基于熵权物元模型的土壤养分评价:以新疆干旱区艾比湖流域人工绿洲为例

Soil Nutrients Evaluation Based on Entropy Weight and Matter Element(EWME) Model:A Case Study on Artificial Oasis in the Ebinur Lake Basin,an Arid Zone of Xinjiang

调查新疆艾比湖流域人工绿洲并按不同土地利用类型分层采集土样,以土壤有机质(OM)、全氮(TN)、全磷(TP)、全钾(TK)、速效氮(AN)和速效磷(AP)、速效钾(AK)含量这7项土壤肥力因素为土壤养分评价指标,建立熵权物元(EWME)模型评价人工绿洲15个不同样地59个土样的土壤养分等级。结果表明,人工绿洲土壤养分总体处于极贫乏等级,TK和AK为土壤肥力优势因子,OM、TN、TP、AN和AP为限制因子,农业施肥应具有针对性;不同土地利用类型土壤养分状况不同,耕地养分含量最高,林地次之,这与人工干扰程度有较大关联性;整体而言,不同土层的养分水平变化不明显。在自然状况下,深层土养分含量高于表层土。在人为种植利用状况下,表层土养分含量高于深层土。评价结果符合当地的生产实际状况,EWME模型在人工绿洲土壤养分评价中具有较好的适用性。

A soil survey was carried out of the artificial oasis in the Ebinur Lake Basin,an arid zone of Xinjiang,and soil samples were collected by soil layer and by land use for analysis of soil organic matter（ SOM）,total nitrogen（ TN）,total phosphorus（ TP）,total potassium（ TK）,readily available nitrogen（ AN）,readily available phosphorus（ AP） and readily available potassium（ AK）,the seven major soil quality evaluation indices. An EWME model（ entropy weight and matter element model） was established for grading by soil fertility the 59 soil samples collected from 15 sampling lots in the oasis. Results show that the soils in the oasis on the whole could be sorted into the category of ＂poverty＂in soil fertility.TK and AK are two advantageous factors,while all the others are limiting. Agricultural fertilization should be done casespecifically and vary with type of land use and nutrient status of the soil. Farmland soil is the highest in nutrient content,and followed by forest soil,which is significantly associated with the degree of human disturbance. On the whole,the soil does not vary much in nutrient content from layer to layer. Under natural conditions,soil nutrient content in the deep layers is generally higher than that in the surface layer,while under cultivation,the trend is reversed. The findings of the evaluation are in consistence with the actual situation. Apparently,EWME model is very applicable to the evaluation of soil nutrient status of the artificial oasis.