Acid Soils Research Articles

Tea and Pleurotus ostreatus intercropping modulates structure of soil and root microbial communities.

Intercropping with Pleurotus ostreatus has been demonstrated to increase the tea yield and alleviate soil acidification in tea gardens. However, the underlying mechanisms remain elusive. Here, high-throughput sequencing and Biolog Eco analysis were performed to identify changes in the community structure and abundance of soil microorganisms in the P. ostreatus intercropped tea garden at different seasons (April and September). The results showed that the soil microbial diversity of rhizosphere decreased in April, while rhizosphere and non-rhizosphere soil microbial diversity increased in September in the P. ostreatus intercropped tea garden. The diversity of tea tree root microorganisms increased in both periods. In addition, the number of fungi associated with organic matter decomposition and nutrient cycling, such as Penicillium, Trichoderma, and Trechispora, was significantly higher in the intercropped group than in the control group. Intercropping with P. ostreatus increased the levels of total nitrogen (TN), total phosphorus (TP), and available phosphorus (AP) in the soil. It also improved the content of secondary metabolites, such as tea catechins, and polysaccharides in tea buds. Microbial network analysis showed that Unclassified_o__Helotiales, and Devosia were positively correlated with soil TN and pH, while Lactobacillus, Acidothermus, and Monascus were positively correlated with flavone, AE, and catechins in tea trees. In conclusion, intercropping with P. ostreatus can improve the physical and chemical properties of soil and the composition and structure of microbial communities in tea gardens, which has significant potential for application in monoculture tea gardens with acidic soils.

A NAC transcription factor represses a module associated with xyloglucan content and regulates aluminum tolerance.

The transcriptional regulation of aluminum (Al) tolerance in plants is largely unknown, although Al toxicity restricts agricultural yields in acidic soils.. Here, we identified a NAM, ATAF1/2, and cup-shaped cotyledon 2 (NAC) transcription factor that participates in Al tolerance in Arabidopsis (Arabidopsis thaliana). Al substantially induced the transcript and protein levels of ANAC070, and loss-of-function anan070 mutants showed remarkably increased Al sensitivity, implying a beneficial role of ANAC070 in plant tolerance to Al toxicity. Further investigation revealed that more Al accumulated in the roots of anac070 mutants, especially in root cell walls, accompanied by a higher hemicellulose and xyloglucan level, implying a possible interaction between ANAC070 and genes that encode proteins responsible for the modification of xyloglucan, including xyloglucan endo-transglycosylases/hydrolase (XTH) or ANAC017. Yeast one hybrid analysis revealed a potential interaction between ANAC070 and ANAC017, but not for other XTHs. Furthermore, dual-luciferase reporter assay, RT-qPCR, and GUS analysis revealed that ANAC070 could directly repress the transcript levels of ANAC017, and knockout of ANAC017 in the anac070 mutant partially restored its Al sensitivity phenotype, indicating that ANAC070 contributes to Al tolerance mechanisms other than suppression of ANAC017 expression. Further analysis revealed that the core transcription factor SENSITIVE TO PROTON RHIZOTOXICITY1 (STOP1) and its target genes, which control Al tolerance in Arabidopsis, may also be involved in ANAC070-regulated Al tolerance. In summary, we identified a transcription factor, ANAC070, that represses the ANAC017-XTH31 module to regulate Al tolerance in Arabidopsis.

Effect of Soil Acidification on Temperature Sensitivity of Soil Respiration

Effect of Soil Acidification on Temperature Sensitivity of Soil Respiration

Sustained bacterial N2O reduction at acidic pH

Nitrous oxide (N2O) is a climate-active gas with emissions predicted to increase due to agricultural intensification. Microbial reduction of N2O to dinitrogen (N2) is the major consumption process but microbial N2O reduction under acidic conditions is considered negligible, albeit strongly acidic soils harbor nosZ genes encoding N2O reductase. Here, we study a co-culture derived from acidic tropical forest soil that reduces N2O at pH 4.5. The co-culture exhibits bimodal growth with a Serratia sp. fermenting pyruvate followed by hydrogenotrophic N2O reduction by a Desulfosporosinus sp. Integrated omics and physiological characterization revealed interspecies nutritional interactions, with the pyruvate fermenting Serratia sp. supplying amino acids as essential growth factors to the N2O-reducing Desulfosporosinus sp. Thus, we demonstrate growth-linked N2O reduction between pH 4.5 and 6, highlighting microbial N2O reduction potential in acidic soils.

Comparative Effects of Straw and Biochar on N2O Emissions from Acidic Soils

Comparative Effects of Straw and Biochar on N2O Emissions from Acidic Soils

Integrating Omics Approaches for Climate-Resilient Crops: A Comprehensive Review

Climate change is a looming threat to global agriculture, impacting temperature, rainfall patterns, pest dynamics, and soil quality. These challenges transcend numerous crops vital for global food security. Drought, soil acidity, and nutrient fluctuations induced by climate change impede crop productivity, necessitating the development of breeding strategies to produce climate-resilient varieties. This review delves into the integration of omics approaches, including genomics, transcriptomics, proteomics, and metabolomics, to bolster breeding programs across diverse crops. By harnessing high-throughput technologies, researchers gain insights into the genetic and molecular mechanisms underlying traits such as stress resistance, yield, and disease tolerance. The cultivation of elite cultivars with enhanced stress tolerance is paramount for sustainable agriculture in the face of climate change. Various breeding approaches, encompassing functional genomics and mutagenomics, are explored alongside the application of genome editing tools like CRISPR/Cas9 and TALEN for targeted trait enhancement. Through the integration of multi-omics data, novel genetic targets are unearthed, facilitating the development of crop varieties resilient to climate-induced stressors beyond maize. This review underscores the significance of multi-omics in crop breeding and highlights strides made toward climate-resilient crop production. Understanding crop responses to abiotic stresses induced by climate change is imperative for the development of resilient varieties. The integration of modern genetics into classical breeding methods aims to cultivate stress-resistant cultivars, mitigating food security risks. Multi-omics approaches play pivotal roles in unraveling crop performance and stress tolerance mechanisms under diverse environmental conditions. Moving forward, the integration of multi-omics approaches will pinpoint candidate genes and pathways, enabling precision breeding to enhance crop performance amidst changing climates. These endeavors will propel the advancement of climate-resilient crops, safeguarding global food security in the face of climate change's challenges.

The de‐domestication of Ornithopus sativus Brot. to develop cultivars with physical dormancy (hardseed)

AbstractOrnithopus sativus Brot. (French serradella) is a forage legume that is well adapted to acidic coarse textured soils (sands) which are characterized by poor nutrition and an inability to retain water. During the process of domestication of O. sativus, there was an unintentional loss of seed physical dormancy (PY) thus compromising its self‐regeneration after a cropping interval. Through mass screening of seed, we identified for the first time that heritable sources of PY exist in three populations of O. sativus. This rare genetic material was then incorporated into suitable genetic backgrounds of differing maturity through targeted hybridization. We demonstrated that the heritability of PY was dominant in the population of 97ZAF5sat but inconsistently recessive in the population of cv. Emena. Flowering time was variable in each source population, with a large variation in time to emergence of first flowers (95–175 days). Selection for early flowering maturity was heritable and stable. F6 generations selected for PY in different maturity classes were then evaluated in situ to establish whether PY would allow a proportion of seeds to survive in the soil through consecutive seasons exposed to a Mediterranean climate. The breeding lines FHS3, 7 and 23 remained dormant, thus viable, in the soil for up to 3 years, indicating the likelihood that O. sativus with PY could survive and persist in a ley farming system. The de‐domestication program in O. sativus has resulted in commercially successful cultivars (most recently cv. Fran2o) suited to sustainable dryland agriculture in a Mediterranean climate.

Metabolic potential of Nitrososphaera-associated clades.

Soil ammonia-oxidizing archaea (AOA) play a crucial role in converting ammonia to nitrite, thereby mobilizing reactive nitrogen species into their soluble form, with a significant impact on nitrogen losses from terrestrial soils. Yet, our knowledge regarding their diversity and functions remains limited. In this study, we reconstructed 97 high-quality AOA metagenome-assembled genomes (MAGs) from 180 soil samples collected in Central Germany during 2014-2019 summers. These MAGs were affiliated with the order Nitrososphaerales (NS) and clustered into four family-level clades (NS-α/γ/δ/ε). Among these MAGs, 75 belonged to the most abundant but least understood δ-clade. Within the δ-clade, the amoA genes in three MAGs from neutral soils showed a 99.5% similarity to the fosmid clone 54d9, which has served as representative of the δ-clade for the past two decades since even today no cultivated representatives are available. 72 MAGs constituted a distinct δ sub-clade, and their abundance and expression activity were more than twice that of other MAGs in slightly acidic soils. Unlike the less abundant clades (α, γ, and ε), the δ-MAGs possessed multiple highly expressed intracellular and extracellular carbohydrate-active enzymes responsible for carbohydrate binding (CBM32) and degradation (GH5), along with highly expressed genes involved in ammonia oxidation. Together, these results suggest metabolic versatility of uncultured soil AOA and a potential mixotrophic or chemolithoheterotrophic lifestyle among 54d9-like AOA.

Storage and Distribution of Organic Carbon and Nutrients in Acidic Soils Developed on Sulfidic Sediments: The Roles of Reactive Iron and Macropores.

In a boreal acidic sulfate-rich subsoil (pH 3-4) developing on sulfidic and organic-rich sediments over the past 70 years, extensive brownish-to-yellowish layers have formed on macropores. Our data reveal that these layers ("macropore surfaces") are strongly enriched in 1 M HCl-extractable reactive iron (2-7% dry weight), largely bound to schwertmannite and 2-line ferrihydrite. These reactive iron phases trap large pools of labile organic matter (OM) and HCl-extractable phosphorus, possibly derived from the cultivated layer. Within soil aggregates, the OM is of a different nature from that on the macropore surfaces but similar to that in the underlying sulfidic sediments (C-horizon). This provides evidence that the sedimentary OM in the bulk subsoil has been largely preserved without significant decomposition and/or fractionation, likely due to physiochemical stabilization by the reactive iron phases that also existed abundantly within the aggregates. These findings not only highlight the important yet underappreciated roles of iron oxyhydroxysulfates in OM/nutrient storage and distribution in acidic sulfate-rich and other similar environments but also suggest that boreal acidic sulfate-rich subsoils and other similar soil systems (existing widely on coastal plains worldwide and being increasingly formed in thawing permafrost) may act as global sinks for OM and nutrients in the short run.

Recycled Iron Phosphates: A New Phosphorus Fertilizer for Paddy Rice.

The potential of recycled iron phosphates (FePs), e.g., vivianites (Fe3(PO4)2·8H2O) and Fe(III)-rich phosphorus (P) adsorbent materials, as phosphorus fertilizer is limited by the strong interaction between Fe and P. In this study, the efficiency of FePs as P fertilizer was explored by applying them as granules or powder in flooded strongly P-fixing soils (acid and calcareous), thereby taking advantage of increased P release induced by reductive dissolution of P-bearing Fe(III) minerals. First, no P diffusion from granular FeP fertilizers into flooded soils was detectable by the diffusive gradient in thin films (DGT) technique and microfocused X-ray fluorescence (μ-XRF) analysis of thin soil sections, in contrast to detectable P diffusion away from granules of soluble triple superphosphate (TSP) fertilizer. On the contrary, powdered FePs demonstrated an excellent increase in extractable P (1 mM CaCl2) in a 120-day incubation experiment in flooded soils. Second, a pot experiment was performed with rice (Oryza sativa) grown in flooded acid and calcareous soils. The fertilizer value of FePs was remarkable when dosed as powder, as it was even up to 3-fold higher than TSP in the acid soil and similar to TSP in the calcareous soil. The beneficial effect of FeP over TSP in the acid soil is attributed to the slow release of P from FePs, which allows to partly overcome P fixation. The promising results of FePs as P fertilizer applied as powders in flooded soils debunk the generally accepted idea that FePs are poor sources of P while demonstrating the importance of the timing of FeP fertilizer application.

Exploring the Synergy between Humic Acid Substances, Dehydrogenase Activity and Soil Fertility

The European Commission’s “Farm to Folk” (F2F) strategy recommends reducing fertilizers by at least 20% by 2030. In this aspect, the main goal of our study was to verify whether a 20 and even 40% reduction in nitrogen (N) fertilization rate would be sufficient to maintain soil fertility (expressed as dehydrogenase activity—DHA, humic acid substances—HA substances, E4/E6 ratio), and yields of wheat and rapeseed cultivated in strip-till technology. Two fields (10 ha each) were established for wheat and rapeseed cultivation, and soils (0–20 cm) were sampled before sowing and after harvesting. It was found that a 20% fertilization reduction does not adversely affect the biological activity expressed by DHA. Nevertheless, the reduction in nitrogen (N) fertilizer rates led to a slight decrease in the E4/E6 ratio, which could serve as a potential indicator of fertilization reduction. DHA, E4/E6 ratio and content of HA substances were also dependent on the crop. Following harvesting, both rapeseed and wheat exhibited a positive correlation between the E4/E6 ratio and the degree of fertilization rate (FR), as well as yield.

Impacts on Various Management Practices on Crops Yield and Soil Biology in Maize-Wheat Cropping System

Aims: Integrated approaches that consider the synergies and trade-offs among tillage, residue, and nitrogen management are essential for optimizing agricultural sustainability to highlight the complex interplay between agronomic, environmental, and biological factors. We intended to evaluate the impact of tillage, residue, and nitrogen management on crop growth and soil biological properties under a maize-wheat cropping system in an inceptisol. Study Design: Split-split plot design. Place and Duration of Study: ICAR-IARI research farm, New Delhi, since 2014. Methodology: We collected soil samples at the anthesis stage of wheat crop and silking stage of maize crop at 0-5, 5-15, and 15-30 cm soil depth. Soil properties, namely soil organic carbon, dehydrogenase, acid, and alkaline phosphatase, soil microbial biomass carbon, soil microbial biomass phosphorus, and glomalin content by using standard procedures. Results: We observed that the soil organic carbon, enzyme activities, microbial biomass carbon and phosphorus, and glomalin content were significantly (P<0.05) higher under no-tillage and residue treatment at 0-5 and 5-15 cm soil depth. Enzyme activity and microbial biomass carbon (MBC) were significantly higher by application of 100 and 150% RDN, respectively, at 0-5 and 5-15 cm soil depth. The effect of nitrogen treatment on biomass yield was significant (P<0.05) and found to be higher at 150% Recommended dose of Nitrogen (RDN). The biomass yield of maize was 15.3% and 44.5%, and wheat was 7.8% and 20.4%, significantly increased by applying 150% RDN over the 100% and 50% RDN respectively. Conclusion: Farmers can successfully adopt NT with 5 t ha-1 crop residue mulch with 150% RDN to attain better soil health and higher biomass yield under the maize-wheat cropping system.

Восстановление плодородия малопродуктивных дерново-подзолистых почв, вновь вводимых в сельскохозяйственный оборот

The purpose of research is to develop agro-reclamation measures to restore the fertility of low-productive sod-podzolic sandy loam soils for the conditions of the southern part of the Non-Chernozem Zone of Russia. Objectives: to conduct a comparative assessment of the impact of granular fertilizer based on turkey droppings and a liquid-phase biological product (LPBP) on increasing soil fertility, phenological characteristics of plants, crop yields and their quality. Six variants of the field experiment were developed: control variant (without fertilizers); granular fertilizer based on turkey droppings at a dose of 15 t/ha; granular fertilizer based on turkey manure at a dose of 15 t/ha together with pre-sowing seed treatment with 1 % LPBP; pre-sowing seed treatment with 1 % LPBP; granular fertilizer based on turkey droppings at a dose of 30 t/ha. The application of organic ameliorant and pre-sowing treatment of seeds with a biological pre¬paration help to improve the agrochemical parameters of the soil, and, as a result, a higher yield of perennial grasses. The best option is option G30, where the yield was 48.3 t/ha of green mass of grass in total for 2 cuttings, which is 33.8 % more than the control option. In the G15 and G15 LPBP options, the harvest was practically not inferior and exceeded the control option by 30.5 and 24.4 %, respectively, soil fertility indicators improved: soil acidity decreased to 4.8–5.0 (pHsol) and 5.4–5.6 (pHwod), an increase in organic matter by 33.9 %, the content of mobile phosphorus and mobile potassium, and the concentration of total nitrogen increased significantly.

Linking phosphorus fertility to soil microbial diversity and network complexity in citrus orchards: Implications for sustainable agriculture

Continuous input of chemical fertilizers causes soil acidification, land degradation, and water eutrophication, but its impact on soil microbial communities and co-occurrence patterns of microboes is unclear. In this study, we evaluated the impact of chemical fertilizer on bacterial community diversity and ecological network at 75 citrus sites in a watershed where chemical fertilizer is continuously applied. In addition, 25 natural forest sites adjacent to citrus sites were used as references to compare the potential effects of land conversion from natural forests to citrus orchards on soil bacterial diversity and microbial network. The results showed that the cultivation of citrus results in soil phosphorus (P) accumulation, with significantly higher available and mineral-bound phosphate contents than those found in soils of natural forests. Citrus soil average soil available P was 73.2 mg/kg, which was 20 times higher than that in forest soils. As the P content accumulates, soil bacterial Shannon index linearly decreases from 7.06 to 5.93 and is significantly lower than that of adjacent natural forest soils (7.13). Low P fertility soils have higher microbial network complexity and stability, containing more microbial communities and tighter relationships between microbes compared to higher P fertility soils. Soil P content and soil pH regulates soil microbial network complexity and stability. In addition, soil bacterial community structure in soils of natural forests is significantly different from that in citrus soils, and the bacterial community structure in high P soils is different from that in medium and low P soils. Soil P fertility reduces the relative abundance of dominant communities including Proteobacteria, Bacteroidetes, and Gemmatimonadetes, and also changes the relative abundance of some functional microbial communities, such as some phosphorus cycling microorganisms, including Acetobacteraceae and Beijerinckiaceae. In conclusion, soil phosphate accumulation severely alters soil bacterial community diversity, complexity, stability, and functionality. This could have negative impacts on soil functional stability and the sustainability of citrus orchards.

Nickel iron mining slag and soil acidity correction

Soil acidity is one of the limiting factors of agricultural production most commonly reported in oxidic soils, such as Oxisols often found in the Brazilian Cerrado regions for example. The dredging is the most efficient management practice in the correction of soil acidity and increase of base saturation levels. The nickel iron mining scora is a residue that has relevant amounts of magnesium silicate, and may have neutralization capacity of soil acidity. Therefore, the objective of this work was to value the potential of magnesium silicate as a soil acidity corrective. The experimental design used was completely randomized, arranged in a 2x5x5 factorial scheme with twelve replications, where the 1st factor consisted of two hatching dates, 30 and 60 days, the 2nd factor consisted of five doses of mining slag: 0, 90, 120, 150 and 180 Mg ha-1, and the 3rd factor consisted of five doses of dolomític limestone: 0, 90, 120, 150 and 180 Mg ha-1. The mining slag did not present soil pH neutralization power under the evaluated conditions. However, it presented potential for neutralization under conditions of lower granulometry and greater solubilization.

Effects of Microbial Inoculants Combined with Chemical Fertilizer on Growth and Soil Nutrient Dynamics of Timothy (Phleum pratense L.)

Microbial inoculants derived from plant growth-promoting rhizobacteria (PGPR) offer eco-friendly alternatives to traditional chemical fertilizers, maintaining microbiota balance in agricultural systems. However, limited research has explored the combined effects of microbial inoculants and chemical fertilizers on crop growth and soil properties. In this study, we investigated seven fertilizer combinations, ranging from no fertilizer to various proportions of chemical fertilizers with microbial inoculants, on timothy (Phleum pratense L.) growth, chlorophyll content, soil properties, enzyme activities, and soil microbial communities. A randomized block design was employed to analyze these effects. The results indicate that the combination of 85% chemical fertilizer with microbial inoculants significantly increased timothy yield and chlorophyll content. In addition, a reduction to 55% chemical fertilizer in conjunction with microbial inoculants resulted in comparable yield to that of 100% fertilizer with no inoculants. The microbial inoculants treatments notably elevated soil catalase, urease, acid phosphatase, and invertase activities, along with soil fast-acting nutrient content. The sequencing results show that the abundance of beneficial bacteria increased, while that of fungi decreased in the soil rhizosphere after the application of microbial inoculants. This study underscored the potential of microbial inoculants combined with reductions in chemical fertilizers to enhance soil microbiology, nutrient content, and beneficial microbial abundance while suppressing pathogenic fungi, thereby promoting timothy growth and yield. These findings provide a theoretical basis for the use of microbial inoculants in sustainable agricultural practices, providing valuable insights for optimizing microbial inoculants and chemical fertilizer formulations to mitigate the sustainability challenges posed by conventional fertilizers.

Impact of Malayan Uniform System and Selective Management System of Logging on Soil Quality in Selected Logged-over Forest in Johor, Malaysia

Understanding the effects of various forest management systems, including logging practices, on soil properties is essential for implementing sustainable management strategies. In Malaysia, two types of forest management systems were commonly used: Malayan Uniform System (MUS) and Selective Management System (SMS) practices. However, their effects on soil quality remained elusive, especially after decades of recovery. To address this need, we selected three plots for the MUS and SMS in Johor, Malaysia, to assess soil properties in logged-over forest plots. All the plots were natural forest reserves. Soil properties analyzed include soil acidity, electrical conductivity, cation exchange capacity, selected nutrient contents, and soil compaction. Generally, the results of the study indicate that forests logged using the SMS exhibit superior soil quality compared to those logged using the MUS according to several key soil properties. Specifically, significantly higher cation exchange capacity, potassium content, calcium content, and magnesium content with lower soil compaction was observed in the SMS when compared to MUS plots. In short, the SMS enhances soil quality more effectively than the MUS, even with a shorter logging cycle. This is because the SMS does not harvest all trees and distributes the impact of harvesting more evenly over time, rather than concentrating it at a single time point. Ultimately, this highlights that the SMS can play a significant role in promoting sustainable forest management practices by preserving soil quality.

Genomic fingerprints of the world's soil ecosystems.

Despite the explosion of soil metagenomic data, we lack a synthesized understanding of patterns in the distribution and functions of soil microorganisms. These patterns are critical to predictions of soil microbiome responses to climate change and resulting feedbacks that regulate greenhouse gas release from soils. To address this gap, we assay 1,512 manually curated soil metagenomes using complementary annotation databases, read-based taxonomy, and machine learning to extract multidimensional genomic fingerprints of global soil microbiomes. Our objective is to uncover novel biogeographical patterns of soil microbiomes across environmental factors and ecological biomes with high molecular resolution. We reveal shifts in the potential for (i) microbial nutrient acquisition across pH gradients; (ii) stress-, transport-, and redox-based processes across changes in soil bulk density; and (iii) greenhouse gas emissions across biomes. We also use an unsupervised approach to reveal a collection of soils with distinct genomic signatures, characterized by coordinated changes in soil organic carbon, nitrogen, and cation exchange capacity and in bulk density and clay content that may ultimately reflect soil environments with high microbial activity. Genomic fingerprints for these soils highlight the importance of resource scavenging, plant-microbe interactions, fungi, and heterotrophic metabolisms. Across all analyses, we observed phylogenetic coherence in soil microbiomes-more closely related microorganisms tended to move congruently in response to soil factors. Collectively, the genomic fingerprints uncovered here present a basis for global patterns in the microbial mechanisms underlying soil biogeochemistry and help beget tractable microbial reaction networks for incorporation into process-based models of soil carbon and nutrient cycling.IMPORTANCEWe address a critical gap in our understanding of soil microorganisms and their functions, which have a profound impact on our environment. We analyzed 1,512 global soils with advanced analytics to create detailed genetic profiles (fingerprints) of soil microbiomes. Our work reveals novel patterns in how microorganisms are distributed across different soil environments. For instance, we discovered shifts in microbial potential to acquire nutrients in relation to soil acidity, as well as changes in stress responses and potential greenhouse gas emissions linked to soil structure. We also identified soils with putative high activity that had unique genomic characteristics surrounding resource acquisition, plant-microbe interactions, and fungal activity. Finally, we observed that closely related microorganisms tend to respond in similar ways to changes in their surroundings. Our work is a significant step toward comprehending the intricate world of soil microorganisms and its role in the global climate.

Dolomitic lime and silicate in no‐till: Nutritional status, soil fertility, and soybean agronomic performance

AbstractLimestone is the most widely used agricultural input for soil acidity correction and calcium (Ca) and magnesium (Mg) fertilization. However, other materials have the potential to fulfill these purposes, such as steel slags, also known as silicates. Silicates have higher solubility than limestone, serving as agents for increase pH in no‐till, in addition to being a source of Ca, Mg, and silicon (Si). This study aimed to compare the effects of surface application of dolomitic lime and calcium magnesium silicate on soil chemical properties, soybean [Glycine max (L.) Merr.] nutritional status, and grain yield under no‐till. The experiment was installed in the northwest Paraná State, Brazil, on a Rhodic Eutrustox. Lime and silicate rates were applied by broadcasting before the sowing of soybean. Silicate treatment increases soil Ca2+, pH, and base saturation up to a depth of 0.10 m. By contrast, liming effects on soil chemistry were restricted to the 0.05 m top layer after 24 months of application. The acidity correction and Ca2+ supply to greater soil depths and the increased leaf Si as a beneficial element provided by silicate treatment contributed to increasing soybean yield in the 2018/2019 and 2019/2020 seasons. Lime application, regardless of the rate, did not improve soybean yield. Waste from the steel industry can be used as acidity correctives and source of Si, Ca, and Mg, improving the agronomic performance of soybean.

Decrease in fertility of typical chernozem due to long-term anthropogenic pressure in grain-beet crop rotations

The saturation of sugar beet rotations under different fertilizer application systems and long-term cultivation induces significant changes in soil properties, leading to decreases in humus content, mineral nitrogen, phosphorus, and potassium. The study was conducted in a stationary multifactorial experiment in grain-beet crop rotations: crop rotation, row-crop, and grain-row crop rotations with the application of 40 t/ha of manure under sugar beets + NPK 100:90:90 and a variant without fertilizers. The paper presents the results of monitoring changes in humus content during each rotation, reduction of humus reserves in the plow layer, and physicochemical and agrochemical soil indicators. In the variants without fertilizers, we observed 0.24–0.41% decline in humus content in all crop rotations during 3 rotations of ten-field crop rotations (30 years). Overall, there occurred 0.89–1.00% decrease over 50 years of anthropogenic influence, equivalent to 31.8–35.7 t/ha, or 23.1–26.1% of initial reserves per hectare. Despite application of 40 t/ha of manure + NPK 100:90:90 under sugar beets, humus loss was 27.5 t/ha in the row-crop rotation and 16.8 t/ha in the grain-row crop rotation. Fertilizer application led to increase in exchangeable and hydrolytic soil acidity. With the application of 6.7 t/ha of manure + NPK 53:42:42 per 1 ha of crop rotation area, there was a tendency towards increase in mineral nitrogen content, mobile phosphorus doubled to 280.1–302.8 mg/kg compared to the variant without fertilizers, and exchangeable potassium decreased regardless of the fertilization system, which was associated with its utilization by plants. Sugar-beet yield increased to 44.76 t/ha in the crop-rotation under the organo-mineral-fertilizer application system, exceeding the spring wheat rotation by 4.63 t/ha and the variants without fertilizers by 2.45–2.72 times. Therefore, the modern fertilizer application system under sugar beets did not ensure stabilization of humus content in the soil and increased its acidity. It is necessary to more broadly use cover crops in crop rotations, incorporate crop residues, and apply biological preparations to improve soil fertility.