Effects of Long-term Fertilization History and Current N and S Fertilizer Applications on Nitrous Oxide Production from S-deficient Soils in a Laboratory Incubation

Abstract

Nitrous oxide (N 2 O) production in four soils with unique fertilization management historiescollected from long-term fertility treatments receiving no fertilizer, NPKS, PKS, and NPK in a 5 yr cereal-forage rotationin response to three sources of added N [100 kg N ha −1 urea, NH 4 Cl, Ca(NO 3) 2 ] with and without co-addition of elemental S (20 kg S ha −1) plus a 0-N and 0-S control was investigated in a 7 wk laboratory incubation in a loamtextured soil at 40% water-filled pore space. In all soils, cumulative N 2 O emissions and apparent, cumulative, net nitrification were significantly higher following addition of urea compared with other N fertilizers with and without co-addition of elemental S. Lower N 2 O emissions were observed in soils without a history of long-term N fertilization following addition of urea compared with soils that had historically received urea. Because the preincubation soil total N levels were similar in soils with a history of urea application (NPKS) and without urea (PKS), the results of this investigation suggest that the higher N 2 O production in the NPKS soil may be the result of a priming effect and (or) changes in microbial community composition induced by long-term urea applications rather than differences in the long-term soil N balance.

Soil nitrous oxide emissions most sensitive to fertilization history during a laboratory incubation

“…It is not clear why this process would be in operation in the NPKS soil but not in the PKS soil, when both showed similar level of nitrification and S oxidation. It should be noted that the same soil (same long-term fertilization history) did not show a reduction in N 2 O emissions compared with other soils that had received long-term applications of N or S fertilizers in response to N fertilizer additions in a subsequent laboratory incubation described in a Giweta et al (2017a). Note: Values in the same column followed by the same letters are not significantly different at (P < 0.05) probably level using least significant difference-based pairwise comparison.…”

“…However, when grouped according to added fertilizers, there was a positive, linear relationship between NO 3 − -N supply and N 2 O emissions in fertilizer treatments. Therefore, the implication of our results for nutrient management, in terms of reduction the GHG emissions, is that soil management history, and the long-term soil N balance, significantly influences soil N 2 O emissions in response to N fertilizers added within the growing season of observation (Giweta et al 2017a(Giweta et al , 2017b. It is, therefore, likely that some of the variation in soil N 2 O emissions between fields with similar soil types within a given agroclimatic region is based on differences in management history, complicating accurate quantification of GHG inventories.…”

“…Long-term experiments have shown that long-term soil management practices such as rotation, tillage, and fertilization affect soil nutrient cycling, crop response to fertilizer, soil C and N stocks, and GHG emissions (Skiba and Smith 2000;Richter et al 2007;Drury et al 2008Drury et al , 2014Malhi et al 2010;Li-mei et al 2011;Venterea et al 2011;Malhi 2012;Giweta et al 2014Giweta et al , 2017aGiweta et al , 2017bLaHue et al 2015;Pearce 2016;Dyck and Puurveen 2020). With respect to soil N 2 O emissions, there has been much focus in the literature on the contribution of applied fertilizer N to annual or growing season emissions in proportion to the rate of application within the growing season of application.…”

“…Because details of soil management history are not often available, or because management history is homogeneous within experiments, the contribution of historical fertilizer applications and crop rotations to soil N 2 O emissions is not often quantified. Previous investigations have shown that the long-term soil N balance, determined by the sum of historical N inputs (fertilizers, crop residues, and biologically fixed N) and losses (harvest removals, leaching, and gaseous emissions), is a significant factor affecting soil N 2 O emissions in response to contemporary fertilizer N applications (Skiba and Smith 2000;Drury et al 2008Drury et al , 2014Li-mei et al 2011;Venterea et al 2011;LaHue et al 2015;Pearce 2016;Giweta et al 2017aGiweta et al , 2017b. Further, the aforementioned potential interaction between N and S transformations with respect to soil N 2 O emissions suggests that the form of N and S in applied fertilizers, and the potential interaction with soil N and S pools that have been influenced by historical management, may affect soil N 2 O emissions.…”