宁夏引黄灌区猪粪还田对麦田土壤硝态氮淋失的影响

Effect of swine manure application on nitrate leaching in winter wheat field in the Yellow River irrigation area of Ningxia,China

以宁夏引黄灌区为例，探索猪粪还田条件下冬小麦田土壤硝态氮淋失规律．试验设置3个处理：常规施化肥225kgN·hm^-2（CK）、常规施肥基础上施用4500kg·hm^-2（T1）和9000kg·hm^-2（T2）猪粪．利用树脂芯法吸附30、60和90cm土层的硝态氮淋失量．结果表明：在常规施肥基础上增施猪粪，小麦生育期土壤硝态氮（纯N）淋失量为9．33～14．04kg·hm^-2,占施N量的4．2％～6．2％．与CK相比，30cm土层T1、T2的硝态氮淋失量增加2．6％和2．1％；60cm土层增加1．5％和减少1．3％；90cm土层减少8．7％和增加4．0％．增施猪粪与对照在30、60和90cm土层处的硝态氮淋失量均无显著差异，而在深层土壤表现出减少趋势．硝态氮淋失主要发生在返青至灌浆期间，日均淋失量高于全生育期平均水平，该阶段的硝态氮淋失量占生育期内总淋失量的58．7％-75．3％．T1、T2春小麦产量比对照分别增加9．3％和12．5％．

The effect of swine manure application on nitrate nitrogen leaching was investigated in the Yellow River irrigation area of Ningxia. The field experiment was conducted with 3 Treatments： Traditional fertilization 225 kg N kg ·hm^-2 without swine manure （CK）, traditional fertilization with swine manure 4500 kg · hm^-2 （Tl ） and traditional fertilization with swine manure 9000 kg · hm^-2 （ T2 ）. Nitrate nitrogen leaching rates were measured for 30, 60, 90 cm depth soil layers with a resin core absorption method. The results indicated that the nitrate leaching losses of T1 and T2 treatments ranged from 9.33 to 14.04 kg · hm^-2 （pure nitrogen） , which accounted for 4.2%- 6.2% of applied nitrogen fertilizer. Compared to CK, the nitrate leaching losses of T1 and T2 in- creased by 2.6% and 2.1% at 30 em depth, increased by 1.5% and decreased by 1.3% at 60 cm depth, decreased by 8.7% and increased by 4.0% at 90 cm depth, respectively. The difference did not reach statistical significance among CK and T1 and T2 in nitrate leaching loss at 30, 60 and 90 cm depths. However, there was a declining trend of nitrate leaching at deep soil layers of treat- ments. The key period of nitrate leaching loss was from spring reviving to early filling stage, whichhad a higher daily leaching loss than the average of the whole growth period, and accounted for 58.7%-75.3% of total leaching loss. Compared with CK, the yields of T1 and T2 increased by 9.3% and 12.5%, respectively.