核桃是重要的木本油料、干果和用材树,是山区农民经济收入重要来源之一。但是多种原因,造成产量低、质量差,资源潜力得不到合理开发。因此改造低产林是核桃生产亟待解决的问题。 1.低产原因 (1)立地不当。核桃喜深厚疏松的土壤,如果种植在土壤瘠薄的山坡或粘重土区,则生长缓慢,产量 Walnut is an important woody oil, dried fruit and timber trees, is one of the important sources of economic income of mountain farmers. However, for a variety of reasons, low yields, poor quality and limited potential for resources can not be exploited. Therefore, the transformation of low-yielding forest is an urgent issue to be solved in the production of walnut. 1. Low yield causes (1) improper site. Walnut Hi deep loose soil, if planted in barren hills or clay soil area, the slow growth, yield