With the intensification of agricultural production, the significance of soil biological health and microbial network structure has grown increasingly critical. Replacing chemical fertilizers with organic ones has garnered widespread attention as an effective strategy for enhancing soil quality. This study explored the mechanisms of how partial substitution of chemical fertilizers with organic ones affects the microbial community structure in soybean rhizosphere soil of Albic soil. Potting trials and high-throughput sequencing analysis revealed that, compared with conventional fertilization, the soil ACE and Chao1 diversity indices in the treatment with 75% organic fertilizer substitution significantly increased by 19.49% and 21.02%, respectively. The soil pH, organic matter, total phosphorus (TP), effective phosphorus (AP), and hydrolyzed nitrogen (HN) levels exhibited a marked increase of 4.33%, 18.67%, 20.90%, 23.35%, and 32.97% with high levels of organic fertiliser replacement, as compared to NPK. Meanwhile, the dominant phyla of Proteobacteria and Basidiomycota significantly increased by 36.11% and 286.79%, respectively. LEfSe analysis revealed that the fungal community was more sensitive to the fertilizer application strategy than the bacterial communities. Furthermore, redundancy analysis (RDA) demonstrated that soil pH and organic matter were primary environmental factors influencing microbial community structure. The co-occurrence network analysis showed that the partial utilization of organic fertilizers could strengthen the interrelationships among species, leading to a more complex and dense bacterial network. The findings can offer a significant scientific foundation for refining the fertilization strategies for Albic soil and facilitating the shift from conventional to sustainable agricultural practices.
This research targets straw return in Farm 852’s albic soil, China. The soil is nutrient-poor with few microbes and slow straw decomposition. Through fixed-point sampling and bacterial screening, an actinomycete consortium consisting of four strains was assembled, and two of them were identified as new actinomycetes. After 7 days of fermentation, the lignocellulose degradation rates of this consortium outstripped those of single strains, with cellulose degraded at 69.07%, hemicellulose at 64.98%, and lignin at 68.95%. FTIR, XRD, and SEM verified the damage inflicted on the straw structure. Lab simulations found group D (with the consortium) had a higher straw weight loss rate than group C (with commercialized microbial agents) and controls. The compound actinomycetes stepped up the bacterial abundance with the passage of time. In contrast, their effect on fungal abundance was hardly noticeable, but they had markedly ameliorated the soil fertility. These findings prove that the microbial consortium effectively accelerates straw decomposition and boosts soil microbe abundance and fertility in albic soil. It shows great potential for straw return and provides a microbial solution for this field.
Albic soil, which is generally oligotrophic, is a typical low-yield soil widely distributed in China. It is still unclear how to effectively improve soil fertility and strengthen the sustainable development of agricultural cultivation. For this purpose, 8-year field experiments were performed to determine the effects of continuous rice straw return on soil nutrient characteristics, yield, and the soil microbial community. Straw incorporation into albic soil significantly contributed to nutrient accumulation, containing alkali-hydrolysed nitrogen, available phosphorus, available potassium, and total organic carbon, thereby increasing rice yield. The number of spikelets per panicle increased from 93.96 to 97.58, and the grain filling value increased from 88.11 to 91.44%. Additionally, rice yield increased over the 8 consecutive years of straw return, and the rice yield of straw return treatments ranged from 10,048.27 to 10,605.18 kg/ha. High-throughput sequencing and classification revealed that the composition of bacterial and fungal communities was similar among treatments, but there were significant differences in species abundance, which was associated with lignocellulose degradation. Overall, the continuous return of straw, a native organic material, is a promising approach for soil amendment, with resource-saving and environmentally friendly characteristics.
The main soil type in the Sanjiang Plain of Northeast China, dryland albic soil is of great significance for studying nutrient distribution characteristics. This study focuses on 852 Farm in the typical dryland albic soil area of the Sanjiang Plain, using a combination of paired t-test, geostatistics, correlation analysis, and principal component analysis to systematically reveal the spatial differentiation of soil nutrients in the black soil layer and white clay layer of dryland albic soil, and to clarify the impact mechanism of plow layer nutrient characteristics on crop productivity. The results show that the nutrient content order in both the black and white clay layers is consistent: total potassium (TK) > organic matter (OM) > total nitrogen (TN) > total phosphorus (TP) > alkali-hydrolyzable nitrogen (HN) > available potassium (AK) > available phosphorus (AP). Both layers exhibit a spatial pattern of overall consistency and local differentiation, with spatial heterogeneity dominated by altitude gradients—nutrient content increases with decreasing altitude. Significant differences exist in nutrient content and distribution between the black and white clay layers, with the comprehensive fertility of the black layer being significantly higher than that of the white clay layer, particularly for TN, TP, TK, HN, and OM contents (effect size > 8). NDVI during the full maize growth period is significantly positively correlated with TP, TN, AK, AP, and HN, and the NDVI dynamics (first increasing. then decreasing) closely align with the peak periods of available nitrogen/phosphorus and crop growth cycles, indicating a strong coupling relationship between vegetation biomass accumulation and nutrient availability. These findings provide important references for guiding rational fertilization, agricultural production layout, and ecological environmental protection, contributing to the sustainable utilization of dryland albic soil resources and sustainable agricultural development.
In this study, a method for creating networked macropores through tillage using Eisenia fetida attracted by food sources derived from decomposing straw was proposed. The effects of Eisenia fetida activity and corn stalk addition, as well as the synergistic effects of Bacillus subtilis, on macropore formation were systematically studied. A 3D visualization technique was used to render the pore network model. When compared with undisturbed soil, the results demonstrate that cultivation using earthworms attracted by food sources from decomposing straw creates a soil pore structure with the most significant effect. The 3D porosity of the soil increased 6.90-fold, its average pore volume increased 5.49-fold, and its equivalent diameter increased 4.88-fold. Cylindrical pores, which accounted for the largest proportion (4.38%), had a channel radius of 1–5 mm and comprised approximately 86.7% of all macropores. The channel length increased by 28.5%, the average roundness decreased by 2.5%, and the average coordination number increased by 33.3%. The macroporous network structure formed by these earthworm-generated pores was more beneficial for improving the structure of phaeozem, offering technical support for the field application of earthworm farming.