温州蜜柑施氮效应的研究

STUDY ON THE EFFECT OF NITROGEN APPLICATION ON WENZHOU MANDARIN

不同氮素用量对柑桔产量的影响具有极显著差异,经方差分析,中肥力土壤,F值为13.7;低肥力土壤,F值为20.22,均达到极显著水准。经应用3次多项式分析,柑桔产量与氮素用量方程:y=b_0+b_1x+b_2x^2+b_3x^3。中肥力土壤,经济合理施氮量1.18kg/株,对应产量40.46kg/株,低肥力土壤,经济合理施氮量1.03kg/株,对应产量35.91kg/株,均相当最高产量施氮量的999.7g·kg^(-1)。 经对1987～1988年2年测定结果分析,在每株施氮1.15kg范围内,施氮量与叶片含氮量、9月份叶片含氮量与翌年产量:施氮量与土壤水解氮含量均呈极显著或显著相关。土壤水解氮的增加,影响到枝条、总叶片数增加和枝条增粗,柑桔产量相应增加。超过上述用量则表现减产。

The result of this study has shown that the different N fertilizer application amount has very significant different effect on the yield. Through variance analysis, very significant level has been achieved when soil with medium level fertility has F value 13.7 and soil with low level fertility has F value 20.22. The relationship between the yield and the N fertilizer application amount is as shown in the following equation. Y = b_0 +b_1x+ b_2x^2+b_3x^3 In soil with medium level fertility, 1.18 kg of N fertilizer per plant economically and rationally was applied producing correspondingly a yield of 40.46kg per plant and that applied in soil with low level fertility was 1.03kg per plant giving a corresponding yield of 35.9lkg per plant. Both were equivalent to 999.7gkg^(-1)of the amount applied to the plants giving the highest yield. Measurements made in two years ( 1987-1988 ) have proved that the application amount per plant within the range of 1.15kg, there was a very significant or significant correlation between the N fertilizer application amount and the N content in leaf, the N content in leaf in September and the yield in the following year and the N fertilizer application amount and hydrolitic nitron in soil. The increase in hydro-litic nitrogen in soil resulted in the increase in number of shoots and leaves and the enlargement of the shoots hence the yield increase. Over the above-mentioned amount resulted in yield decrease.