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.454-463, 2000-08-05

参考文献数

7

被引用文献数

4

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The author investigated the regional growth disorders of early-planted rice, of which initial growth is severely and peculiarly inhibited, causing yellow stunting of lower leaves and no increase in stem number after approximately 30 to 40 d of transplanting, to paddies supplemented with a basal paste-like fertilizer at the row sides. No specific responses were found among rice varieties. The field experiments and soil analysis of paddies were carried out; firstly to reproduce the disorders in the late planting of rice, and secondly, to diagnose the components of a commercial fertilizer which has been effectively used by a farmer to recover the disorders. The results obtained were as follows; 1) Disordered paddies contained appreciable amounts of ammonium nitrogen in the soil, indicating no effects of nitrogen deficiencies to rice plants. 2) The specific growth disorders of yellow stunting were also found in the late-planted rice cultivation. Furthermore, the application of a granular fertilizer at the row sides showed less growth disorders as compared to the paste-like fertilizer when they were treated in the same experimental paddy. 3) An experiment to separate the farmers practical fertilizer into a few nutrients for diagnosis showed that any nutrient other than sulfate contributed less to recover the disorders. Consequently, in the following early rice planting experiment, in which the growth disorders by paste-like fertilizer were also induced, the application of magnesium sulfate responded well for recovery within several days under a submurged condition, whereas the recovery by surface drainage took more than 10 d. As a conclusion, the author suggests the disorders will be induced primarily by developed soil reduction, hence causing nutritional disorders in rice plants related to temporary sulfate starvation in the soil.