Investigation into Possible Use of Methane Fermentation Digested Sludge as Liquid Fertilizer for Paddy Fields

Difference in vegetation growth, taste properties, and grain yield between liquid fertilizer (LF) and chemical fertilizer (CF) applied fields were identified and analyzed to promote the use of the methane fermentation digested sludge as LF using precision agriculture technology. Vegetation growth and these ratios of LF to CF were different at panicle initiation and heading stages but no significant difference in nitrogen content was at the heading stage. Dry mass is greater in CF fields and nitrogen concentration is higher in LF fields is confirmed. In spite of no topdressing in 2006, differences in vegetation growth ratios were decreased because of the organic nitrogen in LF. Difference in GreenNDVI was decreased at the heading stage but the pattern was not changed. Differences in taste properties were significant in 2006 but not in 2005. When grain yield would be decreased 25% by hulls, brown rice yield of LF fields in 2005 was 93% of the average amount in the region (510 kg/10a) and 84% of that (505 kg/10a) in 2006.