Short‐Term Effects of Mineral and Organic Fertilizer on Denitrifiers, Nitrous Oxide Emissions and Denitrification in Long‐Term Amended Vineyard Soils

Abstract

Short‐term effects (i.e., 21 d) of mineral or organic fertilizer application on long‐term (i.e., 8 yr of applications) amended soil on denitrifier community abundance, denitrification gene mRNA transcript numbers, denitrification rate, and emissions of N2O were explored. Soil was collected from a vineyard in Italy receiving annual applications of either mineral fertilizer (conventional management system, CS) or municipal compost (organic management system, OS). Each soil was incubated using three treatments: no amendment, NH4NO3, or municipal compost. Microcosms set up with soil treated with compost showed higher nirS, nirK, and nosZ abundance in comparison to conventional fertilization. Short‐term compost addition increased nirK gene abundance over time in OS and CS soils, whereas nirS and nosZ gene abundance increased after compost addition only in OS soil. In OS soil, nosZ gene mRNA transcript numbers were higher at all time‐points for all treatments compared with CS soil. Furthermore, nosZ gene mRNA transcript number increased over time after compost addition for both soils, N2O emissions were higher in both soils after NH4NO3 addition compared with no amendment and compost addition. Denitrification was higher in OS than CS soil following NH4NO3 treatment. Denitrification rates were much higher than N2O rates in all cases suggesting most emissions occurred as N2. Our study demonstrated that long‐term urban‐waste compost application clearly changed soil denitrifier communities and the response of denitrification and N2O emissions to different short‐term soil amendments.

Consequences on macroporosity and bacterial diversity of adopting a no-tillage farming system in a clayish soil of Central Italy

“…In contrast, N fertilization seemed to have a negative influence on the richness and diversity of active nosZ bacterial community and supported the hypothesis that fertilizer management could affect the N 2 O:N 2 emission ratio from denitrification and consequently the potential activity of bacteria involved in the last step of denitrification process (Philippot et al, 2007). Moderate to important modifications in the structure of the denitrifying community in response to fertilizer addition have been reported depending on the type of fertilizer and also on the time scale of the field experiment (Philippot et al, 2007;Chèneby et al, 2009;Tatti et al, 2012).…”

Soil properties impacting denitrifier community size, structure, and activity in New Zealand dairy-grazed pasture

“…To a lesser extent nir richness, diversity and abundance correlated with other measures of soil fertility such as increase in pH, soluble C, and NH 4 + contents, these findings agree with previous studies that have found the composition of soil denitrifier communities to be sensitive to a variety of soil chemical characteristics (Jones and Hallin, 2010;Reyna et al, 2010;Chon et al, 2011;Miller et al, 2008;Tatti et al, 2013).…”

New model for capturing the variations of fertilizer‐induced emission factors of N2O

“…E-N relationships corresponding to the subfunctions of EFs are illustrated in Figure 2 for upland grain crops and paddy rice under positive or negative ΔEFs. The diagnostic of negative ΔEFs (Figures 2b and 2d) suggests that activity or efficiency of nitrifier and denitrifier communities may reach thresholds and further stabilize around these thresholds, when N inputs exceed crop requirements [Ju et al, 2009;Tatti et al, 2013]. However, the strange decrease in E (as the green line in Figure 2b and ΔEF = À0.0037% · kg À1 N 2 O-N · ha) does not have a satisfactory theoretical explanation, though this type of trend was occasionally observed [van Groenigen et al, 2004;Hoogendoorn et al, 2008;Iqbal, 2009;Wang et al, 2011a;Zhang et al, 2012;Signor et al, 2013;Zhou et al, 2013].…”