Rice Uptake of Nitrogen from Aerobically and Anaerobically Composted Poultry Manure

Abstract

The availability of NH₄-N and organic nitrogen (N) for paddy rice under the combined application of aerobically composted poultry manure (organic N accounted for 97% of total N) and ¹⁵N-labeled (NH₄)₂SO₄ was estimated, and the N availability of anaerobically composted ¹⁵N-labeled poultry manure (NH₄-N accounted for 41% of total N) was compared with the aerobic compost and (NH₄)₂SO₄ in a field experiment. Application rates of N were 40.4 kg NH₄-N ha⁻¹ plus 56.4 kg organic N ha⁻¹ for the aerobic compost + (NH₄)₂SO₄ and anaerobic compost treatments, and 40.4 kg NH₄-N ha⁻¹ for the (NH₄)₂SO₄ treatment. Nitrogen uptake at maturity was in the following order: aerobic compost + (NH₄)₂SO₄ treatment > anaerobic compost ≈ (NH₄)₂SO₄ treatment > control. Dry matter production varied in the same order as N uptake. ¹⁵NH₄-N recovery efficiency was slightly lower in the aerobic compost + (NH₄)₂SO₄ treatment (38.1%) than in the (NH₄)₂SO₄ treatment (42.8%). Organic N recovery efficiency in the aerobic compost was estimated to be 16.5% based on the difference method. ¹⁵N recovery efficiency in the anaerobic compost treatment (16.6%) was lower than that in the (NH₄)₂SO₄ treatment. Although fertilizer equivalent organic N in the aerobic compost was higher than that in the anaerobic compost, N derived from soil plus compost was greater in the anaerobic compost treatment. It is suggested that N availability from the anaerobic compost is greater than that from the aerobic compost when the same amounts of N are applied by compost alone.

Keywords:

• Compost
• ¹⁵N
• Poultry manure
• Rice