(25(1):64-72)STUDIES ON THE NUTRIENTS VARIATIONS IN GROWTH STAGE OF CORN AND ITS VALUE IN ECONOMIC ASPECTS

1. 為提供玉蜀黍合理栽培利用方法，自民國61年秋至63年春季二年間，先後在臺中霧峰及嘉義，以密植一疏株法進行玉蜀黍田間栽培試驗，並就疏株所得各期收穫物（I～Ⅲ期青草，IV期玉米）進行化學成份分析比較。 2. 各期所得試驗成績數值，概見於表一～表四。在62年春～63年春季本試驗所得結果，如表六。至於玉蜀黍生育中成份變化情形，如表七。 3. 試驗結果指出密植栽培可獲多收，增產營養成份50％以上，但密植亦可影響植物體木身生產能力。 4. 分期收穫成績顯示，玉蜀黍在生育二個月時，其成長異常迅速二故可考慮：(1)早收為青飼料用，以增加栽培次數而利土地週轉使用，或以(2)密植一疏株方式栽培，兼得青草及玉米飼料而提高單位面積收益。 5. 在本密植一疏株法試驗，由61年秋作預備試驗與63年春作加強試驗成績，尚無法看出若何施肥效應，原因何在，尚不得而知。 6. 由田間試驗觀察及所得試驗結果，發現充裕之水份供應及日照乃為王蜀黍栽培上重要因素，此生理上問題尚待今後詳細研究。 In order to offer an information concerning about the nutrients variations in growth stage of corn (Zea maize), more over, to present an advantageous cultivation accompanied with useful land utilization, studies were conducted in 1972 autumn~1974 spring. A Close-spacing and Thinning cultivation method was applied and four of periodical products in every crop were subjected to chemical analyses. The results of each crop were shown in Table 1~4. It was found that an extremely rapid growth of corn appeared two-month after germination and it was recognized that the maximum nutrients formation of corn was got in this period. With the Close-spacing and Thinning method, one could obtain about two folds production of protein and above one and a half production of other nutritive constitunents, including calories, when compared with ordinary cultivations. The details were shown in Table 6. The data of experiments showed valuable of Close-spacing and Thinning method, even though, unfavourable effects of Close-spacing were also observed, therefore, too tight Close-spacing is undesirable from the points of view, such as reduce in yield, needs of much seeds and labours, and so on. The moderate design for the Close-spacing seems to be that starting from 30×15 cm to 60×30 cm in row and space distances via once thinning process. At last, it should be emphasized that enough moisture contents of soil is the principal factor in corn cultivation, and it becomes more important for a Close-spacing plantation