不同处理对河套灌区玉米土壤硝态氮和铵态氮动态及氮肥利用率的影响

Effect of different materials on dynamic change of soil nitrate and ammonium nitrogen and N uptake by maize in Hetao irrigation area

为了探讨内蒙古河套灌区农业化肥面源污染检测和治理措施,采用大田土壤淋溶试验,分析了河套灌区农田在缓控释尿素、活性炭、生物菌肥处理下,玉米生育期内土壤硝态氮、铵态氮动态变化特征及氮肥利用情况。结果表明,缓控释尿素、活性炭、微生物菌肥处理与常规处理相比,在玉米拔节期、大喇叭口期土壤NO-3-N、NH+4-N含量变化不太显著,而苗期土壤NO-3-N含量平均分别提高24.76%、18.36%、4.31%,收获期平均分别降低23.98%、12.53%、5.47%;苗期土壤中NH+4-N含量较常规处理分别平均提高28.21%、15.47%、5.24%,收获期平均分别降低26.33%、16.93%、7.37%;氮肥利用率分别较常规处理提高15.71%、10.65%和5.16%。

To support the agricultural non-point source pollution detection and control strategies in Hetao irrigation area of Inner Mongolia, field soil leaching tests were conducted with different kinds of materials to study the dynamic change of soil nitrate and ammonium nitrogen and N uptake by maize. Four treatments were set up, including CK （farmer conventional fertilization with urea）, HK （controlled release urea was used）, C （farmer conventional fertilization with urea, plus activated carbon） and W （farmer conventional fertilization with urea, plus microbial fertilizer）. The results showed that compared to CK, soil NO3--N accumulation amount of the treatments HK, C and W increased by 24. 76%, 18.36%, 4. 31% in corn seedling period, but reduced by 23.98%, 12. 53%, 5.47% on average in the harvest period. Soil NH4＋-N accumulation amount in- creased by 28.21%, 15.47%, 5.24% in seedling period, but in the harvest period reduced by 26. 33%, 16. 93%, 7.37%. Nitrogen utilization rates were 15.71% , 10. 65%, 5.16% higher than the conventional ones. It was concluded that controlled release urea, activated carbon and microbial fertilizer effectively adsorbed NO3--N and NH4＋ -N in shallow soil and reduced nutrient leaching.