不同施肥处理对青稞根际土壤铵态氮和硝态氮的影响

试验以青稞新育品种‘黄青2号’不同生长期的土壤为材料,对比测定不同施肥处理、不同土层土壤铵态氮、硝态氮含量,研究了土壤中铵态氮、硝态氮动态变化规律。结果显示：土壤中铵态氮、硝态氮含量在整个生育期都呈现“降低—升高—降低”的变化趋势,铵态氮含量在抽穗期最高,硝态氮含量在苗期最高,分别为2.75 mg/kg和22.64 mg/kg。0~20 cm土壤中铵态氮、硝态氮含量为1.76 mg/kg和11.82 mg/kg,分别是20~40 cm的1.76倍和2.00倍,说明物质的转化、吸收和运输主要在上层土壤中进行。土壤中铵态氮达到一定浓度时,硝态氮含量与铵态氮浓度没有相关性,而与硝酸酶活性有关。不同施肥处理下铵态氮、硝态氮含量有所差异,3种缓释肥料处理下土壤中铵态氮、硝态氮有效利用率更高。

Effects on Ammonium Nitrogen and Nitrate Nitrogen in Rhizosphere Soil of Highland Barley Under Different Fertilization Treatments

The experiment took the rhizosphere soil of the new highland barley variety ‘Huangqing No.2’ in different growth stages as material, comparatively measured the contents of ammonium nitrogen and nitrate nitrogen in different soil layers under different fertilization treatments and studied the dynamic change rule of ammonium nitrogen and nitrate nitrogen in soil. The results showed that the content of ammonium nitrogen and nitrate nitrogen in the soil demonstrated a trend of ‘decrease, increase and then decrease’ during the whole growth period of highland barley; the content of ammonium nitrogen reached the highest during the heading period and the content of nitrate nitrogen reached the highest during the seedling period, which were 2.75 mg/kg and 22.64 mg/kg, respectively. The contents of ammonium nitrogen and nitrate nitrogen in the 0-20 cm soil layer were 1.76 mg/kg and 11.82 mg/kg, respectively, which were 1.76 and 2.00 times of those in the 20-40 cm soil layer, indicating that the transformation, absorption and transportation of substances were mainly carried out in the upper soil. Meanwhile, it was also shown that when ammonium nitrogen in soil reached a certain concentration, nitrate nitrogen content had no correlation with ammonium nitrogen concentration, but was related with nitrate enzyme activity. The content of ammonium nitrogen and nitrate nitrogen were different under different fertilization treatments, while the effective utilization rates of ammonium nitrogen and nitrate nitrogen were higher in the soil treated by three kinds of slow released fertilizers.