The Influence of Different Type of Composted Manure on Nitrous Oxide Emissions from Upland Soil.

Animal composted manure added for improving soil quality and enhancing crop productivity can lead to greenhouse gas emissions such as nitrous oxide (N2O) by processes of nitrification and denitrification. In addition, the amount of N2O emission from composted manure amended soils can vary greatly with composted manure type and application rate. Therefore, the influence of different type of composted manure and rate application on N2O emissions were evaluated during growth of sweet potato (Ipomoea batatas). The treatments included fertilized control treatment, cattle composted manure (CACM), pig composted manure (PCM), and chicken composted manure (CCM), which were applied at rate of 0, 10 and 30 Mg ha-1 in the spring. N2O emissions were significantly affected by composted manure type and application rate. The majority of N2O emissions were occurred shortly after composted manure and chemical fertilizer application compared with the rest of the growing seasons for all treatments. The CCM had greater N2O emissions compared with CACM and PCM, which corresponds to different nitrogen contribution of composted manure. Higher rate (30 Mg/ha) of composted manure had always greater nitrous oxide emission than lower rate (10 Mg/ha) of composted manure. At a rate of 30 Mg/ha, the CCM at (17.7 kg N ha-1) had 2.7 times greater nitrous oxide emissions than the control (6.6 kg N ha-1), 1.5 times greater emission than the CACM (11.8 kg N ha-1) and 1.2 times greater emission than the PCM (14.4 kg N ha-1).