坝上地区紫花苜蓿土壤有效磷、钾丰缺指标初探

Preliminary study on abundance and deficiency index of available phosphorus and potassium for alfalfa in Bashang soil

从坝上地区的17个土壤样品中选取养分含量差异较大的5个地点的土壤,进行盆栽试验,设全肥（施N、P、K肥）、缺磷、缺钾和不施肥的4个处理,初步探索坝上地区紫花苜蓿（Medicago sativa）土壤磷、钾丰缺指标。结果表明,用坝上地区土壤种植紫花苜蓿,土壤有效磷极缺、缺、中等、丰富和极丰富的指标依次为〈3.5、3.5~9.8、9.8~21.4、21.4~27.7和〉27.7 mg/kg;有效钾极缺、缺、中等、丰富和极丰富的指标依次为〈2.4、2.4~15.6、15.6~63.4、63.4~101.2和〉101.2 mg/kg。

Seventeen soil samples collected from different areas of Bashang region were analyzed for their soil fertility levels in the laboratory.Five samples which had different soil fertility from 17 soil samples were chosen for pot experiments to study on the abundance and deficiency index of available phosphorus and potassium for Medicago sativa.Treatments of the experiments were included well fertilized（added right amount of N,P,K）,phosphate deficiency（added right amount of N,K）,potassium deficiency（added right amount of N,P） and no fertilized（did not add N,P,K）.The results of this study showed when M.sativa was planted in Bashang soil,the indexes of available phosphorus in the soil at serious deficiency,deficiency,no deficiency,abundance and great abundance were 3.5,3.5-9.8,9.8-21.4,21.4-27.7 and 27.7 mg/kg,respectively.The indexes of available potassium in the soil at serious deficiency,deficiency,no deficiency,abundance and great abundance were 2.4,2.4-15.6,15.6-63.4,63.4-101.2 and 101.2 mg/kg,respectively.