Biochar amendment and Calamagrostis angustifolia planting affect sources and production pathways of NO in agricultural ditch systems.

Nitrous oxide (N2O) from agricultural ditches is a non-negligible source of anthropogenic greenhouse gas (GHG) emissions, but few studies have addressed this topic in depth. On the other hand, although there are numerous reports that biochar application can affect N2O emissions from soil, the understanding of the process and source of changes is still incomplete. To examine the effect of biochar and Calamagrostis angustifolia on N2O emissions, we conducted experiments with constructed ditches where corn stalk biochar (pyrolysis temperature of 450 °C) was applied at a rate of 16.

Fate of nitrogen in overlying water with biochar addition to sediment in planted ditches.

Best management practice (BMP) in drainage ditch systems is of high concern due to its importance in intercepting and removing pollution. Biochar has recently become an interesting option for agricultural pollution elimination, but knowledge is still limited on the fate of nitrogen (N) in drainage ditch systems with biochar added into the sediment. This isotope tracer study examined the effects of biochar addition into the sediment on the fate of inorganic N (N-NO and N-NH) in sediment microcosms through a 93 day incubation experiment.

Nitrate behaviors and source apportionment in an aquatic system from a watershed with intensive agricultural activities.

Nitrate pollution in aquatic systems caused by intensive agricultural activities is a serious problem in the Sanjiang Plain. In this study, a dual isotope approach (δ(15)N-NO3(-) and δ(18)O-NO3(-)) was employed to identify potential nitrate sources (atmospheric deposition, AD; NO3(-) derived from soil organic matter nitrification, NS; NO3(-) derived from chemical fertilizer nitrification, NF; and manure and sewage, M&S) and transformation processes occurring in the Abujiao River watershed located in the Sanjiang Plain. The Bayesian model (stable isotope analysis in R, SIAR) was utilized to apportion the contribution of the potential sources.