Organic Matter Fractions in a Quartzipsamment Under Cultivation of Irrigated Mango in the Lower São Francisco Valley Region, Brazil

Abstract

aBstractimproper land use has lead to deterioration and depletion of natural resources, as well as a significant decline in agricultural production, due to decreased soil quality. Removal of native vegetation to make way for agricultural crops, often managed inadequately, results in soil disruption, decreased nutrient availability, and decomposition of soil organic matter, making sustainable agricultural production unviable. Thus, the aim of the present study was to evaluate the impact of growing irrigated mango (over a 20 year period) on the organic carbon (Oc) stocks and on the fractions of soil organic matter (sOM) in relation to the native caatinga (xeric shrubland) vegetation in the lower são Francisco valley region, Brazil. The study was carried out on the Boa Esperança Farm located in Petrolina, Pernambuco, Brazil. In areas under irrigated mango and native caatinga, soil samples were collected at the 0-10 and 10-20 cm depths. After preparing the soil samples, we determined the Oc stocks, carbon of humic substances (fulvic acid fractions, humic acid fractions, and humin fractions), and the light and heavy SOM fractions. Growing irrigated mango resulted in higher Oc stocks; higher c stocks in the fulvic acid, humic acid, and humin fractions;

Climate Change Impacts on Net Ecosystem Productivity in a Subtropical Shrubland of Northwestern México

“…Along with the simulated SWC and T soil conditions, litterfall determined inputs to the SCM from which heterotrophic respiration ( R h ) fluxes were simulated (Figure b). Simulated carbon amounts in the litter and microbial biomass pools ranged from 20 to 200 g C m −2 and from 70 to 130 g C m −2 , respectively, whereas the carbon amount in the humus pool remained relatively stable at 895–900 g C m −2 during the study period, similar to measured values in semiarid shrublands (e.g., Bolton, Smith, & Link, ; Cardoso et al, ; Cheng et al, ; Goberna et al, ). As expected, low amounts of R h occur during the winter and spring and increase substantially after the first rainfall event during the NAM due to the available SWC and labile substrate, consistent with Verduzco et al () and Zhang et al ().…”

“…the study period, similar to measured values in semiarid shrublands (e.g., Bolton, Smith, & Link, 1993;Cardoso et al, 2015;Cheng et al, 2015;Goberna et al, 2007). As expected, low amounts of R h occur during the winter and spring and increase substantially after the first rainfall event during the NAM due to the available SWC and labile substrate, consistent with Verduzco et al (2015) and Zhang et al (2014).…”

Assessment of Sequestered Organic Carbon and Its Pools Under Different Agricultural Land-Uses in the Semi-Arid Soils of South-Western Punjab, India

“…The recorded values of POC status were highest under orchards in our study which corroborates with many other findings (Gale et al 2000;Jamala and Oke 2013;Niaz et al 2017). This may be attributed to year-round decomposition of litter biomass and addition of root exudates as orchards have deep and well-developed root systems (Cardoso et al 2015). Thus, greater magnitude of POC under orchards, particularly the fruit trees, imparts a positive impact on stable C build-up (Guimaraes et al 2014).…”

Impact of deforestation on the soil physical and chemical attributes, and humic fraction of organic matter in dry environments in Brazil

“…The similarity of TOC contents between PNV and EAC areas in the soil surface layer showed that increase in TOC content is favored by continuous deposition of litter and by the presence of more developed root systems on the surface (Cardoso et al 2015, Monroe et al 2016, which may contribute to maintain soil moisture and reduce soil erosion (Fultz et al 2013). In this study, the reduction of TOC in the DNV and CCC areas indicated that the soil preparation, which exposes SOM to weathering, and the lack of conservation practices in the CCC area have reduced physical protection of SOM and left the soil exposed to erosion (Melo et al 2016, Villarino et al 2017.…”