The Effect Of Organic Fertilizer On The Seasonal Inorganic Nitrogen Use Efficiency And The Aftereffect

In China, vegetable growing area has been increased rapidly in order to satisfy the demand for vegetable. In practice, large amount of manure and chemical fertilizer have been applied for vegetative soil by grower for high profit. Consequencely, low nitrogen use efficiency (NUE) (about 8%) was found for vegetable growth in previous study; meanwhile higher nitrate-N content is observed in the layer of soil profile below root zone than that of top soil. Those may be brought about by either high N content in soil, or large amount manure application. Thus major aim of this research was to explore the effects of manure application on NUE of chemical N by mean of 15N tracer. Tomato and green pepper were employed as indicate plants for the first and second growing season, repectively. The results demonstrated that:1) Combination of chemical fertilizer and manure could increase biomass, N accumulation amount, edible quality and yield of tomato compared with chemical fertilizer applied only did; The resdidual effects of manure was also noticed for the second growing season.2) The application of manure decreased N in plant devired from chemical fertilizer (NDF) for both growing seasons and dimished NUE.3) After the first growing season, higher nitate-N content in 0-60 cm of soil profile was caused by combination of chemical fertilizer and manure than that by chemical fertilizer. Further combination of chemical fertilizer also resulted in a relative increased nitrate-N content in 100-200 cm soil profile after the second growing season.