Interesting new open source paper on MAOM-N, Mineral-associated organic nitrogen pool size, composition, and accessibility mediated by agricultural management and soil geochemical characteristics.
Link to full paper here:
tinyurl.com/mnv5ntb9
Below are some excerpts:
"...Organic matter can provide a relatively slow-cycling source of bioavailable N that may be better matched to plant demand than mineral N fertilizers (Franklin et al., 2017, Yang et al., 2020)..."
"...However, in many soils, the majority of SOM-N is held within mineral-associated organic matter (MAOM).."
"....Agricultural management practices could also exert a significant influence on MAOM-N stocks (Villarino et al., 2023). On average, soils maintained under long-term cropping systems contain 37 % less MAOM-N compared to grasslands (Lugato et al., 2021). Tillage practices are likely partly responsible for this observed decline: soils maintained under conventional tillage may contain 9–20 % less MAOM-N compared to soils maintained under reduced tillage practices (Jilling et al., 2020, St. Luce et al., 2022). Mineral N fertilizers applied to agricultural soils can accelerate MAOM-N loss by stimulating microbial decomposition or through pH changes that disrupt mineral-organic associations (Ren et al., 2024). Agricultural management may also reduce the quantity of new organic N inputs available to form MAOM-N. A decrease in the amount and diversity of root exudates and other rhizodeposits under annual monocropping systems has been linked to a decline in SOM stocks and mean residence time compared to soils maintained under perennial grasslands and mixed croplands (Cotrufo et al., 2022, Domeignoz-Horta et al., 2024, Eisenhauer et al., 2017, Ma et al., 2022, Poeplau et al., 2021, Seitz et al., 2023)...."
cc.
@Johnkempf @IntegratedSoils @samdknowlton @UnderstandingAg @CSUChicoRegenAg @MattPowersSoil @SusFoodTrust @ffinlocostain