Effects of inorganic and organic fertilizers on CO2 and CH4 fluxes from tea plantation soil

Abstract

Agricultural practices such as fertilization considerably influence soil greenhouse gas fluxes. However, the effects of fertilization on greenhouse gases fluxes remain unclear in tea soil when soil nitrogen is low. In the present study, soil CO2 and CH4 fluxes under various fertilization treatments in tea soil were investigated during a 50-day period. The experiment consisted of five treatments: no fertilizer (CK), single nitrogen (urea, N), single oilseed rape cake fertilizer (R), nitrogen + cake fertilizer (2:1, NR1), and nitrogen + cake fertilizer (1:2, NR2). The fertilization proportion of NR1 and NR2 was determined by the nitrogen content of nitrogen fertilizer and cake fertilizer. The results revealed that the single application of nitrogen had no significant effect on soil CO2 flux. However, the addition of cake fertilizer significantly increased CO2 emissions through enhanced soil microbial biomass carbon (MBC). Additionally, CO2 emissions were directly proportional to the amount of carbon (C) in the fertilizer. All treatments were minor sinks for CH4 except for the treatment NR1. Specifically, the cumulative CH4 fluxes of NR1 and NR2 were significantly higher than rest of the three treatments, which implies that application of urea and oilseed rape cake reduced the capability of CH4 oxidation in tea soil. Structural equation models indicated that soil CO2 flux is significantly and positively correlated with soil dissolved organic carbon, MBC and soil pH, while mineral nitrogen content was the main factor affecting CH4 flux. Overall, the application of oilseed rape cake increased the oxidation of CH4 and promoted soil C sequestration but inevitably increased the soil CO2 emissions.

Short-Term Assessment of Nitrous Oxide and Methane Emissions on a Crop Yield Basis in Response to Different Organic Amendment Types in Sichuan Basin

“…Previous studies have reported that the use of organic amendments such as manures, composts, and crop residues could affect the CH 4 uptake capacity of soils [68]. In our study, however, such a relationship was not found.…”

“…These studies report a range of values varying over approximately one order of magnitude. In this study, the combined GWP across all the treatments ranged from 161.2 kg CO 2 eq ha −1 for PMRC to 412.0 kg CO 2 eq ha −1 for the NPK treatment, which was within the range of GWP reported by Linquist et al (2012) from a meta-analysis of 62 studies and 328 global observations [42], and similar to the values obtained during the maize season within the area, and from previous studies in wheat systems reported in the area [5,68,70]. The combined GWP for N 2 O and CH 4 observed during the maize season were significantly lower for all the organically amended treatments than the NPK treatment, as seen in Table 3.…”

Integrated nutrient management - promising way to reduce carbon dioxide and methane emission in flooded rice ecosystem: A review

“…The application of organic and inorganic fertilizers highly influence soil CO 2 and CH 4 emissions (Nyamadzawo et al, 2014).In addition to that application of organic fertilizers can enhance microbial decomposition activities and root respiration, leading to the increase of the CO 2 emission of soil (Qiu et al, 2015;. Addition of oil cake fertilizer significantly increased soil MBC content and CO 2 emissions, especially single cake fertilizer alone nourished treatments showed the highest emissions (Lin et al, 2021).…”

“…Fertilizers with low C/N ratio can substantially increase the decomposition of residues and contribute to GHG emissions (Zhou et al, 2019). Similarly, some research studies have shown that soil respiration was positively correlated with soil DOC and soil microbial biomass carbon (MBC) and application of nitrogenous fertilizers was not influenced CH4 emission (Lin et al, 2021).…”

“…Application of FYM @ 12.5 t ha -1 integrated with 100% RDF + Azospirillum and Phosphobacteria @ 2 kg ha -1 recorded a lower value of 4.4 and 2.06, 7.2 and 1.94 and 2.7 and 1.59 mg m -2 h -1 CH 4 emission during both the day and night time at 40, 80 DAS and at harvest respectively over other organic manure combinations during the Thaladiseason of the rice crop (Ravikumar and Ganapathy, 2018). The integrated application of urea and oilseed rape cake fertilizer reduced the emission of CO2, whereas enhanced the emissions of CH4 (Lin et al, 2021).…”