黄土高原旱地苹果园生草对土壤养分影响

 对黄土高原渭北旱地苹果园生草土壤养分测定结果表明：生草能提高0～60cm土层有机质含量,种植禾本科牧草有机质年积累0.1%,种植豆科牧草年积累0.15%;随生草年限的增加较深土层土壤有机质趋于增加。生草对N、P、K营养的影响主要表现在0～40cm土层,生草的前期土壤养分消耗大于积累,全N、全P、全K的演变呈现“S”型的演变过程,生草能提高0～40Cm土层水解N、速效P及速效K含量,黑麦草活化P的作用大于白三叶,而白三叶活化N的作用大于黑麦草。随着生草年限的增加,苹果产量及品质得到提高。

Effects of Interplanting of Herbage on Soil Nutrient of Non-irrigated Apple Orchard in the Loess Plateau

The soil nutrients of the interplanted herbage of apple orchard in Weibei areas in the loess plateau were studied. Results showed that the content of soil organic matter within 60 cm soil layer was increased by 0.1% in grass family herbage land and by 0.15% in the pulse family herbage per year respectively. With growing herbage years, the soil organic matter increased in dept soil layers.Effects of herbage-interplanted on total N, P and K were within 40 cm soil layer. Nutrient competition existed between herbage and apple tree within 40cm soil layers in four years after planting herbage. In the fifth year of herbage growth, the content of total N, P and K were increased. The content of total N, P and K appeared "S" type change within five years. But the content of hydrolytic N, available P and available K within 40cm soil layer was increased. The activated organic P and hydrolytic N were different in the various kinds of herbage lands. The activated organic P in perennial ryegrass land was more effectively than that in white clover land. The hydrolytic N in white clover land was increased in compared with perennial ryegrass land. With growing herbage years,fruit output and quality were enhanced.