Residue decomposition and priming of soil organic carbon following different NPK fertilizer histories

Abstract

The effect of mineral fertilizer practices on increasing crop yield has been well studied, but few studies have examined the influence of different long-term subtractive fertilization designs on decomposition of crop residues or influence of soil organic carbon (SOC) levels. To assess the combined effects of the long-term (27 yrs) subtractive fertilizer inputs on SOC mineralization rates, we studied the change in added 13 C-labelled corn stem and leaf residue decomposition and the magnitude of priming effect (PE) on SOC in a 56-day lab incubation. The long-term history of nitrogen (N), phosphorus (P) and potassium (K) combinations showed that coupling N and P fertilization had a strong effect on SOC content, which increased by 6% relative to the unfertilized treatment. SOC mineralization rates with no residue added were highest in soils that received N, P and K. Cumulative CO 2 production in soils amended with residue was significantly affected by residue type and was 9-19% higher for leaves than stems across treatments with varied fertilization histories. After a 56-day incubation 14-16% of leaf carbon (C) and 18-19% of stem C was mineralized. The cumulative PE was significantly higher in the unfertilized soil with leaf addition, but was not affected by residue type in other treatments. Our data show that crop residue decomposition and SOC is affected by historical N, P and K fertilization, with long-term complete NPK application resulting in greater SOC content and slower SOC mineralization rates.

Influence of woodchip size and nitrogen fertilization on carbon dioxide and nitrous oxide emissions from soils amended with orchard biomass

“…They concluded that N fertilization decreases SOM decomposition and increases the efficiency of C sequestration in soil through higher portions of un-decomposed crop residues. You et al (2020) assessed the combined effects of the long-term (27 years) subtractive fertilizer inputs on SOC mineralization rates and concluded that crop residue decomposition and SOC is affected by historical N, P, and K fertilization, with long-term complete NPK application resulting in greater SOC content and slower SOC mineralization rates with corn leaf addition. All the data indicated the positive role of N application in soil C retention.…”

Topographic attributes override impacts of agronomic practices on prokaryotic community structure

“…Moreover, rotation × N fertilizer interaction affected bacterial richness, evenness, and Shannon indices (Table 5). Many studies have exploited the fact that crop residues along with the application of N fertilizer are capable of boosting soil C and N inputs due primarily to higher organic residue deposition within the field (Adiku et al, 2008;Lupwayi et al, 2018;Verzeaux et al, 2016;You et al, 2020). According to Lupwayi et al (2018), the appropriate application of mineral N fertilizer accompanied with the effective turnover of organic amendments such as cover crops is vital in supporting the diversity of soil microbiota.…”

Priming of carbon decomposition in 27 dairy grazed soils after bovine urine additions

“…Capture of CO 2 was undertaken to assess microbial activity, and therefore priming, response to urine additions (e.g. Lambie et al 2013;Zhang et al 2017;Chen et al 2019;You et al 2020). Following solution application, each core was placed into 2.2 L plastic containers (Sistema, Auckland, New Zealand), with 40 mL of 2 M sodium hydroxide solution to trap CO 2 , sealed, and incubated at 25°C, in the dark, for 21 days (Lambie et al 2013).…”