西藏拉萨温棚蔬菜基地土壤营养元素含量的初步研究

用靛酚蓝比色法、碳酸氢钠浸提—钼锑抗比色法和四苯硼钠比浊度法对从拉萨堆龙德庆县、北郊夺底乡、蔡公堂乡、纳金乡、八一农场蔬菜基地采集的23个温棚土壤样品进行速效氮、速效磷和速效钾含量的测定。结果显示：速效氮＂极缺＂占96%、＂缺＂占4%,速效氮含量极低;速效磷＂极缺＂占17.5%、＂缺＂占17.5%、＂中等＂占48%、＂丰富＂占13%、＂很丰富＂占4%,速效磷含量属于中等水平;速效钾＂缺＂占44%、＂中等＂占26%、＂丰富＂占17%、＂很丰富＂占13%,速效钾含量属于中等偏高水平;温室土壤中N、P、K营养元素含量差异性较大,并且具有区域不平衡性。

Analysis of nutrient elements content in soil of vegetable greenhouse in Lhasa, Tibet

The available nitrogen,phosphorus and potassium content in twenty three soil samples from vegetable greenhouse in Tolung Dechen,Togde,Ngaqen,Caigungtang and Bayi were analyzed by Berthelor reaction,Olsen,Turbidimetric and Tetraphenylborate.The result showed that the scarcity and lack of available nitrogen content were 96% and 4% respectively,the scarcity and lack of available phosphorus were17.5%,48% of medium level,13% in reach grades and 4% in plentiful grades,and available potassium content was also medium level with 44% in lack grades,26% in secondary grades,17% in reach grades,13% in plentiful grades.The soil of vegetable greenhouse has significant difference in content of N,P and K Nutrition elements and contents of available nitrogen,phosphorus and potassium were imbalance in the soil regionally.