2021 Volume 90 Issue 3 Pages 334-342
This study was conducted to test a high yielding feed rice production system at a farmer’s paddy fields in the Nasu area of northern Tochigi Prefecture. This labor-saving and sustainable cultivation method uses sparse planting of “Oonari”, a high yielding indica cultivar, with cattle manure and controlled availability fertilizer. We applied manure at the rate of 2–2.5 kg m-2 and controlled availability fertilizer at the nitrogen rate of 12 g m-2, and obtained gross hulled rice yields of 879–920 kg/10 a. The numbers of spikelets per panicle were higher in the sparse planting than in the normal density planting. This increased the sink capacity, and likely increased the translocation of nonstructural carbohydrates to the panicles during the ripening stage, contributing to the high yields in the sparsely planted rice. The percentage of spikelets on primary and secondary rachis branches was not affected by planting density, which helped maintain the grain-filling ability. Vitamin E contents, including tocotrienol in the rice brans, did not vary with planting density. These results suggest that the sparse planting of “Oonari”, with cattle manure and controlled availability fertilizer, is an effective, labor-saving, and sustainable feed rice production system for the Nasu area.
