Effects of fertilizer types and water quality on carbon dioxide emissions from soil in wheat-maize rotations

The use of fertilizers as addition inputs in agricultural systems can increase the yield of wheat and maize, while also stimulating the emission of carbon dioxide from soil that the main man-made greenhouse gas. Our objectives focused on the impact of different types of synthetic fertilizers and water quality. The purposes were to determine the feasibility of using wasted water for irrigation and to relate CO₂ fluxes to the yield of maize and wheat, as well as to select the best fertilizer type with low CO₂ emission and high yield. The experiment consisted of a double factors test focusing on four forms of fertilizer (urea, amine and slow release fertilizer) and the quality of water (reclaimed water and underground water). The results showed that the reclaimed water was not significant on the CO₂ discharge rate, the maize-wheat yield or the soil properties in 2014 or 2015; however, the CO₂ emission increased slightly in 2015. Focusing on fertilizer treatments, the reclaimed water & amine fertilizer treatment (CAF) that had higher cumulative CO₂ emissions was 32.75 t·ha^-1 in 2014 and 33.86 t·ha^-1 in 2015. According to the ratio CO₂/Y, the slow released fertilizer that reduces CO₂ emissions and keeps the yield high is the preferred choice.