主要作物施肥適量試驗 三、黃麻施肥適量試驗

Abstract

Owing to the bulk production of rice and sugar in Taiwan, a great quantity of jute fiber is annually needed for packing these goods. In recent years, the cultivation area of jute, through our government's effort, has been extended from 11,000 to 16,000 hectares. Available data concerning the rational application of N-P-K fertilizer for jute in different locations are insufficient for present use. That was why this experiment was conducted in the places of Chunan, Taichung, Chiayi, Tainan, and Taitung, from 1951 to 1953. In these tests nitrogen as ammonium sulfate was varied on different plots in amounts of none, 40, 80, 120, 240 kilograms per hectare, the P203 as calcium superphosphate in the amounts of 0, 40, 80, and 120 kilograms per hectare, and the K2O as potassium sulfate in the amounts of 0, 60, 120, 180, and 240 kilograms per hectare. There were 16 treatments in a systematically arranged block with two replications. Following are the summaries of this experimental results: Ⅰ. Effect of N-F-K fertilizer on the growing state of jute It was observed that nitrogen or potash would significantly increase the height of whole plant and enlarge the diameter of stem, but the potash would cause a much better effect on the available height of jute (that is the height from the surface of ground to the first leaf of the stem) than did the nitrogen. There were no striking effect on the growing state of jute from phosphatic fertilization. Ⅱ. Effect of N-P-K fertilization on yield of crude jute fiber It was found that increases in yields were obtained with insreasing amounts of nitrogen applied in the fertilizer up to 80 kilograms per hectare, in 4 of 5 experiments. Further increase in yield were obtained from use of 240 kilograms of nitrogen in 2 of 5 experiments. Results of the phosphorus rates test were striking in showing the lack of response of jute to high rates of a application of P2O5. Of the 5 tests only one showed a response to more than 40 to 80 kilograms of P2O applied per hectare. Response of jute to potash is something similar to nitrogen, but it should be noted that potash would cause higher increase in yield of crude jute fiber than that of green stem as compared with the checks respectively. Ⅲ. Relationship between the yield crude jute fiber and N:K (K2O) in the fertilizer The exact ratio of N:K (K2O) in fertilizer in relation to the yield of crude jute fiber has not been found yet. However, the smaller the ratio of N:K, the higher the increase in yield of crude jute fiber was found in the places of Chunan, Chiayi, and Taitung while the reverse was something evident in the place of Taichung and Tainan. Ⅳ. A recommandation concerning the optimum fertilizer ratio for jute According to the result of this experiment, a recomandation concerning the optimum fertilizer ratio for jute in different locations of this province has been suggested as follows: (The form abridges) Ⅴ. Based on the farmers' profitable point of view, a suggestion concerning the economical fertilizer ratio for jute has also been submitted.