一、问题的提出理论和实践证明,冻害是北方寒冷地区气温多变和低温的影响,是果树生产发展的主要限制因素。而大苹果匍甸栽培又是安全越冬、免遭冻害的有效措施。但是,几年来随着实验的深入,我们逐步认识到:由于树令的增加,树冠空间容量逐年扩大,培土与撤土的土方逐年增多。更主要的是由于低接,地上部易受冻害的部位都是不耐寒的大苹 First, the issue put forward Theory and practice show that frost damage is cold and cold in North China is changing temperature and low temperature, is the main limiting factor in the development of fruit trees. The big apple is also an effective way to protect the winter from creeping cultivation. However, with the deepening of experimentation over the past few years, we have come to realize that due to the increase of tree orders, the space capacity of canopy has been expanding year by year, and the earthwork of earth-lifting and earth-removing has been increasing year by year. More importantly, due to low access, the parts of the ground are vulnerable to cold damage are not hardy big apple