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为提高旱作麦区土壤水分贮备能力,并探明此基础上提高产量的适宜施氮水平,本文采用大田试验在山西农业大学闻喜试验基地研究了夏闲期覆盖与不覆盖条件下75、150、225 kg·hm-23个施氮量对旱地土壤水分、小麦氮素吸收运转及产量的影响。结果表明:夏闲期深翻覆盖后,播种前0~300 cm土层土壤蓄水量提高约70~80 mm,尤其是80cm以下土层;成熟期0~300 cm各土层土壤蓄水量均低于播种前,尤其是0~160 cm各土层低20~30 mm;各生育期群体茎数、穗数提高,且低、高氮条件下处理间差异显著,小麦总耗水量提高5.68~31.30 mm,产量提高1.43%~7.16%,水分利用效率提高1.27%~4.23%;各生育时期植株氮素积累量、花前氮素运转量和花后氮素积累量提高,且各生育时期植株氮素积累量处理间差异显著,氮肥农学效率提高0.47~1.24 kg·kg-1,氮肥当季回收率显著提高3.01%~4.96%;覆盖配施氮肥后,成熟期0~160 cm土层土壤蓄水量、总耗水量以施氮量150 kg·hm-2最低;各生育期群体茎数、产量构成因素、产量和水分利用效率以施氮量150 kg·hm-2显著最高,75 kg·hm-2最低,且中氮较低氮与高氮处理产量分别提高574.75和341.14 kg·hm-2,水分利用效率提高12.89%和7.77%;各生育时期植株氮素积累量、花前氮素运转量及其对籽粒的贡献率、氮肥农学效率和氮肥当季回收率均以施氮量150 kg·hm-2显著最高,75 kg·hm-2最低,且中氮较低氮与高氮处理氮肥农学效率分别提高1.91 kg·kg-1、3.12 kg·kg-1,氮肥当季回收率提高1.74%和5.32%;此外,产量与穗数的相关性最大(r=0.906),穗粒数居中,千粒重最小;总之,旱地小麦休闲期深翻覆盖有利于蓄水保水,提高底墒,且配施氮量为150 kg·hm-2更有利于水氮互作,促进氮素吸收、运转,达到增产、高效的目的。
In order to improve the capacity of soil moisture reserve in dryland wheat area and to find out the suitable nitrogen application level to increase the yield, this paper studied the effects of summer and afternoon cover and uncovered condition by using field experiment at Wenxi Experimental Base of Shanxi Agricultural University, Effects of 150 and 225 kg · hm-23 nitrogen rates on soil moisture and N uptake and yield of wheat in dry land. The results showed that the soil water storage in 0 ~ 300 cm soil layer before sowing increased about 70 ~ 80 mm, especially under 80 cm soil layer after deep plowing and turning over in summer and summer. The soil water storage capacity of 0 ~ 300 cm soil layer Were lower than those before sowing, especially in 0 ~ 160 cm soil layer. The number of stalks and panicles increased in each growth period, and there was significant difference between the treatments under low and high nitrogen conditions. The total water consumption of wheat increased by 5.68 ~ 31.30 mm, yield increased 1.43% ~ 7.16%, water use efficiency increased 1.27% ~ 4.23%. The nitrogen accumulation, pre-anthesis nitrogen flowering and post-anthesis nitrogen accumulation increased in each growth period, There was significant difference between the treatments of nitrogen accumulation in plant, the agronomic efficiency of nitrogen fertilizer increased by 0.47-1.24 kg · kg-1, the recovery of nitrogen fertilizer increased significantly by 3.01% -4.96% Soil water storage and total water consumption were the lowest with nitrogen application rate of 150 kg · hm-2. The number of stalks, yield components, yield and water use efficiency of each group were significantly higher than those of 150 kg · hm-2 N kg · hm-2, and the yield of middle-low nitrogen and high-nitrogen increased by 574.75 and 341.14 kg · hm-2, respectively, and the water use efficiency increased by 12.89% and 7.77% Nitrogen accumulation, pre-anthesis nitrogen flow rate and its contribution to grain, agronomic efficiency of nitrogen fertilizer and seasonal recovery of nitrogen fertilizer were significantly higher at the rate of 150 kg · hm-2 and 75 kg · hm-2 And the agronomic efficiency of low-N and high-N treatments increased 1.91 kg · kg-1 and 1.12 kg · kg-1, respectively, and the seasonal recovery rate of nitrogen increased by 1.74% and 5.32% respectively. In addition, In conclusion, the deep-tillage and over-cover of dry land wheat during the fallow period is conducive to water storage and water conservation, and increased soil moisture at the end of planting, and it is more beneficial to use 150 kg · hm-2 nitrogen fertilizer with the highest correlation (r = 0.906) Interaction between water and nitrogen to promote nitrogen absorption, operation, to increase production, high efficiency.