Human-altered soils – Signatures of Anthrosols and their potential for arable lands

● Past human activities result in the formation of Anthrosols and the accumulation of nutrients. ● Enrichment in physicochemical properties relates to the intensity of settlement activities. ● The level of releasability contributes to the extended retention of nutrients in soils. ● Past settlement sites represent nutrient-rich Anthrosols suitable for arable fields. The fertility of human-altered soils, Anthrosols, developed from past settlement activities for crop production is scarcely studied. The study evaluated the fertility of Anthrosols developed from the 15th to mid-20th century AD settlement in Old Buipe, Savanna region, Ghana, to determine whether abandoned localities are suitable for arable fields. Human activities enhanced the physical attributes of the Anthrosols: brown to dark brown intergrain fine soil, 15%−35% organic matter, 15%−30% potsherd, and 5%−15% charred materials. The Anthrosols were slightly acidic to neutral reactions (<inline-formula><math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="mathml_Z-20221125100116" display="inline" overflow="scroll"><mml:mrow class="MJX-TeXAtom-ORD"><mml:mtext mathcolor="red">\textcolor</mml:mtext><mml:mo stretchy="false">[</mml:mo><mml:mi>R</mml:mi><mml:mi>G</mml:mi><mml:mi>B</mml:mi><mml:mo stretchy="false">]</mml:mo><mml:mrow class="MJX-TeXAtom-ORD"><mml:mn>32</mml:mn><mml:mo>,</mml:mo><mml:mn>147</mml:mn><mml:mo>,</mml:mo><mml:mn>147</mml:mn></mml:mrow><mml:mrow class="MJX-TeXAtom-ORD"><mml:msub><mml:mrow class="MJX-TeXAtom-ORD"><mml:mrow class="MJX-TeXAtom-ORD"><mml:mi mathvariant="normal">p</mml:mi><mml:mi mathvariant="normal">H</mml:mi></mml:mrow></mml:mrow><mml:mrow class="MJX-TeXAtom-ORD"><mml:mo stretchy="false">[</mml:mo><mml:msub><mml:mrow class="MJX-TeXAtom-ORD"><mml:mrow class="MJX-TeXAtom-ORD"><mml:mi mathvariant="normal">H</mml:mi></mml:mrow></mml:mrow><mml:mn>2</mml:mn></mml:msub><mml:mrow class="MJX-TeXAtom-ORD"><mml:mrow class="MJX-TeXAtom-ORD"><mml:mi mathvariant="normal">O</mml:mi></mml:mrow></mml:mrow><mml:mo stretchy="false">]</mml:mo></mml:mrow></mml:msub></mml:mrow></mml:mrow></math></inline-formula> 5.67−6.83, <inline-formula><math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="mathml_Z-20221125100125" display="inline" overflow="scroll"><mml:mrow class="MJX-TeXAtom-ORD"><mml:mtext mathcolor="red">\textcolor</mml:mtext><mml:mo stretchy="false">[</mml:mo><mml:mi>R</mml:mi><mml:mi>G</mml:mi><mml:mi>B</mml:mi><mml:mo stretchy="false">]</mml:mo><mml:mrow class="MJX-TeXAtom-ORD"><mml:mn>32</mml:mn><mml:mo>,</mml:mo><mml:mn>147</mml:mn><mml:mo>,</mml:mo><mml:mn>147</mml:mn></mml:mrow><mml:mrow class="MJX-TeXAtom-ORD"><mml:msub><mml:mrow class="MJX-TeXAtom-ORD"><mml:mrow class="MJX-TeXAtom-ORD"><mml:mi mathvariant="normal">p</mml:mi><mml:mi mathvariant="normal">H</mml:mi></mml:mrow></mml:mrow><mml:mrow class="MJX-TeXAtom-ORD"><mml:mo stretchy="false">[</mml:mo><mml:mrow class="MJX-TeXAtom-ORD"><mml:mrow class="MJX-TeXAtom-ORD"><mml:mi mathvariant="normal">C</mml:mi><mml:mi mathvariant="normal">a</mml:mi><mml:mi mathvariant="normal">C</mml:mi><mml:msub><mml:mi mathvariant="normal">l</mml:mi><mml:mn>2</mml:mn></mml:msub></mml:mrow></mml:mrow><mml:mo stretchy="false">]</mml:mo></mml:mrow></mml:msub></mml:mrow></mml:mrow></math></inline-formula> 5.83−6.95), high cation exchange capacity (CEC; 18.77−45.31me/100 g), electric conductivity (EC = 0.28−0.36 dS m−1), accumulation, and distribution of organic C, total N, P, Mn, Cu, Zn, K, and Fe, and available P, K, Ca, Mg, S, Mn, Fe, Cu, and Zn. Plant-available nutrients were comparatively higher than concentrations in non-anthropogenic soils. The level of releasability (bioavailable fractions of total concentrations) of P, K, Ca, Mn, Fe, Cu, and Zn partly compensates for low plant-available portions. Enrichment of chemical and physical properties of Anthrosols make them fertile for arable fields. The signatures of settlement activities are strong and can remain in soils for a long time, even under harsh environmental conditions.