頁籤選單縮合
題 名 | 作物數種生理作用與葉片水分潛勢、土壤水分應力及生長期之關係研究 |
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作 者 | 陳清義; 張杏生; | 書刊名 | 中華農學會報 |
卷 期 | 88 1974.12[民63.12] |
頁 次 | 頁1-16 |
關鍵詞 | 土壤水分; 水分潛勢; 生長期; 生理作用; 作物; 葉片; 數種; |
語 文 | 中文(Chinese) |
中文摘要 | 為瞭解本省主要旱作物--玉米、高粱、大豆、落花生及甘藷--之生理作用與葉片水分潛勢、土壤水分及栽植期,曾以素燒給水式自動灌水裝置,於不同時期栽植供試作物後,將其土壤水分調整為不同狀態,並以色素法(Dye method)測定葉片水分潛勢及以乾重測定法、CO2定量法(圖1)、碘試法測定光合作用外,另以氣孔開度自記計測定氣孔開度,獲得部分結果,茲摘要如下。 (一) 葉片水分潛勢在晝間有明顯的增減現象,惟其變化情形及呈現最低值的時間與土壤含水量有關,?在高濕土壤下生長者,其葉片水分潛勢之變化程度較小,反之?變化較著(圖2、3)。 (二)葉片水分潛勢對土壤水分多寡所呈現之反應因生長期不同而異,?在生長初期,不同土水區間之差異較小,但至生長後期時,其差異顯著化,且此時之葉片水分潛勢較生長初期之場合約減低-2~-4 bars (圖4)。 (三)以甘藷為材料所得生長初期之光合速率與土壤水分不顯著,而至生長中期後,兩者之關係顯著化,且其適宜土壤水分範圍亦隨著生長而發生變化,惟至成熟期時,不同土水區間光合速率之差異復趨於減少(圖6、7、13)。又本實驗所得光合作用適宜的土壤水分為容水量之60%附近,且該區之葉片水分潛勢在六種不同土壤水分區中為最高(圖5)。又在光度及溫度一定的人工生長室內,甘藷之外表光合作用仍然有明顯的日變化(圖15)。 (四)大豆光合作用適宜土壤水分較玉米、高粱及甘藷為低,?約為容水量之40%~60%,表示大豆不喜高濕。至於落花生之光合作用,除土壤水分40%區者,其在生長後期之光合能力特別旺盛外,其他時期尚未見有明顯差異(圖11)。又大豆及落花生全生長期之光合曲線均呈現類似生長曲線的S型(圖11、12)。 (五) 高粱之光合能力與土壤水分之關係在生長初期尚無明顯差異,且此時光合能力最弱,但至抽穗期時,光合能力顯著增加,而不同土水區間之差異亦極明顯(圖11)。本實驗所得高粱光合作用適宜的土壤水分約為容水量之50%~70%。 (六)玉米之光合作用亦隨著生長而增強,但其與土壤水分之關係乃因栽植期不同而異,?春植玉米不同土壤水分間之差異始終不顯著(圖9),但冬植時則有不同土水區間之差異,而以容水量50%~60%之光合能力最強(圖8)。此種差異可能為栽植期間之氣候條件不同所致。 (七)大豆中興一號在不同土壤水分下之光合能力有明顯差異,?其高?出現於容水量之60%處,但中興2號在不同土壤水分下之光合能力幾乎相同,表示中興2號對土壤水分多寡之適應性較大(圖14)。 (八)這些結果表示供試作物之光合作用均以生長初期最小,而生長中、後期較強,惟其能力仍與土壤水分、品種及栽植期有關係。 (九)大豆之氣孔開度與葉片水分潛勢有負關係,而氣孔開度之變化先於葉片水分潛勢之變化,故葉片水分潛勢在晝間之最低值出現於氣孔最大開度之約1小時後(圖16)。 (十)甘藷之氣孔最大開度出現於容水量之60%附近(圖17),此與該作物光合能力最高的土壤水分域一致。 (十一)大豆生長開始減退之土壤水分高於水分當量,表示在極低的水分應力下生長已受抑制(圖18)。 (十二)根據本實驗結果可知本省數種旱作物之諸生理作用,均在多於水分當量的土壤水分下受到抑制,暗示本省的土壤有效水分似不宜再以水分當量pF.2.7或pF3.0為其上限。 |
英文摘要 | In order to apprehend the relations of the physiological functions of the main landcrops, such as corn, kuoliang, soybean, peanut and sweet potato, cultivated in Taiwan to the leaf water potential (LWP), soil moisture and growth stage, the comprehensive experiments with the test plants cultivated at different stage under autoirrigation in different soil moisture conditions were separatively proceeded by means of dye method for LWP, dry weight determination, quantitative supply of carbon dioxide (Fig. 1) and iodine test for photosynthesis, and the electric autorecording apparatus for stomatal aperture. The partial results obtained are summarized as follows: 1. In the daytime, there was a significant alteration of increase and decrease in LWP of crops tested, but the changes of LWP and the time at which the minimum value appeared were relative to the soil moisture i.e. a slight change in LWP occurred as the crop grew in higher moist soil, and as the soil became dry, on the contraty, it changed markedly (Fig. 2,3). 2. In addition, the LWP responded to the quantity of soil moisture was quite different with different growth stages. A trifling difference happened at the early growth stage of crops grew in different soil moisture areas, but the difference signalized at the later stage of growth and the LWP value determined was -2 to -4 bars less than that at the early stage of growth (Fig. 4). 3. In the case of sweet potato, the relation of photosynthesis rate (PR) to the soil moisture was not significant at the early stage of growth, but it became signal as the crop plants reached their middle stage of growth. Furthermore, the scope of the optimum soil moisture for photosynthesis changed with the growth of plants cultivated. And, the difference in PR of plants grew in different soil moisture areas again tended to diminution at the mature stage of growth (Fig. 6, 7, 13). A result obtained from this experiment showed that the optimum soil moisture for photosynthesis of sweet potato was near 60% of the maximum water holding capacity (use the percent only in the statement below), and the LWP of sweet potato grew in this area got the highest value determined among the six different soil moisture areas. In addition, the apparent photosynthesis of sweet potato plants grew in the growth chamber showed its daily varietions as well (Fig. 15). 4. The optimum soil moisture for photosynthesis of soybean was rather low than that for corn, kuoliang and sweet potato. It was of 40% to 60% as appeared. It showed that the higher moist condition was not to its liking. In the case of peanut, there was no significant difference in photosynthetic capacity (PC) observed in any stage of growth (Fig. 11) with the exception of the later growth stage of crop cultivated in the soil moisture area of 40%. However, the expression of PC in graph for both crops mentioned above was a sigmoid curve which was similar to the characteristic form of growth curve (Fig. 11, 12). 5. The relationship between the PC of kuoliang and the soil moisture had no significant difference at the early growth stage of crops grew in different soil moisture areas, and the PC was weakest at this period of time. But, it increased apparently as the crops reached their earing stage, and the difference in PC of plants among the different soil moisture areas also became quite significant. The optimum soil moisture for photosynthesis of kuoliang was likely of 50% to 70%. 6. Also, the PC increased with the growth of plant in corn crop, but the relation of photosynthesis to the soil moisture would be varied with the different cultivation stage, i.e. in the spring crop of corn, the difference in PR of crop plants grew in different soil moisture areas was not signal at all (Fig. 9), but it occurred promptly in the winter crop, and the PC of corn plants grew in the soil moisture of 50% and 60% was experimently the strongest (Fig. 8). This resulted probably from the different climatic conditions of two cultivation stages. 7. The PC of soybean plants of variety Chung Hsing No. 1 grew under the different soil moisture conditions was significantly diffenent from one area to another. The peak appeared for the crop grew in the soil moisture area of 60%. But, the PC in variety Chung Hsing No. 2 of soybean was the same in general among the different soil moisture areas. It showed that the adaptation of plants of the latter variety to the quantity of soil moisture was rather great than that of the former variety (Fig. 14). 8. All the results mentioned above showed the net photosynthesis of each crop tested was minimum at the early stage of growth. However, the PC was relative to the soil moisture, variety and cultivation stage. 9. There was a significant negative correlation existed between the stomatal aperture of soybean and its LWP. And, the stomatal aperture changed prior to the changes of LWP. So, the time at which the minimum value of LWP appeared was one hour later than the maximum stomatal aperture reached (Fig. 16). It showed that the diminution of LWP was closely relative to the stomatal aperture. 10. In the case of sweet potato, the maximum stomatal aperture reached for those plants grew in the soil moisture area of 60% (Fig. 17). This agreed about the soil moisture for the maximum photosynthetic capacity of the same crop. 11. The soil moisture started the diminution of growth in length of soybean was greater than the moisture equivalent. It showed that the growth of soybean plants was already inhibited under the condition in which the soil moisture stress was extremely low (Fig. 18). 12. According to the experimental results obtained, it was known that some physiological functions of the landcrops cultivated in Taiwan were totally inhibited by the soil moisture which was greater than the moisture equivalent. It implies that the expressions of pH 2.7 (moisture equivalent) or pF 3.0-3.2 (field capacity of the drought areas in the United States) were undue to be used again as the upper limit of available water of soil in Taiwan. |
本系統中英文摘要資訊取自各篇刊載內容。