内蒙古草原暗栗钙土中氮的形态及放牧的影响  

Nitrogen forms and grazing's influence in dark chestnut soils of Inner Mongolian grassland

作　　者：李香真[1] 张淑敏[1] 

机构地区：[1]中国科学院植物研究所,北京100093

出　　处：《草业学报》2002年第2期15-21,共7页Acta Prataculturae Sinica

基　　金：中国科学院知识创新工程重大项目 (KSCX1 - 0 8)资助

摘　　要：研究了内蒙古羊草草原暗栗钙土的氮形态特征及放牧的影响。结果表明 ,暗栗钙土中有机 N占全 N的 86 %以上 ,其中 NH3- N含量较高 ,约占土壤全 N的 15 %～ 30 % ,其次是氨基酸 N,约占全 N的 15 %～ 2 0 % ,氨基糖 N含量低于 10 %。α-氨基酸中以中性氨基酸 N含量最高 ,其次是酸性和碱性氨基酸。无机 N中非交换性 NH4 + - N所占比例最高。放牧使 0～ 10 cm土壤 KCl浸提的无机 N显著降低 ;氨态 N、氨基酸 N、酸水解 N的绝对量均是禁牧区大于放牧区 ,但占全 N的比例二者无显著差异。放牧使酸不溶性 N比例提高 ,而 NH3-Nitrogen forms in dark chestnut soil and grazing's influence were investigated in Inner Mongolian plateau. The results indicated that organic N accounted for more than 85% of total nitrogen in our studied soil; NH 3 N accounted for 15%~30%. Amino acid N accounted for 15%~20%. Amino sugar was less than 10%. Neutral amino acids dominated α amino acid. Next was acid and alkali amino acids. Grazing decreased KCl extractable N significantly. Absolute value of ammonium N, amino acid N, acid hydrolyzed N was higher in ungrazing sites than that in grazing sites, but the proportion to total N didn't show significant differences. Grazing increased the proportion of acid insoluble N, but decreased the proportion of NH 3 N significantly.

关 键 词：暗栗钙土 氮形态 放牧 

分 类 号：S153.61[农业科学—土壤学]