花生品种与氮钾施用量正交试验研究

影响花生荚果产量的因素很多，为了探讨花生品种和氮钾因素的最优配比，选择品种、施钾量和施氮量3个因素进行正交试验研究。结果表明：采用合油77-4品种、施用尿素75kg／hm2、氯化钾150kg／hm2的产量最高，纯收益最多，成本收益率也最高。增施氮肥，株高增加，侧枝增长，结果枝数减少，500g果数增加，产量下降；同时成本增加，纯收益减少，成本收益率下降。在施用氯化钾75～225kg/hm2的范围内，施钾量的增产、增收效果不显著。

Effects of Nitrogen,Phosphorus and Potassium Application on Growth and Dry Matter Accumulation in Mulberry

In this paper, the effect of different fertilizer treatments on the main indexes of growth and development and dry matter accumulation of perennial mulberry, which is cut and pruned in summer, were studied with ‘3414’ field experiment design. The results showed that N, P, and K at proper amounts could promote mulberry growth and development, improve its dry matter content, increase its dry matter accumulation. The effects of N, P, K on leaf yield per plant were respectively expressed as follows： N2 N3 N1 N0 , P2 P1 P3 P0 , K2 K1 K3 K0 . It can be concluded that the recommended fertilizer amounts of dry matter accumulations in mulberry leaf were 694.36 kg/hm2 of N, 198.15 kg/hm2 of P, and 274.26 kg/hm2 of K and the dry matter achieved the maximum at 8 045.04 kg/hm2 . The recommended fertilizer amounts of accumulated dry matter in branch were 1 000.05 kg/hm2 of N, 242.04 kg/hm2 of P, and 218.01 kg/hm 2 of K, and the dry matter achieved the maximum at 5 969.05 kg/hm2 . The recommended fertilizer amount in young shoots were 883.76 kg/hm2 of N, 204.48 kg/hm2 of P and 426.59 kg/hm2 of K and dry matter achieved the maximum at 1 410.24 kg/hm2 . This paper could provide reference for the construction of highly-qualified mulberry field in Sichuan hilly area.

Evolution of Nitrogen, Phosphorus and Potassium Fertilizer Application Rates in Cotton Fields and Its Influences on Cotton Yield in the Yangtze River Valley

[Objective] The historical evolution pattern of nitrogen （N）, phosphorus （P） and potassium （K） fertilizer application rate and its effects on lint cotton yield were explored to provide the theoretical basis for reasonable fertilizer management strate-gy in the cotton planting region of the Yangtze River Val ey. [Method] GGE biplot analysis method was adopted to analyze the correlation among N, P and K fertilizer application rate and lint cotton yield with the dataset of national cotton regional trials of the Yangtze River Val ey during 1991-2013. The linear and nonlinear regression analysis method was used to reveal the evolution of the fertilizer applying patterns, and analyze the effects of N, P, K application rates on cotton lint yield. [Result] The application rates of N, P and K fertilizer presented highly significant positive corre-lation with lint cotton yield, among which the potassium fertilizer was the strongest relative factor with lint cotton yield, fol owed by phosphorus fertilizer, while nitrogen fertilizer was the weakest factor. The application rate of nitrogen fertilizer was relat-ed with the test year in the pattern of a quadratic function, while phosphate and potassium had progressive increase linear relation with the test year in the cotton planting region of the Yangtze River Val ey. Meanwhile, cotton lint yield was in re-sponse to nitrogen fertilizer content increase with a quadratic parabola function, and increased with the applying phosphate fertilizer and potassium fertilizer content with linearly increasing function. [Conclusion] The increasing application amount of N, P and K fertilizer was general y beneficial to cotton yield improvements, however, ex-orbitant applying nitrogen fertilizer was unfavorable for cotton production, and a reasonable mixture formula of N, P and K fertilizer was better in terms of cotton yield-increasing effect.