Effects of different application timings of methane fermentation digested liquid to paddy plots on soil nitrogen and rice yield

Abstract

Treatment of animal and food wastes using a methane fermentation technique is drawing considerable public attention as a suitable option for the utilization of biomass resources. The application of a fermentation byproduct (methane fermentation digested liquid) as an agricultural fertilizer has been investigated. Determining the appropriate timing required for applying digested liquid on a rice (Oryza sativa L.) paddy plot is important. The concentrations of soil nitrogen (N) components and rice yield should be considered because digested liquid contains both inorganic and organic N. This study compares the N transformation and the rice yield and growth at different application times over a period of 3 y. The effects of the timing of basal application on soil N were different and the timing that maximized the rice yield was different in each year. Days before ponding (DBP) affected soil N before mid-summer drainage, and rice growth rates at the panicle formation stage and the ear emergence stage. The effects of DBP disappeared before harvest. The results indicated that sufficient potentially mineralizable N existed regardless of DBP, and the effect of DBP lessened after the mid-summer drainage, which coincides with the period when N uptake is most active.

Temporal Growth Inhibition of Rice Plant and Growth Recovery Observed under Application of Anaerobically-DigestedCattle Manure

“…However, a temporal growth inhibition by the ADM treatment was observed during the eight year experiment. Inhibition of initial growth by ADM has been shown to cause a serious yield decline under some cropping conditions depending on soil type, rice cultivar, fertilization and water management (Watanabe et al, 2011). It is therefore important to elucidate the growth-inhibiting factors for promoting normal growth and grain yield of rice plants supplied with ADM as a fertilizer.…”