Search Results (86)

Natural radionuclides (⁴⁰K, ²¹⁰Pb, ²²⁶Ra, ²³²Th, and ²³⁸U) were evaluated for the first time on volcanic ash soils of the Argentine Patagonian Andes. The study was carried out along a topoedaphoclimatic gradient, encompassing soils from Xeric Mollisols to Udic Andisols, and different land uses. Median mass-specific activities of the lithogenic radionuclides ⁴⁰K, ²¹⁰Pb, ²²⁶Ra, ²³²Th, and ²³⁸U were 375, 8, 17, 19, and 29 (Bq kg⁻¹), respectively, all falling within global natural background levels, yet distinct spatial and vertical patterns emerged. Radionuclide activities increased with sand content and decreased with organic matter, highlighting the role of the parent material and texture. In dry-site Mollisols, ⁴⁰K and ²¹⁰Pb increased with depth, while in humid-site Udands, activities declined with depth, suggesting leaching and surface accumulation by allophane–organic matter complexes. The 238U/226Ra activity ratio showed disequilibrium, indicating young, developing soil profiles. In Xerolls, where native forest was replaced by afforestation and rangeland use, erosion-driven degradation was evident. The distribution of radionuclides along the slopes was closely linked to the topographic position and slope gradient. These results underscore the sensitivity of radionuclide patterns to parent material, soil-forming processes and land use and provide a valuable reference for environmental monitoring in volcanic landscapes. Full article

Under refined management, high-yield cotton fields are approaching their maximum output. However, how to break this yield upper limit, specifically the source–sink relationship is still inadequately researched. This experiment was conducted to explore the interaction mechanism between yield formation and source–sink parameters (photosynthesis, nitrogen content, canopy structure and dry matter accumulation and distribution). The treatments consisted of a no cutting source and sink treatment (CK), cutting 1/2 leaves per plant (1/2L) and cutting 1/2 bolls per plant (1/2B) at the initial flowering stage (IFS), the flower and boll stage (FABS), and the full boll stage (FBS). The results showed that 1/2L treatment minimized yield losses to 2.3–5.9% by enhancing photosynthetic compensation, with FBS-1/2L showing the smallest reduction (2.3–2.9%) due to higher leaf N content and SPAD values, whereas, the 1/2B treatments resulted in significant yield losses attributable to fewer bolls, especially the FBS-1/2B treatments, which reduced yields by 35.7–41.9%, with a compensatory rate of only 8.1–14.3%. It is noteworthy that the compensation rates of IFS-1/2B and FABS-1/2B could reach 26.7–32.3% and 18.7–23.8% of their yields due to the higher leaf N content. In a word, the source damage can be buffered by physiological compensation, while the sink loss leads to yield collapse due to the irreversibility of reproductive development. Thus, the core regulator of high-yield cotton fields was sink strength. Accordingly, optimizing the sink quality was performed through moderate boll thinning at the IFS, enhancing water and fertilizer supply at the FABS and strengthening sink organ protection at the FBS in order to realize a breakthrough in yield limit. Full article

Due to the widespread distribution of F. oxysporum, the search for mechanisms of tolerance to this disease in Solanum lycopersicum L. is an ongoing endeavor. This research aimed to identify F. oxysporum-tolerant genotypes at the germination and seedling stages in order to use them as sources of resistance. Ninety-six tomato lines were inoculated with the F. oxysporum strain with NCBI accession key PQ187438. The germination test was carried out in a germination chamber at a constant temperature of 28 ± 2 °C with 70 ± 5% relative humidity in darkness for the first 3 days and then 7 days with light. Clustering and discriminant analysis identified 14 genotypes with tolerance, showing great seed vigor and lower disease severity. Seedling evaluation was conducted in a floating raft system for 10 days after inoculation. Nine genotypes showed greater tolerance to the pathogen by developing a larger leaf area and accumulating more dry matter (p ≤ 0.05). No genotypes with tolerance were identified at both phenological stages (germination and seedling), indicating that tolerance mechanisms are independent at both phenological stages, so genotype selection should be carried out independently. Full article

Calcium (Ca) is an essential nutrient element crucial for plant growth and development, especially in tomatoes. This study investigated the effects of foliar spraying with different concentrations (3 g·L⁻¹, 6 g·L⁻¹, 9 g·L⁻¹) of calcium chloride (CaCl₂) on growth, calcium uptake, distribution, fruit yield, and quality of tomato plants. The results showed that foliar application of calcium fertilizer significantly increased dry matter accumulation, fruit quality, and yield. Calcium application promoted calcium uptake by tomato plants, significantly increased the distribution proportion of calcium in roots and fruits, and significantly decreased the distribution proportion in stems and leaves. The overall calcium distribution proportion within the plant was leaf > stem > root > fruit. In conclusion, foliar spraying with 3–6 g·L⁻¹ CaCl₂ can significantly improve tomato yield and quality by regulating calcium distribution and enhancing dry matter accumulation, providing a theoretical basis for the efficient application of calcium fertilizer in protected tomato cultivation. Full article

Planting patterns and irrigation amounts are key factors affecting maize yield. This study adopted a two-factor experimental design, with planting pattern as the main plot and irrigation amount as the subplot, to investigate the effects of irrigation levels under different planting patterns (including uniform row spacing and alternating wide-narrow row spacing) on spring maize yield and water use efficiency in Xinjiang. Through this approach, the study examined the mechanisms by which planting pattern and irrigation amount influence maize growth, yield formation, and water use efficiency. Experiments conducted at the Agricultural Science Research Institute of the Ninth Division of Xinjiang Production and Construction Corps demonstrated that alternating wide-narrow row spacing combined with moderate irrigation (5400 m³/hm²) significantly optimized maize root distribution, improved water use efficiency, and increased leaf area index and net photosynthetic rate, thereby promoting dry matter accumulation and yield enhancement. In contrast, uniform row spacing under high irrigation levels increased yield but resulted in lower water use efficiency. The study also found that alternating wide-narrow row spacing enhanced maize nutrient absorption from the soil, particularly phosphorus utilization efficiency, by improving canopy structure and root expansion. This pattern exhibited comprehensive advantages in resource utilization, providing a theoretical basis and technical pathway for achieving water-saving and high-yield maize production in arid regions, which holds significant importance for promoting sustainable agricultural development. Full article

The nutrient requirements of coffee plants vary according to their phenological stages, with each nutrient playing specific roles in different structures and developmental phases. This study evaluated dry matter accumulation and the concentrations of N, P, K, Ca, Mg, S, Fe, Mn, Cu, Zn, and B in the leaves, branches, and reproductive organs of five Coffea canephora genotypes during three phenophases: flowering, fruit development, and fruit ripening. This work aimed to evaluate the distribution of nutrients in three phenophases in Coffeea canephora genotypes. Significant differences were observed among genotypes and phenophases. During flowering, leaves accumulated the highest amount of dry matter, but this pattern reversed in later stages, with greater accumulation in the fruits, especially during fruit ripening. The Verdim TA genotype showed the lowest dry matter accumulation in the branches across all phenophases. Genotypes A1 and Clementino presented the highest mean concentrations of P, Ca, Mg, Fe, Cu, and Zn in the leaves during the fruit development phase, while Verdim TA showed the lowest concentrations of P, K, Ca, Mn, Zn, and B. Future studies may include additional phenological stages and quantify nutrient remobilization efficiency in each genotype, contributing to improved management recommendation. Full article

In integrated crop–livestock systems (ICLSs), grazing intensity and crop rotation influence residue dynamics, making it essential to assess shoot and root contributions to soil carbon (C) and nitrogen (N) inputs. This study aimed to assess the shoot and root biomass of Italian ryegrass, soybean, and maize; the distribution of roots within the soil profile; and the contributions of shoot and root biomass to soil C and N under varying winter grazing intensities and summer crop rotations. The experiment was conducted within a long-term (12-year) field protocol, arranged in a randomized complete block design with split plots and four replicates. Grazing intensity was defined as the following: (i) moderate grazing—forage allowance equivalent to 2.5 times the potential dry matter intake of sheep, and (ii) low grazing—forage allowance equivalent to 5.0 times the intake potential. Grazing intensities (moderate and low) were allocated to the main plots, while cropping systems—monoculture (soybean/soybean) and crop rotation (soybean/maize)—were assigned to the subplots. Soil depth layers (0–10, 10–20, 20–30, and 30–40 cm) were treated as sub-subplots. Root samples of Italian ryegrass, soybean, and maize were collected using the soil monolith method. Low grazing intensity (8.6 Mg ha⁻¹) promoted greater aboveground biomass production of Italian ryegrass compared to moderate intensity (6.6 Mg ha⁻¹). Maize exhibited a higher capacity for both root and shoot biomass accumulation, with average increases of 85% and 120%, respectively, compared to soybean. Root biomass was primarily concentrated in the surface soil layer, with over 70% located within the top 10 cm. Italian ryegrass showed a more uniform root distribution throughout the soil profile compared to soybean and maize. Carbon inputs were higher under crop rotation (17.2 Mg ha⁻¹) than under monoculture (15.0 Mg ha⁻¹), whereas nitrogen inputs were greater in soybean monoculture (0.23 Mg ha⁻¹) than in crop rotation (0.16 Mg ha⁻¹). Low grazing intensity in winter and summer crop rotation with high-residue and quality species enhance the balance between productivity and soil C and N inputs, promoting the sustainability of ICLSs. Full article

Root systems are pivotal for nutrient absorption, exhibiting high plasticity in phosphorus (P) acquisition, and significantly influencing soil phosphorus availability. However, the impacts of different P application methods on root parameters and P utilization efficiency in cotton (Gossypium hirsutum L.) under Xinjiang conditions are still not well understood. To identify optimal P fertilization strategies, a consecutive two-year field experiment (2023–2024) under mulched drip irrigation was conducted. Three P application methods were tested: no P (CK), basal P application (PB), and drip P application (PD). Results revealed that P application methods significantly affected cotton dry matter, P use efficiency, root morphology, and yield (p < 0.05). Over the two years, the optimized treatment (25% P applied at bud stage and 25% at flowering-boll stage, PD) increased yield by 13.62% and 9.50% compared to full basal application (PB), with P use efficiency improved by 22.04–31.51% and agronomic efficiency improved by 6.56–9.75 kg kg⁻¹. PB significantly increased soil-available P in 0–20 cm (34.17–70.09%) and 20–40 cm layers (30.37–70.32%) compared to CK. During the bud stage, PD treatment exhibited higher soil-available P in the 20–40 cm layer than PB. PD enhanced P uptake and dry matter accumulation, with increases of 22.43–36.33% and 7.90–15.55% in reproductive organ P accumulation compared to other treatments. Root parameters followed PD > PB > CK across all treatments. At the seedling stage, PB increased total root length by 19.79% compared to CK, while PD increased root volume by 46.15% compared to PB. During the bud stage, PB increased root volume by 53.33% compared to CK, and PD enhanced root surface area and volume by 39.25% and 47.82% compared to PB. Root volume showed a significant positive correlation with phosphorus absorption across growth stages. The PD treatment significantly enhanced soil P availability and P use efficiency and optimized root spatial distribution. This treatment consistently increased cotton yield by 30.41–39.09% (p < 0.05) compared to CK, demonstrating stable positive effects. This study highlights that adjusting P application methods can establish sustainable, high-yield agricultural fertilization systems. Full article

To better understand the physiological mechanisms underlying the variation of Cadmium (Cd) accumulation in wheat, Cd absorption, translocation, and distribution in five low grain-Cd-accumulating wheat (LCA) and five high grain-Cd-accumulating wheat (HCA) were studied at four growth stages under three soil Cd concentrations. Grain Cd concentration of HCA was 2.92 times, 1.61 times, and 1.40 times more than that of LCA under the soil with 0.3 mg/kg,1.5 mg/kg, and 7.5 mg/kg Cd concentrations, respectively. LCA was more tolerant of Cd pollution than HCA. Consequently, dry matter in LCA roots, stems + leaves, glumes, grains, and the entire plant was significantly higher than that of HCA at all growth stages under all three soil Cd concentrations, and the most pronounced difference was observed during the maturity stage. The critical period governing the disparity in Cd uptake between LCA and HCA primarily occurred before jointing and the maturity stage. LCA absorbed more Cd than HCA under the three Cd soil concentrations before the jointing stage, during which Cd uptake of LCA was 1.92 times, 1.86 times, and 1.46 times that of HCA under 0.3, 1.5 and 7.5 Cd soil concentrations. But LCA absorbed less Cd than HCA at the maturity stage, during which Cd uptake of LCA was 50%, 50%, and 49% of HCA under 0.3,1.5 and 7.5 mg/kg soil Cd concentrations, respectively. Cd uptake or accumulation per plant in LCA was significantly lower than that of HCA throughout the entire growth period, but the difference between them becomes increasingly smaller as the concentration of Cd contamination increases. Early absorption and accumulation of Cd played a limited role in grain Cd accumulation, and Cd transport played a critical role in determining grain Cd content at maturity. In addition, tolerance to Cd was higher, and grain Cd concentration was lower. Full article

Soybean (Glycine max) nitrogen fixation is inhibited by nitrate, which has been linked to a reduction in carbon allocation and metabolism within nodules. However, the underlying mechanisms remain unclear. In this study, we tested the hypothesis that the nitrate-induced suppression of nitrogen fixation is mediated through altered sucrose allocation and catabolism in nodules. Using unilaterally nodulated dual-root soybean plants in sand-based systems, we applied 200 mg·L⁻¹ nitrate exclusively to the non-nodulated roots for 14 days. Nitrate supply enhanced the proportion of dry weight in leaves but reduced it in nodules at 3, 7, and 14 days. Similarly, nodule dry weight, nodule number, acetylene reduction activity (ARA), and specific nodule activity (SNA) all declined significantly during the same intervals. Notably, sucrose content in the nodules decreased significantly by 20.4% after 3 days but recovered at 7 and 14 days. In contrast, sucrose synthase (SuSy) cleavage activity and malate content in nodules decreased significantly following nitrate treatment, with reductions of 27.8% and 30.7% observed at 7 days, and further decreased to 38.5% and 39.2% at 14 days, respectively. These results suggest that transient sucrose scarcity may drive the initial decline in nitrogen fixation capacity, while restricted sucrose catabolism and decreased malate levels may be a consequence rather than a cause. Full article

Bupleurum scorzonerifolium Willd. is a commonly used bulk Chinese herbal remedy. Due to the large-scale mining of wild Bupleurum scorzonerifolium Willd., its natural resources are gradually exhausted. In addition, there are some problems in Bupleurum scorzonerifolium Willd. cultivation, such as lack of guidance, excessive application of fertilizers and so on, which lead to the yield and quality of Bupleurum to be below the standard value. Therefore, it is significant to clarify the regulation of quality and yield under different levels of fertilizers. In this study, three different levels of potassium fertilizer were applied; then, the metabolites in different parts of Bupleurum were analyzed by gas chromatography–mass spectrometry (GC–MS) to detect the alterations in the metabolic spectrum and recognize both the accumulation and distribution of key metabolites in response to each level of potassium fertilizer. The contents of various mineral elements, such as sodium, calcium, potassium, magnesium, manganese, zinc, iron, and copper, in different parts of Bupleurum under different potassium levels were determined. Potassium fertilizer had a significant impact on the absorption and distribution of these mineral elements. There were synergistic and antagonistic effects between each element and K⁺. The results showed that low and high potassium levels could promote the progression of main shoots and roots, but inhibited the accumulation of dry matter in lateral shoots and flowers. Low potassium levels stimulated the content of saikosaponin a in all plant parts, while high potassium levels inhibited the accumulation of most saikosaponin a,c and d. A total of 77 metabolites were identified by GC–MS, of which glycerol, d-glucose, silane and copper phthalocyanine were highlighted as the key metabolites in response to potassium fertilizer. The abovementioned metabolites are mapped into insulin signaling pathways, streptomycin biosynthesis, galactose metabolism and other metabolic pathways, sustaining the metabolic regulation of Bupleurum scorzonerifolium Willd. Full article

Eucalyptus plantations suffer from soil degradation and reduced productivity due to short rotation cycles and multiple generations of replanting. This study investigated the effects of different thinning intensities (CK, 30%, 45%, and 60%) on the size composition, stability, and distribution of metal nutrient elements (K, Ca, Mg, Fe, Mn, Cu, and Zn) of soil aggregates in Eucalyptus plantations by collecting 0–20 cm soil samples and using the dry-sieving method to separate soil aggregates into four sizes (>2 mm, 1–2 mm, 0.25–1 mm, and <0.25 mm). Our findings were as follows: (1) The majority of aggregates comprised larger sizes, predominantly exceeding 2 mm in diameter, which were the most abundant. (2) Compared with unthinned stands (CK) and stands that were thinned by 30%, those thinned by 45% and 60% demonstrated enhanced soil aggregate stability. (3) The stands that were thinned by 30% had the highest Mg and Fe content, whereas those that were thinned by 45% contained the highest levels of Ca, Mn, Cu, and Zn. Larger aggregates (>2 mm) harbored the greatest quantities of metal nutrients, whereas smaller aggregates (<0.25 mm) stored the least. (4) The primary determinants of the metal nutrient content were the soil’s pH and organic carbon levels. (5) The distribution of aggregate sizes played a pivotal role in influencing the nutrient reserves within the aggregates. Overall, this study demonstrated that the thinning intensity not only impacts the stability of soil aggregates in Eucalyptus plantations, but also influences the accumulation of metal nutrient elements within these aggregates, which confirms the significance of macroaggregates as a reservoir for metal nutrient elements. To preserve and enhance soil macroaggregates, it is recommended to implement measures such as reducing the amount of mechanical disturbance, increasing the amount of organic matter, optimizing the stand structure, mitigating water erosion risks, and promoting biological activity while conducting regular assessments of the aggregate stability. Full article

Wheat growth is highly sensitive to temperature fluctuations, and with the intensification of global climate change, low-temperature stress has become more frequent during various growth stages of wheat, severely affecting its growth and reducing wheat yield. An experiment examined the effects of low-temperature (daytime 8:00–20:00/nighttime 20:00–next day 8:00: 16 °C/8 °C, 12 °C/4 °C, 8 °C/0 °C, and 4 °C/−4 °C) and exposure durations (1, 3, and 5 days) on winter wheat yield during the anthesis stage. Compared to exposure duration, temperature was the main factor affecting dry matter accumulation, distribution, and transport. Temperature had an average influence of 79.7%, 57.5%, 61.9%, and 79.0% on dry matter distribution in the stem-sheath, leaf, spike axis+glume, and grain, respectively. It also affected pre-anthesis translocation amount, the contribution of pre-anthesis translocation to grains, post-anthesis accumulation amount, and the contribution of post-anthesis accumulation to grains by 48.3%, 55.1%, 44.2%, and 48.2%, respectively. Conversely, exposure duration mainly influenced grain-filling parameters, with an average effect of 43.8%, 44.0%, 83.3%, and 43.8% on the maximum filling rate, average filling rate, filling rate in the fast-increasing period, and filling rate during the slow growth period, respectively. Low-temperature duration also significantly altered the fast-increasing period, slow growth period, and grain weight per spike by 79.9%, 79.9%, and 51.3%, respectively. Low-temperature stress alters the accumulation and distribution of dry matter in wheat, and the duration of exposure further affects the grain-filling process, ultimately resulting in a decrease in yield. Full article

We investigated the effects of light quality and photoperiod on the phenotypic characteristics, dry matter production, and yield of ginger under three light quality ratios (A1: blue light: white light = 1:4; A2: blue light: white light = 1:1; A3: pure white light) and two photoperiod conditions (B1: 12/12 h·d⁻¹; B2: 16/8 h·d⁻¹). The results demonstrated that blue light treatment significantly reduced plant height and the dry matter distribution ratio of stems and sheaths. In contrast, stem diameter, tiller number, leaf area, theoretical biomass (TBY), maximum accumulation rate (V_max), average accumulation rate (V_aver), time point of maximum accumulation (T_max), rapid growth period (DRGP), dry matter distribution ratio of leaves, roots, and rhizomes, number of rhizomes per plant, average rhizome weight, and yield all significantly increased with an increasing blue light ratio. Principal component analysis revealed distinct phenotypic traits, dry matter production characteristics, and yield-related traits under different blue light treatments. Blue light promoted tillering and increased stem thickness, which are key mechanisms for enhancing ginger yield. Additionally, prolonged photoperiods significantly increased plant height, stem diameter, branch number, leaf area, and biomass, while promoting the redistribution of photosynthetic products from leaves to rhizomes and increasing the proportion of dry matter allocated to rhizomes, thereby boosting ginger yield. These findings provide valuable insights into optimizing light conditions for ginger cultivation, highlighting the importance of a balanced blue-to-white light ratio and extended photoperiods in improving ginger growth and productivity. Full article

Elevation, as a comprehensive ecological variable, is considered one of the decisive factors in the distribution pattern of plants in a region. We explored changes in functional traits and biomass accumulation and allocation of Gentiana lawrenceni along an elevational gradient and their relationships. We found that leaf size and specific leaf area (SLA) of this species showed a trend of first increasing and then decreasing with elevation, while leaf thickness and leaf dry matter content (LDMC) showed a trend of first decreasing and then increasing. As elevation increases, the aboveground biomass, belowground biomass and total biomass all decline, and above- and belowground biomass allocation is initially reduced and then rise. Leaf size and LDMC positively affected biomass accumulation, while four leaf traits did not affect biomass allocation. In sum, this study found that there is a threshold at ~3600 m above sea level that causes changes in functional traits and biomass allocation strategies of this species to adapt to harsher high-elevation environments. Gentiana lawrenceni can maintain its biomass accumulation and fitness by adjusting leaf size and LDMC. This study has enhanced our understanding of the changes in functional traits, biomass accumulation and allocation strategies of alpine plants along an elevation gradient. Full article