常有菜农反映说随着保护地蔬菜种植年限的增加,虽然施入的肥料增多了,但蔬菜不仅没有长得更好,反而色淡叶小,表现出缺肥症状,且长势越来越差、病害越来越多,特别是生理性病害逐年加 Vegetable farmers often say that with the increase in the number of years of vegetable planting in protected areas, although the amount of manure applied has increased, the vegetables not only do not grow better, but they have fewer colors and leaves and show signs of lack of fertility and their growing status is getting worse. More and more diseases, especially physiological diseases increase year by year