风沙土氮素运动及对麻黄生长的影响

Movement of Nitrogen in Sand Soil and Effect of Nitrogen Fertilizer to Growth of Ephedra

风沙土有机质易于分解,难以积累,腐殖质是风沙土有机质的主体,胡敏素是腐殖质的主要成分,HA/FAD的比值在0.16～0.57,风沙土土壤全氮与有机质含量显著相关。施用氮肥可以显著增加土壤中硝态氮的含量,NO3--N含量在0～30cm,30～60cm,60～90cm和90～120cm土层的高峰分别出现在5,6,7,8月。土壤有机质的含量与施入土壤的有机肥量相关,而且随着有机肥施用量的提高,土壤有机质、全氮、NH4+-N、NO3--N、速效氮均显著增加。有机肥和氮肥配合施用对麻黄不同阶段的硝态氮含量具有明显的影响,且NO3--N的积累峰明显上移。麻黄氮肥于4,5,6,7月施肥用量分别为153.8～153.9kg/hm2,15.2～15.5kg/hm2,105.5～105.6kg/hm2,112.8～113.0kg/hm2。

Organic matter of sand soil was easy to decompose, and difficult to accumulate. Humic substance was main in organic matter, and humin was main in humic substance, and proportion of HA to FAD was between (0.16) and 0.57. The content of full nitrogen and organic matter was correlative considerably. The content of NO_3^--N in varied soil layer was increased by applying nitrogen fertilizer. The peak of NO_3^--N in different soil layer appeared in May, June, July and August. The content of organic matter was related with quantity of applied organic matter, and increased with increasing of applied organic matter. The content of organic, full nitrogen, NH_4^+-N, NO_3^--N and valid-N increased notably after applied organic matter and nitrogen fertilizer, and it effected the content of NO_3^--N in different stage of ephedra, and the peak of NO_3^--N moved up. The quantity of fertilization in April, May, June and July were: 153.8～153.9 kg/hm^2,15.2～15.5 kg/hm^2,105.5～(105.6) kg/hm^2,112.8～113.0 kg/hm^2.