Characteristics of annual NH emissions from a conventional vegetable field under various nitrogen management strategies.

High N-fertilizer applications to conventional vegetable production systems are associated with substantial emissions of NH, a key substance that triggers haze pollution and ecosystem eutrophication and thus, causing considerable damage to human and ecosystem health. While N fertilization effects on NH volatilization from cereal crops have been relatively well studied, little is known about the magnitude and yield-scaled emissions of NH from vegetable systems. Here we report on a 2-year field study investigating the effect of various types and rates of fertilizer application on NH emissions and crop yields for a pepper-lettuce-cabbage rotation system in southwest China.

Effects of crop residue incorporation and properties on combined soil gaseous NO, NO, and NH emissions-A laboratory-based measurement approach.

Crop residues may serve as a significant source of soil emissions of NO and other trace gases. According to the emission factors (EFs) set by the Intergovernmental Panel on Climate Change (IPCC), NO emission is proportional to the amount of N added by residues to the soil. However, the effects of crop residues on the source and sink strength of agroecosystems for trace gases are regulated by their properties, such as the C and N content; C/N ratio; lignin, cellulose, and soluble fractions; and residue humidity.

NO emissions from decomposing crop residues are strongly linked to their initial soluble fraction and early C mineralization.

The emission of nitrous oxide (NO), a strong greenhouse gas, during crop residue decomposition in the soil can offset the benefits of residue recycling. The IPCC inventory considers agricultural NO emissions proportional to the amount of nitrogen (N) added by residues to soils. However, NO involves several emission pathways driven directly by the form of N returned and indirectly by changes in the soil induced by decomposition.

Effect of vole bioturbation on NO, NO, NH, CH and CO fluxes of slurry fertilized and non-fertilized montane grassland soils in Southern Germany.

Populations of rodents such as common vole (Microtus arvalis) can develop impressive soil bioturbation activities in grasslands. These burrowing and nesting activities highly impact soil physicochemical properties as well as vegetation coverage and diversity. Managed grasslands in livestock production regions receive significant amounts of slurry, commonly at high loads at the beginning of the vegetation period.

Earthworms offset straw-induced increase of greenhouse gas emission in upland rice production.

Increasing water scarcity and rapid socio-economic development are driving farmers in Asia to transform traditionally flooded rice cropping systems into non-flooded crop production. The management of earthworms in non-flooded rice fields appears to be a promising strategy to support residue recycling and mitigate greenhouse gas (GHG) emissions triggered by residue amendment. We conducted a field experiment on non-flooded rainfed rice fields, with and without residue amendment.

Greenhouse gas emissions and global warming potential of traditional and diversified tropical rice rotation systems.

Global rice agriculture will be increasingly challenged by water scarcity, while at the same time changes in demand (e.g. changes in diets or increasing demand for biofuels) will feed back on agricultural practices.