、50%、70%)对水稻产量构成及氮吸收利用的影响。结果表明,荒漠土和滨海盐土稻田均以50%秸秆还田产量最高,分别比对照(无秸秆)还田处理增加9.09%和9.55%,而棕壤土稻田70%秸秆还田量产量最高,比对照增加7.87%。不同土壤间秸秆还田均抑制了拔节期以前的干物质积累量,降幅为4.48%~28.30%,但能促进荒漠土和棕壤土的后期干物质积累。秸秆还田均能提高土壤间农学利用率和氮肥偏生产力,砂壤稻田土以50%还田量最高,分别比对照增加33.39%和9.20%;棕壤土稻田以70%秸秆还田量最高,分别比对照增加44.54%和7.86%;滨海盐土稻田以50%还田量最高,分别比对照增加25.00%和9.55%。秸秆还田增加了荒漠土和棕壤土的氮肥表观利用率,分别以50%和70%还田量处理最高,比对照增加32.07%和18.66%,但降低了滨海盐土的氮肥表观利用率。综合水稻产量和氮吸收利用效率,辽宁省中晚熟荒漠土、滨海盐土和棕壤土稻区,秸秆还田量以50%、50%和70%较为适宜。

An pot experiment was conducted using Liaojing 2501 of northern japonica rice.The total nitrogen application was N 200 kg/hm2,and N application ratio of basal and topdressing was 50-30-20.The effects of straw returning amounts(0,30%,50%and 70%)on rice yield components and fertilizer-N use efficiency among different soil types(sandy soil,soda-salinization soil,brown clay)were studied.The results showed that,50%straw returning treatment obtained the highest yield in sandy soil and soda-salinization soil,which increased 9.09%and 9.55%respectively compared with no straw returning(control)treatment,while the 70%straw returning treatment had the highest yield in brown clay,increasing by 7.87%compared with control.Straw returning reduced the dry matter accumulation before jointing stage by 4.48%~28.30%,but promoted dry matter accumulation in sandy soil and brown clay at the other stages.Straw returning improved agronomy efficiency of nitrogen applied and the partial factor productivity of nitrogen in all types of soil.The agronomy efficiency and the partial factor productivity of nitrogen were the highest with the 50%straw-returning treatment in sandy soil,which was 33.39%and 9.20%higher than the control;the highest with the 70%straw-returning treatment in brown clay,which was 44.54%and 7.86%higher than the control respectively;the highest in the 50%straw-returning treatment in soda-salinization soil,which was 25.00%and 9.55%higher than the control respectively.Straw returning increased the nitrogen apparent recovery efficiency of sandy soil and brown clay increased by 32.07%and 18.66%for the 50%and 70%straw-returning treatments,respectively,but decreased in soda-salinization soil.Based on the comprehensive rice yield and nitrogen absorption and utilization efficiency,50%,50%and 70%straw-returning amounts are suitable for medium-late mature rice areas under the sandy soil,soda-salinization soil and brown clay in Liaoning province.