淮北地区位于苏皖两省北部,地势平坦,气候溫和,盛产三麦、杂谷和棉花,但以冬小麦比重最大。淮北土壤以石灰性冲积土为主,一般含碳酸鈣5~12%,幷富合矿物质养分,如有效鉀,一般每亩在50~100斤,全磷含量在0.15~0.18%。但在表土中一般有机质含量仅0.8~1.2%,全氮量为0.05~0.06%,因而土壤性状不良,作物氮素营养不足。生产实践証明,在目前情况下,种植綠 Huaibei is located in the northern part of Jiangsu and Anhui provinces, flat, mild climate, rich in three wheat, miscellaneous grains and cotton, but the largest proportion of winter wheat. The soil in Huaibei mainly consists of calcareous alluvial soil, usually containing 5-12% calcium carbonate. The content of mineral nutrients, such as available potassium, is generally 50-100 kg per acre and the total phosphorus content is 0.15-0.18%. However, in the topsoil, the content of organic matter is only 0.8-1.2% and the total nitrogen content is 0.05-0.06%, which leads to poor soil characteristics and insufficient crop nitrogen nutrition. Production practice has proved that under the current circumstances, planting green