| Abstract: In order to study the optimal application amount of nitrogen, phosphorus and potassium on shallot in Central and Southern Hebei, the experiment was conducted to investigate the effect of N, P and K fertilizers on the yield, soluble sugar and SPAD value of shallot by using 'Qingye No.1' as material, and adopting '3414' method with different ratios of N-P-K. The optimal fertilizer application amount of shallot in Central and Southern Hebei was obtained by using monadic quadratic and ternary quadratic functions of fertilizer effect. The results showed that the SPAD value and soluble solid content of medium level nitrogen fertilizer reached the maximum, which were 26.3 and 20.0%, respectively. The effect of increase yield of single fertilizer was nitrogen>phosphorus>potassium, and the ratio of inputto-output was phosphorus>nitrogen>potassium. When the application amounts of nitrogen, phosphorus and potassium were medium, the yield of shallot reached the best, which was 63 860.3 kg/hm2 . Under the experimental conditions, it was recommended that the optimal fertilization amount of shallot in
Central and Southern Hebei was 456.0 kg/hm2 of N, 158.3 kg/hm2
of P2O5 and 233.3 kg/hm2
of K2O. |