Zhang, et al (2024) One–third substitution of nitrogen with cow manure or biocharBiochar is a carbon-rich material created from biomass decomposition in low-oxygen conditions. It has important applications in environmental remediation, soil improvement, agriculture, carbon sequestration, energy storage, and sustainable materials, promoting efficiency and reducing waste in various contexts while addressing climate change challenges. More greatly reduced N₂O emission and carbon footprint in saline–alkali soils. Field Crops Research. https://doi.org/10.1016/j.fcr.2024.109517

In the latest study published in Field Crops Research, researchers explored the effects of substituting one-third of nitrogen (N) fertilizer with cow manure or biochar on maize yields and greenhouse gas (GHG) emissions in saline-alkali soils. Conducted in the Tarim River Basin from 2021 to 2022, the study tested five treatments: fallow (CK), no fertilization (0N), conventional N fertilizer (N), one-third substitution of N with biochar (NB), and one-third substitution of N with cow manure (NM).

The results were promising. The NB treatment reduced cumulative CO2 emissions by 21%, while NM showed no difference from conventional N treatment. Both NB and NM significantly lowered cumulative N2O emissions by 61% and 49%, respectively. They also reduced carbon footprints (CF) by 68% for NB and 10% for NM, with corresponding reductions in yield carbon footprints (CFy). Moreover, maize yields increased by 3% with NB and 2% with NM, while soil organic carbon (SOC) storage saw a rise of 43% with NB and 6% with NM.

The net ecosystem carbon budget (NECB) improved substantially under both treatments, with NB achieving an 80% increase and NM a 24% rise. Agronomic nitrogen use efficiency (ANUE) also improved slightly. The study concluded that substituting a portion of synthetic N fertilizer with biochar or manure offers significant environmental benefits, including reduced GHG emissions and enhanced carbon sequestration, making it a viable strategy for sustainable agriculture in saline-alkali soils.