摘要
选取西藏隆孜县青稞（Avena nuda）地、马铃薯（Solanum tuberosum）地、紫花苜蓿（Medicago sativa）地、黄花苜蓿（Medicago falcata）地、油菜（Brassica campestris）、豌豆（Pisum sativum）混播地5种常见农作物样地,研究其土壤各种形态氮素、磷、有机质含量以及土壤pH的变化。结果表明,1）隆孜不同作物耕地土壤养分含量存在差异,马铃薯地有机质与全氮含量显著高于其它样地（P〈0.05）;所有样地有机质平均含量为2.59%,全氮平均含量为0.18%,整体而言土壤肥力中等偏高。2）5种样地铵态氮含量变化较小,而硝态氮含量则呈强变异性,黄花苜蓿地硝态氮含量最高。3）土壤有机质C/N很低,有助于土壤有机氮的矿化。4）所有样地平均磷含量为0.13%,含量较丰富;而两种苜蓿地磷含量相对较低。5）所有样地pH平均变化范围是8.12~8.48,均呈微碱性;青稞地pH最高,不同作物对土壤pH的影响不同。6）土壤不同养分性状之间存在较为复杂的相关性、有机质与全氮和全磷、铵态氮与硝态氮之间均呈极显著的正相关（P〈0.01）,土壤全氮与铵态氮和硝态氮则均无相关性,而土壤pH与硝态氮之间为极显著的负相关。
Five different types of cultivated lands,which were mainly planted for barley（Avena nuda）,potato（Solanum tuberosum）,alfalfa（Medicago sativa）,sickle alfalfa（Medicago falcata）and rape（Brassica campestris）mixed with pea（Pisum sativum）,respectively,were selected in Longzi County,Tibet and the nitrogen status of various forms,phosphorus content,soil organic matter（SOM）content and soil pH were analyzed in the present study.The results showed that the average soil nutrient contents in different types of cultivated lands were different and SOM and total N contents in potato land were significantly higher（P〈0.05）than the other four cultivated lands.In general,the average contents of SOM and total N for all five cultivated lands were 2.59% and 0.18%,respectively,which indicated that the soil fertility was high in all cultivated lands.There was little variations for ammonium contents in different cultivated lands,however,there was strong variations for nitrate contents in different cultivated lands with the highest nitrate content in sickle alfalfa farmland.The C/N ratio of SOM was low which attributed to accelerate the mineralization of soil organic nitrogen.Phosphorus content was rich in all the five types of cultivated lands with the average content of 0.13%although it was a little bit lower in the two types alfalfa lands.The mean pH of all the lands changed from 8.12 to 8.48,which suggested that it was all alkalescence in Longzi.Different crops had different effects on soil pH and barley land had significantly higher pH than that of other lands.There were complicated correlations between soil nutrient properties in the soils of cultivated lands.Both SOM and total N had very positively significantly correlation（P〈0.01）with total P,ammonium and nitrate N.There was no correlations between each other of total N,ammonium and nitrate N.Soil pH had very negatively significantly correlation（P〈0.01）with nitrate N.
出处
《草业科学》
CAS
CSCD
北大核心
2016年第6期1054-1061,共8页
Pratacultural Science
基金
河南省教育厅人文社会科学研究青年项目(2015-QN-057)
关键词
西藏
作物
耕地
土壤养分
Tibet
crop
cultivated land
soil nutrient
