EFFECTS OF DIFFERENT NITROGEN LEVEL ON THE NODULATION,NITROGEN SUPPLY AND YIELD OF PEANUTS

The results obtained from using different nitrogen level in field expriments were as follows: Nodulation and development of peanuts were inhibited by inorganic nitrogen fertilizer. When applying 2. 5 kg net nitrogen per mu, the number and dry weight of nodules per peanut plant were both notably inhibited (P< 0. 05), and nodulation date was later than that of untreated control. The nitrogen supply to the plants varied with different nitrogen levels. Before the podding slage .such as the seedling stage and pod-pin stage, the nitrogen content of plant body was increased by increasing the amount of applied nitrogen fertilizer. After the podding stage, that is, the maturation stage, the nitrogen content of the plant was increased as the number and dry weight of nodules per plant increased. Nitrogen content of plant was highest in the podding stage, but with excessive nitrogen fertilizer, the nitrogen content of the plant was highest in the pod-pin stage. The yield of peanuts was highest in the N2.5 treament group and lowest in the N10.