Dicyandiamide increased ammonia volatilisation and decreased carbon dioxide emission from calcareous soil during wheat–maize rotation on the Loess Plateau

Abstract

Nitrification inhibitors (NIs) have been found to retard the nitrification process, reduce N losses and increase nitrogen use efficiency; however, their effect on carbon dioxide (CO2) emission from calcareous soil has rarely been reported. A 2-year field experiment was conducted to study whether nitrification inhibition by dicyandiamide (DCD) has any effect on CO2 release from calcareous soil. The experiment comprised five treatments: a control (0 kg N ha–1) and two levels of N fertiliser applied on wheat (160 and 220 kg N ha–1) and maize (180 and 280 kg N ha–1) crops, with and without DCD. Compared with the control, a decrease in soil pH (mean 0.21 units in N fertiliser treatments without DCD and 0.11 units with DCD) and increases in cumulative CO2 emission (mean 17% and 23% in wheat and maize respectively) and cumulative ammonia (NH3) volatilisation (mean 28% and 446% in wheat and maize respectively) was recorded under all N fertilised treatments (with and without DCD). The application of DCD with N fertiliser retarded the nitrification process, as indicated by a higher NH4+-N and lower NO3–-N content, as well as a relatively higher soil pH, compared with application of N fertiliser without DCD. In addition, DCD application significantly reduced CO2 emission in both wheat (10–20%) and maize (13–14%) crops compared with crops grown with N fertiliser without DCD. However, the losses from NH3 volatilisation increased when DCD was applied at both N fertiliser levels in both wheat (38–41%) and maize (24–36%) crops. Inhibition of nitrification by DCD was more effective during the wheat than during maize season. Controlling nitrification using DCD is an effective approach to minimise CO2 emission from calcareous soils on the Loess Plateau; however, DCD application increases in NH3 volatilisation.

Dramatic loss of inorganic carbon by nitrogen‐induced soil acidification in Chinese croplands

“…N fertilization should be performed strictly based on the crop requirements while also considering the amount of residual N that is available to the crops. Enhanced efficiency additives, such as urease and nitrification inhibitors, retard acidification and, therefore, should be incorporated with N fertilizer (Raza et al, 2019). Crop and livestock farms should be integrated with a major focus on effectively reusing crops and animal waste.…”

“…However, recent studies have reported that CO 2 absorption occurs in alkaline soils and deserts by abiotic mechanisms (Li, Wang, Houghton, & Tang, 2015; Wang, Wang, et al, 2015; Xie, Li, Zhai, Li, & Lan, 2009; Zhao, Zhao, Wang, Stahr, & Kuzyakov, 2016). Agricultural practices can also fundamentally alter the SIC cycle (Lal & Kimble, 2000; Raza et al, 2019; Rey, 2015). The contribution of SIC to CO 2 efflux should not be neglected and SIC maintenance has great significance for decreasing C losses and maintaining soil health and productivity (Zamanian & Kuzyakov, 2019; Zamanian, Zarebanadkouki, & Kuzyakov, 2018).…”

Biochar and compost effects on soil microbial communities and nitrogen induced respiration in turfgrass soils

“…To reduce the diurnal effects, readings were taken each day at the same time for 16 days. Depending on the bulk densities of each sample, the flux per hour (F = g·kg -1 ·h -1 ) was measured by using the formula [ 40 ]; Where,…”

Benefits and Risks for the Environment and Crop Production with Application of Nitrification Inhibitors in China

“…3). Previous studies have indicated that a decrease in soil pH will stimulate hydrolyzation of inorganic carbon and release CO 2 , especially in calcareous soils (Raza et al 2019;Yu et al 2018b). DMPP and DCD have been proven to have no effect on non-target microbial activity, biomass, or respiration (Kong et al 2016;Maienza et al 2014;Singh et al 2008); thus, it could be speculated that the effects of DMPP and DCD on decreasing CO 2 emissions could be attributable to their effect on reducing soil acidification.…”

“…As well as these benefits, several environmental risks have also been identified with applying NIs. Some research has indicated that NIs increase ammonia (NH 3 ) volatilization and NH 4 + -N leaching (Li et al 2009;Raza et al 2019;Sun et al 2015;Yu et al 2008). Thus, benefits and risks both exist with the use of NIs.…”