Effect of biochar-coated urea and manure on N2O and CO2 flux dynamics during sorghum growth in rainfed fields

Rainfed land in Indonesia is vulnerable to the impacts of climate change and is constrained by low soil fertility.External inputs such as biochar-coated urea and livestock manure can reduce greenhouse gas emissions from rainfed land, particularly nitrous oxide (N2O) and carbon dioxide (CO2).Anthropogenic CO2 and N2O emissions from rainfed fields contribute to global warming.The research aims to determine the effect of urea-coated biochar-enriched consortia microbes and manure on flux dynamics of CO2and N2O under sorghum growth (Sorghum bicolor L. Moench) in a rainfed field.A field experiment was conducted using a two-factor randomized complete block design with three replicates and two-factor treatments.The three levels of first factor treatment were no manure, cow manure, chicken manure, and the four levels of second factor treatment was farmer's recommended dose, prilled urea, biochar-coated urea, biochar-coated urea with microbial enrichment.Observed parameters included plant height, biomass yield, N2O flux, and CO2 flux.Only manure application significantly affected plant height, but its interaction with N input was nonsignificant for either plant height or sorghum biomass yield.The N2O flux pattern is high at the beginning of sorghum growth and decreases towards harvest, while the CO2 flux pattern is irregular.Manure treatment and N input significantly affect N2O emissions, but not CO2 emissions.Biochar-coated urea from corn biomass, either without or with microbial enrichment, can reduce N2O emissions by 20.8%-40.5% or 15.3%-36.4%,respectively.The combination of biochar-based fertilizer with organic manure can potentially mitigate greenhouse gas emissions in rainfed fields.