耕起法と窒素肥料種が全量基肥・接触施肥栽培におけるデントコーンの出芽に及ぼす影響

抄録

The objective of this study was to clarify the effects of single basal co-situs application of polyolefin-coated urea (POCU) and ammonium sulfate (AS) on crop emergence in no-tillage and tillage cultivation of dent corn. Field experiments were conducted for three years (1996-1998) in Andisol. Emergence percentages of corn in the POCU plot were high and varied from 81 to 93% under different soil moisture conditions, whereas those in the AS plot ranged from 22 to 95%. Severe salt damage to the crop was observed in the AS plot in 1996 due to less precipitation after sowing. In the AS plot, the emergence percentage of corn in the no-tilled plot was higher than that of the tilled plot. POCU maintained a low electrical conductivity (EC) in the soil solution around the seeds. The soil solution EC of the no-tilled plot was lower than that of the tilled plot because of the higher water potential in no-tilled soil. The reason for the higher EC in the AS plot was ammonium sulfate. Accordingly, single basal co-situs application of POCU is a suitable method for the fertilization of no-tilled soil systems.