Organic Residues and Ammonium Effects on CO2 Emissions and Soil Quality Indicators in Limed Acid Tropical Soils

Abstract

Aglime (agricultural lime), commonly applied to acid soils to increase the soil pH and productivity, may lead to the release of CO2 into the atmosphere or to carbon (C) sequestration, although the processes involved are not fully understood. As large acreages of arable land are limed annually, exploring soil management practices that reduce aglime-induced CO2 emissions from acid soils while maintaining or improving the soil quality is paramount to mitigating the effects of global climate change. This study, therefore, assessed the effects of organic residues and ammonium on CO2 emissions and soil quality indicators in two limed soils. Two contrasting acid soils (Nariva series, Mollic Fluvaquents and Piarco series, Typic Kanhaplaquults) were amended with varying combinations of aglime (0% and 0.2% w/w CaCO3), organic residue (0% and 5% w/w biochar or poultry litter), and NH4-N (0% and 0.02% w/w) and were incubated in 300 mL glass jars for 31 days. The sampling for CO2 was performed on 11 occasions over the course of the incubation, while soil sampling was conducted at the end. The results indicate that aglime application significantly (p < 0.05) increased the cumulative CO2 emissions in all cases except with the addition of poultry litter. Alternatively, ammonium did not regulate the effect of aglime on CO2 emissions, which was l because of the low rate at which it was applied in comparison to aglime. The results also showed that poultry litter significantly (p < 0.05) increased the soil electrical conductivity (EC), available nitrogen (N), and pH, especially in the Piarco soil, while the hardwood biochar had little to no effect on the soil properties. Our findings indicate the potential for utilizing poultry litter to reduce the impact of aglime on CO2 emissions while improving the soil quality. Further studies utilizing 13C to trace aglime CO2 emissions are, however, required to identify the mechanism(s) that contributed to this reduction in the emissions.

Organic carbon mineralization of the biochar and organic compost of poultry litter in an Argisol

“…During the 61 days of incubation, a cumulative increase of C-CO 2 was observed due to the application of increasing doses of biochar and organic compost (Figures 2A and 2B). The observation is in agreement with the results of Sistani, Simmons, Jn-Baptiste and Novak (2019), and Bramble et al (2019).…”

“…These results are corroborated by Cross andSohi (2011), andSagrilo, Jeffery, Hoffland andKuyper (2015). The C-CO 2 evolution decreases in soils incubated with biochar (Shen et al, 2017;Bramble, Gouveia, & Ramnarine, 2019), suggesting a low amount of degradable substrate, and access of more recalcitrant by the microbes with time, at lower rates (Andrade, Oliveira, & Cerri, 2006).…”

Effects of Lime Application and Understory Removal on Soil Microbial Communities in Subtropical Eucalyptus L’Hér. Plantations

“…Acrisol is a common type of soil, distributed mainly in humid tropical/subtropical and even warm temperate regions, such as Southern Asia, South China, and Southeast US [7]. Lime application is one of the most widely applied management practices for amending Acrisol [8]. In addition to lowering soil acidity, lime application could improve soil structure, and thus typically promote agriculture and forest productivities [4,9].…”

“…Therefore, the soil microbial community generally shifts from fungi to bacteria as the pH increases after lime application [15]. However, most of these studies focused on the soil microbial communities in agricultural soil [8,16]. We still have a poor understanding of how fungal and bacterial communities respond to lime application in forests, especially for Eucalyptus plantations in South China where soils are strongly acidic.…”

The Role of Organic Fertilizers in Transition to Sustainable Agriculture in the MENA Region

“…The use of agricultural lime to improve acidic soils can either lead to increased release of CO 2 in the atmosphere, or to carbon sequestration. For instance, Bramble, Gouveia and Ramnarine [81] found that combining the application of agricultural lime with poultry litter prevented CO 2 emissions. Finally, it is important to also consider energy conservation in climate mitigation strategies.…”