Abstract
We analyzed the spatial variability of paddy rice nitrogen at the panicle formation stage (Npf) in paddy-upland rotational field (8.6ha) and non paddy-upland rotational field (1.6ha) in Sakurai, Nara Japan. Npf was estimated by GNDVI ((R860-R560)/(R860+R560)) using aerial photography. The variation of Npf had a strong spatial dependence with a range distance of 40-55m in paddy-upland rotational field and 10-30m in non paddy-upland rotational field. Our results showed that the stable management unit of Precision Agriculture for top-dressing, which depend on a range distance, in the paddy-upland rotational field was larger than that in the non-paddy-upland rotational field. The uniformity of the cropping system, the cultivation method and the land utilization among fields influenced these spatial dependences.
