休闲期深翻覆盖配施氮磷肥对旱地小麦群体动态、叶面积的影响及其与产量的相关性

采用大田试验方法,研究了休闲期深翻覆盖配施氮磷肥对旱地小麦群体动态、叶面积的变化及其与产量相关性的影响。结果表明,氮磷比为1∶0.5和1∶0.75时,增加施氮量可提高各生育期群体茎数、单株叶面积及成穗率,可显著提高可育小穗数、干物质量,降低不可育小穗数,从而提高穗数、穗粒数及产量;施氮量为150 kg/hm2时,增加施磷量可提高各生育期群体茎数、单株叶面积及成穗率,可显著提高可育小穗数、干物质量,可提高产量及其构成因素,其中,氮磷比为1∶1较1∶0.5提高成穗率13.10%,从而提高穗数22.7%,提高穗粒数3.79%,提高产量18.92%;施氮量为180 kg/hm2时,各生育期群体茎数、单株叶面积、成穗率、穗长、可育小穗数、不可育小穗数、干物质量以氮磷比为1∶0.75最高,1∶1居中,1∶0.5最低,其中,氮磷比为1∶0.75较1∶0.5提高成穗率11.43%,提高穗数19.35%,提高穗粒数4.95%,提高产量17.31%;施氮量为180 kg/hm2时,氮磷比为1∶0.75对各生育期群体茎数、叶面积、成熟期农艺性状、产量及其构成因素的影响较施氮量为150 kg/hm2、氮磷比为1∶1时效果更好。相关分析表明,各生育期群体茎数与穗数、穗粒数密切相关,且与穗数关系更密切;生育中后期单株叶面积与穗数、穗粒数相关较密切,且与穗数关系更密切。总之,休闲期深翻覆盖配施氮肥180 kg/hm2、氮磷比为1∶0.75时更有利于促进群体有效分蘖,提高成穗率;有利于提高叶面积,从而提高干物质量;有利于提高穗数、穗粒数,最终提高产量。

Effect of Deep Tillage and Mulch in Fallow Period and Nitrogen and Phosphorus Fertilizer before Sowing on Change of Groups Tiller,Leaf Area and Their Correlation with Yield in Dryland Wheat

Field test was carried out to study the effect of deep tillage and mulch in fallow period and nitrogen and phosphorus fertilizer before sowing on change of groups tiller,leaf area and their correlation with yield in dryland wheat.The current data showed that increaseing nitrogen rate could increase the change of groups tillers and leaf area at different stages,increase the rate of heading,increase sterility spikelet number and dry weight,decreased the bearing spikelet,and finaly could increase ear number,grain number per spike,1 000-grain weight when the ratio of N and P was 1 ∶ 0.5 and 1 ∶ 0.75.The result also showed that when nitrogen application rate was 150 kg/hm2,increasing the phosphorus could increase the change of groups tillers and leaf area at different stages,the rate of heading,sterility spikelet number,dry weight,yield and its constritution.Compared with the rate of N and P was 1 ∶ 0.5,the rate of N and P was 1 ∶ 0.75 could improve the rate of heading 13.10%,could improve ear number 22.7%,grain number per spike 3.79%,could improved yield 18.92%.When nitrogen application rate was 180 kg/hm2,the change of groups tillers and leaf area at different stages,the rate of heading,spike length,sterility spikelet number,dry weight,were the best when the ratio of N and P was 1 ∶ 0.75,were the lowest when the ratio of N and P was 1 ∶ 0.5.Compared with the rate of N and P was 1 ∶ 0.5,the rate of N and P was 1 ∶ 0.75 could improve the rate of heading 11.43%,could improve ear number 19.35%,grain number per spike 4.95%,could improved yield 17.35%.In addition,nitrogen rate at 180 kg/hm2,the rate of N and P 1 ∶ 0.75 was the best conduct.Interrelated analyses was concluded that the correlation between the change of groups tillers,leaf area and ear number,grain number per spike were closely,and more close with ear number.In one word,when deep tillage and mulch in fallow period,nitrogen rate at 180 kg/hm2,the rate of N and P was 1 ∶ 0.75,would be positive for group tillers increasing,heading rate improvement; would be positive for leaf area increasing,dry matter weight improvement; would be positive for ear number increasing,grain number per spike and yield improvement.