Search Results (211)

Nutrients recovered from municipal and dairy wastewaters in a bioelectrochemical system constructed with terracotta and biochar were used in different soil amendments. These amendments included addition of terracotta (TS), biochar (BS), terracotta and biochar nutrient-rich mixtures from bioelectrochemical systems, DWW (dairy wastewater), and SWW (synthetic wastewater), respectively. Corn growth affected by these amendments was compared with control, termed straight soil (SS). The first experimental setup consisted of 60 plants, four replications per group, and nutrient loadings (0%, 50%, and 100% Hoagland Nutrient Solution, HNS) in the fall season. After harvesting, the plants and soil were analyzed for agro-physical characteristics by various methods. At the 100% nutrient treatment, the TS soil had the best yielding plants. Overall, plants grown in DWW and SWW soil amendments with 0% and 50% nutrient treatments had the best results in plant height, total plant dry weight, the average number of leaves per plant, leaf surface area, shoot dry weight, root/shoot ratio, root surface area, and NBI when compared to the control group. Another test was carried out with 80 corn plants grown using five different soil mediums and using four different nutrient treatments in the spring season. Twenty of the plants were put through a simulated drought to evaluate drought resistance (as measured by plant growth) in different soil amendments. In this test, the SWW soil amendment had a negative effect at 0% HNS and in warm weather. The SWW soil medium had large retention in soil moisture, which had a negative growth effect. It is recommended that the irrigation be monitored closely when applying the SWW soil amendment to avoid overwatering. This research provides critical insights into nutrient reuse in crop production. Full article

Using plants to restore soils subjected to salinization and polychemic pollution can be an effective way to return agricultural land to circulation and obtain safe products. In this study, experiments were conducted with oats and lupine to evaluate their ability to purify soils contaminated with copper (II) and nickel (II) ions, carbonate and sulfate anions and oil and their combinations. The biological activity of the soil, phytotoxicity, and hydrocarbon content, as well as plant growth and biochemical parameters in polluted soil, were studied. The enzymes most sensitive to soil contamination were catalase, urease, and phosphatase. Copper ions inhibited oat root growth by 45.7% and lupine by 46.6%. Oil and its mixtures with other pollutants inhibited shoot growth by up to 50.3% in oats and up to 28.6% in lupine. The content of malonic dialdehyde increased in oats when exposed to copper, while in lupines, it increased 2.9-fold when exposed to oil. Flavonoids in oats increased with metal contamination (by 9–16.7%), while in lupines with oil (by 8.6%). Chlorophyll fluctuations were less pronounced in oats than in lupine. Despite the stress experienced by plants due to soil pollution, the degradation rate of petroleum hydrocarbons under oat and lupine crops was 33–46%. In general, oats and lupine are promising for the phytoremediation of complexly polluted and saline soils. Full article

The rational use of reclaimed water for irrigation is a vital strategy to alleviate water scarcity in arid and semi-arid regions. Assessing its impact on heavy metal behavior in soil–plant systems is crucial for ensuring agricultural safety. This study evaluated the effects of four irrigation water sources—well water (CK, control), river water (R0), a 1:1 mixture of river and reclaimed water (R1), and reclaimed water (R2)—on the distribution of heavy metals (Mn, Zn, Cu) in soil profiles and their accumulation in corn organs across growth stages. Results indicated that soil Mn content increased over time, whereas Zn and Cu levels generally decreased, with the smallest reduction observed in the R2 treatment at deeper soil layers. In corn, Mn and Cu were primarily concentrated in roots and leaves, while Zn accumulated notably in grains. Plant heavy metal content was generally lower under R2 than CK. Risk assessment indicated slight Mn pollution in soil, whereas Zn and Cu remained within safe limits. Health risk indices (THQ) for R1 and R2 were lower than CK. Overall, the mixed water treatment (R1) showed the strongest potential for controlling heavy metal contamination, suggesting that blended reclaimed water can support sustainable irrigation with long-term Mn monitoring recommended. Full article

The scouring of cohesive and non-cohesive materials downstream of sluice gates is primarily based on high-velocity flow. The present study considered an experimental hydraulic model of submerged water flow issuing from a sluice gate installed on an apron that leads to the scour hole and dune in a downstream mixture of sand and clay bed. The purpose was to achieve a suitable efficiency of the weight ratio of clay in the sand–clay mixture (c) for the sediment bed. Scour parameters, including maximum scour depth (d_se) and its longitudinal location (x_se), and maximum dune height (h_d) and its location (x_d), were measured and compared for three variations, c = 0.1, 0.2, and 0.3, under five hydraulic conditions. Results revealed that all scour parameters were reduced by adding clay to the sand soil, and the maximum reduction was for d_se with the maximum value of 27.66%. The observed data were analyzed by multiple nonlinear regression analyses for each scour parameter to present new prediction equations for practical uses. The computed statistical parameters of correlation coefficient (R²), root mean square error (RMSE), mean absolute percentage error (MAPE), Nash–Sutcliffe efficiency (NSE), and scatter index (SI) present good accuracy for the predicted equations in the ranges of experimental data. Full article

Artemisia frigida (subshrub) communities, which are indicators of grassland degradation, are widespread in overgrazed Eurasian steppes. After 4–6 years of enclosure, the community can recover to an Agropyron cristatum-dominated grass community. Understanding the competitive mechanisms between these two key species provides critical insights for the management of semi-arid steppes, where vegetation dynamics are primarily driven by soil moisture. Nevertheless, how soil moisture distribution mediates above- and belowground competition between A. cristatum and A. frigida remains unclear. To address this, we conducted a pot experiment that simulated natural vertical soil moisture heterogeneity with four soil moisture regimes in two soil layers (0–30 cm and 30–60 cm): uniformly dry (D–D), wet upper/dry lower (W–D), dry upper/wet lower (D–W), and uniformly wet (W–W), using both monoculture and mixed planting methods. Key results showed that (1) A. cristatum was more sensitive to soil moisture regimes than A. frigida. Its above- and belowground biomass were significantly higher under moist treatments (W–W, W–D, D–W) than under drought (D–D), whereas the biomass of A. frigida did not differ significantly among water treatments. (2) Compared with monoculture, mixed planting significantly increased the root–shoot ratio of A. frigida but did not affect that of A. cristatum. (3) Competitive ability differed between aboveground and belowground parts: competitive indices (aggressivity and relative competition intensity) revealed that A. cristatum exhibited stronger aboveground competitiveness under moist treatments, while A. frigida dominated aboveground under drought conditions. However, A. frigida consistently exhibited greater belowground competitive ability than A. cristatum across all water treatments in the mixture. These results emphasize that assessments of grass–shrub competition based solely on aboveground indicators may underestimate the competitive advantage of shrubs. Therefore, integrating belowground competitive processes is essential for accurately predicting grass–shrub competition and succession in semi-arid steppes. Full article

The cultivation of Physalis peruviana has emerged as a promising alternative for small- and medium-sized producers due to its high added value and low production cost. However, information on the cultivation of this vegetable crop under Brazilian edaphoclimatic conditions is still scarce. Seedling production is one of the most critical stages for crop development, as this species does not establish well from seeds under field conditions. Therefore, this study aimed to evaluate seed germination and seedling growth of P. peruviana under different container volumes and substrate compositions. The experiment was carried out from February to March 2020 in a screened greenhouse environment, using a completely randomized factorial design. The treatments consisted of different container volumes and substrate compositions, including commercial containers of varying sizes and soil-based substrates formulated with mineral components and organic manures. Four replications were used, each consisting of seven plants. Seed emergence was favored by substrates containing well-composted cattle manure, whereas smaller container volumes reduced the emergence of P. peruviana. The greatest seedling growth, including higher stem base diameter, number of leaves per plant, leaf area, and shoot and root dry mass, was obtained in larger-volume containers filled with soil-based substrates enriched with well-composted cattle manure. Therefore, for the production of high-quality P. peruviana seedlings, the use of 400 cm³ polyethylene containers filled with a mixture of soil, sand, commercial substrate, and well-composted cattle manure in a 1:1:1:2 ratio is recommended. Full article

Low soil nutrient availability and uptake negatively affect crop productivity in acidic soils. For example, phosphorus (P) availability is reduced by fixation of aluminium (Al) and iron (Fe) hydrous oxides and precipitation with soluble Al and Fe. In addition, soil acidity inhibits root growth, and application of agricultural lime ameliorates these challenges, thereby improving yields. However, resource-limited farmers in the Eastern Cape Province can rarely afford to procure lime and chemical fertilisers, which necessitates alternative approaches to addressing the challenge of low nutrient availability for crops. The present study explores interactions between cattle manure and mineral fertiliser applications coupled with arbuscular mycorrhizal fungi (AMF) inoculation on the agronomic performance of Amaranthus grown in acidic soil. The treatments were 100% cattle manure, 50% cattle manure + 50% NPK fertiliser and lime, 33% cattle manure + 33% NPK and lime + AMF, the recommended rate of mineral fertiliser and lime, AMF, and an absolute control. Cattle manure and mineral fertiliser application, including mixtures of their microdoses, coupled with AMF inoculation, significantly improved the growth and yield of Amaranthus species. Leaf tissue concentrations of N, P, K, Ca, Mg and Zn and their uptake, and selected residual soil properties and nutrients increased significantly following application of the treatments relative to the unfertilised control. The findings of this study imply that application of manure and mixtures of microdoses and mineral fertiliser, together with AMF, improve nutrient uptake and yield of Amaranthus and residual nutrients that benefit subsequent crops. Full article

New Zealand’s only tea (Camellia sinensis) plantation supplies a niche market for organically produced high value tea but faces challenges from climatic conditions and the decision to use only organic production methods. Fungi from the genus Trichoderma have been commercialised in New Zealand and elsewhere as disease-suppressing and plant growth-promoting agents. However, the potential benefits of using Trichoderma as a microbial biostimulant for tea cultivation have not been investigated in New Zealand. The ability of T. atroviride application to stimulate tea plant growth at a tea plantation was investigated over one year of production. The study involved foliar application of the biostimulant either once, twice or three times, one month apart, using 12 g of a commercially formulated spore mixture of four strains of T. atroviride per 5 m² of experimental plots. Treatment with T. atroviride significantly increased tea yield by between 17% and 28% compared to the control over the harvesting season, but there were no statistically significant yield differences among the number of applications. The foliar applied T. atroviride was not detected in the soil or root samples six months after application, in either a soil metabarcoding analysis or on re-isolation media. This was likely due to the dense tea foliage and ground cover under the tea plants which impeded its movement to the soil. While the specific nature of T. atroviride interaction with perennial crops like tea is not known, in this trial it appeared to have remained on the phyllosphere and provided biostimulation without reaching the soil. Full article

Potassium (K) is a vital macronutrient for plant growth and yield, yet most soil K occurs in insoluble mineral forms, limiting availability to crops. Reliance on chemical K fertilizers is unsustainable due to cost and environmental concerns. Microbial solubilization of mineral K, particularly by purple nonsulfur bacteria (PNSB), offers an eco-friendly alternative. This study focused on isolating mica-potassium-solubilizing purple nonsulfur bacteria (MK-PNSB) from in-dyke alluvial soil and assessing their effects on hybrid maize germination and seedling growth. Among the isolates, the results showed that strain M-Wa-19 released the highest amount of soluble K under microaerobic light conditions (27.4 mg∙L⁻¹). Under aerobic dark conditions, M-Wa-24 and M-Wa-26 released 20.1–21.0 mg∙L⁻¹ of soluble K. Strains M-Wa-21, M-Wa-25, and M-Sl-13 solubilized K in the range of 14.3–25.1 mg∙L⁻¹ and 12.9–24.4 mg∙L⁻¹ under both incubation conditions. The selected strains were identified by 16S rRNA as Rhodopseudomonas palustris strain M-Sl-13 (PX588604), Rhodoplanes pokkaliisoli strain M-Wa-19 (PX588605), Afifella marina strain M-Wa-21 (PX588606), Rhodocista pekingensis strain M-Wa-24 (PX588607), Rhodocista pekingensis strain M-Wa-25 (PX588608), and Rhodocista pekingensis strain M-Wa-26 (PX588609). None exhibited toxicity to maize seeds; instead, all enhanced seed vigor indices by up to 99.7% and improved plant height and root biomass by 19.0–26.2% and 14.4–22.9%, respectively, under static hydroponic conditions. At a 1:1000 (bacteria and distilled water) dilution rate, strains M-Wa-26, M-Wa-25, M-Sl-13, M-Wa-24, M-Wa-19, and M-Wa-21, along with the six-strain mixture, improved seed vigor index by 3.96–7.91%. These findings suggest that MK-PNSB, individually or in mixtures, hold promise as biofertilizer candidates for sustainable K management in crop production. Full article

Substrate composition plays a vital role in the soilless cultivation of Helleborus; high-quality substrates can create optimal growth conditions and enhance plant quality. However, knowledge regarding suitable substrates for Helleborus remains limited. The aim of the study was to test the effects of different substrates on growth of potted Helleborus × hybridus seedlings. In total, 12 treatments were formulated by mixing organic components (moss peat, cocopeat, domestic peat) with inorganic particles (perlite, kanuma soil, vermiculite) at a 1:1 ratio, using moss peat moss as the control. The results indicated that substrates of moss peat + vermiculite (1:1) and cocopeat + vermiculite (1:1) significantly promoted plant height, shoot number, leaf number, and root development. The treatment with domestic peat + perlite + kanuma soil + vermiculite (3:1:1:1) yielded the highest soluble protein content, whereas the CK group showed the highest soluble sugar content. A comprehensive evaluation by Principal Component Analysis (PCA) identified moss peat + vermiculite (1:1) as the optimal substrate, followed by coir + vermiculite (1:1). Considering economic costs and environmental protection factors, the cocopeat + vermiculite (1:1) mixture demonstrated superior potential. Collectively, our study clarifies the effects of different substrate compositions and provides new insights for achieving cleaner and more efficient soilless cultivation of Helleborus. Full article

Lolium perenne L. (perennial ryegrass) has various applications, including as a high-quality forage species for livestock feed; in seed mixtures used for revegetation of eroded or degraded areas as well as for lawns due to its resistance and rapid germination; for erosion control on slopes and areas with excessive steepness; for phytoremediation of soils contaminated with potentially toxic elements due to its ability to accumulate metals in its tissues; and as a cover crop to improve soil conditions and control erosion. Accordingly, L. perenne provides several ecosystem services, primarily related to soil stability, agriculture, and recreation. Climate change poses challenges for L. perenne, particularly heat and drought stress, which can reduce its yield and alter its geographical distribution. Climate change also impacts the interactions between L. perenne and its environment, affecting aspects like phenology (e.g., flowering time), carbon fixation, and overall resilience. However, the species’ significant genetic and endophyte-related variability may allow for adaptation. The aim of the present study was to assess the drought tolerance of three Bulgarian varieties of L. perenne, namely Harmoniya (diploid), Tetrany, and Tetramis (tetraploids). We performed induced drought stress under laboratory conditions and monitored its effect on plants in the early stages of growth and development. A variety-specific response was found regarding the effect of different concentrations of sucrose on seed germination, primary root and stem elongation (cm), fresh biomass accumulation (g), as well as on seedling vigor index and plant development. Field experiments and yield elements were also used to assess drought susceptibility and sensitivity to stress in a real environment. The tetraploid perennial ryegrass varieties Tetrany and Tetramis showed better germination, growth, and development in laboratory tests and had higher and more stable field productivity under both optimal and stress conditions than the diploid variety Harmoniya. Ploidy was the factor that characterize them as drought-tolerant genotypes under water-limited conditions, and its potential could be used in future breeding programs. Full article

Daknamu (Broussonetia × kazinoki), the primary fiber source for hanji (traditional Korean handmade paper), provides fibers that are highly durable and used in fine-edition publishing as well as in the conservation and restoration of cultural heritage materials and historic books. However, hanji production has declined due to decreased farm cultivation of B. × kazinoki, emphasizing the need for efficient vegetative propagation. This study evaluated the effects of three rooting media (commercial substrate, a mixture of commercial substrate and decomposed granite soil, and decomposed granite soil) and two plant growth regulators (auxins), 1-naphthaleneacetic acid (NAA) and indole-3-butyric acid (IBA), including a rooting powder containing 0.8% IBA, on rooting performance and physiological responses. Decomposed granite soil produced the highest rooting rate, and the rooting effect index peaked with the rooting powder treatment. Exogenous auxins consistently increased the rooting rate and improved root traits. Photosynthetic activity was enhanced in decomposed granite soil, indicating improved water uptake following root development. Chlorophyll fluorescence showed a low F_v/F_m ratio and a JIP pattern indicative of stress. Soil analyses confirmed greater aeration and drainage in decomposed granite soil but revealed limitations in post-rooting water and nutrient availability. Root traits were positively correlated with photosynthetic parameters and available phosphorus, whereas electrical conductivity, cation-exchange capacity, moisture, organic matter, total nitrogen, and exchangeable cations were negatively correlated. Decomposed granite soil combined with 1500 mg·L⁻¹ IBA or rooting powder provided practical conditions for nursery-scale propagation. These findings provide a scientific basis for developing efficient cutting propagation systems for B. × kazinoki in farms and nurseries. Full article

In the semi-arid Loess Plateau of China, afforestation frequently leads to soil water depletion, threatening ecosystem sustainability. Although mixed-species plantations are encouraged to enhance resource use efficiency, their effects on deep soil water and root distribution strategies remain unclear. This study compared soil water content (SWC), deep soil water deficit (SWD), and fine root distribution in pure and mixed plantations of Robinia pseudoacacia, Platycladus orientalis, and Hippophae rhamnoides to assess whether species mixing intensifies consumption for deep soil water. Soil moisture and root samples were collected with a maximum depth of 20 m across five stand types in August 2018 and during the 2019 growing season. Results showed that mixed stands exhibited shallower water depletion depth and lower SWC below 2 m than pure stands, but a more severe deep soil water deficit, with observed SWD exceeding the expected values by 12% in the R. pseudoacacia-P. orientalis mixture (MRP) and 22% in the H. rhamnoides-P. orientalis mixture (MHP), indicating intensified water consumption below 2 m. In the MRP, the maximum rooting depth was shallower than in the corresponding pure stands. Within the mixture, species-specific root plasticity was observed: the normalized fine root length density (FRLD) of P. orientalis was four times greater in mixture than in pure stand, whereas that of R. pseudoacacia was 62% lower, suggesting divergent foraging strategies. Correlation analyses indicated that SWC was differently associated with root traits between pure and mixed stands, with relationships varying by soil depth. Mixed-effects models confirmed that both plantation type and soil depth significantly influenced FRLD and Root dry weight density (RDWD), while specific root length (SRL) was mainly affected by plantation type and its interaction with depth. These findings demonstrated that mixed-species afforestation intensifies deep soil water competition. Therefore, sustainable management should prioritize the selection of species with complementary root foraging strategies and the optimization of planting densities in semi-arid regions. Full article

Potassium (K) is present in soils mainly in minerals, including feldspar. However, most of it is unavailable to plants. In the in-dyked alluvial soils of the Mekong Delta, available K is typically low despite the abundance of K-bearing feldspar, leading to nutrient imbalances and yield constraints. This study aimed to (i) select potential feldspar-potassium-solubilizing purple nonsulfur bacteria (K-PNSB), (ii) determine their ability to enhance hybrid maize seed vigor (Zea mays L.), and (iii) evaluate their effects on the growth of maize seedlings. Fifty-eight K-PNSB strains were isolated from maize-cultivated in-dyked alluvial soils, with soluble K concentrations ranging from 0.108 to 15.0 mg L⁻¹. Among these, strain M-Sl-03 released the highest K concentration under microaerobic light conditions, whereas strains M-Sl-01 and M-Sl-06 produced best under aerobic dark conditions. In addition, two more strains, M-Sl-02 and M-Wa-06, were also selected for their K solubilization ability. The selected strains were identified as Cereibacter sphaeroides strains M-Sl-01 and M-Sl-02, Rhodopseudomonas palustris strain M-Sl-03, and Rhodoplanes pokkaliisoli strains M-Sl-03 and M-Wa-06, according to their 16S rDNA region. None of them exhibited toxicity to germinating maize seeds. Both individual strains and the five-strain mixture significantly improved seed vigor. At a 1:1000 dilution, individual and mixed inoculants increased the vigor index of maize seeds by 47.5–68.8%. In addition, the selected PNSB strains contributed to improving the growth of maize seedlings, particularly plant height and root dry biomass. These promising strains have potential for application as biofertilizers to support hybrid maize cultivation. Full article

Progressive urbanization and increasing pressure on urban green areas necessitate the search for innovative, ecological, and efficient solutions for lawn management. The shallow root system of grasses, combined with a long vegetation period, makes these plants particularly sensitive to water and nutrient deficiencies. One research direction involves the use of zeolites, natural aluminosilicate minerals that, due to their porous structure and high sorption capacity, improve water retention and nutrient availability in soil. The aim of this study was to assess the effect of different zeolite doses on the initial growth and development of two turfgrass species (Lolium perenne, Festuca rubra), as well as on selected lawn performance traits, and to determine the persistence of these effects over time. This research was conducted in 2020–2023 under pot and micro-plot experiment conditions, using mixtures containing the above species. Four levels of zeolite addition to the substrate were applied: 0% (control), 1%, 5%, and 10%. The results clearly confirmed the beneficial effects of zeolite. Its addition improved the germination, growth, and biomass yield of aboveground parts and roots, as well as enhancing turf aesthetics, ground cover, and winter hardiness, while reducing the proportion of dicotyledonous species. The best effects were obtained with the 5% dose, which should be considered optimal—it significantly improved lawn utility parameters with lower material input compared to the 10% dose. Species response varied: L. perenne responded more strongly to improved water–air conditions, whereas F. rubra utilized higher zeolite doses more effectively in root system development. The highest overall effectiveness was recorded with the 10% dose. Zeolite effectiveness was greatest in the first year after application, showing a declining trend in subsequent years, although a positive effect was still observed in the third year of use. The findings support the recommendation of zeolite as an ecological soil additive that enhances lawn quality and durability, particularly in low-fertility soils and under water deficit conditions. Its application may represent an important component of modern green space management technologies in line with the principles of sustainable development. Full article