Combined Application of Organic and Inorganic Fertilizers Mitigates Ammonia and Nitrous Oxide Emissions in a Maize Field

This long-term study used a lysimeter platform to monitor the NH3 and N2O emissions of summer maize resulting from various fertilization treatments in the Huanghuaihai area, with the goal to assess the efficiency of fertilization measures aimed at reducing NH3 and N2O losses during the production of summer maize; the results provide a theoretical basis for synergistically improving maize yield and fertilizer utilization efficiency. A 2-year field trial was conducted. The trial included a no-N-fertilizer treatment as a control to study the following three fertilizer treatments: the exclusive application of urea, the exclusive application of cattle manure, and the combined application of organic and inorganic fertilizers. The results show that during the two maize growth seasons included in the trial, the average N2O losses associated with exclusively applying urea, exclusively applying cattle manure, and the combined application of organic and inorganic fertilizers were 273%, 542%, and 376% higher than those associated with the control treatment, respectively. During the same period, the average accumulative ammonia volatilization losses were 311%, 542% and 376% higher than those for the control treatment, respectively. The average nitrogen accumulation resulting from the combined application of organic and inorganic fertilizers was 82% higher than that for the control treatment, 12% higher than that for the exclusive application of cattle manure, and 6% higher than that for the exclusive application of urea. The average grain yield for the combined application of organic and inorganic fertilizers, the exclusive application of urea and the exclusive application of cattle manure were 76%, 68% and 61% higher than that for the control treatment, respectively. Overall, the combined application of organic and inorganic fertilizers showed a lower ammonia volatilization loss than the exclusive application of urea, which resulted in a higher ammonium nitrogen and nitrate nitrogen content in the soil, an increased nitrogen uptake, an increased dry matter accumulation of maize, and a high grain yield and nitrogen recovery efficiency.