For saving the expenses and time involved in the routine soil testing, a novel multi-nutrient soil extractant (OM-MES-VERA) comprising 0.0025 M EDTA +0.01 M oxalic acid +0.02 M acetic acid +0.02 M maleic acid +0.02 M 2-(N-Morpholino) ethane sulfonic acid (MES) + 0.1% polyacrylamide with final pH (6.0) has been developed. This extractant was used to assess the availability of macronutrients from soil and compared with the conventional soil test methods. In a laboratory evaluation with diverse soils (n = 32), OM-MES-VERA extracted K similar to 1 M ammonium acetate (pH 7.0) but extracted significantly lower amounts of inorganic N (NH4 + + NO3 -), P, S, Ca and Mg compared to conventional alkaline KMnO4 hydrolysable N, Olsen's- or Bray's- P, 0.15% CaCl2 extractable S, 1 M ammonium acetate extractable Ca and Mg, respectively. Interestingly, the absorbance ratio (OD465/OD665) of OM-MES-VERA extracts significantly correlated with the conventional alkaline KMnO4 hydrolysable N (R2-value = 0.386, Significant at p <= .01) and additional inclusion of clay and organic C contents, pH and electrical conductivity led to an improved prediction of N (R2-value = 0.501, significant at p <= .01). Other macronutrients (P, K, S, Ca, Mg) extracted by OM-MES-VERA could be successfully regressed on the conventional soil test values (R2-value 0.342-0.633, all significant at p <= .01). The soil test values by OM-MES-VRA and conventional methods were correlated with soil properties. Further greenhouse and field studies are required to prove the suitability of OM-MES-VERA extractant for assessing the availability macronutrients.
Phosphorus (P) management is a key aspect of sustainable agriculture. However, its effectiveness also depends on the phosphate source. We investigated whether phosphate sources contribute to soil P availability, grain yield (GY), and P uptake by chickpea, wheat, and soybean cropping sequences. We conducted a pot experiment under controlled conditions, with six commercial phosphate sources, a rate of 150 mg P kg-1 of soil, one control, and four replications. Triple superphosphate (TSP) increased the GY by 25.6%, whereas the lowest yields, -20.9 and -18.4%, were recorded from the Alvorada and Gafsa phosphates, respectively, for chickpea. With respect to the residual effect, only Bay & oacute;var increased the wheat GY by 20.5%; in contrast, compared with the control, the residual effect of all the phosphate sources applied increased the soybean GY, compared to the control. However, the variation in the P concentration in plant tissues was influenced by the phosphate source and P use efficiency (PUE). Additionally, phosphate sources increased soil P availability, depending on the phosphate source, soil pH, and extractant used. Finally, Olsen P and Mehlich-3 were significantly correlated with the GY and P concentrations in the plants. Under low-P conditions, plants increased their root growth to mine P and PUE and sustain development and yield. More soluble phosphate sources, such as TSP, are better for immediate crop response, whereas phosphates with less solubility contribute more to long-term soil P availability. However, the limitation of some current methods for accurately reflecting the true P status of the soil can be a challenge.
This study developed an innovative fertilization framework integrating nano-urea with diverse organic amendments to enhance nutrient efficiency, salinity tolerance, and productivity in tomato (Solanum lycopersicum L. cv. Pusa Sheetal). Conducted over two years (2021-23) in Noida, India, the research employed a randomized block design to compare various combinations of nano-urea foliar sprays (2% and 4% w/v) and organic amendments, including farmyard manure, vermicompost, organic cakes, under both normal and saline (EC 4 dS m(-1)) conditions. Results demonstrated that replacing conventional nitrogen doses with integrated nano-urea and organic treatments significantly improved soil health by increasing soil organic carbon (up to 37%), macronutrient availability (N, P, K) while reducing electrical conductivity (up to 24.4%) in saline soils. Morphologically, the synergy between nano-urea and organic matter mitigated salt stress, resulting in substantial increases in plant height (21-25%), branching (13-26%), leaf production (13-24%), fruit number (20-53%), fruit weight (23-30%), and overall yield (44-89%) compared to control and saline-only treatments. Biochemically, the integrated approach upregulated the plant's antioxidant defense system, showing significant increases in ascorbate peroxidase (34-74%) and superoxide dismutase (35-68%) activity. Concomitantly, a reduction in reactive oxygen species (ROS), hydrogen peroxide, and malondialdehyde (MDA) levels indicated a mitigation of salinity-induced oxidative damage. In addition, fruit quality was enhanced through elevated levels of carotenoids, lycopene, and vitamin C. Overall, the findings reveal a synergistic nutrient-delivery framework where nano-enabled nitrogen, coupled with organic amendments, optimizes rhizosphere chemistry and reinforces the ascorbate-glutathione cycle. This integrated approach represents a scalable, cost-effective advancement in precision nutrient management for sustainable tomato production in stress-prone agroecosystems.
With rising populations, boosting agricultural productivity is essential. Although chemical fertilizers are common, excessive use increases costs and harms the environment. Zeolite offers an alternative due to its porous structure and cation exchange capacity. In this study, ammonium nitrate was loaded into natural zeolite from Manisa/T & uuml;rkiye, and the nitrogen content of the fertilizer was 5.80%. Raw zeolite and zeolite-based fertilizer samples were characterized using Brunauer-Emmett-Teller (BET), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR) techniques. The zeolite-based fertilizer was tested on lettuce (Lactuca sativa L) plants in a greenhouse experiment and its usability as a fertilizer and its effect on yield were investigated. According to the results obtained, while the length, leaf number, head diameter, and head weight data of the ZN25 (187.5 ppm Nitrogen) group containing zeolite-based fertilizer were measured as 31.28 cm, 28.88, 16.83 cm and 135.10 g, respectively, for the pure ammonium nitrate applied group (N50; 375 ppm Nitrogen), the related parameters were measured as 29.53 cm, 26, 12.87 cm and 106.80 g, respectively, and it is clear that ZN25 provided better efficiency than N50. Additionally, because of the greenhouse experiment, it was observed that there was a correlation between nitrogen and chlorophyll contents in the application groups. The nitrogen and chlorophyll contents of the ZN25 and N50 groups were measured as 4.29%, 38.14 soil plant analysis development (SPAD) and 5.97%, 43.38 SPAD, respectively. According to these results obtained, zeolite-based fertilizer increased crop yield by using less nitrogen and has the potential to be used in agriculture.
The aim of the present study was to evaluate the interactive effects of various biochar sources (sheep manure, rice husk, and municipal solid waste, applied at 3% (w/w)) and Si application rates (200 and 400 mg Si kg-1 soil) on grain yield, nutrient composition of triticale (X Triticosecale Wittmack), and the chemical properties of Pb-contaminated calcareous soil in a greenhouse trial. Among the biochars tested, sheep manure biochar was the most effective at reducing soil available Pb concentration (16.6% reduction), likely because of its high pH, phosphorus, and soluble salt content. The highest Si application rate (400 mg Si kg-1) also significantly reduced soil available Pb concentration by 6.6%. However, the most effective treatment for enhancing triticale grain yield (68% increase) and reducing grain Pb concentration (54% reduction) compared to the control was the combined application of sheep manure biochar and the lower Si level (200 mg Si kg-1). At the higher Si application rate (400 mg Si kg-1), both grain yield and macro- and micronutrient uptake were markedly suppressed, potentially due to nutrient antagonisms associated with sodium metasilicate. These results underscore the synergistic effects of sheep manure biochar and moderate Si application in immobilizing soil Pb, enhancing triticale nutrient uptake, and improving grain yield in Pb-contaminated calcareous soils. The study recommends further investigations into using other silicon compounds, such as calcium and potassium silicates, and biochars produced at varying pyrolysis temperatures, to assess their potential in mitigating the adverse effects of Pb on triticale growth in calcareous soils.
Heavy reliance on synthetic nitrogen (N) fertilizers has resulted in soil degradation, declining soil productivity, and lower N use efficiency (NUE). Sustainable alternatives such as biochar (BC) and biofertilizers (BFs) offer promising solutions to enhance soil health and support yield improvement. This study investigates the individual and combined effects of BC and microbial BFs on soil properties, corn growth, and yield under controlled greenhouse conditions. A randomized experiment with seven treatments consisting of granular urea, BC, BFs, and their combinations were conducted using clay loam soil. Soil samples collected at four growth stages were analyzed for inorganic N forms, including ammonium-N (NH4+-N) and nitrate-N (NO3--N), as well as organic matter (OM), phosphorus (P), potassium (K), and other physicochemical properties, while plant growth traits, chlorophyll content, biomass, and grain yield were measured. Treatments containing BC and/or BFs significantly increased soil OM and nutrient availability, including N, P, and K. In addition, these treatments improved plant height, leaf number, and chlorophyll concentration, resulting in 14-17% greater biomass and 14-19% higher yield compared to the control. Notably, the integrated application of BC, BFs, and 50% urea treatment increased yield and biomass by 25% and 28%, respectively, values comparable to full urea application, indicating that N fertilizer use can be reduced without compromising productivity. Overall, the results highlight strong synergistic benefits of BC and BFs for sustainable corn production.
Silicon (Si) is known to alleviate several abiotic stresses in plants, including ammonium (NH4+) toxicity. However, the availability of Si in the nutrient solution depends on factors such as the Si source and NH4+ concentration. This study evaluated the effects of two Si sources, stabilized silicic acid (ASiE) and potassium silicate (SiK), on Micro-Tom tomato grown under NH4+ toxicity. In the first experiment, plants were supplied with 0.0, 0.2, 0.4, 0.6, and 0.8 mmol L-1 Si from either SiK or ASiE. NH4+ toxicity was induced at a NO3-:NH4+ ratio of 3.8:11.2 mmol L-1. In the second experiment, plants received 0.0, 1.0, 2.0, and 2.5 mmol L-1 Si supplied as SiK. NH4+ toxicity was induced by 5.9 mmol L-1 NH4+, while 5.9 mmol L-1 NO3- was used as the control treatment. In the first experiment, Si supply did not increase shoot Si content or Si accumulation, and NH4+ toxicity was not alleviated. In contrast, in the second experiment, Si supply increased shoot Si content and Si accumulation, resulting in greater shoot and root dry weight under NH4+ toxicity. Similarly, plants supplied with NO3- also showed increased shoot and root dry weight in response to Si application. In conclusion, low concentrations of Si supplied as either SiK or ASiE were ineffective in alleviating NH4+ toxicity. However, SiK at 1.29 mmol L-1 Si alleviated NH4+ toxicity induced by 5.9 mmol L-1 NH4+ alone.
Reliable data on cadmium (Cd) leaching from fertilizers into agroecosystems is crucial for accurately assessing mass balances in agricultural soils. This study tried to study the behavior of Cd in two different soils including Karaj soil (Equivalent Calcium Carbonate (CaCO3) = 15.2%, organic carbon (OC) = 0.27%, and pH = 8.1) from central and Lahijan soil (Equivalent CaCO3 = 1.8%, OC = 3.83%, and pH = 7.2) northern parts of Iran. Additionally, three types of salts including NaCl, CaCl2, and Na2SO4 were applied at a concentration of 100 meq l(-1) to leach soil column using a 25 cm pressure head. Adsorption isotherms were applied to simulate Cd movement by the HYDRUS-1D software. The hydraulic parameters were adjusted by 25%, 50%, 75%, and 100% relative to estimated baseline values to determine the most sensitive parameters. The results indicated that higher Cd movement was achieved by CaCl2 > NaCl > Na2SO4 > H2O as well as the lowest Cd adsorption based on the CRM (Residual Mass Coefficient) index for two studied soils. This trend can be attributed to i) saline solutions with Cl- source facilitated greater Cd mobility as compared to those with SO42- as the anion source. The sulfate anion in Na2SO4 is less effective at complex formation, resulting in lower Cd mobility and ii) in the CaCl2 and NaCl treatments, the movement of Cd was influenced more significantly by Ca2+, which can displace exchangeable Cd. These findings highlight the importance of considering both soil properties and ionic composition of irrigation or fertilizer solutions when assessing Cd leaching risk. Implementing management strategies that minimize chloride-based inputs could help reduce Cd mobility and its environmental impact.
