Effects of Afforestation on Soil Bulk Density and pH in the Loess Plateau, China

Abstract

Sustainable land management requires a clear understanding of the changes in soil quality. In exploring whether afforestation has the potential to improve the soil quality in China’s Loess Plateau, soil bulk density ( ρ s ) and pH were compared under five treatments: three forested treatments (16-and 40-year-old apricot stands, and 40-year-old poplar stands), and individual abandoned and cultivated treatments, serving as the controls. Bulk density across the 0–1.0 m soil profile under the 16-year-old apricot treatment (1.12 Mg m−3) and 40-year-old poplar treatment (1.16 Mg m−3) were significantly smaller than their counterparts under the cultivated (1.20 Mg m−3) and abandoned treatments (1.23 Mg m−3). Soil pH of the cultivated treatment (8.46) was significantly lower than that of the abandoned treatment (8.51) or than that of any forested treatment. The ρ s and pH were both affected by stand age, with the ρ s and pH of the 40-year-old apricot treatment being 0.10 Mg m−3 and 0.05 units greater, respectively, than those of the 16-year-old apricot treatment. Treatment and soil depth appeared to interact to influence the ρ s , but this same interaction did not influence the soil pH. This study suggested that afforestation species and stand age should be taken into consideration to harvest maximum benefits from the afforestation efforts.

Effects of stand age on carbon storage in dragon spruce forest ecosystems in the upper reaches of the Bailongjiang River basin, China

“…As biotic and abiotic interactions strongly impact ecological processes, many studies have explored the effects of these interactions on variables (e.g. 63,64 ). For example, Wu et al .…”

“…Soil samples were taken at depths of 0–0.1 m, 0.1–0.2 m, 0.2–0.4 m, and 0.4–0.6 m, using a cutting ring (volume, 1.0 × 10 −4 m 3 ), and divided into two parts. Compared with other methods, this approach provided researchers with a better comparison of soil properties at multiple depths 39,63,71,73 . One part of each soil sample was used to measure ρ , f and θ , while the other part was used to measure pH, SOC, TN, TP, AN, AP and AK in each layer of the soil profile.…”

A Comparative Study of Rotation Patterns on Soil Organic Carbon in China’s Arid and Semi-Arid Regions

“…SBD was then calculated as SBD (Mg m −3 ) [37] = dry weight volume . The pH of a 2:5 soil: water suspension was measured using a Sartorius PB-10 pH meter [37], and the SOC (g kg −1 ) was determined with wet dichromate oxidation using an air-dried homogenized subsample of 0.2 g soil and titration with FeSO 4 [38].…”

“…This disagreement in results suggests that the relationship between SBD and soil depth is inconstant. The increase of SBD in the upper three soil layers was the result of sustained pressure from the upper layers [37]. In addition, SBD was affected by the amount of residue available in the soil; even when these residues were not mechanically mixed into the soil, but rather left on the surface, SBD decreased as organic materials were slowly incorporated into the surface soil by soil fauna [16].…”

Soil and Water Conservation in Agricultural and Forestry Systems

“…Sustainable forest management requires a clear understanding of the changes in soil quality owing to human activities. Zhang et al [13] evaluated the effects of afforestation on soil bulk density (BD) and pH in the Loess Plateau, China. These authors explored whether afforestation had the potential to improve the soil quality by comparing five treatments: three forested treatments (16-and 40-year-old apricot stands, and 40-year-old poplar stands), with individual abandoned and cultivated treatments serving as the controls.…”