Mineralization of Farm Manures and Slurries for Successive Release of Carbon and Nitrogen in Incubated Soils Varying in Moisture Status under Controlled Laboratory Conditions

Abstract

Having up-to-date knowledge on the mineralization of organic materials and release of nutrients is of paramount significance to ensure crops’ nutrient demands, increase nutrient use efficiency and ensure the right fertilizer application at the right time. This study seeks to evaluate the mineralization patterns of various manures viz. cowdung (CD), cowdung slurry (CDSL), trichocompost (TC), vermicompost (VC), poultry manure (PM), poultry manure slurry (PMSL), and mungbean residues (MR). The objective being to establish their efficiency in releasing nutrients under aerobic (field capacity) and anaerobic (waterlogging) conditions. The incubation experiment was designed using a Completely Randomized Design (CRD) that took into account three variables: Manures, soil moisture, and incubation period. The mineralization of carbon (C) and nitrogen (N) ranged from 11.2 to 100.1% higher under aerobic conditions rather than anaerobic ones. The first-order kinetic model was used to mineralize both elements. C mineralization was 45.8 to 498.1% higher in an amount from MR under both moisture conditions. For N release, MR and PM exerted maximum amounts in anaerobic and aerobic scenarios, respectively. However, the rate of C and N mineralization was faster in TC compared to other manures in both moisture conditions. Although TC was 1.4 to 37.7% more efficient in terms of rapidity of mineralization, MR and PM performed better concerning the quantity of nutrient release and soil fertility improvement. PM had 22–24% higher N mineralization potential than PMSL while CDSL had 46–56% higher N mineralization potential than CD. C and N mineralization in soil was greater under aerobic conditions compared to what occurred in the anaerobic context. Depending on mineralization potential, the proper type and amount of manure should be added to soil to increase crops’ nutrient use efficiency, which in turn should lead to better crop production.

Carbon and nitrogen dynamics in agricultural soil after application of cattle manure and eastern redcedar wood chips

“…The CO 2 ‐C release rates for all amendments were greatest during the first 30 days of the experiment and decreased over time ( p ≤ 0.05; Figure 3; Table S6). Previous studies documented an exponential decrease in C respiration for different types of organic amendments over time (Bechini & Marino, 2009; Cavalli et al., 2017; Dodor et al., 2018; Helgason et al., 2004; Islam et al., 2021; Morvan & Nicolardot, 2009). This is related to the decomposition of more labile organic components that are easily oxidizable by microbes in early stages.…”

“…To predict the time required for varying degrees of decomposition, rate constants ( k ) were calculated using a first‐order decay model as follows:$$$$\begin{equation*}{{\;}}{C_t} = {C_0}\;({{ex}}{{{p}}^{ - kt}})\end{equation*}$$$$where C t is the C content in the amendment at time t , C 0 is the initial C content in the amendment, k is the first‐order rate constant, and t is time (days). First order decay models are valued due to their simplicity in interpretation and have been used to predict decomposition rates for multiple organic materials including animal manures (Islam et al., 2021; Murwira et al., 1990; Saviozzi et al., 1993) and wood products (Johnson et al., 2014). Once rate constants ( k ) were generated for each treatment, the time required for 50%, 75%, 90%, and 99% C mineralization of the amendment was estimated based on the following equations (Al‐Kaisi et al., 2017): $$$$\begin{equation*}{\mathrm{\;}}{t_{\left( {0.50} \right)}} = \ln 2\;({k^{ - 1}}\;),\end{equation*}$$$$$$$$\begin{equation*}{\mathrm{\;}}{t_{\left( {0.75} \right)}} = \ln 4\;({k^{ - 1}}\;),\end{equation*}$$$$$$$$\begin{equation*}{\mathrm{\;}}{t_{\left( {0.90} \right)}} = \ln 10\;({k^{ - 1}}\;),\end{equation*}$$$$…”

“…where C t is the C content in the amendment at time t, C 0 is the initial C content in the amendment, k is the first-order rate constant, and t is time (days). First order decay models are valued due to their simplicity in interpretation and have been used to predict decomposition rates for multiple organic materials including animal manures (Islam et al, 2021;Murwira et al, 1990;Saviozzi et al, 1993) and wood products (Johnson et al, 2014). Once rate constants (k) were generated for each treatment, the time required for 50%, 75%, 90%, and 99% C mineralization of the amendment was estimated based on the following equations (Al-Kaisi et al, 2017):…”

“…All treatments showed statistically significant differences from each other at the end of the experiment. These values represent NNM of 9.8% (mineralized), 12.3% (mineralized), Negative NNM values were observed for WC at the conclusion of the 120-day experiment, meaning it immobilized N. Nitrogen mineralization rates in organic amendments applied to soils have been shown to be connected with the total organic N and C:N ratio of the amendments (Islam et al, 2021;Morvan et al, 2006). Treatment WC had the lowest concentration of organic N and a C:N ratio of 124.4, whereas CM and MW had larger organic N pools and C:N ratios of 10.7 and 22.2, respectively.…”

Biochar and Compost-Based Integrated Nutrient Management: Potential for Carbon and Microbial Enrichment in Degraded Acidic and Charland Soils

“…Using the measured SOC, MBC, POC, and POX C data, the CMI was calculated (Islam et al, 2021d;Begum et al, 2021;Franzluebbers, (2002)) as follows:…”