Mitigation of Nitrous Oxide Emissions during Nitrification and Denitrification Processes in Agricultural Soils Using Enhanced Efficiency Fertilizers

Abstract

Through the increasing use of nitrogen (N) fertilizers due to an increasing food demand, the agricultural sector is the main contributor of anthropogenic nitrous oxide (N 2 O) emissions, mainly through microbial processes called nitrification and denitrification. One option to mitigate N 2 O, a major greenhouse gas, is to use enhanced efficiency fertilizers (EEFs). There are different types of EEFs like nitrification inhibitors or controlledrelease fertilizers that aim to match the N release from fertilizers with N demands from plants. Parts of the chapter are also dedicated to organic amendments and their effects on N 2 O emissions. Overall, EEFs can improve the N-use efficiency of plants, which has two positive effects. First, farmers can increase their yields, and second, environmental pollution through excessive fertilizer N can be minimized. However, the effectiveness of EEFs strongly depends on numerous factors like land use type, application method, and climate. More studies are needed to establish individual fertilizer plans that are optimized for the prevalent conditions. In conclusion, N 2 O mitigation using EEFs is only advisable when "initial" N 2 O emissions from conventional fertilizers are critically contributing to annual N 2 O emissions. Thus, careful assessment is needed before EEFs are introduced to the system especially when economic and ecologic results are considered.

Sorgoleone release from sorghum roots shapes the composition of nitrifying populations, total bacteria, and archaea and determines the level of nitrification

“…High nitrification has been a concern for decades for the negative impact on the environment, due to high N losses via nitrate leaching which cause soil pollution or emission of nitrous oxide (N 2 O) through denitrification (Timilsena et al 2015;Uchida and von Rein 2018). Reducing nitrification rates in soils represents a strategy to mitigate the negative impact of nitrate to the environment (Subbarao et al 2012).…”

Conservation Agriculture as a Climate Change Mitigation Strategy: A Review

“…Destruction of the ozone layer due to N2O is an important consideration beyond the concern for nitrogen losses from applied fertilizers and manures. Experiments have shown that both the processes of nitrification and denitrification contribute to the release of N2O from the soils into the atmosphere" [28]. N2O production is significantly influenced by soil water content, as water creates anaerobic conditions by reducing the oxygen diffusion rate by ten thousand times.…”

Lignite Scaffolding as Slow-Release N-Fertilizer Extended the SN Retention and Inhibited N Losses in Alkaline Calcareous Soils

“… 1 In addition, these losses lead to a decline in nitrogen use efficiency (NUE) and environmental pollution. 2 It has been reported that NUE in alkaline calcareous soils is much lower (15–23%) 3 compared to non-calcareous soils (30–40%). 4 High soil pH, temperature, and low cation-exchange capacity (CEC) and organic matter content are the main causes of lower NUE in alkaline calcareous soils.…”

“…However, the plants do not utilize the excess N completely, and a considerable portion of applied N is lost as NH 3 -volatilization, NO 3 -leaching, and N 2 O emissions result in the wastage of resources and money . In addition, these losses lead to a decline in nitrogen use efficiency (NUE) and environmental pollution . It has been reported that NUE in alkaline calcareous soils is much lower (15–23%) compared to non-calcareous soils (30–40%) .…”