Abstract
A 2-year field experiment was conducted to examine the fertilizing effect of digested effluent of manure (DEM) on growth attributes, dry matter yield, forage quality and nitrogen (N) recovery rate of maize (Zea mays L.)-Italian ryegrass (Lolium multiflorum Lam.) cropping system, compared with application of conventional fertilizer (commercial cattle manure and chemical fertilizer) and sole chemical fertilizer. The DEM solution was applied at three levels : 40, 70 and 100 gN/m^2/year for low, medium and high levels, respectively. The N application level in the chemical and conventional fertilizer treatment were 40 and 69.2 g N/m^2/year, respectively, which were similar to and the same as in the low and medium levels of DEM, respectively. The effect of DEM on growth attributes, yield, forage quality and nitrogen recovery rate of each cropping and total of this cropping system was almost corresponded with that of the chemical fertilizer at the same N application rate. This suggests that DEM can be used in short-term as substitution of fastly effective chemical fertilizer and optimum application rate of DEM should be below 40 gN/m^2/year in the maize-Italian ryegrass cropping system in southern Kyushu.
