1叶莱类这类蔬菜的生长特点是全生育期需要肥水较多，尤其对速效氮肥更为敏感和迫切，如氮肥不足，则叶片黄绿、生长迟缓、产量大为减少。所以，除施足底肥外，在苗期、中后期如能喷施1％－2％尿素（或硫酸铁）溶液，7－10天一次，连续喷2－4次，不仅能加速叶片抽生和迅速生长 1 leafy class growth characteristics of these vegetables is the need for more fertilizers during the whole growth period, especially for quick-acting nitrogen fertilizer is more sensitive and urgent, such as nitrogen deficiency, the leaves of yellow-green, slow growth, yield greatly reduced. Therefore, in addition to applying enough fertilizer, in the seedling, mid-late if you can spray 1% -2% urea (or ferric sulfate) solution, 7-10 days, spray 2-4 times in a row, not only can accelerate leaf pumping And grow rapidly