Effects of different proportions of soft rock additions on organic carbon pool and bacterial community structure of sandy soil

Abstract

The sandy soil leaks water and fertilizer, and the ecological degradation is serious. The structural characteristics of soft rock and sandy soil are complementary, and the improvement of sandy soil by adding soft rock is of great significance to improve soil fertility, restore biodiversity, and maintain sustainable development of the Mu Us sandy land region. In this study, total organic carbon (TOC), particulate organic carbon (POC), dissolved organic carbon (DOC), easily oxidized organic carbon (ROC), microbial biomass carbon (SMBC), bacterial community structure and crop yield were examined using soft rock:sand volume ratios of 0:1 (CK), 1:5 (C1), 1:2 (C2) and 1:1 (C3). Our results indicated that, compared with the CK treatment, TOC (9.66–22.34%), POC (85.65–120.41%) and ROC (114.12–192.31%) noticeably increased in C1, C2 and C3 treatments; SMBC in treatment C3 increased by 42.77%. The three dominant bacteria in the soil (Proteobacteria, Actinobacteria and Chloroflexi), as well as Proteobacteria abundance, greatly declined in the treatments with the addition of soft rock. Pseudarthrobacter was the dominant Genus in all treatments, having an abundance between 11.83 and 19.33%. Bacterial diversity, richness and evenness indices all recorded an increase under the treatments. POC, TOC and SMBC recorded the most significant effects on the bacterial community structure. The largest increases in wheat and corn yields were recorded in the C2 treatment (16.05% and 16.30%), followed by the C1 treatment (8.28% and 8.20%, respectively). Our findings indicate that a soft rock:sand ratio between 1:5 and 1:2 recorded the most improvement in the sandy soil environment.

Internal Force Mechanism of Pisha Sandstone as a Soil Amendment to Improve Sandy Soil Structural Stability in Mu Us Sandy Land

“…After ten years of tillage management, the SOC content of compound soils increased with increasing PSS application rates (Table 1). This is consistent with prior literature [7,36], which also found significantly higher fertility in compound soils with the addition of Pisha sandstone compared to sandy soil. This result can be explained as follows: on the one hand, the addition of PSS to sandy soil increased the presence of fine particles, and Ingelmo et al (2003) indicated that the soil organic matter (SOM) tended to concentrate around these fine particles, allowing for the formation of more organic-inorganic complexes [37].…”

High-efficiency remediation of Hg and Cd co-contaminated paddy soils by Fe–Mn oxide modified biochar and its microbial community responses

“…The porous structure of BC and FMBC provided an ideal habitat for soil microbes, and the microorganism metabolism and the efficiency of C utilization were improved, so part of the LOC was decomposed by microorganisms, which increased the DOC concentration (Meng et al 2018). The portion of soil C that is readily oxidized by KMnO 4 is referred to as the ROC (Li et al 2021b). Compared with control, the ROC concentration was significantly increased by 25.45-44.99% and 15.61-23.97% after adding BC and FMBC, respectively (P < 0.05), which may be related to the decomposition of easily oxidized components on the surface of biochar materials, as well as the increase in root exudates and microbial activity (Yang et al 2018).…”