主要蔬菜作物之養分吸收及施肥效應　Ⅱ韮菜對不同型態氮肥之效應及所施氮肥之消長

A Study on Nutrient Uptake and Fertilizer Response of Vegetables Ⅱ. Response of Chinese Leek to Different Source of Nitrogen Fertilizer

連深(Shen Lian) ； 吳啓東(Chi-Tong Wu)

《中華農業研究》 26卷3期 (1977/09) Pp. 195-203

https://doi.org/10.29951/JARC.197709.0004

摘要

爲探討若韮菜對不同形態氮肥之效應，及所施氮肥在土壤中之消長，於彰化縣田尾鄉舉辦田間試驗。自韮菜定植起一年間之試驗結果如下。
1．韮菜之氮肥效應全年高達1,500公斤／公頃氮素，但如按生長季節調節施肥，則以氮素約800公斤／公頃即可達到最高收量。其全年各生長期之氮肥適量如下：
方程式略。
2．就各種氮肥之肥效而言，尿素顯然優於硫酸錏，而SCU（TVA製，含氮34.8%及38.4%者）則與尿素相當。太試驗中SCU分施僅7次，尿素和硫酸錏則多達25次。每次施肥均掘淺溝，施用後並需要覆土，可見SCU節省施肥勞力之功效非常顯著。
3．就多氮肥區（氮1,545公斤／公頃）所施氮肥之消長與無氮區比較而言，其爲韮菜所吸收者僅約14%，以硝酸殘留於0-15公分及15-30公分各土層者各約17及5%，30公分以下之土層則甚少有硝酸態氮之殘留，顯示約有三分之二之氮肥係因脫氮作用或被灌溉水淋洗流失。韮菜氮肥用量如能依照本試驗結果所示按生長季節調節，當可提高其吸收率，因而可節省服料用量。

並列摘要

To study the nutrient uptake of Chinese leek, a vegetable commonly fertilized with extraordinarily large amounts of nitrogen (1,000-2,000 kg/ha), while examining the relative eicffiencies of different sources of nitrogen including the slow-release type and the balance of nitrogen applied to the soil, a field experiment was conducted.
1．The nitrogen response of Chinese leek was so large that the leaf yield increased with the rate of nitrogen up to 1,500 kg/ha for the first year, however the optimum rate was about 800 kg/ha, if the applications were regulated according to the actual requirements of individual growth seasons. The optimum rates of nitrogen for various growth stages in the whole year were as follows:
The equation is abbreviated.
2. As for the relative efficiencies of different source of nitrogen, urea was superior to ammonium sulfate. On the other hand, the effect of sulfur coated urea (made by TVA, U. S. A. N 34.8% and N 38.4%, respectively for the former three fourth of application and the remainder) applied in 7 splits corresponded to that of the urea applied in 25 splits, all the fertilizers were in corporated into surface soil on each split application, showing the labor saving effect of the former compared with the latter.
3. As a balance of the 1545 kg/ha nitrogen applied to the soil, it was estimated that only 14% of the nitrogen was absorbed by the crop, about 17 and 6% of the nitrogen remained respectively in the soil stratum of 0-15cm and 15-30cm as nitrate and the remaining two third of the nitrogen was lost either by denitrification or by leaching with rain or irrigation water.
The loss of nitrogen, however, would have been minimized, if the applications were regulated according to the actual requirements of individual growing seasons, as shown previously.