Does Co-Application of Compost and Mineral Fertilizers Reduce Gaseous Nitrogen (NH3 and N2O) Losses and Improve Nitrogen Use Efficiency from Maize-Growing Soil?

Abstract

Nitrogen (N) has been considered one of the vital elements to enhance agricultural productivity. However, excessive use of N fertilizer can deteriorate environmental quality, increasing ammonia (NH3) and greenhouse gases (GHGs) emissions from agricultural ecosystems. The combined use of inorganic and organic fertilizers may improve nutrient holding capacity, which can potentially reduce N losses (NH3 and N2O), resulting in high N use efficiency (NUE) and crop productivity. To investigate gaseous N losses and NUE in a maize (Zea mays L.) field experiment, four treatments for N fertilizers were laid out: NPK (urea), compost (compost), NPK+Compost (urea and compost), and control (no fertilizer) treatments. As compared to the control, seasonal NH3 emissions significantly increased with all fertilization. In particular, combination of organic and inorganic fertilizers was effective on reducing N losses including NH3 volatilizations and N2O emissions, showing ca. 16% and 47% reduction, respectively over sole NPK treatment even though the same amount of N was incorporated in all treatments except the control. Maize productivity was significantly improved by N fertilizations, but was the highest in the NPK+Compost treatment, showing no statistical difference with NPK treatment. The NUE was the highest in the NPK treatment (35%) and followed by NPK+Compost (27%), compost (11%), respectively. In conclusion, mixing of organic-inorganic fertilizers could be a reasonable countermeasure to reduce the loss of gaseous N and simultaneously maintain productivity and NUE in agricultural soils.The amount of ammonia volatilization, nitrous oxide emission and total gaseous N losses at different N fertilization regimes from maize-growing soil. Treatments Total N input (kg ha-1) NH3-N loss (kg ha-1) N2O-N loss (kg ha-1) Total N losses (kg ha-1) (%) Control - 4.24 c† 0.84 b 5.08 c - NPK 158 6.74 a 2.93 a 9.66 a 6.11 a Compost 158 4.50 c 1.44 b 5.94 c 3.76 b NPK+Compost 158 5.64 b 1.55 b 7.19 b 4.55 b †Different letters for each row showed a significant difference at p ≤ 0.05 according to LSD’s test.