Can seasonal soil N mineralisation trends be leveraged to enhance pasture growth?

• DOI: 10.1016/j.scitotenv.2021.145031
• Publication Date: 2021-02-02T23:41:40Z
• Authors: Franco Bilotto; Matthew Tom Harrison; Massimiliano De A...; Karen M. Christie; David W. Rowlings; Peter R. Grace; Andrew P. Smith; Richard P. Rawnsley; Peter J. Thorburn; Richard J. Eckard
• Keywords: Soil carbon

Soil N mineralisation is the process by which organic converted into plant-available forms, while soil immobilisation transformation of inorganic matter and microbial biomass, thereafter becoming bio-unavailable to plants. Mechanistic models can be used explore contribution mineralised or immobilised pasture growth through simulation plant, environment interactions driven management. Our objectives were (1) compare performance three agro-ecosystems (APSIM, DayCent DairyMod) in simulating N, biomass water using same experimental data diverse environments (2), determine if tactical application fertiliser different seasons could leverage seasonal trends influence (3), sensitivity changes fertilisation, cutting frequency irrigation rate. Despite considerable variation model sophistication, no consistently outperformed other with respect shoot water. Differences accuracy simulated NH4 NO3 greater between sites than overall, all cumulative N2O well. While had immediate effects on NO3, NH4, growth, long-term relationship discerned. It was also shown that more sensitive compared models. results suggest superfluous fertilisation generally stimulates a pulse emissions, subsequent mineralisation/immobilisation are variable. We further controlled incubation research may help separate successive overlapping cycles make it difficult diagnose implications for (and associations with) growth.