頁籤選單縮合
題 名 | 利用葉片分析診斷茶樹需氮狀況(1)=Leaf Analysis as a Guide to Nitrogen Fertilization of Tea Bushes (1) |
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作 者 | 林家棻; | 書刊名 | 中華農學會報 |
卷 期 | 41 民52.03 |
頁 次 | 頁27-42 |
關鍵詞 | 葉片分析; 茶樹需氮; |
語 文 | 中文(Chinese) |
英文摘要 | Though the improvement of sampling technique and greater accurancy of laboratory chemical analysis made by previous investigators, the method of plant analysis has been widely used as a guide for crop fertilizations. This paper deals with the development of sampling technique in order to find out the applicability of leaf analysis as an estimation of nitrogen requirements of tea bushes followed by a preliminary leaf analysis survey to reveal nitrogen status of tea groves scattered in the northern part of Taiwan. Data from these studies suggested the following conclusions. Before using chemical leaf analysis for diagnostic purpose, it is essential to know the errors invloved in leaf sampling. Factors relating the precision of analytical method, the method of sampling, diural and seasonal changes in the major nutrient contents of leaves, positions of leaf upon the plant, degree of maturity, and the variation in the apparent sizes of leaves, have been studied. It showed that the second or third young leaves from the terminal, taken from a new tender shoot having one bud and three young leaves on it, was the most sensitive to reflect the nitrogen status of tea plant. If two leaves of average size were selected for each tree, it was found that leaf smple taken from 15 per cent of trees surveyed was able to minimize sampling error as indicated by the coefficient o variation. Leaf sample taken from May to mid-July, when the seasonal changes are slight, would be less variable, otherwise, it might be subject to large sampling error. For avoiding diural variation in leaf nitrogen, especially in sampling the third young leaves, samples should be taken before noon. With the above informaiton of leaf sampling, the applicability of leaf analysis as a guide to nitrogen fertilization of tea plant was confirmed with a field trial which was laid out in the design of randomized block with quadruplication. Nitrogen as ammonium sulphate was applied to different plots at the rates of 0, 30, 60, 90, and 120 kg/ha of nitrogen. All treatments received the same amount of P2O5 as superphosphate and K2O as muriate of potash at the rate of 40 kg/ha. Tea variety of Ying-tze-hong-shin of 12 years old was used in the experiment. Data from the results indicated that leaf-N concentration and the annual yield of eat leaves were increased in accompany with the increase in the rate of nitrogen applied. The correlation coefficients of leaf-N concentrations measured during successive growing periods to the annual yield of tea leaves were significant through t-tests. The leaf-N concentrations observed in summer season and associated with deficiency, sufficiency, and excess are tentatively established for the variety, Ying-tze-hong-shin. For investigating the nitrogen status of tea bushes in Taiwan, large number of leaf samples were taken separately from 145 demonstration plots with and without manuring in May, 1959. Data showed that the critical leaf nitrogen concentration for different varieties was 4.6% in the third young leaves for the variety Ching-shin-ta-pang, 3.6% for Huangkan, and 3.8% for miscellaneous varieties. Data also indicated that 87.5% of the total samples for Ching-shin-ta-pang, 71.4% for Huangkan and 44.4% for miscellaneous varieties were deficient in nitrogen. Taking the advantage of the percentage of sample leaf with less than 4.0% of N as an indication of deficient in nitrogen, the percentage of such samples to the total samples is 70.3% for Taipei, 91.7% for Taoyuan, 88.3% for Hsinchu, 45.5% for Yilan and 23.3% for Miaoli. It indicated that most of the tea groves in Taipei, Taoyuan, and Hsinchu might be more deficient in nitrogen than those in Yilan and Miaoli. Although the concentratin of leaf nitrogen has been found to be influenced by the climate, regions and the variety of tea plant, the results obtained from the above, at least, give the first clue as to applicability of leaf analysis to estimate nitrogen requirements of tea bushes and reveal the fact that the shortage of nitrogen is one of the most important factors limiting tea yield in Taiwan. |
本系統中英文摘要資訊取自各篇刊載內容。