Search Results (101)

To further enhance nutrient use efficiency for maize cultivation in the Changbai Mountains—Liaodong Hilly Region and to safeguard both grain production and soil quality, 2441 pairs of data points extracted from 47 publicly published papers were selected for analysis to investigate the effects of different fertilizer types, their application rates, and field management practices on spring maize yield enhancement, crop growth, and soil physicochemical properties. According to the subgroup analysis of the above indicators, the results demonstrated that various fertilization management practices can effectively increase maize yield and soil nutrient content. Specifically, applications of nitrogen fertilizer (39.78%) and top-dressing (34.10%) had the best effect on increasing maize yield. The combination of organic–inorganic application (22.93%) and straw returning (20.46%) had the best effect on increasing soil organic matter. Based on grain yield and its components, crop physiology and soil physicochemical properties, we recommend an optimal nutrient management strategy for this region: an application rate of 180 kg/ha for nitrogen and 70–100 kg/ha for both phosphorus and potassium, and the field management practice of combined application of chemical fertilizers and manure based on full-amount straw returning in the field. This study provides a reference for nutrient management of maize fields in the Changbai Mountains—Liaodong Hilly Region. Full article

In this study, a survey was conducted in 14 fields (6 in Thessaloniki and 8 in Serres) before barley harvest during three growing seasons (2019–20, 2020–21, 2021–22) to map the occurrence of ACCase and ALS multi-resistant populations and evaluate the influence of agronomic practices and environmental conditions on their dynamics. Specifically, weed cover and tiller number/plant were assessed in each field using a W pattern, while questionnaires were used to collect information from farmers on agronomic practices applied, such as seedbed preparation, the rate of fertilization at sowing, the time of sowing, the time and rate of top-dressing nitrogen fertilizer, the time of application of the herbicide pinoxaden, and the harvest time. Soil properties and climatic conditions were also recorded. These results indicated that regardless of the different agricultural practices applied in the fields of the studied regions, no significant association was found with L. rigidum’s ground cover or number of tillers/plant. Additionally, no association was identified between weed ground cover and climatic characteristics. Therefore, the findings of this study strongly support the dependence of the dispersal of the resistant strain L. rigidum on the interactions between genetic, biological, and soil factors; fertilizer or herbicide use; sowing or other agronomic practices; and climatic factors that drive resistance dynamics, rather than any individual practice alone. Full article

Maize–tropical grass intercropping has been adopted during the dry season as a strategy for soil cover; however, a knowledge gap remains regarding adequate nitrogen (N) supply and the efficiency of this system in degraded pasture areas. The objective of this study was to evaluate dry biomass, grain yield, and macronutrient concentrations in maize–tropical grass intercropping as a function of N rates applied as side-dressing in the dry season. The experimental design consisted of a randomized complete block design in a split-plot arrangement with four replications. Main plots comprised maize monoculture, maize intercropped with Urochloa ruziziensis (Congo grass), and maize intercropped with Megathyrsus maximus cv. Aruana (Aruana Guinea grass). Subplots consisted of N rates (0, 50, 100, and 150 kg ha⁻¹). Maize–Aruana intercropping showed a positive linear response to N rates for grain yield; specifically, the nitrogen rate of 150 kg ha⁻¹ resulted in a 71.71% increase in grain yield compared to the lack of nitrogen supply. Conversely, maize monoculture showed a negative linear response, where the highest N rate (150 kg ha⁻¹) resulted in a 68.83% reduction in grain yield compared to the lack of nitrogen supply. Despite yield potential being capped by seasonal water deficits and frost events, the intercropping systems maintained essential growth dynamics. Aruana grass provided a protective effect for maize development under stress. The findings demonstrate that N side-dressing in the maize–Aruana intercropping system in a minimum of 71.83 kg ha⁻¹ is an adequate strategy to enhance grain yield and biomass production. Full article

Reconciling high crop productivity with reduced resource inputs is a primary challenge for sustainable agriculture in water-scarce regions. This study evaluated the feasibility of reducing nitrogen (N) fertilizer application for winter wheat under limited micro-sprinkler irrigation in the Huang-Huai-Hai Plain, China. A field experiment compared five treatments: a non-fertilized and non-irrigated control (CK), conventional flood irrigation with standard N (FI), and limited micro-sprinkler irrigation (80 mm) with standard N (MI), a 20% N reduction (MI1), and a 40% N reduction (MI2). We analyzed grain yield, water and N use efficiency (WUE and NUE) and the apparent soil N balance. WUE in this study was expressed as grain yield per seasonal evapotranspiration (ET), and NUE was evaluated using agronomic indices. The results showed that the MI1 treatment maintained a high grain yield that was not significantly different from the high-input FI and MI treatments. This high yield was sustained by a compensatory mechanism involving enhanced post-anthesis N assimilation and increased extraction of deep soil water, which offset the reduced inputs. Consequently, MI1 significantly improved WUE, irrigation water use efficiency (IWUE), and NUE, while reducing the apparent soil N surplus by 74.5% compared to FI. In contrast, the greater N reduction (MI2) led to a significant yield penalty. In conclusion, a moderate (20%) reduction in N top-dressing under limited micro-sprinkler irrigation presents a viable strategy to maintain high wheat yield, simultaneously enhance resource-use efficiency, and markedly reduce environmental N losses. Full article

N is the most crucial nutrient for plant growth and yield. Soybeans require a large amount of N for growth and seed production because of their high protein content. Soybean plants fix N₂ by root nodules in association with soil bacteria, rhizobia, but both the fixed N and the N absorbed from roots are essential to obtain a maximum seed yield. However, excess or inappropriate N fertilizer application represses N₂ fixation and reduces seed yield. A basal deep placement of lime nitrogen promoted soybean seed yield without inhibiting N₂ fixation activity in Japan. This study aimed to evaluate whether this technology can be applied in the Far East of Russia. The effects of deep placement of lime N with a wide row (75 cm) on the growth and seed yield of four Russian varieties were investigated. Without N fertilization, the average seed yield in wide rows was 2.77 t/ha, which was not significantly different from that in narrow rows (2.39 t/ha). Deep placement of lime nitrogen with wide rows increased total mechanical seed yield by 38%, 53%, 17%, and 6% in Primorskaya 4, 13, 81, and 86, respectively. The effect of basal urea application in narrow rows varied among cultivars. Soil analysis and the N composition in xylem sap indicated that the Russian field is richer in soil N than that in Niigata, and the contribution of N derived from N₂ fixation was lower than that in Niigata. The effects of row spacing and N fertilization on seed yield varied by variety; therefore, it is necessary to evaluate each variety to determine the optimal row spacing and N fertilization. The field experiment indicated that the deep placement of lime N promoted seed yield of Russian cultivars. This technique may be applied in soybean cultivation in a large field if the appropriate machine is available. Full article

This study explores the potential of Precision Agriculture (PA) to optimize top-dressing nitrogen (N) fertilization in rainfed barley under drought conditions in Central Catalonia (Spain). Efficient N management is critical in Mediterranean dryland winter cereal systems, where water scarcity and environmental regulations limit fertilization strategies. Two plots (2.93 ha and 1.80 ha) were zoned using soil apparent electrical conductivity (ECa) and elevation data obtained with the VERIS 3100 ECa soil surveyor. An on-farm experimental design tested four N dose rates (0 kg N/ha, 32 kg N/ha, 64 kg N/ha, and 96 kg N/ha) across two management zones per plot. Yield data were collected using a combine harvester equipped with a yield monitor and were mapped using geostatistical methods. A linear model (ANOVA) was used to analyze barley yield (kg/ha at 13% moisture), with nitrogen rate and soil zone (management class) as explanatory factors. Results showed low average yields (~1200 kg/ha–1300 kg/ha) due to severe water stress during the 2022–2023 season. Non-fertilized plots (N0) and those receiving moderate (N64) or high fertilization (N96) achieved the best performance, with the latter likely enhancing crop N uptake during the post-stress recovery period. In contrast, low fertilization (N32) proved less effective. Marginal return analysis supported variable-rate N application only in one plot, whereas under drought conditions, a no-fertilization strategy proved more suitable in the other. Ultimately, additional trials conducted under more favourable climatic scenarios are necessary to assess and validate the effectiveness of Precision Agriculture-based fertilization strategies in rainfed barley. Full article

The aim of the study was to determine the effect of cultivar and nitrogen fertilization on the morphological and physiological traits and yield of soybean (Glycine max (L.) Merrill) grown in central-eastern Poland. In a strict, two-factor field experiment, four soybean cultivars were used: ‘Abelina’, ‘Malaga’, ‘Coraline’, and ‘Petrina’, and three nitrogen rates: 0, 30, and 60 kg N ha⁻¹. The moderate rate (N30) was applied before sowing, while the higher rate (N60) was divided into two parts, with 50% applied before sowing and 50% top-dressed at BBCH 61. The studies were conducted during two growing seasons. It was shown that both the cultivar and nitrogen fertilization significantly affected plant height, leaf area index (LAI), leaf greenness index (SPAD), and chlorophyll fluorescence indices (Fv/Fm, PI). The interaction among cultivar, fertilization, and years was significant for SPAD and Fv/Fm index, indicating a strong influence of environmental factors on plant response. Nitrogen fertilization increased plant height and chlorophyll content but reduced fluorescence indices. Among the cultivars studied, the late-season cultivar ‘Malaga’ was characterized by the highest SPAD index (502), Fv/Fm (0.800), and PI values (4.3), and achieved the highest seed yield (5.06 t ha⁻¹) and thousand-seed weight (230 g). In contrast, the medium-season cultivar ‘Abelina’ showed the lowest SPAD (454), and significantly lower Fv/Fm and PI values (0.790 and 3.51, respectively), resulting in the lowest yield (4.25 t ha⁻¹) and TSW (169.7 g). The application of a moderate rate of nitrogen (N30) improved the physiological indicators of plants and elements of yield structure without reducing the potential photochemical efficiency of PSII, while a higher rate (N60) did not result in a significant increase in yield, despite a greater number of pods and seeds per plant, which may have been due to a reduction in thousand-seed weight. The results highlight the importance of cultivar selection and moderate N fertilization of soybean grown in temperate climates and indicate the need for further research on the physiological mechanisms that determine cultivar-specific nitrogen use efficiency and yield stability under environmental stress. Full article

Biosurfactants (BSs) are natural, biodegradable compounds crucial for replacing synthetic emulsifiers in the food industry, provided their production costs can be reduced through the use of sustainable and low-cost substrates. This study evaluated the viability of licuri oil as a carbon source for BS production by Candida utilis and assessed the product’s functional stability in food formulations. Production kinetics confirmed the yeast’s efficiency, reducing the water surface tension to a minimum of 31.55 mN·m⁻¹ at 120 h. Factorial screening identified a high carbon-to-nitrogen ratio as the key factor influencing ST reduction. The isolated BS demonstrated high surface activity, with a Critical Micelle Concentration of 0.9 g·L⁻¹. Furthermore, the cell-free broth maintained excellent emulsifying activity (E₂₄ > 70%) against canola and motor oils across extreme pH, temperature, and salinity conditions. Twelve mayonnaise-type dressings were formulated, utilizing licuri oil, and tested for long-term physical stability. Six formulations, featuring the BS in combination with lecithin and/or egg yolk, remained stable without phase segregation after 240 days of refrigeration, maintaining a stable pH and suitable microbiological conditions for human consumption. The findings confirm that the valorization of licuri oil provides a route to produce a highly efficient and robust BS, positioning it as a promising co-stabilizer for enhancing the shelf-life and natural appeal of complex food emulsions. Full article

Production of a healthy crop of protein- and oil-rich soybean seeds requires a significant amount of nitrogen. Under ideal conditions, most of this nitrogen comes from the root nodules, where a symbiotic relationship with Bradyrhizobium japonicum fixes nitrogen from the atmosphere. Thus, growers generally think of soybeans as not needing nitrogen fertilization. However, a lack of B. japonicum or other unfavorable field conditions can produce inefficient nodulation, which leads to reduced vigor and yield under conditions of low soil nitrogen availability. Thus, additional resources for identifying nitrogen deficiency in soybean and strategies for the rescue application of nitrogen are needed. To generate a gradient of nitrogen deficiency, we applied different amounts of nitrogen (in the form of urea) to nodulation-deficient soybeans grown in sandy fields in South Carolina. Comparison of the ground truth data and aerial imagery suggest that leaf nitrogen deficiency can be effectively identified in the field based on plant height and color. Side dressing nitrogen fertilizer in the form of urea to nitrogen-deficient plots at the R1 stage was shown to rescue plant growth and increase crop yield. We conclude that identification and fertilization of patches of soybeans with low nitrogen content is a feasible strategy to increase soybean productivity. Although additional studies are needed to expand these results to other soil conditions, we recommend that nitrogen-deficient soybeans be treated with 40–50 pounds per acre (45–56 kg per hectare) of nitrogen at or before flowering to restore yield potential. Full article

This study investigated the impacts of dietary thymol–carvacrol cocrystal (CEO) supplementation on broiler production performance, antioxidant status, intestinal health, and cecal microbiota. Eight hundred one-day-old chicks were randomly divided into four groups, receiving basal diets supplemented with 0, 40, 60, or 80 mg/kg CEO. The results showed that CEO addition increased average daily gain, superoxide dismutase activity in the serum, liver, and jejunum, jejunal villus height/crypt depth ratio, cecal butyric acid concentration, and Lactobacillus abundance, while reducing serum alanine transaminase activity and malondialdehyde content in the serum, liver, and jejunum. Furthermore, 60 mg/kg CEO enhanced the final body weight, dressing percentage, serum total protein and glucose levels, and jejunal trypsin and amylase activities, while lowering the feed-to-gain ratio and serum cholesterol, urea nitrogen, and aspartate transaminase concentrations; it also increased the activities of superoxide dismutase, catalase, and glutathione and mRNA expressions of related genes in the liver and jejunum. It also increased cecal concentrations of acetic acid and isovalerate acid, while decreasing serum diamine oxidase and D-lactate concentrations, as well as malondialdehyde concentrations in the serum, liver, and jejunum. Therefore, dietary CEO supplementation improved the production performance, antioxidant status, and liver and gut health and function in broilers, with 60 mg/kg CEO demonstrating the most pronounced effects. Full article

This study explored how top-dressed biogas slurry at winter wheat’s (Triticum aestivum L.) jointing stage (JS) and grain-filling period (GP) affects soil enzyme–microbe interactions, aiming to address nutrient supply–crop demand mismatches. A field experiment with five treatments (water [CK], chemical fertilizer [CF], and three biogas slurry topdressing regimes [S1–S3]) was conducted. Soil samples (0–20 cm) were collected at JS, flowering stage (FS), GP, and reaping period (RP) to analyze soil properties (total nitrogen [TN], available phosphorus [AP], available potassium [AK], soil organic matter [SOM], ammonium nitrogen [AN], pH), enzyme activities (urease [UE], neutral phosphatase [NP], sucrase [SC], catalase [CAT]), and microbial community abundance (via Illumina NovaSeq sequencing). Results showed biogas slurry altered enzyme activities, microbial structure (e.g., Actinomycetota, Ascomycota), and their interactions by regulating soil properties. JS application boosted Pseudomonadota and UE activity, GP application increased Ascomycota and CAT activity, and S3 had the most complex enzyme–microbe network, enhancing nutrient cycling. The analysis indicated that UE activity was strongly and positively correlated with several bacterial phyla (e.g., Planctomycetota, Verrucomicrobiota) (p < 0.01) and fungal phyla (e.g., Ascomycota) (p < 0.01). Full article

Corn stunt complex, transmitted by the corn leafhopper (Dalbulus maidis), poses significant yield risks to corn production. This study evaluated the effects of two corn hybrids and top-dressed nitrogen (N) and potassium (K) fertilization on D. maidis incidence and corn stunt symptom expression under field conditions. Eighteen treatments were tested in a randomized complete block design with six replications over two seasons. Leafhopper populations were monitored using yellow sticky traps, and symptom incidence and severity were assessed at R₁ and R₃ stages, respectively. While D. maidis populations varied substantially between seasons, neither N nor K fertilization, nor hybrid selection, significantly affected vector abundance. Importantly, symptom frequency and severity were not directly proportional to leafhopper density. Top-dressed fertilization, particularly with K, reduced the visual expression of corn stunt symptoms although it did not prevent infection. Hybrid responses to fertilization varied, with a genotype exhibiting greater symptom mitigation. Grain yield was not significantly influenced by nutrient rates or hybrid choice. These findings suggest that balanced N and K fertilization enhances crop resilience to corn stunt disease without directly suppressing vector populations. Integrating nutritional management with hybrid selection presents a promising strategy to add in corn stunt control and deepens our understanding of the environmental factors that mitigate severe symptoms. Full article

Nitrogen (N) fertilizer management in winter wheat production faces challenges from volatilization losses and sub-optimal application strategies. This is particularly problematic in the Southern Great Plains, where environmental conditions during top-dressing periods favor N losses. This study evaluated the effects of a fertilizer placement method, enhanced-efficiency fertilizers, and application timing on grain yield and protein concentration (GPC) across six site-years in Oklahoma (2016–2018). Treatments included broadcast applications of untreated urea and SuperU^® (urease/nitrification inhibitor-treated urea). These were compared with subsurface placement using single-disc and double-disc drilling systems, applied at 67 kg N ha⁻¹ during January, February, or March. Subsurface placement increased the grain yield by 324–391 kg ha⁻¹ compared to broadcast applications at sites with favorable soil conditions. However, responses varied significantly across environments. Enhanced-efficiency fertilizers showed limited advantages over untreated urea. Benefits were most pronounced during February applications under conditions favoring volatilization losses. Application timing effects were more consistent for GPC than for the yield. Later applications (February–March) increased GPC by 0.8–1.2% compared to January applications. Treatment efficacy was strongly influenced by soil pH, equipment performance, and post-application environmental conditions. This indicates that N management benefits are highly site-specific. These findings demonstrate that subsurface placement can improve nitrogen use efficiency (NUE) under appropriate conditions. However, success depends on matching application strategies to local soil and environmental factors rather than adopting universal recommendations. Full article

We provide an approach to detect a nitrogen-vacancy (NV) center, which might be a defect in a diamond nanomembrane, using a dual-coupling optomechanical system. The NV center modifies the energy-level structure of a dual-coupling optomechanical system through dressed states arising from its interaction with the mechanical membrane. Thus, we study the photon blockade in the cavity of a dual-coupling optomechanical system in which an NV center is embedded in a single-crystal diamond nanomembrane. The NV center significantly influences the statistical properties of the cavity field. We systematically investigate how three key NV center parameters affect photon blockade: (i) its coupling strength to the mechanical membrane, (ii) transition frequency, and (iii) decay rate. We find that the NV center can shift, give rise to a new dip, and even suppress the original dip in a bare quadratic optomechanical system. In addition, we can amplify the effect of the NV center on photon statistics by adding a gravitational potential when the NV center has little effect on photon blockade. Therefore, our study provides a method to detect diamond nanomembrane defects in a dual-coupling optomechanical system. Full article

Choosing appropriate tillage methods and nitrogen application are important steps in the management of wheat production for obtaining high-yield and high-quality products, as well as managing the level of weed infestation. The aim of this research was to examine the impacts of three different tillage practices (conventional tillage—CT, mulch tillage—MT, and no tillage—NT), and two top dressing fertilization nitrogen levels (rational—60 kg ha⁻¹ and high—120 kg ha⁻¹) on the grain yield and quality of winter wheat, as well as on weed infestation. The present study was carried out in field experiments on chernozem luvic type soil at the Faculty of Agriculture Belgrade-Zemun Experimental field trial “Radmilovac”, in the growing seasons of 2020/2021–2022/2023. The C/N ratio in the soil was also assessed on all plots. The results showed that the number of weeds and their fresh and air-dry weights were higher on the MT and NT plots, compared to the CT plots. Therefore, the CT system has better effects on the yield (5.91 and 5.36 t ha⁻¹) and the protein content (13.3 and 13.1%). Furthermore, the grain weight per spike and the 1000-grain weight were higher in the wheat from the CT system (41.83 and 42.75 g) than from the MT (40.34 and 41.49 g) and NT (40.26 and 41.08 g) systems. Also, the crops from the CT system had higher values of grain density and grain uniformity compared to the crop from the MT and NT systems. Fertilization with a high nitrogen level (120 kg ha⁻¹) causes higher grain yield and more weediness compared with the rational level (60 kg ha⁻¹). Top dressing fertilization in each tillage system resulted in an increase in the number of weeds, but, at the same time, it also resulted in stronger competitive ability of the wheat crop against weeds. The most favorable C/N ratio occurred on the NT plots, and the least beneficial one on the CT ones. A correlation analysis showed strong negative correlations of number (r = −0.82) and fresh weed mass (r = −0.72) with yield. It is concluded that the conventional tillage practice with a low nitrogen dose manifests its superior performance in minimizing weed infestation and maximizing crop productivity. Full article