Phyto-purification of livestock-derived organic waste by forage rice under subtropical climate

摘要: Soil and water pollution caused by organic waste is a concern for livestock-breeding areas. Nitrogen balance in paddy-field water-purifying system which cattle feces were applied was studied 4 years to assess the suitability of subtropical area, Japan. Three successive harvestings using ratoon forage rice following one transplanting conducted with chemical fertilizer high low rates cattle-feces application. load 81.3–495.0 kg N ha−1 year−1, while nitrogen uptake highly dependent on yield first harvesting. Annual variation yields large, ranging from 15.5 26.8 Mg ha−1 owing fluctuation at second later harvestings. On average, lost leaching rate 2.3–3.4 kg N ha−1 year−1. The content soil depth 0–5 cm increased up 12.2 kg N ha−1 over 4-year period compared that before field experiment. However, continuous application could slightly increase greater than 35 cm. Our results showed ability flooded remove 320.1 kg ha−1 year−1 applied. Further investigation needed produce stable harvesting each year, prevent accumulation nitrogen, gaseous loss.