Planting practices and mulching materials improve maize net ecosystem C budget, global warming potential and production in semi-arid regions

Planting and mulching practices have long been used to change soil water storage, which may increase crop yields in dry-land farming systems. But, few research works have focused on mulching practices on the greenhouse gas intensity (GHGI), global warming potential (GWP), and net ecosystem C budget (NECB). Therefore, a two years field study was carried out in 2017-2018 to evaluate NECB, GWP, GHGI, biomass and maize production under six treatments: RPS: ridge tillage with film mulch on ridges and straw on furrows; RP: ridge tillage with film mulch on ridges; RT: ridge tillage without film mulch; FM: film mulching; SM: straw mulching; CT: conventional tillage. Finding of our results showed that both plastic film and straw mulching under two planting methods considerable reduced (41.3 %) GHGI, and improving the maize production and soil water status. The RPS treatment improved the soil environment, thus significantly increased corn productivity, C breathing loss, NECB, GWP, N2O, and CH4 emissions. The improve in NPP through RPS treatment is higher than the C loss in respiration, but seasonal NECB shows larger negative values because more NPP is removed as grain and straw. In the RPS treatment increased (22.3 %) the net GWP over flat planting without mulched, but decreased GHGI, due to increased (42.1 %) biomass productivity. The RPS treatment results in higher N2O, CO2 emissions and GWP, and therefore, has an adverse impact on the environment compared to CT treatment. However, the higher WUEg (72.1 %), WUEb (34.4 %), biomass and (83.1 %) grain yields obtained through RPS treatment may balance the negative ecological impacts associated with climate change. Thus, under dry farming systems, RPS treatment may be an effective water-saving management strategy that can increase WUE, biomass, corn yield and reduce the impact of global warming by increasing crop yields.