Abstract
The need for labor-saving and cost-reducing techniques has been increasing in rice production. High-density sowing reduces the number of nursery boxes required, and application of basal fertilizer directly to nursery boxes enables a 10–40% reduction in fertilizer use compared with conventional field fertilization. Although the combination of these techniques may enhance labor and cost efficiency, the seedling growth and grain yield have not been fully investigated. We evaluated a combination of two techniques for seedling growth, yield, and quality. The plots were divided into three groups using the sample fertilizer (Naebako-Makase, N400-100): high-density seedling plots with 20% less fertilizer (HD20 group), high-density seedling plots with 40% less fertilizer (HD40 group), and high-density seedling plots without fertilizer in the nursery box due to conventional fertilizer in the field (HDC group). The quality of seedlings grown in the HD20 and HD40 groups was still within the acceptable range for transplanting. Between the different fertilizer reduction rates, the yield in the HD20 group was 3–71 g m-2 larger than that in the HD40 group, whereas both protein content and amylose content were 0.1–0.3 points and 0.1–0.4 points lower in the HD40 group. From the above results, the combination of the two techniques produced healthy seedlings, and the yield was better in the HD20 group, whereas the brown rice ingredient quality was better in the HD40 group.
