FUNDAMENTAL STUDY FOR UTILIZING METHANEFERMENTED DIGESTED SLUDGE AS LIQUID FERTILIZERFOR PADDY IN 2003

摘要

Methane fermentation is within reason and promising in even Japan. It might be suitablefor treating animal waste. Japan however imports 72% of concentrate feed and 22% of roughage.Thus most Japanese dairy farmers do not have enough fields for applying slurry. If the methanefermentation would be widely utilized in Japan, the digested sludge should be applied to paddy asliquid fertilizer. For this purpose application of methane digested sludge to paddy was tried in 2003.As liquid fertilizer, digested sludge from Yagi Bio-ecology Center (YBEC) was used. From 2004,project research begins. It is based on the result the experiments in 2003. YBEC at Ygai in KyotoPrefecture is a methane fermentation plant. YBEC has been operated since 1997. Two paddy fieldswere prepared for experiment at Yagi. One is called T-field and other is called K-field. Both fieldswere about 0.3ha in area. Rice variety at T-field was Kinuhikari and the rice were transplanted onMay 21, 2003 and harvested by the head-feeding combine equipped with yield monitor system onSeptember 19. Rice variety at K-field was Matsuribare. The rice were transplanted on June 6, 2003and harvested by the combine on October 9.Variability of T-N, NH4-N, K2O in irrigation water, and T-N and VS in soil at just and 24 hours laterafter the application into the fields were analyzed. Nutritious element next to inlet of irrigation waterwas lower than next to closed outlet. The variability after 24 hours was relaxed. NH4-N and K2O inthe water, and T-N and VS in soil had similar variability. The variability of the yield at T-field wasalmost similar to the variability of the nutritious elements. Undulate plate was set at north side of Kfield.It influenced to variability of nutritious elements. Except that condition, yield depended onvariability of the nutritious elements. Average grain yields were 6.23t/ha at T-filed, and 7.43t/ha at Kfield,respectively.Sufficient yield was gotten by application of methane digested sludge. Effect of digested sludge ontaste could not be confirmed. Applying way should be improved and safety also had to be confirmedfurthermore.