Effects of Planting Density and Basal Nitrogen Fertilizer on Grain Yield, Quality, Taste of Rice Cultivar in Aomori Prefecture

Abstract

We evaluated effects of high nitrogen (N) input on grain yield, grain quality and taste of rice grown at a low planting density under a cool climate in Aomori prefecture, Japan. We grew a rice cultivar “Mashhigura” under four combinations of two basal nitrogen and two planting densities for three consecutive years. Climate conditions differed among years especially at the early tillering stage; air temperature and solar radiation in 2016 were lower than in 2014 and 2015, resulting in lower tiller production in 2016. Although in 2014 and 2015, no yield reduction was observed by the low planting density, the yield was significantly reduced by the low planting density under a normal N condition. This yield reduction caused by the low planting density was compensated by a high N input. Grain appearance, eating quality and protein content were not significantly affected by planting density and N input. The income was stable at a high level under the conditions of low planting density with a high N input.