华北北部地区无霜期在180～200d左右,适合搞两茬种植及间混套种。同时随着海河平原农业开发项目的实施,大部分农田的水利条件及土壤条件均得到改善。为间套种技术提供了水源及优异的土壤条件。1　小麦、玉米、大白菜(花椰菜、芹菜)三茬连套。采用200cm带田种植,小麦占地120cm种 The frost-free period in the northern part of North China is about 180-200 days, which is suitable for planting two crops and interplanting. At the same time, with the implementation of Haihe Plain Agricultural Development Project, the water conditions and soil conditions of most farmlands have been improved. For intercropping technology provides a water source and excellent soil conditions. 1 wheat, corn, Chinese cabbage (broccoli, celery) three stubble sets. 200cm with field planting, wheat covers an area of ​​120cm species