Abstract
We studied the method of raising paddy rice seedlings using the single whole basal fertilizer application to the nursery box in the rice-wheat double cropping area in Gunma Prefecture. The seedlings were raised by the pool method which is widely used in Gunma Prefecture. We applied single whole basal fertilizer named “Naebako-makase” (N400-100 and NK301-100) , and raised the seedlings for 20-22 days. From the studies for 3 years, we found that could be raised seedlings in April without any problems, but in May-June feritilizer tended to be dissolved excessively in the latter period, and the seedlings tended to show spindly growth, along with lower mat intensity. The type of fertilizer and the position of feritilizer in nursery boxes scarcely influenced seedling growth. The use of grained soil to cover the seeds did not affect the emergence and growth of seedlings. On the other hand, seedlings could hardly emerge when covered by grained-fused phosphate. Covering with powdering fused-phosphate caused growth injury and decreased the seedling-mat intensity. The small decrease of seedling mat intensity caused by covering with grained-soil was avoidable by increasing the sowing rate, and healty seedlings suitable for transplanting could be grown. Therefore, we found that this method can be introduced to the rice-wheat double cropping areas in Gunma Prefecture.
