Abstract:

Vegetables with different root depth have different nutrient uptake characters. In this research, a field experiment with different cropping system, intercropping and monocropping, and different nitrogen fertilization was conducted to study the effect on temporal and spatial dynamic of soil nitrate, and the apparent loss of nitrogen. This study chose eggplant and green onion as experimental crops which as the deep and the shallow root vegetable respectively. The results showed that the soil nitrate accumulation and migration of the intercropping treatments were less than the monoculture under the fertilizer optimizing conditions. It showed that intercropping can prevent nitrate leaching effectively and reduce the amount of nitrate. Under the conditions of intercropping cultivation, fertilizer optimizing treatments reduce the soil nitrate content, especially in the deep soil layer. The nitrate content of the optimizing treatment was lower than the conventional fertilization significantly during the whole growing period. The nitrate accumulation of the fertilizer optimizing area was also lower than the normal one in the whole soil profile. The apparent loss of nitrogen can be reduced by using intercropping or fertilizer optimizing management.