稻田轉作玉米長期不整地栽培對土壤肥力及玉米產量之影響

The Influnce of Long-term Non-tillage Cultivation on Soil Fertility and Corn Yield on Paddy Field

10.6959/RBTDAIS.199406.0025

張茂盛(Mor-Shen Chang)；周泰鈞(Tai-Chun Chou)

玉米 ； 整地 ； 不整地 ； 土壤肥力 ； 氮素效應 ； Corn ； Tillage ； Non-tillage ； Soil fertility ； Nitrogen effect

臺東區農業改良場研究彙報

5輯（1994 / 06 / 01）

25 - 36

繁體中文

為探討稻田轉作玉米時在長期不整地之耕作下，對土壤肥力之變化及玉米產量之影響，提供推行稻田轉作時土壤及肥培管理之參考。從1987年春作起至1991年春作止，共五年九作，在本場試驗地（麥氏座標豐里圖089166）進行。試驗地土壤屬片岩沖積土，光復系坋質壤土，土壤深度50公分左右，排水不完全，土壤能限分類為Le。試驗結果顯示土壤pH值不論整地與否均有下降趨勢，尤以氮素施用量高之處理其下降幅度越大；土壤有機質含量略有增高，土壤磷含量有累積現象；而在鉀、鈣、鎂含量則有下降趨勢，且整地者略高於不整地；土壤總體密度變化不大。玉米子實產量1987年春作不整地比整地增產14%；1987年秋作後則以整地處理為高。但不論整地與否，除1989年及1990年秋裡作玉米和1991年春作玉米因受不正常氣候影響外，在正常期作及氣候條件下，如1988、1989及1990年春作及1988年秋作、1990年秋裡作等似有因連作之關係而使產量下降之趨勢。然而1989年及1990年原定秋作玉米因受颱風豪雨之影響，改為秋裡作，其產量又回升至6,000kg/ha左右，且以不整地之處理為高。1991年春作則長期乾旱，在適當之灌溉下，產量亦達7,000kg/ha左右，且以不整地之處理為高。氮素用量對玉米產量之效果，因年度及期作不同而異。整地處理，春作、秋作及秋裡作玉米，氮素適用量在120－180kg/ha之間，春作不整地者在180－240kg/ha之間，秋作及秋裡作不整地處理者在180kg/ha為適量，整體而言以180kg/ha為合理施用量。

The changes of soil fertilily and corn yield under long-term non-tillage continuous corn cultivation on paddy field had been studied for 5 years initiated from 1987. The purpose of this study was to compare the effect of non-tillage and conventional tillage of corn on certain chemical and physical properties of the soil and corn yield. A field experiment was initiated in 1987, two crops each year on schist alluvial soil, moderately shallow (＞60 cm), imperfect drainage, silt loam (F. C. C. Le) at Taitung. After five years experiment, the soil pH was declined from 7.2 to 6.7 in both tillage and non-tillage treatments, especially, it was lowered by increasing N rates. The soil organic matter content was higher than that was beginning. Available had accumulated from 326Kg/ha to 503-577Kg/ha. Available CaO and MgO content trented to lower from beginning under both tillage treatments. The change of soil bulk density in both treatments were the same as beginning.Corn yield of the first crop (Spring corn) from non-tillage increased by 14% as comparison to conventional tillage in 1987, while afterward higher inconventional tillage. Most of seasonal crops, the yields seemed to decread due to continous cultivation except fall/winter crop in 1989 and 1990 and spring crop in 1991.Corn yields in fall/winter crop of 1989 and 1990 and spring crop of 1991 had risen to 6 t/ha due to reasonable irrigation under arid condition which were higher in non-tillage treatments. The effects of nitrogen rates on corn yields were diverse from years and cropping seasons. According to the result obtained from this experiment, it is suggested that 120~180Kg N/ha was better for conventional tillage treatment in spring, fall and fall/winter corn, and 180~240 Kg N/ha was better for non-tillage treatment in spring corn. In generally, 180 Kg N/ha was reasonable for corn yields in all seasons.