岷江上游干旱河谷岷江柏木幼林地绿肥种植研究

在岷江上游干旱河谷岷江柏木幼林地经过连续4 a利用雨季种植绿肥压青,增加土壤肥力,提高水分利用率,促进幼树生长研究。结果表明:(1)种植红豆草的土壤0～40 cm含水量旱季增加3.68 g·kg-1,0～20 cm土壤容重降低0.07 g·cm-3;种植草木樨土壤0～40 cm含水量旱季增加4.18 g·kg-1,0～20 cm土壤容重降低0.05 g·cm-3;种植沙打旺土壤0～40 cm含水量增加2.46 g.kg-1,0～20 cm土壤容重降低0.18 g·cm-3。(2)种植绿肥压青,土壤有机质增加0.37 g·kg-1～0.55 g·kg-1,土壤CaCO3含量下降0.66 g·kg-1～1.36 g·kg-1,有效氮增加4.5 mg·kg-1～18.5 mg·kg-1,有效磷含量增加1.0～3.46 mg·kg-1,CEC比对照增加0.54～0.58mg.100g-1。(3)种植红豆草、草木樨、沙打旺绿肥压青对岷江柏木树高、地径生长有显著的促进作用,尤其种植红豆草的岷江柏木幼树生长最好,高、径生长为对照的1.7倍和1.6倍。

Experiment on Planting of Green Manure under the Young Growths of Cupressus chengiana S.Y.Hu in the Arid Valleys of the Upper Reaches of the Minjiang River

The experiments on planting of green manure were carried out in the arid valleys of the upper reachers of the Minjiang River in the rainy seasons of the successive 4 years so as to fertilize soil,increase moisture utilization and promote the growth of the young growths of Cupressus chengiana S.y.Hu.The results are as follows.（1） By planting of Onobrychis viciaefolia,soil water in 0~40 cm in the dry season increases by 3.68 g·kg-1;weight volume of soil in 0~20 cm decreases 0.07 g·cm-3 as compared with control.By planting of Melilotus officonahs,soil water in 0~40 cm in the dry season increases by 4.18 g·kg-1;weight volume of soil in 0~20 cm decreases 0.05 g·cm-3 as compared with control.By planting of Astragalus adsurgens,soil water in 0~40 cm in the dry season increases by 2.46 g·kg-1;weight volume of soil in 0~20 cm decreases 0.18 g·cm-3 as compared with control.（2）Through planting of green manure,organic matter of soil increases by 0.37 g·kg-1~0.55 g·kg-1;content of CaCo3 decreases by 0.66 g·kg-1~1.36 g·kg-1;available N and P increase by 4.5 mg·kg-1~18.5 mg·kg-1 and 1.0 mg·kg-1~1.4 mg·kg-1 respectively;CEC increases 0.54 mg·100 g-1~0.58 mg·100 g-1 as compared with control.（3） Planting of Onobrychis viciaefolia,Melilotus officinalis and Astragalus adsurgens under the plantations of Platycladus oriendalis can significantly increase their growth in the height and basal diameter.The growth in the height and basal diameter for Cupressus chengiana S.y.Hu is 1.6~1.7 times higher as compared with control.