Optimal coupling of straw and synthetic fertilizers incorporation on soil properties, active Fe dynamics, and green house gas emission in Jasminum sambac (L.) field in southeastern China

In agriculture, synthetic fertilizers have played a key role in enhancing food production and keeping the world's population adequately fed. China's participation is essential to global efforts in reducing greenhouse gas (GHG) emissions because it is the largest producer and consumer of synthetic fertilizers. A field experiment was conducted in a Jasminum sambac (L.) field to evaluate the impact different doses of fertilizers (half, standard, and double) and their combination with straw on ecosystem (including crop plants and soil) GHG emissions. The results showed that in comparison with the control or straw treatments, the straw + standard fertilizer treatment increased the soil water content. The fertilizer treatments decreased the soil pH, but the straw and combination treatments, especially the straw + standard fertilizer treatment, had higher soil pH in comparison with the fertilizer treatment. The active soil Fe (Fe²⁺ and Feᶟ⁺) concentration was slightly increased in the straw + standard fertilizer treatment in comparison with the control. Moreover, fertilizer increased the CO₂ emission, and we detected a positive interaction between the straw application and the double fertilization dose that increased CO₄ emission, but the straw + standard fertilizer treatment decreased it. Fertilizer decreased CH₄ and N₂O emissions, but when straw and fertilizer treatments were applied together, this increased CH₄ and N₂O emissions. Overall, considering the soil properties and GHG emissions, the straw + standard fertilizer treatment was the best method to enhance soil water retention capacity, improve soil acid, and mitigate greenhouse gas emissions for sustainable management of J. sambac dry croplands