土壤酸鹼度與雄穗抽出後乾旱對玉米生長與產量的影響

Growth and Yield Response of Maize (Zea mays) to Soil Acidity and Post-Tasseling Drought Stress

馬弗席(Nicholas Futhi Manana)

指導教授 ： 蔡秀隆 博士 ； 顏才博 博士

國立屏東科技大學/國際學院/熱帶農業暨國際合作系/碩士(2013年)

https://doi.org/10.6346/NPUST.2013.00123

摘要

玉米是世界第三大主要作物，僅次於小麥與水稻。近年來氣候變遷頻繁諸如乾旱、淹水，除此之外，耕地土壤亦逐漸酸化，造成作物巨大的損失。因此，研究調查土壤酸化與乾旱對穀類作物生產的衝擊是極其重要的。基此，本論文的主要目的在探討玉米在不同土壤水分與酸度的反應。糯玉米品種玉美珍種植在田間和塑膠棚內分別進行兩個期作的試驗，土壤水分的處理於雄穗抽出後執行包括80 %、65 %、50 %與30 %田間容水量等四個處理，土壤酸度於種植前調整土壤成為pH 4.0、pH 5.5、pH 6.0 與 pH 6.5等四個處理。玉米於雄穗抽出期土壤嚴重缺水造成葉片水分含量與光合作用速率下降，而葉片脯氨酸含量則顯著增加，抽絲期延遲並且使得玉米穀粒充實不良。試驗結果亦顯示生物質量、鮮穗產量、乾穀粒產量與產量構成成分均顯著減少。土壤水分65 %田間容水量的處理穫得最高的鮮穗產量（11.36 tons ha-1）和乾穀粒產量（3.76 tons ha-1），而土壤水分30 %田間容水量處理的鮮穗產量減少成6.31 tons ha-1、乾穀粒產量降低至1.64 tons ha-1。至於不同土壤酸度並未影響
抽絲期與葉片水分含量，然而土壤pH 4.0與6.5的處理會降低光合作用速率，進而減少產量與產量構成成分。低的土壤pH (4.0)處理於泡狀期亦造成葉片脯氨酸含量顯著增加。總而言之，土壤pH 5.5以及於雄穗抽出後土壤水分為65 %田間容水量最適合玉米生長與產量。

關鍵字

玉米 ； 土壤水分 ； 土壤酸度 ； 光合作用 ； 脯氨酸 ； 產量構成成分

並列摘要

Maize (Zea mays L.) is one of the most important crops for animal and human food and agro-industrial purposes worldwide. It is the third major cereal crop of worldwide economic importance after rice and wheat, respectively. Extreme weather events such as droughts and floods are becoming more frequent, resulting to huge crop losses. In addition, many other environmental concerns are emerging, such as degradation of arable lands in the form of soil acidity. Therefore, it is vital to investigate the impacts of soil pH and drought in relation to cereal production. Hence, the objective of this research is to investigate the response of maize to different soil moisture and soil pH levels. To achieve this objective, the effect of soil moisture and pH levels on the following parameters was investigated; tasseling-silking duration, yield and yield components, growth characteristics, photosynthesis rate, leaf relative water content and leaf proline content. The study was carried out in two environmental conditions, that is, the field (open environment) and pots in a plastic house (closed environment) during two different maize growing periods. Glutinous white maize (White pearl) was used as the test variety in all experiments. The experimental designs
employed were complete randomized design for field and factorial design for the plastic house. The different soil moisture levels used included: 80 % of field capacity (FC); 65 % FC; 50 % FC and 30 % FC. The pH levels were pH 4.0; pH 5.5; pH 6.0 and pH 6.5.The pH levels were only monitored in the pot experiment. Soil moisture treatment was started at tasseling stage, while, soil pH levels were adjusted before maize planting during soil preparation. The growth parameters assessed include, plant height, leaf number, green leaf area, above ground biomass and leaf chlorophyll content. The leaf chlorophyll content was determined using SPAD-502 meter. The yield components measured (per plant basis) include, ear fresh weight, ear dry weight, ear kernel number, ear kernel weight and 100 kernel weight. The results indicated that under severe water stress (30 % FC) after tasseling in maize, leaf relative water content decreased, and photosynthesis rate decreased as it was shown by the reduction in oxygen evolution obtained from the leaves. Leaf proline content significantly increased as a response to water shortage, and tasseling-silking interval increased from 5 to 9 days resulting in poor grain filling due to delayed silking stage. Results also showed a significant decrease in total above ground biomass, fresh ear yield, dry grain yield and the grain yield components. Furthermore, soil moisture level 65 % FC was to a large degree equal to 80 % FC level. The highest fresh ear and dry grain yields of 11.36 and 3.76 tons ha-1, respectively were obtained from 65 % soil moisture level. Lowest fresh ear and dry grain yield of 6.31 and 1.64 tons ha-1, respectively, were from 30 % soil moisture level. On another note, soil pH levels did not affect tasseling-silking interval and leaf relative water content. Low soil pH 4.0 increased the leaf proline content at blister stage. Overall, findings of this research suggest that soil moisture of 65 % FC at tasseling throughout the reproductive stage combined with a soil pH of 5.5 is optimal for maize growth and yield.

並列關鍵字

Zea mays ； soil moisture ； soil pH levels ； photosynthesis ； proline ； yield component

參考文獻

Yang, C. M., M. J. Fan, and W. M. Hsiang. 1993. Growth and Yield Response of Maize (Zea mays L.) to Soil Water Deficits. II. Effects of Water Deficit Timing and Strength. Journal of Agriculture Research 42(2):173-186.

Andersen, M. N., F. Ash, C. R. Jensen, H. Naested, V. O. Mogensen, and K. E. Koch. 2002. Soluble Invertase Expression is an Early Target of Drought Stress during the Critical, Abortion-Sensitive Phase of Young Ovary Development in Maize. Plant Physiology 130:591-604.

Anderson, S. R., M .J. Lauer, J. B. Schoper, and R. M. Shibles. 2004. Pollination Timing Effects on Kernel Set and Silk Receptivity in Four Maize Hybrids. Crop Science 44:464-473.

ASTM Standards D422. 2007. Standard Test Methods for Particle Size Analysis. Retrieved on October 29, 2011, from the World Wide Web: http://www.astm.org.

Bai, L. P., F. G. Sui, T. D. Ge, Z. H. Sun, Y. Y. Lu, and G. S. Zhou. 2006. Effect of Soil Drought Stress on Leaf Water Status, Membrane Permeability and Enzymatic Antioxidant System of Maize. Pedosphere 16(3):326-332.