[Effects of potash fertilizer on nutrient absorption by peanut and its yield and benefit]

Studies in Jianghuai hilly region showed that at definite N and P levels, applying potash fertilizer could regulate the transportation and distribution of nutrients in peanut plants, accelerate their absorption of N, P and K, increase the dry matter accumulation in their reproductive organs, and increase their yield, quality, and disease resistance. For each 100 kg pod products, the absorption of N, P and K was 3.08-5.35 kg, 0.6-1.2 kg and 3.45-6.66 kg, respectively. The K absorption was the biggest, and it was accumulated mainly in nutritive organs. The absorbed N and P were mainly accumulated in pods and other reproductive organs. The contents of N, P and K in all organs were increased with increasing potassium levels, and the amount of increased K was the biggest. The yield and economic benefit were the highest when the amount of applied potassium reached to 150-180 kg.hm-2 and N:P:K = 2:1:2. The highest pod yield was 5425.5 kg.hm-2, the highest benefit was 13,878.7 yuan.hm-2, and the ratio of output/input reached 6.75:1. The yield and economic benefit of peanut were decreased obviously when the amount of applied potassium was over 225 kg.hm-2. Thus, the prescription of N150, P75 and K150 was recommended for the balance fertilization of peanut production in this region.