養液氯及鉀濃度對水耕小白菜生長、硝酸態氮及其他養分含量之影響

Effects of Concentration of Chloride and Potassium in Nutrient Solution on the Growth, Nitrate and Other Nutrients' Content of Pak - Chio in Hydroponic Cultivation

黃裕銘(Yuh Ming Huang) ； 陳建中(Chang Chung Chen)

《土壤與環境》 6卷2期 (2003/06) Pp. 87-95

https://doi.org/10.30058/SE.200306.0005

摘要

蔬菜硝酸態氮含量受許多關注，有些研究指出氯離子及鉀離子在養液中濃度提高能降低植體中硝酸態氮含量，有必要探討其綜合效應。本研究以吳和王水耕液養液(Tnchu)為基礎並提高養液鉀濃度為氮之1.5倍，然後降低0.5度(T0.5cl)或提高0.5倍(T1.5cl)養液氯離子濃度，或鉀離子為氮之兩倍及氯提高0.5倍(T2k1.5cl)，另T1.5cl處理養液配方夜間養液扣掉硝酸態氮(T1.5cl-NO3)或夜間只提供去離子水(T1.5CIDW)等共六種處理。小白菜(Brassica Chinensis L.三鳳)種子用TNCHU養液育苗至三片葉後移植到處理養液培養三週後採收，秤鮮重及乾重並測定各種養分成分。本研究於溫室重複兩次式驗，各處理每衖做三重複，以完全逢機排列擺置。
結果顯示當養液中鉀濃度為氮濃度1.5倍時降低氯離子濃度(T0.5cl)對小白菜之產量及養分含量沒有渡顯差異，提高氯離子濃度(T1.5cl)則極顯著降低小白菜產量，同時顯著提砲植體中氯含量，也極顯著降低植體硝酸酸態氮含量。若於提高氯濃度同時將養液鉀濃度提高為氮濃度2.0倍(T2k1.5cl)，則小白菜產量極顯著的提高，高過TNCHU處理達極顯著水準。夜間養液不含硝酸態氮處理T1.5cl-NO3雖然植體硝酸態氮含量比TNCHU伱低了43-49%，但是鮮重降低約50%。夜間只用去離子水T1.5CIDW處理，鮮重極顯著低於TNCHU，但乾重差異已經不顯著，且植體硝酸態氮含量降低50-55%。T1.5CIDW處理養分含量除氯及有機氮(ON)含量外，其餘成分在六個處理中皆為最低或次低。結果顯示小白菜植體氯含量到2.42%~2.51%時北有氯毒害現象，而提高養液鉀濃度可以降低氯之毒害現象。夜間養液去除硝酸態氮加重氯離子毒害作用並極顯著降低植體磷、鉀、鈣及鎂含量。夜間以去離子水取代養液，則植體磷、鉀、鈣及鎂含量分別降低41、48、27及55%。

關鍵字

硝酸態氮 ； 氯離子 ； 鉀離子 ； 小白菜

並列摘要

The nitrate content in vegetables has been concerned in recent years. A lot of papers focused on the effects of concentrations of chloride and potassium in medium on decreasing the nitrate content in vegetables. Their combined effects were carried out in this study by using Pak-chio (Brassica Chinensis L. Sanfong). The main formula of hydroponic solution was adopted from Wu and Wong (1995), TNCHU, and increased the potassium concentration to 1.5 times of nitrogen concentration. Then decreased 50% of chloride concentration (T0.5cl) and increased 50% of chloride concentration (T1.5cl), and the nitrate was removed (T1.5cl-NO3) or deionized water was used instead of nutrient solution (T1.5CIDW) during the night. In treatment T2k1.5cl, the concentration of potassium was doubled as the concentration of nitrogen. Six treatments were conducted twice in green house with three replications and completely random design. Results showed that comparing to treatment TNCHU, decreasing 50% of chloride concentration in nutrient solution, T0.5cl, did not have significant effect on the fresh and dry weight and all contents of nutrient of Pak-chio. Increasing 50% of chloride (T1.5cl) highly significantly reduced the fresh and dry weight and highly significantly increased chloride content, although it highly significantly reduced nitrate content. With the same formula except removed nitrate in night solution, T1.5cl-NO3, the fresh and dry weight were the lowest among all treatments, although the nitrate content in plant reduced 43-49%, compared to TNCHU. While using deionized water instead of nutrient solution, T1.5CIDW, the fresh and dry weight were both highly significant higher than those of T1.5cl and T1.5cl-NO3 treatments. The nutrients’ content of plant tissue of T1.5CIDW were the lowest or the second lowest among all treatments, except contents of chloride and organic nitrogen. Results suggested that the toxicity of chloride shown up as the chloride content of Pak-chio reached 2.42%~2.51%, and the chloride toxicity could be reduced by raising concentration of potassium in nutrient solution. The contents of phosphorus, potassium, calcium, and magnesium of plant were highly significantly decreased with the removal of NO3-N from night solution. While the contents of phosphorus, potassium, calcium, and magnesium of plant decreased 41, 48, 27, and 55%, respectively, as deionized water used instead of nutrient solution.

並列關鍵字

Nitrate ； Chloride ； Potassium ； Pak-chio