Studies on Cultural Techniques of Corn Production in Paddies with Particular Reference to Nitrogen Application

• Main Authors: Wang,Chong-Ho, 王鐘和
• Other Authors: Houng,Kun-Huang
• Format: Others
• Language: zh-TW
• Published: 1993
• Online Access: http://ndltd.ncl.edu.tw/handle/60808036400377119432

博士 === 國立臺灣大學 === 農業化學系 === 81 === The purpose of this study was to investigate cultural techniques related to the management of nitrogen nutrition in corn production under the cropping system developed in drained paddies. Theeffect of plant growth regulator, ethephon, on plant growth was also studied. The results were summarized as follows: 1. The percentages against totals of the nitrogen uptake and dry matter production by knee-high stage were low (12.8% and 5.6% respectively). Dry matter accumulation increased rapidly after knee-high stage,thus a higher rate of nitrogensupply was required after heading. The nitrogen top- dressing at tasseling had favorable effects on both the efficiency of fertilizer-N uptake and that of the N absorbed to produce yield ( 54-60% and 68-78%, respectively), and about 10-20% increase in yield was observed. The top-dressing of nitrogen at 2 weeks after silking, however, was unfavorable for grain production because of the negative effect on the harvest index of the crop. Thus, the conventional method of fertilization with one half of the nitrogen as basal and another half as top-dressing hat knee-high stage, need to be adjusted. It is recommended that only one-third to one-fifth of the nitrogen is applied as basal, while the remainder nitrogen divided into two splits are applied as top-dressing at knee- high and that at tasseling stage. The top-dressing of nitrogen at tasseling stage significantly increased the number and weight of kernels in the upper portion of the ear. Though the rate of increase in the weight of kernel was slower in the plant with the nitrogen splitly applied up to the stage of tasseling than the plant with the nitrogen application concentrated in the earlier stages, the duration of increase was longer, which resulted in