甜玉米生育期間輻射利用效率變化之探討

Abstract

玉米提供許多國家飼料和工業產品的生產製造，更是某些貧窮地區主要的糧食、飼料、及健全營養之來源。全球暖化造成氣候顯著變遷，影響作物生長及產量。透過前人研究結果證實日照輻射量為影響生物量變化的重要因子，太陽輻射量下降顯著影響玉米所有生長階段的發育。輻射利用效率（Radiation use efficiency, RUE）用於量化太陽輻射與生物量之間關係，通常用於作物生長的分析和模式的建立。本研究使用2017年在臺灣中部種植的甜玉米（華珍Bright Jean和Honey 236）的生育資料和氣象資料進行研究。估計RUE的方法有很多種，本研究的RUE主要透過生育期間定期收穫的地上部乾物質與截至收穫時相應的累積截獲的光合有效輻射之間的線性關係斜率估計而得。甜玉米Bright Jean和Honey 236的RUE分別為1.30 g MJ^(-1)和0.91 g MJ^(-1)。RUE在甜玉米整個生育期不一致，因此探討甜玉米RUE不同的估計方法，觀察甜玉米全生育期RUE的變化。Bright Jean最大RUE為1.44 g MJ^(-1)，Honey 236最大RUE為1.03 g MJ^(-1)，皆出現在乳熟期，爾後RUE隨後下降。說明紀錄作物全生育時期資料的重要性，並提供估計RUE簡單又便利的方法，研究中動態的RUE變化可以應用在未來建立作物產量模式。以期在例行的玉米生育調查計畫中，能有更精確測值及新的研究領域。 Corn (Zea mays L.) is the major source of feed and industrial products in many countries, and providing nutrition in some poor areas. Global warming causes rapid changes in climate and affects crop growth and yield. The results of previous studies have confirmed that the amount of solar radiation is an important factor affecting the change of biomass, and the decrease of the amount of solar radiation significantly affects the development of all growth stages of corn. Radiation use efficiency (RUE) is used to quantify the relationship between solar radiation and biomass, and is often used for crop growth analysis and model establishment. This study was conducted using growth and meteorological data from sweet corn (Bright Jean and Honey 236) grown in central Taiwan in 2017. There are many methods for estimating RUE. The RUE in this study was primarily estimated from the slope of the linear relationship between aboveground dry matter during periodic harvests and the corresponding cumulative intercepted photosynthetically active radiation up to the time of harvest. The RUE of sweet corn Bright Jean and Honey 236 were 1.30 g MJ^(-1) and 0.91 g MJ^(-1), respectively. RUE was inconsistent throughout the growth stage of sweet corn. Therefore, different estimation methods of RUE of sweet corn were discussed, and the changes of RUE during the whole growth stage of sweet corn were observed. The maximum RUE of Bright Jean was 1.44 g MJ^(-1), and the maximum RUE of Honey 236 was 1.03 g MJ^(-1), both of which appeared at milk stage, and then the RUE decreased. Explains the importance of recording data throughout the growth stage of crops, and provides a simple and convenient method for estimating RUE. Dynamic RUE changes can be applied to establish crop yield patterns in the future. It is expected that there will be more accurate measurements and new research fields in the routine corn fertility survey plan.