Optimum Application Rate of Nitrogen in Summer Peanut in Southern Shandong Area

[Objectives]To study the effect of nitrogen (N) on the growth demand of summer peanuts under a certain level of phosphorus and potassium fertilizers, and to carry out experiments on nitrogen fertilizer control of summer peanuts. [Methods]Four treatments were set up in the experiment: no-nitrogen plot (N0P4K4), optimized nitrogen plot (N7P4K4), 70% optimized nitrogen plot (N5P4K4), 130% optimized nitrogen plot (N9P4K4), repeated 3 times, and arranged in random blocks. The area of the plot was 42 m2, ridges were set between the plots, and protective rows of more than 1 m were set around the experimental site. The types of fertilizers were urea, superphosphate, and imported potassium chloride, and the variety of peanuts was Linhua 5. Except for the level of fertilization, other agricultural operations were the same, and soil sampling tests, field records, and yield testing were carried out according to the requirements of the plan. [Results]On the basis of 60 kg/haof phosphorus and potassium fertilizer application, the optimum economical fertilizer application rate and the highest application rate of pure nitrogen were about 115.20 and 131.25 kg/ha, respectively. [Conclusions]This study is expected to provide a certain basis for the high-quality and high-yield summer peanuts in southern Shandong area.