有机肥氮替代20%化肥氮提高豫北冬小麦氮肥利用率和土壤肥力

Improving winter wheat N utilization efficiency and soil fertility through replacement of chemical N by 20%organic manure

【目的】探究有机肥氮替代不同比例化肥氮对冬小麦产量和土壤肥力的影响,为豫北冬小麦筛选适宜有机肥替代比例、提高氮素利用率以及小麦产量提升提供参考。【方法】在2018和2019年以小麦新品种百农207为供试材料进行大田试验,试验设置不施氮肥处理(T1)、常规施氮肥处理(T2)和3种有机肥氮替代化肥氮比例(20%、30%和40%,依次表示为T3、T4、T5)。分析比较成熟期不同处理下小麦产量、产量构成要素、各器官的氮素积累量与分配比例、氮肥利用率以及土壤肥力指标的变化。【结果】2018和2019年的产量结果表明,相比T2处理,有机肥氮替代化肥氮比例为20%(T3)处理能实现小麦产量的稳产增产。2019年T3处理比T2处理小麦产量显著增加16.59%,随着有机肥氮替代化肥氮比例增加,小麦增产效应降低。2019年在T3处理下,植株氮素总积累量比T2处理显著提高25.71%,T3处理相比T2处理籽粒的氮素积累量两年分别显著提高14.45%和22.20%。2019年T3处理氮素偏生产力、氮素回收率和氮肥农学效率都显著高于T2处理。连续两年施用有机肥处理对土壤中全氮含量影响不大,但相比T1和T2处理,2018和2019年在T3处理下土壤有效磷、铵态氮和硝态氮含量显著提高。通过产量与其他因素的相关分析可知,小麦产量与植株氮素总积累量、籽粒氮素积累量、小麦穗数呈极显著正相关,而穗数与土壤养分中的NH4+-N含量和NO3–-N含量均呈极显著正相关。【结论】在氮施用量为300 kg/hm2时,通过连续两年有机肥与化肥配施可改善土壤肥力水平。本试验条件下,有机肥氮替代化肥氮的比例为总施氮量20%时,能显著增加籽粒氮素积累量,提高小麦氮素利用效率和产量,实现豫北冬小麦稳产和高产。

【Objectives】The effects of different proportion of organic N in the total N input on winter wheat yield and soil fertility were explored.The purpose of this study is to provide technical support for selecting suitable replacement proportion of organic fertilizer,improving N use efficiency and high-quality wheat yield for winter wheat in the north of Henan Province.【Methods】A field experiment was conducted in 2018 and 2019 using a new wheat variety Bainong 207 as experimental material.Treatments of no N fertilizer(T1),conventional N fertilizer input(T2)and three proportion of organic N(20%,30%and 40%,recorded as T3,T4 and T5)were set up in the experiment.The wheat yield,yield components,N accumulation and allocation ratio in different organs,N use efficiency and soil fertility were investigated at harvest.【Results】Compared with T2 treatment in2018 and 2019,the replacement ratio of 20%(T3)achieved stable increased yield of winter wheat.Under the T3 treatment in 2019,the yield was increased significantly by 16.59%,while T4 and T5 treatments decreased the yield increment.Compared to T2,the total N accumulation of plants under the T3 treatment was significantly increased by 25.71%in 2019;the N accumulation of grains was significantly increased by 14.45%and 22.20%in2018 and 2019,respectively;under the T3 treatment,the N partial factor productivity,N recovery efficiency,N agronomic efficiency were significantly higher than those under the T2 treatment.Application of organic manure for two consecutive years had little effect on soil total N content.However,the contents of available P,NH4+-N and NO3–-N in the soil were significantly increased under the T3 treatment in 2018 and 2019.According to the correlation analysis,wheat yield was significantly and positively correlated with total N accumulation in plant,grain N accumulation and spike number per area.The spike number per area was positively and correlated with the contents of NH4+-N and NO3–-N in soil.【Conclusions】At the base of total N input of 300 kg/hm2,replacing a certain proportion of N with organic fertilizers for two consecutive years is capable of increasing soil fertility and winter wheat yield.Under the current soil fertility condition,replacement of chemical N by 20%organic fertilizer could significantly increase the grain N accumulation,improve wheat N use efficiency and yield,and ensure the goal of stable and high yield of winter wheat in northern Henan.