Search Results (53)

Meadow albic soils in the Sanjiang Plain of Northeast China are characterized by a compact plow layer, weak structural stability, low organic matter content, and limited nutrient availability, which restrict crop productivity in maize–soybean rotation systems. A two-year field experiment (2023–2024) was conducted to compare the effects of mineral fertilizer alone (CF) and CF combined with carbon-based organic fertilizer (CF+COF), humic acid organic fertilizer (CF+HA), or biochar-based fertilizer (CF+BC) on soil properties and crop yield. Soil aggregate composition, pH, organic carbon, total nitrogen, alkali-hydrolyzable nitrogen, available phosphorus, available potassium, and enzyme activities were measured together with yield and 100-grain weight. Compared with CF alone, the combined application of organic amendments generally improved soil properties and increased crop yield, although the magnitude and pattern of response differed among materials. CF+COF was more effective in increasing the proportion of medium-sized aggregates, enhancing alkali-hydrolyzable nitrogen and some enzyme activities, and achieving relatively high yields in both maize and soybean seasons. CF+HA showed comparatively balanced effects on aggregate composition and nutrient availability, whereas CF+BC was more effective in maintaining relatively high soil pH, increasing available phosphorus, and promoting larger aggregates at later growth stages. Overall, all three organic amendments combined with mineral fertilizer were beneficial for improving meadow albic soil and increasing crop yield, with CF+COF showing the best overall performance under the conditions of this study. Full article

Soil quality degradation and low nutrient use efficiency constrain sustainable maize–soybean rotation in the Albic soil region of Northeast China. A field experiment was conducted in 2023–2024 at Qixing Farm (Jiansanjiang, Heilongjiang, China) to evaluate chemical fertilizer combined with cattle manure or microbial inoculants. Five treatments were established: no fertilization (CK), chemical fertilizer alone (CF), chemical fertilizer combined with cattle manure (CF+CM), chemical fertilizer combined with a Bacillus subtilis inoculant (CF+CRA), and chemical fertilizer combined with a Bacillus megaterium inoculant (CF+CRB). Soil available nutrient dynamics, crop nutrient accumulation and translocation, fertilizer use efficiency, and yield were assessed. In maize, CF+CRB significantly enhanced pre-anthesis N translocation and post-anthesis P accumulation, increasing grain yield to 14,533 kg ha⁻¹ (+28.6% vs. CF). In soybean, CF+CRB produced 3328.15 kg ha⁻¹, 15.8% higher than CF. CF+CRA significantly increased soil available P during the soybean flowering-pod stage and improved K allocation at later stages. Overall, integrating chemical fertilizer with CRB improved yield and nutrient use efficiency. Based on crop-specific nutrient requirements, CRB is recommended for the maize season to strengthen nutrient translocation, whereas cattle manure or CRA can be applied in the soybean season to sustain K supply. Full article

Maize is a globally significant cereal crop, while Albic soils in Northeast China are characterized by low available phosphorus (P), poor humus (HS) quality, and constrained maize yield. The synergistic effects of P fertilization on maize yield and HS quality in these soils remain poorly understood. This three-year field experiment was conducted to determine the optimal P application rate for concurrently enhancing crop productivity and HS quality. Four P application rates were established: 0 kg P₂O₅ ha⁻¹ (no P application, P0), 40 kg P₂O₅ ha⁻¹ (low P application, LP), 80 kg P₂O₅ ha⁻¹ (moderate P application, MP), and 120 kg P₂O₅ ha⁻¹ (high P application, HP). Soil nutrients status, HS fractions, dissolved organic matter (DOM) fluorescence characteristics, and structural properties of humic acid (HA) were systematically analyzed following standard analytical procedures. Principal component analysis (PCA) and Pearson correlation analysis were integrated to facilitate comprehensive data interpretation. Results indicated that the MP treatment achieved the highest maize yield (12,257.1 kg ha⁻¹) and soil organic matter (SOM, 14.8 g kg⁻¹) content, with no further yield improvement observed under HP. The MP treatment significantly increased DOM carbon content (C_DOM, 0.350 mg L⁻¹) and its humification index (HIX, 6.80), promoting the transformation of labile DOM into stable HS. HA under MP treatment exhibited enhanced structural stability, as evidenced by a lower H/C ratio (1.72), a higher O/C ratio (0.880), and a reduced E₄/E₆ ratio, reflecting increased aromatic condensation and a greater abundance of oxygen-containing functional groups. Fourier transform infrared (FTIR) spectroscopy and differential thermal analysis (DTA) confirmed that MP improved the structural complexity and thermal stability of HA. In contrast, P0 and LP restricted nutrient availability and HS formation, whereas HP induced soil acidification (pH 5.68) and disrupted HS equilibrium. Principal component analysis (PCA) and correlation analysis revealed significant positive associations between the MP treatment and SOM, C_DOM, and maize yield. This implied that moderate P input promoted stable soil organic carbon accumulation and nutrient availability, synergistically enhancing maize productivity—consistent with the study’s core goal of optimizing P management for concurrent yield and HS quality improvement in Albic soils. Accordingly, this study concluded that moderate P application (80 kg P₂O₅ ha⁻¹) was optimal for Albic soils, synergistically enhancing both maize productivity and HS quality. These findings provided theoretical support for precise P management in sustainable agricultural systems within the Albic soil regions of Northeast China. Full article

Maximizing the agricultural output on inherently infertile land and minimizing the environmental cost remain central research imperatives. Albic black soil typifies such infertility. Conventional practice relies on fertilization and straw incorporation, but the albic layer’s impermeability funnels applied nutrients into adjacent aquatic systems. Therefore, this study developed deep placement fertilization by lodging fertilizer directly within the albic layer to block hydrologic loss. The feasibility of mechanization was first validated in pot experiments. Soybeans were allocated to six treatments simulating fertilizer placement at different soil depths: control (C), control and fertilizer (CF), surface soil mixing (SM), surface soil mixing and fertilizer (SMF), plow pan soil mixing (PM), and plow pan soil mixing and fertilizer (PMF). The treatments used 20 cm tillage, and the data were collected after 15, 25, and 35 days and at harvest. Integrative transcriptomic, proteomic, metabolomic, and soil microbiome profiling revealed that fertilizer positioned at 25 cm in the albic layer increased yield, restructured the rhizobiont community and promoted arbuscular mycorrhizal fungal colonization. Among the fertilizer treatments, CF had the best growth, and SMF was inhibited by a nutrient shortage. SMF and PMF lost water faster than CF. Abscisic acid (ABA) conveyed the subterranean fertilization signal to the leaf. The enrichment of Vicinamibacterales, Xanthobacteraceae, and Glomeromycota in soil lowered the ABA content in the roots, which upregulated thymidine kinase and peroxidase upon arrival in the leaf, increasing yield. These findings provide a transferable benchmark for any parent material exhibiting poor hydraulic conductivity. Full article

Soils with an albic horizon (characterized by a bleached, nutrient-poor eluvial layer), classified primarily as Albic Planosols and associated groups (e.g., Albic Luvisols and Retisols) in the World Reference Base for Soil Resources (WRB), are widespread in Northeast China and suffer from inherent poor nutrient availability and low crop productivity. The present study aimed to evaluate the efficacy of novel microbial–enzyme composite biofertilizers in ameliorating Albic soils. This comprehensive assessment investigated their effects on soil nutrient availability, microbial community structure, and the activities of key enzymes involved in nutrient cycling (e.g., dehydrogenase and phosphatase). Concurrently, the impact on maize crop performance was determined by measuring changes in agronomic traits, including chlorophyll content, stem diameter, and final grain yield. A field experiment was conducted in Heilongjiang Province during the 2023 maize growing season using a randomized block design with six treatments: CF (conventional chemical fertilizer, 330 kg·ha⁻¹ NPK), OF (chemical fertilizer + 1500 kg·ha⁻¹ organic carrier), BF1 (OF + 75 kg·ha⁻¹ marine actinomycetes), BF2 (OF + 75 kg·ha⁻¹ actinomycetes + 45 kg·ha⁻¹ phytase), BF3 (OF + 75 kg·ha⁻¹ actinomycetes + 45 kg·ha⁻¹ mycorrhizal fungi + 45 kg·ha⁻¹ phytase), and BF4 (OF + 75 kg·ha⁻¹ actinomycetes + 45 kg·ha⁻¹ mycorrhizal fungi + 45 kg·ha⁻¹ phytase + 45 kg·ha⁻¹ β–glucosidase). The results showed that biofertilizers significantly increased microbial abundance and enzyme activity. The integrated treatment BF4 notably enhanced topsoil fungal abundance by 188.1% and dehydrogenase activity in the 0–20 cm layer, while also increasing available phosphorus by 92.6% at maturity. Although BF4 improved soil properties the most, BF3 produced the highest maize yield—boosting grain output by 18.3% over CF—and improved stem diameter and chlorophyll content. Strong correlations between microbial parameters and enzyme activities indicated a nutrient-cycling mechanism driven by microorganisms, with topsoil fungal abundance positively linked to alkaline phosphatase activity (r = 0.72) and subsoil bacterial abundance associated with available phosphorus (r = 0.65), demonstrating microbial–mediated carbon–phosphorus coupling. In conclusion, microbial–enzyme biofertilizers, particularly BF4, provide a sustainable strategy for enhancing Albic soil fertility and crop productivity. Full article

Biochar is known to enhance soil potassium (K) availability and promote plant K uptake; however, its influence on the transformation pathways of fertilizer potassium and the mechanisms regulating crop potassium accumulation remains insufficiently understood. This study conducted a pot experiment using three soil types—Albic, Brown, and Sandy soils—with different biochar application rates (0, 10, and 20 g·kg⁻¹) in combination with potassium fertilizer, to systematically evaluate the regulation of soil K forms, K fertilizer transformation rates, K use efficiency, and K uptake and accumulation in soybeans. The results demonstrated that the combined application of biochar and K fertilizer significantly increased the contents of available, water-soluble, exchangeable, and non-exchangeable K across all three soils. At the highest biochar application rate (20 g·kg⁻¹), available K increased by 15.37%, 16.78%, and 11.77% in the Albic, Sandy, and Brown soils, respectively, compared to the control. Furthermore, biochar altered the transformation pathways of fertilizer K; it consistently reduced the conversion rate of fertilizer K into exchangeable K across all soils, redirecting it toward the water-soluble and non-exchangeable K pools, thus functioning as a potassium “scheduling center”. Adsorption–desorption experiments revealed that biochar exhibits a strong multilayer adsorption capacity for K ions, with most of the adsorbed K not easily desorbed, providing mechanistic support for the observed shift in transformation pathways. In terms of K use efficiency, biochar reduced the K of agronomic efficiency (KAE) due to a “dilution effect” from its inherent K content. Under the high application rate (20 g·kg⁻¹), the KAE decreased by 11.79% in Albic soil, 88.48% in Sandy soil, and 71.73% in Brown soil, while significantly increasing the partial factor productivity of K (PFPK) and apparent recovery efficiency of K (AREK). Ultimately, the co-application of biochar and K fertilizer significantly enhanced total K accumulation and seed yield in soybeans by increasing K concentrations in various plant parts and promoting dry matter accumulation. At the biochar application rate of 20 g·kg⁻¹, the potassium accumulation and soybean yield under biochar treatment reached maximum increases of 70.77% (in Brown soil) and 42.63% (in Albic soil), respectively. This study demonstrates that biochar can synergistically reduce potassium (K) leaching and improve fertilizer use efficiency by regulating K transformation pathways. This provides a practical guideline for utilizing biochar as a dual-function amendment, which acts as both a supplemental K source and a soil conditioner, thereby supporting the development of more sustainable potassium management practices in diverse cropping systems. Full article

Against the backdrop of global warming and a reshaped hydrothermal regime, the albic soil belt of the Sanjiang Plain, a major grain base, requires farm-scale evidence of how meteorological variability couples with staple-crop yields. Using meteorological and yield records from 2000 to 2023 at three large farms (859, 850, and 852), this study applied the Mann–Kendall test, wavelet and cross-wavelet coherence, Pearson correlation, gray relational analysis, and principal component analysis to track the evolution of air temperature, precipitation, evaporation, sunshine duration, relative humidity, and surface temperature, and to assess their multi-scale impacts on rice, corn, and soybean yields. The region warmed and became wetter overall, with dominant periodicities near 21a and 8a. Across the three farms, yields were significantly and positively associated with precipitation and air temperature (R > 0.60). Rice yield correlated strongly and negatively with evaporation at Farm 850 (R = −0.61) and at Farm 852 (R = −0.503). At Farm 859, gray relational analysis ranked precipitation highest for rice, corn, and soybean (γ = 0.853, 0.844, and 0.826), followed by air temperature. The first two principal components explained 67.66% of the variance; PC1 (41.80%) loaded positively for air temperature, and PC2 (25.86%) for precipitation and relative humidity. Cross-wavelet coherence indicated stable coupling between yields and hydrothermal variables, with the strongest coupling for rice with precipitation and air temperature, prominent coupling for corn with air temperature and sunshine duration, and stage-dependent responses of soybean to precipitation and evaporation. These results show that long-term trends together with phase-specific oscillations jointly shape yield variability. The findings support translating phase identification and sensitive windows into crop-specific rules for sowing or transplanting arrangements, irrigation timing, and early warning, providing a quantitative basis for climate-adaptive management on the study farms and, where soils, management, and microclimate are comparable, for the wider Sanjiang Plain. Full article

To investigate the combined impacts of temperature and plant residues on the mineralization capacity of soil organic matter, in addition to the impact on the taxonomic composition and activity of the soil microbiome, a 364-day experiment involving gray forest soil (Greyzemic Phaeozem Albic) was conducted under controlled laboratory conditions. Three substrate treatments were applied, control (C), amendment with aspen leaves (L), and amendment with aspen branches (B), combined with three temperature regimes (2, 12, and 22 °C). The results showed that long-term experimental warming reduced microbial alpha diversity (number of species and richness), increased microbial respiration and decomposition rates, and altered community composition. Over the year, the percentage of mineralization of added carbon was higher for leaves (29.9%–57.8%) than for branches (20.1%–47.6%). The efficiency of organic matter decomposition increased by 1.5- to 2-fold between 2 and 12 °C. Across all treatments, Proteobacteria were found to be the dominant phylum. According to α-diversity analysis, leaves served as the most preferred substrate for enhancing species representation. β-diversity analysis results indicated that temperature was the most significant factor shaping the microbial community’s structure. Our research findings provide new insights into soil organic matter formation and highlight the need for further research on microbial functional genes. Full article

Albic soil is acidic and nutrient-deficient, resulting in low soil fertility that significantly limits the sustainable utilization of arable land. Microbial inoculants have emerged as promising biotechnological interventions to enhance soil quality by stimulating microbial activity and facilitating nutrient accumulation. This study focused on improving the characteristics of albic soil through the incorporation of straw residues combined with inoculation treatments involving arbuscular mycorrhizal fungi (AMF) and Trichoderma. Four experimental treatments were established: a Control (CK), single inoculation with AMF (AM), single inoculation with Trichoderma (TL), and a combined inoculation of both (AT). The investigation focused on assessing the synergistic effects of the AT treatment on albic soil chemical characteristics and its microbial community structure. The AT treatment significantly elevated rhizosphere soil pH, TN, and TP by 3.8%, 19.2%, and 10.9%, respectively, relative to the Control. The AT treatment markedly enhanced soil cellulase, β-glucosidase, and lignin peroxidase activities by 24.9%, 77.6%, and 36.7%, respectively, and increased the SQI by 78.9% compared to CK. Furthermore, the AT treatment led to a higher correlation abundance of Sphingomonas and aerobic chemoheterotrophs taxa. Structural equation modeling (SEM) uncovered that the interactions between AMF and Trichoderma modulated microbial community functions, augmented soil enzyme activities, promoted nutrient accumulation, and consequently improved albic soil quality. This study elucidates arbuscular mycorrhizal and Trichoderma longibrachiatum interactions with the soil environment, providing insights for improving albic soil health and microbial community structure. Full article

This study developed an innovative model integrating straw subsoil deep burial (SD) and mixing plow to mitigate albic soil’s physical and chemical constraints and enhance crop yield. A field experiment with four treatments, including conventional tillage (CT), straw mulching (SM), straw subsoil deep burial (SD), and straw burning (SR), was conducted to assess impacts on soil enzyme activity, nutrient dynamics, crop yield, and soil physical properties. Results showed that SD treatment significantly improved albic soil properties compared to conventional tillage: catalase activity in the albic horizon decreased by 13.51%, reducing peroxide toxicity. In the albic horizon, alkaline hydrolysis nitrogen, total nitrogen, available phosphorus, total phosphorus, available potassium, total potassium, and organic matter increased by 29.98%, 58.70%, 36.86%, 20.46%, 5.00%, 21.70%, and 40.46%, respectively. Correspondingly, maize and soybean yield under SD reached 8686.6 kg/ha and 2245.3 kg/ha, increasing by 15.39% and 19.94% compared to CT, respectively. Additionally, SD treatment improved physical properties of the albic horizon: soil hardness reduced by 43.56%, with enhanced water-holding capacity, permeability coefficient, porosity, and hydraulic conductivity. Its findings not only boost agronomic productivity by improving crop yields but also support environmental sustainability by enhancing soil fertility, which is of great significance for ensuring food security. Full article

Low productivity in albic soils often results in excessive nitrogen input, while straw return further increases nitrogen accumulation through decomposition. To address this issue, a three-year field experiment was conducted in albic soils of high, medium, and low fertility. Two nitrogen management strategies were assessed: nitrogen addition and reduction. Addition treatments included conventional nitrogen application rate alone (N), straw return (8250 kg ha⁻¹) with conventional nitrogen application rate (SN), and straw return with increased nitrogen (SN₊). Reduction treatments comprised SN and straw return with 10%, 20%, and 30% reduced nitrogen (SN_0.9, SN_0.8, and SN_0.7). Soil physical properties, nutrient content, and rice yield were evaluated. Results showed that SN_0.9 exhibited advantages in high-fertility albic soils, as it increased rice yield and improved some soil quality while reducing the nitrogen input by 10%. However, yield under SN_0.9 declined progressively over the three years, indicating limitations of long-term application. SN performed better than both N and SN₊ in medium- and low-fertility albic soils, offering better yield and soil quality improvements. However, nitrogen overaccumulation risk under continuous application should not be overlooked. These findings highlight that fertility-based nitrogen adjustment combined with straw return can simultaneously improve rice productivity and soil quality while reducing nitrogen input in albic soils. Full article

Surfactant-enhanced remediation is a promising approach for treating petroleum-contaminated soils, particularly in areas where conventional methods are limited by environmental constraints. This study investigates the application of Tween 80, a non-ionic surfactant, for remediating diesel-contaminated Albic Podzolic soils typical of boreal regions. Laboratory experiments were conducted over 90 days, using two surfactant concentrations (3.0 × 10⁻⁴ and 1.5 × 10⁻⁴ mol L⁻¹) and two temperature regimes (22–24 °C and 2–3 °C), simulating seasonal variability in cold-climate contaminated sites. The lower Tween 80 concentration—below the critical micelle concentration—proved more effective, achieving up to 21% total petroleum hydrocarbon (TPH) reduction at ambient temperature and 17% under refrigerated conditions. Treated soils also exhibited pH neutralization, indicating improved chemical stability. Acute toxicity bioassays (Vibrio fischeri and Ceriodaphnia affinis) confirmed the environmental safety of the applied concentrations (≤0.3 mol L⁻¹). These results support the practical use of Tween 80 in the remediation of petroleum-contaminated soils under boreal constraints, providing transferable data for designing safe and efficient field-scale treatment strategies. This work also offers insights that are relevant to remediation policies in cold climates and to the adaptation of surfactant-assisted technologies for diverse field conditions. Full article

The vulnerability of regional agricultural systems continues to intensify under the influence of global climate change. Understanding the spatiotemporal variation in meteorological elements and their agricultural response mechanisms has become a critical scientific challenge for ensuring food security. This study focuses on the 852 Farm in the typical area of the albic soil region on the Sanjiang Plain in China. This research integrates multi-source meteorological observations and crop yield data from 2001 to 2024. Using methods such as wavelet analysis, grey relational analysis, and cross-wavelet analysis, this study systematically investigates the dynamic changes and cyclical evolution patterns of key meteorological factors and their impact on the yields of different staple crops. The results indicate that, in terms of trend evolution, air temperature, relative humidity, and surface temperature show no significant upward trend (Z > 0; p > 0.05), while precipitation significantly increases (Z > 0; p < 0.05). Evaporation and sunlight show a nonsignificant downward trend (Z < 0; p > 0.05). The yields of rice, soybean, and corn generally exhibit fluctuating upward trends (Z > 0; p > 0.05). In terms of periodic coupling characteristics, meteorological factors exhibit multi-time-scale oscillations at 22a, 12a, and 8a. The yields of the three staple crops form significant time–frequency couplings with meteorological factors in the 22a and 8a periods. Regarding the correlation, air temperature demonstrates the highest grey correlation degree (γ ≥ 0.8) and strong coherence with crop yields, followed by precipitation and sunlight. These findings provide a theoretical and quantitative basis for understanding the multi-scale interactive mechanisms of climate adaptation in agricultural systems of the albic soil region, as well as for managing and optimizing climate-resilient farming practices. Full article

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. Full article

Biochar enhances soil available potassium and plant uptake, yet its effects on soil potassium supply capacity and crop potassium accumulation require clarification. This study used a pot experiment with three soil types (albic, brown, and sandy soils) and four biochar application rates (0, 10, 20, and 30 g·kg⁻¹) to investigate potassium supply capacity and soybean potassium accumulation using the potassium site coordination theory and Q/I curve analysis. The results showed that biochar significantly increased the available potassium content in soil. At the highest biochar application rate (30 g·kg⁻¹), the available potassium in the albic, sandy, and brown soils increased by 24.84%, 60.90%, and 24.84%, respectively, compared to the control. The biochar boosted the instantaneous potassium supply (elevated AR₀ and ΔK values) through direct water-soluble potassium input. However, the potential potassium supply capacity (PBC) varied by soil type: the PBC increased in the brown soil at low application rates but decreased in the albic and sandy soils with higher rates. The biochar enhanced soybean potassium accumulation through two pathways: the direct enrichment of soil potassium pools and the indirect improvement in soil properties to promote biomass accumulation. These findings provide theoretical insights for optimizing biochar use in agriculture to maximize potassium availability and crop efficiency. Full article