著者

辻 藤吾

出版者

日本土壌肥料學會

雑誌

日本土壌肥料學雜誌 = Journal of the science of soil and manure, Japan (ISSN:00290610)

巻号頁・発行日

vol.71, no.4, pp.464-471, 2000-08-05

参考文献数

7

被引用文献数

1

---

Sulfur absorption and critical contents of sulfur in disordered rice plants during their initial growth were investigated. The results obtained were as follows; 1) The total sulfur content of rice shoots which were inhibited at the time of late planting by the application of a paste-like fertilizer showed 0.12% in dry matter. When this growth was recovered by using the same fertilizer as that used by a farmer, sulfur content was raised to as high as 0.28% in dry matter, together with a remarkable increase in dry matter. 2) A similar response was observed for the early planting of rice in a farmer's paddy with enhanced increments of total sulfur, from 0.09 to 0.40% in dry matter, by the application of magnesium sulfate, the major component of the commercial fertilizer. Also, dry matter increments were twice as high as those recovered by the surface drainage. 3) Surprisingly, the yellow stunting of the initial growth disorders were found by the incorporation of a chloride fertilizer into the plow layer as a basal. Such nutritional disorders were restricted during the tillering stages and the total sulfur content of the shoots decreased to as low as 0.13% in dry matter. However, the higher absorption of inorganic sulfate between the maximum tillering stage and young panicle formation period contributed greatly to the recovery of sulfur deficiency in the rice. 4) Total sulfur contents as well as N/S ratios were significantly correlated to the relative yields. These critical levels were 0.12 to 0.13% of total sulfur and 25 to 21 of N/S ratios when the relative yields were 50 to 55%. The levels were considered practical indicies as far as the present growth disorders are concerned.