2017 Volume 86 Issue 2 Pages 160-168
The aim of this study was to clarify the method of soil management for “Toramame”, (tiger bean) a pole-type kidney bean with tiger-like stripes. We investigated the growth and root system of “Toramame”, and examined the correlation of yield with soil nitrogen level, and the depth of soil penetration resistance 1.5 MPa (effective depth of soil layer, EDS) in upland fields of Hokkaido Kitami district. Dry-matter production and nitrogen uptake rate were highest after the full bloom stage. The yield was positively correlated with autoclaving extractable nitrogen (ACN) level at 0–20 cm depth in andosol and upland soil. This suggested that when the amount of ACN increased, nitrate that could be assimilated by the crop after the bloom stage increased. The deeper the EDS at the full bloom stage within the range of 0 to 50 cm, the higher tended to be the yield. In the upland soil field where the yield was under 200 g m–2, where EDS was deep, the amount of ACN was less than 0.05 g kg–1. The yield on lowland soil tended to be lower than that on upland and andosols estimated from the amount of ACN, or EDS. Thus soil type and nitrate fertility affected the yield deeply and expanded EDS when the amount of ACN was larger than 0.05 g kg–1.
