黄土高原丘陵沟壑区不同土地利用模式对土壤机械组成和速效养分影响分析

The Analysis of Soil Mechanical Composition and Available Nutrient under Different Land Uses Patterns in the Loess Hilly Gully Region

通过对黄土高原丘陵沟壑区不同土地利用模式土壤机械组成和速效养分的测定,论述黄土高原丘陵沟壑区不同土地利用模式对土壤机械组成和速效养分的影响。结果表明:草地的在两个土层速效养分含量差别不大,而其他土地利用模式0～20cm土层的速效养分含量均高于20～40cm土层。关中土壤的速效养分明显高于黄土高原丘陵沟壑区,草地的速效养分都低于其它土地利用模式。黄土高原丘陵沟壑区土壤机械组成分布大致为:粉粒>细砂粒>粗砂粒≈粘粒。速效养分只与0～20cm的粘粒含量承显著正相关。黄土高原丘陵沟壑区土壤肥力结构不协调,尤其是氮磷比失衡,磷肥施用量过度。各种经济模式应调整施肥结构及耕作方式。

According to determination of soil mechanical composition and available nutrient under different land uses in the loess hilly gully region,effect of soil mechanical composition and under different land uses in the loess hilly gully region were discussed in detail.The results showed that available nutrient content have little difference in 0～10cm and 20～40 cm soil of grassplot,but available nutrient content in 0～20cm soil higher than in 20～40 cm soil of other land uses patterns.Available nutrient content in Guanzhong area obviously higher than available nutrient content in loess hilly gully region,available nutrient content in grassplot lower than available nutrient content in other land uses patterns.Soil mechanical composition distribution in loess hilly gully region is silt〉fine sand〉 thick sand≈clay.Available nutrient content and soil mechanical composition content was significant positive correlation.Soil fertility structure isn＇t coordinated,especially for ratio of nitrogen to phosphorus is imbalance,and content of phosphorus is excessive in the loess hilly gully region.Every land uses should adjust fertilization constitution and tillage methods.