소규모 경작지에서 질소 변량시비가 벼 수량 및 품질에 미치는 영향

Influences of Site-specific N Application on Rice Grain Yield and Quality in Small Size Paddy Field

For precision farming the influences of site-specific N application on rice grain yield and quality were investigated in 0.5 ha paddy field from 2001 to 2003. In pre-cultured soil, EC, O.M., total nitrogen, phosphate and potassium content showed high spatial variation, ranging from 11.63 to 52.03% of coefficient of variation, while that of pH was relatively low. In rice growth characteristics, tiller number at panicle formation stage was more than 10% in coefficient of variation, but plant height, SPAD figure at panicle formation stage and milled rice yield, protein content in brown rice showed less below 10%. Spatial dependence was over 0.60 in pH, total nitrogen, phosphate and potassium in pre-cultured soil and was over 0.50 in plant height, SPAD figure and protein content, while it was below 0.22 in tiller number at panicle formation. The range of spatial dependence was longer than 20m in all factors except for protein content in brown rice. Basal dressing nitrogen rate was positively correlated with pH, SiO2, plant height and SPAD figure. Nitrogen fertilization rate at panicle formation stage was positively correlated with EC and O.M.. Protein content in brown rice was positively correlated with SiO2 in pre-cultured soil. Milled rice yield was positively correlated with plant height, tiller number and SPAD figure at panicle formation stage.