Search Results (63)

Non-invasive Micro-test Technology (NMT) represents a pioneering approach in the study of physiological functions within living organisms. This technology possesses the remarkable capability to monitor the flow rates and three-dimensional movement directions of ions or molecules as they traverse the boundaries of living organisms without sample destruction. The advantages of NMT are multifaceted, encompassing real-time, non-invasive assessment, a wide array of detection indicators, and compatibility with diverse sample types. Consequently, it stands as one of the foremost tools in contemporary plant physiological research. This comprehensive review delves into the applications and research advancements of NMT within the field of plant abiotic stress physiology, including drought, salinity, extreme temperature, nutrient deficiency, ammonium toxicity, acid stress, and heavy metal toxicity. Furthermore, it offers a forward-looking perspective on the potential applications of NMT in plant physiology research, underscoring its unique capacity to monitor the flux dynamics of ions/molecules (e.g., Ca²⁺, H⁺, K⁺, and IAA) in real time, reveal early stress response signatures through micrometer-scale spatial resolution measurements, and elucidate stress adaptation mechanisms by quantifying bidirectional nutrient transport across root–soil interfaces. NMT enhances our understanding of the spatiotemporal patterns governing plant–environment interactions, providing deeper insights into the molecular mechanism of abiotic stress resilience. Full article

This study focuses on the alpine meadow ecosystem of the Qinghai–Tibet Plateau, which plays a vital role in carbon sequestration and water resource protection. However, mining activities have severely damaged the ecosystem, posing challenges for ecological restoration. The study selected the Jiangcang mining area and analyzed the physical, chemical, and carbon characteristics and heavy metal content of soil samples from the slag platforms and slopes (0–20 cm), which were restored in 2015 and 2020 to explore the effects of different soil reconstruction methods on soil function and ecological resilience. The results show that the minimum data set (MDS) can effectively replace the total data set (TDS) in assessing soil quality. The assessment indicates good restoration effects in 2020, with some areas rated high in soil quality. Although issues such as high bulk density, high electrical conductivity, low moisture content, nitrogen deficiency, and low organic matter limit ecological restoration, the carbon sequestration capacity of the restored soil is strong. This study provides scientific evidence for ecological restoration in cold mining areas, indicating that capping measures can enhance soil resistance to erosion, nutrient retention, and carbon sink functions. Full article

This study assesses the current status of selected soil properties of an expanding equatorial agricultural region (Arauca, Colombia) across six landscapes, with the final focus being on evaluating overall soil quality. Field surveys, morphological descriptions, and laboratory analyses of 133 soil profiles were investigated. The landscapes include mountains (25 profiles), foothills (17), hills (11), alluvial plains (43), alluvial plains with dunes (21), and alluvial valleys (16). Soils are classified into six Reference Soil Groups (WRB FAO): Gleysols, Acrisols, Arenosols, Ferralsols, Leptosols, and Cambisols. The findings indicate high acidity, low fertility, and deficient exchangeable bases. Indeed, pH ranges from extremely acid to slightly acid (3.5–6.4), and exchangeable acidity saturation percentage (%SAI) values reach 100% in some areas. Soil textures vary from clay loam to sandy loam and clay. Nutrient contents are ranked in the order Cambisols > Gleysols > Arenosols > Ferralsols > Acrisols > Leptosols. Correlation analysis reveals that clay content positively influences the exchangeable basis percentage, while organic matter (OM) negatively correlates with the nutrients phosphorus, calcium, and magnesium. This study highlights that landscape position influences soil quality, with lower landscape positions having better quality than upper ones. These results provide insights into soil fertility and nutrient availability, which helps to predict suitable plant cultivation areas when increasing areas for agricultural use versus forestry in Arauca. The inclusion or maintenance of diverse tree species is a key element in maintaining the production of organic matter and, consequently, generating better soil quality. Full article

Heavy metal contamination in agricultural soils threatens food security and public health, especially in volcanic regions where ash alters soil properties. This study evaluates the effects of soil amendments on physicochemical properties, nutrient availability, and heavy metal accumulation in ash-affected (Mocha) and non-affected (Puyo) soils in Ecuador. A field experiment tested compost, poultry manure, inorganic fertilizer, and a control on onion (Allium fistulosum) and parsley (Petroselinum crispum). Soil analyses assessed the bulk density, texture, pH, electrical conductivity, organic matter, nutrients, metals, and metalloid concentrations of the soils and crops. Mocha soils exhibited volcanic Andisol characteristics, while Puyo soils resembled eastern Ecuadorian soils, both showing high nitrogen but deficiencies in phosphorus, potassium, and calcium. Arsenic (As), lead (Pb), and chromium (Cr) levels in soils varied between regions but not among treatments. In Mocha, As bioavailability decreased with poultry manure and compost, while other metals remained stable except in fertilized soils. In Puyo, organic amendments reduced Hg, Pb, Ni, and Cr but increased them in fertilized soils. All treatments met Ecuadorian limits for As, Cd, Pb, and Ni but exceeded those for Hg and Cr. Organic amendments improved soil quality, reduced metal mobility, and supported sustainable agriculture, with Mocha soils appearing more suitable for cultivation. Full article

Microbial inoculants are vital for promoting plant growth and facilitating the ecological restoration of degraded forested regions near abandoned mine sites. However, the direct application of liquid microbial inoculants is often challenging due to low microbial activities and poor transport efficiencies, which limit their effectiveness in complex soil environments. To tackle these challenges, this study utilized immobilized microbial technology to evaluate the effectiveness of solid microbial inoculants sourced from peat (P), biochar (BC), and spent mushroom substrates (SMSs) in enhancing the soil’s multifunctionality and promoting plant growth. Specifically, this research sought to assess the effectiveness of solid microbial inoculants derived from peat (P), biochar (B), and spent mushroom substrates (SMSs) in enhancing soil multifunctionality and promoting plant growth in nutrient-deficient soils that were affected by abandoned mine sites. We aimed to evaluate the performance of different solid microbial inoculants in improving the soil’s nutrient content and enzyme activities. A 24-week pot experiment was conducted using Medicago sativa L. in nutrient-poor soil. The results demonstrated that, in contrast to peat and biochar, SMSs effectively interacted with microbial inoculants and significantly improved the nutrient content and enzyme activities of nutrient-deficient soil. It was noted that β-1,4-glucosidase (BG), invertase, β-1,4-N-acetylglucosaminidase (NAG), urease, and soil available phosphorus increased by 204%, 405%, 118%, 198%, and 297%, respectively. The soil’s multifunctionality improved by 320% compared with the CK, and the plant biomass also increased significantly. Further, our random forest analysis indicated that the soil available phosphorus, ammonium nitrogen, total nitrogen, total carbon content, arylsulfatase, pH, total phosphorus, NAG, and BG were key environmental factors that induced changes in plant biomass. These findings highlighted the potential of SMSs as an effective carrier for immobilized microbial inoculants, which provides a sustainable approach for the restoration of forest soils surrounding abandoned mine sites, as well as a promising avenue for the valorization of agricultural waste. Full article

Nutrient deficiencies, low organic matter content, and a limited soil–water saturation percentage in calcareous soils hinder plant growth and crop production. To address these challenges, sustainable and green-based farming practices have been introduced. This study investigates the synergistic effects of biochar and nitrogen levels as sustainable solutions for improving soil fertility and supporting wheat growth in calcareous soils. A pot experiment assessed the effects of biochar (5-, 10-, and 15-tons ha⁻¹) and nitrogen levels (60, 90, and 120 kg ha⁻¹) on soil physicochemical properties, nutrient availability, and wheat growth. The randomized complete block design included three replicates and a control. The results highlight that the highest biochar rate (15 tons ha⁻¹) combined with the highest nitrogen level (120 kg ha⁻¹) significantly (p ≤ 0.05) improved soil physicochemical properties and nutrient status. Notably, soil pH increased by 2.8%, electrical conductivity by 29.8%, and soil organic matter by 185%, while bulk density decreased by 22.3%. Soil total nitrogen surged by 163.7%, soil–water saturation percentage by 27.2%, plant-available phosphorus by 66.8%, and plant-available potassium by 96.8%. Wheat growth parameters also showed marked improvement, with plant height up 29.7%, spike length by 20.7%, grains per spike by 41.5%, thousand-grain weight by 24.7%, grain yield by 81.3%, and biological yield by 26.5%. There was a strong positive correlation between enhanced soil properties and improved wheat growth, except for soil bulk density, which showed a negative correlation. This underscores the role of biochar in boosting soil fertility and crop productivity. A principal component analysis further validated these findings, suggesting that integrating biochar with appropriate nitrogen fertilization offers a sustainable strategy to enhance soil health, manage nutrient availability, and strengthen crop yields in calcareous soil. Biochar application combined with elevated nitrogen levels significantly enhances soil fertility and wheat productivity in semi-arid regions, offering a sustainable solution for improving calcareous soils. Future studies should explore the long-term impacts and scalability of this approach. Full article

The composition simplex (N, P, K, Ca, and Mg) of the leaf is the main score used by different approaches, like the Diagnosis and Recommendation Integrated System and Compositional Nutrient Diagnosis, to study nutrient interactions and balance in plant leaves. However, the application and validation of these concepts to grain composition remains unexplored. Contrary to foliar analysis’s early intervention for nutrient deficiency detection and correction, applying this approach to seeds assesses diverse cultivars’ potential, enabling anticipation of their adaptation to climate conditions and informed selection for future crops. In the present study, a collected database of more than 924 scores, including the grain yield (kg ha⁻¹) and the nutrient composition (mg kg⁻¹) of different corn varieties, is used to develop a novel nutrient-based diagnostic approach to identify reliable markers of nutrient imbalance. A ‘nutrient signature’ model is proposed based on the impact of the environmental conditions on the nutrient indices and composition (N, P, K, Ca, and Mg) of the corn grains. The yield threshold used to differentiate between low- and high-yielding subpopulations is established at 12,000 kg ha⁻¹, and the global nutrient imbalance index (GNII) of 2.2 is determined using the chi-square distribution function and validated by the Cate–Nelson partitioning method, which correlated yield data distribution with the GNII. Therefore, the nutrient compositions were classified into highly balanced (GNII ≤ 1.6), balanced (1.6 < GNII ≤ 2.2), and imbalanced (GNII > 2.2). In addition, we found that the Xgboost model’s predictive accuracy for the GNII is significantly affected by soil pH, organic matter, and rainfall. These results pave the way for adapted agricultural practices by providing insights into the nutrient dynamics of corn grains under varying environmental conditions. Full article

Boron (B) is an essential and widely studied element in plants. Due to B dynamics in highly weathered soils, its concentration is generally low. Among other benefits, B interacts with calcium pectate, promotes stability on cellular membrane, and influences directly on plant nutrients uptake and non-structural metabolites synthesis. In sugarcane (Saccharum spp.) crop, adequate B supply has been associated with juice quality and yield of stalks and sugar and its response on adequate B concentration on commercial fields can differ greatly even into a group of varieties recommended for the same production environment. In this context, the authors aimed to assess the effects of B availability on sugarcane root and shoot development, nutrient status, and carbohydrate synthesis and allocation in two sugarcane varieties recommended for the same production environment using hydroponic solution. The experimental design was completely randomized and consisted of four treatments and four replicates. The treatments comprised two sugarcane varieties (RB867515 and RB92579) and two B concentrations (0.05 and 0.5 mg L⁻¹) considered deficient and adequate, respectively, for plant development. Carbohydrate partitioning, nutrient concentrations in various plant parts, and growth and morphological parameters were evaluated. Under adequate B supply, the total concentrations of reducing sugars and sucrose increased 67 and 20% in RB867515 and 30 and 20% in RB92579, respectively, whereas starch decreased by 27% for both varieties. Adequate B supply increased the concentrations of all elements in all plant organs, except for N and K in leaves, and improved most yield and morphological parameters. Principal component analysis correlated the higher carbohydrates concentration and yield parameters with the variety RB92579, whereas the highest concentration of most nutrients was mainly associated with the variety RB867515, especially under adequate B supply. The main influence of adequate B supply was on carbohydrate synthesis. Although the sugarcane varieties responded differently to B availability, their biometric parameters were enhanced by adequate B supply. These results emphasize the need for B fertilization, regardless of the sugarcane variety’s susceptibility to B deficiency. Full article

Monitoring the nutrient status of citrus orchards is fundamental to ensure optimum fruit yield and quality. In the present study, soil and leaf samples of 20 Valencia Late orange orchards were collected in the Gharb plain of Morocco, the second-largest citrus area in the country. The objective was to assess the status of essential macronutrients (N, P, K, Ca, and Mg) and micronutrients (Fe, Zn, Cu, and Mn) in Valencia orange orchards and investigate the relationships between soil properties and nutrient contents in soils and leaves. Soils of the studied orchards had a medium to heavy texture, with low to moderate levels of organic matter content (6–31 g kg⁻¹). They were also non-saline and mostly alkaline and calcareous. These soils exhibited a wide range of macro- and micronutrients. Suboptimum levels of total N, available Fe, and Cu were observed in most soils. Most of soils had also sufficient levels of available P, Mn, and Zn. All soils were sufficiently supplied with available Ca, Mg, and K. Similarly to soil analysis, leaf analysis indicated the prevalence of adequate to very high levels of P, Ca, Mn, and K. Leaf N and Fe status were below optimum levels in most orchards, which is in line with the observed low levels in soils. Nevertheless, unlike soils, leaves did not show any deficiency of Cu; instead, most orchards had adequate to excessive levels of this micronutrient. Additionally, leaf Mg and Zn status were deficient in most orchards, conversely to that of soils. This discrepancy between soil and leaf analysis was also noted in the lack of correlation we observed between soil nutrients and their respective levels in leaves. Correlation analysis revealed also an antagonistic interaction between K–Mg and Ca–Mg, which explained the widespread suboptimum levels of Mg in leaves despite its sufficient status in soils. Such antagonism was also observed between Fe–Mn. In the case of Cu, we suspect the use of Cu-containing plant protection products to contribute to the high levels in leaves despite its low levels in soils. Overall, our results showed that nutrient imbalances leading to antagonistic interaction heavily impacted nutrient status in our study area. We expect unbalanced fertilization to contribute to this issue. Therefore, fertilization practices should be managed judiciously to maintain an adequate nutrient balance in the soil and trees of citrus orchards and ensure their sustainable production. Full article

Sulphur is an essential nutrient that fulfils various important functions in plants, including the formation of amino acids, proteins, chlorophyll and the support of nitrogen uptake, e.g., in legumes. The sulphur content of the atmosphere due to industrial combustion has fallen sharply in recent decades, which has ultimately led to yield and quality deficiencies on farms. In this summarised study, data from 98 sites in Europe were recorded from 1998 to 2023. The sulphur fertiliser trials were conducted on farms, and experimental stations under organic farming conditions. A total of 1169 treatment variants and 598 standard variants without S-fertilisation were analysed. Fertilisation was carried out with various sources of sulphur in different quantities and forms, usually directly before or during crop cultivation. The amounts of plant-available S in the soil were determined at depths of 0–90 cm. Site characteristics such as S_min, N_min, soil type, pH value, precipitation and the extent of livestock farming were recorded. A sufficient amount of data was available for each experimental aspect to quantitatively describe the influence of increasing S supply to the soil or plant species groups (permanent grassland, lucerne-clover-grass, grain legumes and cereals) from severe deficiency to oversupply. The analyses therefore focused on establishing relationships between yield responses, correlations with the nitrogen uptake of crop species and N₂ fixation in legumes and the nutrient supply with plant-available sulphur. An assessment procedure was drawn up for soil supply with available sulphur that is too low (classes A, B), optimal (class C: 20–30 kg S ha⁻¹) and too high (classes D, E). The results were also used to develop practical methods for determining fertiliser requirements for different crop species and the crop rotation in organic farming. Full article

Organic soil amendments, such as composts, mitigate the negative impacts on the environment that are caused by poor waste management practices. However, in the sub-Saharan African region, and Malawi in particular, studies investigating the agronomical efficacy and their ability to ameliorate drought stress when used as a soil amendment are minimal. This study aimed to evaluate the efficacy of sewage sludge and municipal solid waste (MSW) co-compost to ameliorate drought stress and improve crop productivity. Three experiments were conducted (i) to determine optimal application rate for co-compost, (ii) to evaluate yield response of maize and lettuce to co-compost application under contrasting soils, and (iii) to assess the effect of co-compost under water-limited conditions. Our results indicate that an application rate of 350 g co-compost per station was the most effective. This rate is 50% and 37% lower than the currently recommended rate for applying conventional compost to green vegetables and maize, respectively. In addition, under drought conditions, the co-compost application enhanced growth in lettuce, with less wilting, increased biomass and yield, approximately 130% greater leaf yield, and a 138% improvement in root growth. Furthermore, the relative root mass ratio (RRMR) was enhanced with the co-compost application by 103% under drought stress. This suggests that the co-compost amendment resulted in a greater allocation of biomass to the roots, which is a crucial morphological attribute for adapting to drought conditions. The concentration of K in the leaves and roots of plants treated with co-compost was significantly increased by 44% and 61%, respectively, under drought conditions, which may have contributed to osmotic adjustment, resulting in a significant increase in leaf relative water content (RWC) by a magnitude of 11 times. Therefore, in light of the rising inorganic fertilizer costs and the limited availability of water resources, these results demonstrate the potential of MSW and sludge co-composting in ameliorating the drastic effects of water- and nutrient-deficient conditions and optimizing growth and yield under these constraining environments. Full article

The snap bean (Phaseolus vulgaris L.) is highly sensitive to both phosphorus (P) deficiency and hypoxic stress, which together can significantly hinder plant growth, nutrient uptake, and yield; however, limited information exists on the effect of P and oxygen (O₂) fertilization to alleviate these stresses and enhance yield. A two-year field experiment assessed the effects of P and O₂ fertilization on plant growth, pod yield, and P uptake in acidic sandy soil. Using a randomized complete block design with four replications, we tested five P rates (0, 45, 90, 135, and 179 kg ha⁻¹ of phosphorus pentoxide, P₂O₅) in the form of triple superphosphate (TSP) along with two rates (0 and 45 kg ha⁻¹) of solid O₂ fertilizer as calcium peroxide (CaO₂). Phosphorus and O₂ fertilizers improved plant growth and pod yield, with the highest yield from the combination of 135 kg ha⁻¹ P₂O₅ and 45 kg ha⁻¹ CaO₂. Pearson correlation analysis indicated strong associations between plant growth, pod yield, and nutrient accumulation. Principal component analysis (PCA) highlighted notable seasonal differences in snap bean and soil characteristics. This study provides essential insights into the use of O₂ fertilizers as a cost-effective approach to mitigate hypoxia, enhance P use efficiency, and improve yield in snap bean. Our findings may inspire the development of sustainable nutrient protocols for high-quality snap bean production and serve as a foundation for similar applications in other crops. Full article

This study explores the correlation between soil nutrient elements and pepper fruit quality in Guizhou Province, highlighting regional variations in nutrient influence. Guizhou, with its unique mountainous and karst terrain, provides a distinct ecological environment for pepper cultivation. Our analysis of three major pepper-growing regions—Dafang, Guiyang, and Zunyi—demonstrates that the nitrogen, phosphorus, and potassium levels in the soil significantly impact pepper quality. Potassium plays a particularly vital role in fruit development, as deficiencies in potassium often result in flower and fruit drop and reduced yield. In Dafang, AP (available phosphorus) and TK (total potassium) were most closely linked to amino acids, reducing sugars, and capsaicinoid content, while in Bozhou, SAN (available nitrogen) was most influential, and in Qingzhen, TP (total phosphorus) and AK (available potassium) were predominant. The findings suggest that key soil elements, such as available phosphorus, available potassium, available nitrogen, and organic matter, influence the quality indicators—amino acids, reducing sugars, capsaicin, and dihydrocapsaicin—in pepper fruits. Further analysis indicates that Guizhou’s distinct soil composition significantly contributes to its peppers’ unique flavor profile. The combined effects of soil nutrients, pepper varieties, and cultivation practices underline the superior quality of Guizhou peppers. This study provides a foundation for understanding the soil–quality interaction and enhances the market recognition of Guizhou’s pepper varieties. Future research should investigate the integrated effects of environmental and soil factors to better assess Guizhou’s favorable growth conditions for peppers. Full article

The chestnut tree (Castanea sativa Mill.) is gaining importance in the mountainous regions of southern Europe due to the high value of its fruits. It is essential to establish effective cultivation protocols, considering that this species is still relatively understudied. In this study, we present the outcomes of the initial establishment of a chestnut orchard conducted through a nutrient omission trial for four years. The treatments included a fertilization plan with nitrogen, phosphorus, potassium, and boron (NPKB), the control, and four other treatments corresponding to the omission of each nutrient (-NPKB, N-PKB, NP-KB, NPK-B). The -NPKB and NP-KB treatments showed significantly lower trunk circumferences and canopy volumes compared to the other treatments. The NPK-B treatment resulted in the lowest fruit production, with a total accumulated yield (2020–2022) of 0.56 kg tree^–1, a value significantly lower than that of NPKB (1.12 kg tree^–1) and N-PKB (1.19 kg tree^–1). The assessment of nutrient concentrations in the leaves revealed plants with deficient levels of B and K in treatments that did not receive these nutrients. Conversely, N levels in the leaves in the -NPKB treatment fell within the sufficiency range (20 to 28 g kg^–1). This suggests that the sufficiency range should be adjusted to higher values, given the treatment’s effect on tree growth. It was also observed that the -NPKB treatment led to lower soil organic matter compared to the other treatments, likely due to reduced herbaceous vegetation development under the canopy, leading to decreased organic substrate deposition in the soil. The main findings of this study are that N and K were crucial elements for the optimal growth of chestnut trees, while B played a significant role in fruit production. Full article

Saline soils are characterized by organic matter and nutrient deficiencies, and their mineral fraction consists almost exclusively of fine sand particles, resulting in an unstable soil formation process. Due to the high amount of soluble salts in the soil, the osmotic pressure of the soil is elevated, restricting water absorption. This ultimately leads to the death of the plant and adversely impacts crop growth and yield. Incorporating Fe²⁺ can improve fertilizer utilization efficiency by reducing the oxidation of NH₄⁺ to nitrogen (N₂). However, reports on the usage of iron addition for the improvement of saline-alkali soils are scanty. This study conducted an outdoor simulation in pots to assess the soils of soybean crops during the podding stage. The effects of Fe²⁺ along with organic fertilizer or bio-C addition were elucidated on the composition and function of saline and alkaline microbial communities. The findings were correlated with soil environmental factors to analyze the dynamic changes in soil microbial communities. The soil pH decreased by 1.22–2.18% and SOM increased by 2.87–11.77% with organic fertilizer (OF) treatment. Compared to the ck treatment (control without iron supplementation), other treatments showed an average increase in abundance of dominant phylum by 8.25–11.23%, and an increase in the diversity and richness of the microbial community by 1.73–10.87%. The harmful bacteria in the Actinobacteriota, Chloroflexi, and Basidiomycota groups reduced by 57.83%, 74.29%, and 67.29%, and the beneficial bacteria in Ascomycota increased by 18.23–20.39%. Fe²⁺ combined with organic fertilizer or bio-C treatment could weaken the competitive relationship between the various bacterial lineages, enhance synergistic ability, favor the function and structure of the microbial community, and thus, improve the soil environment. Overall, the application of Fe²⁺ combined with organic fertilizers improved the saline-alkali soil, while the biochar (C) treatment mainly affected the soil nutrients. Through its detailed analysis, the study provides actionable insights for farmers to manage soil fertility in saline-alkaline soils, thereby overcoming the challenges of poor yields due to salinity stress. This will lead to resilient and sustainable farming systems, contributing to global food security. Full article