由于棚室蔬菜需肥量大，冬春季节封闭严，且气温低，光照弱，蔬菜体内硝酸还原酶活性低，容易积累硝酸盐。通过科学追施肥料减少蔬菜中硝酸盐的积累，是生产无公害蔬菜的关键。一、不宜施用的化肥１．硝态氮肥。如硝酸铵、硝酸磷钾肥。硝酸磷肥、硝酸钾肥以及含硝态氮的复合肥 Due to the large amount of greenhouse vegetable fertilizer required, the winter and spring closed strictly, and the temperature is low, the light is weak, and the nitrate reductase activity in vegetables is low, which tends to accumulate nitrate. Through the scientific pursuit of fertilizer to reduce the accumulation of nitrate in vegetables, is the key to producing pollution-free vegetables. First, the fertilizer should not be used 1. Nitrate nitrogen fertilizer. Such as ammonium nitrate, phosphorus, potassium nitrate. Nitrophosphate, Potassium Nitrate, and Compound Fertilizers Containing Nitrogen Nitrogen