Differential Impacts of Cropland Expansion on Soil Biological Indicators in Two Ecological Zones

Dora Neina () and Eunice Agyarko-Mintah
Additional contact information
Dora Neina: Department of Soil Science, School of Agriculture, College of Basic and Applied Sciences, University of Ghana, Legon, Accra P.O. Box LG 245, Ghana
Eunice Agyarko-Mintah: Biotechnology and Nuclear Agricultural Research Institute, Ghana Atomic Energy Commission, Legon, Accra P.O. Box LG 80, Ghana

Sustainability, 2023, vol. 15, issue 10, 1-14

Abstract: Agricultural expansion in Sub-Saharan Africa is characterized by different farm ages in smallholder communities. This study investigated changes in microbial indices broadly (i) at the reconnaissance survey level in four agro-ecological zones and (ii) in different farms at the forest (Dompem) and forest–savanna transition (Adansam) zones, as influenced by the duration of cultivation. Soils from one-year (first cultivation of cleared forest/fallow), three-year, five-year, and ten-year farms were analyzed for basic soil properties, active or labile carbon (POXC), basal respiration (BR), microbial biomass (C mic ) using permanganate oxidizable C, alkali trap, and chloroform fumigation incubation. In both study levels, POXC content was <1% of soil organic carbon (SOC) in all zones, higher in the wet agro-ecological zones, and positively correlated with SOC ( r = 0.70, 0.81; p < 0.01, p < 0.001). Dompem SOC and BR declined by 1–23% and 6–25% ( p < 0.001), respectively, in the first three years; C mic ( p = 0.002) and %C mic /SOC ( p = 0.610) decreased from three-year farms onwards. Conversely, the Adansam SOC, BR, C mic , and %C mic /SOC rather had irregular trends. The microbial indices were influenced by exchangeable acidity, the sum of exchangeable bases, and effective cation exchangeable capacity negatively or positively, followed by SOC, pedogenic compounds, particularly dithionite-citrate iron (Fe d ), oxalate iron (Fe ox ), and lastly, soil pH. Therefore, understanding the degree, direction, and changing aspects of these drivers of soil ecosystem services is necessary for sustainable soil management practices in different agro-ecological zones.

Keywords: basal respiration; farm types; labile carbon; metabolic quotient; microbial biomass (search for similar items in EconPapers)
JEL-codes: O13 Q Q0 Q2 Q3 Q5 Q56 (search for similar items in EconPapers)
Date: 2023
References: View references in EconPapers View complete reference list from CitEc
Citations:

Downloads: (external link)
https://www.mdpi.com/2071-1050/15/10/8138/pdf (application/pdf)
https://www.mdpi.com/2071-1050/15/10/8138/ (text/html)

Related works:
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: https://EconPapers.repec.org/RePEc:gam:jsusta:v:15:y:2023:i:10:p:8138-:d:1148934

Access Statistics for this article

Sustainability is currently edited by Ms. Alexandra Wu

More articles in Sustainability from MDPI
Bibliographic data for series maintained by MDPI Indexing Manager ().