Effects of nitrogen application on source of nitrogen accumulation and yields of different peanut cultivars

Effects of nitrogen application amounts on source of nitrogen accumulation and yields of two peanut cultivars were studied by using the method of pot culture and 15N tracer. The results indicate that dry matter weights of stem + leaf, peg + unfilled pod and root of the two cultivars are all increased under the higher nitrogen amounts. The pod yields of Huayu17 are increased along with nitrogen amount increases, while the pod yields of Baisha1016 are increased when nitrogen application amount is less than 90 kg/ha, the pod yield would decrease when the amount is larger than 135 kg/ha. These indicate the yield increasing effects of the nitrogen application are different. The nitrogen amount absorbed from soil and fixed from air are both improved along with the increases of nitrogen application amount, which shows that the increases of nitrogen application could enhance the nitrogen amount absorbed from soil and fixed from air by peanut plant. Proportions of nitrogen absorbed from soil, fertilizer and fixed from air by peanut are 41.85%-48.63%, 0%-13.93% and 41.25%-56.85% respectively. The proportion of nitrogen absorbed from the fertilizer is increased, while the fixed proportion is decreased along with the increases of nitrogen application amount.