播期对青稞农田氨挥发和土壤NH4^+-N含量的影响

Effect of Different Sowing Date on Ammonia Volatilization and NH4^+-N Content in Soil

为探明不同播期对青稞农田氨挥发、土壤氨态氮变化特性和对生产的影响。本试验采用完全随机试验设置早播(4月12日)和晚播(4月25日)2个处理,分析氨挥发和土壤氨态氮含量特性、二者的相关性及对产量相关农艺性状的影响。早播的氨挥发积累量<晚播,影响氨挥发的施肥时期主要为基肥期表现为挥发峰值高、挥发周期长、挥发积累量占比高;不同播期土壤NH4^+-N含量的峰值均出现基肥期,且晚播>早播;土壤NH4^+-N含量与氨挥发极显著正相关;早播有利于青稞形成高株,但不同播期对青稞生物量影响差异不显著。综上所述,建议河谷农区根据环境条件适时早播,降低氨挥发损失。

Ammonia volatilization is one of the important ways of nitrogen loss in farmland.Field trials were conducted to estimate the influences of different sowing dates on highland barley yield,NH 3 volatilization,and NH4^+-N content in soil in a highland barley system in Tibet.The results showed that,the accumulation of ammonia volatilization in early sowing was less than that of late sowing.Ammonia volatilization mainly occured in the base fertilizer phase,which was characterized by high volatilization peak,long volatilization cycle and high ratio of volatilization accumulation.The peak of NH4^+-N content in soil at different sowing dates all appeared in the basal fertilizer stage,and late sowing>early sowing.There was a significant positive correlation between NH4^+-N content in soil and ammonia volatilization.Early sowing was beneficial to the formation of high strains,but the effect of different sowing dates on barley biomass was not significant.From what has been discussed above,it suggested that sow early can be a feasible way of mitigating ammonia volatilization from highland barley fields in Tibet.