Urea Fertilizer Research Articles

Enriched rice husk biochar superior to commercial biochar in ameliorating ammonia loss from urea fertilizer and improving plant uptake

Adding value to agricultural leftovers and turning them into biochar is a viable way to replenish soil nutrients and boost crop productivity. To further validate the efficacy of enriched rice husk biochar, an incubation study and a pot experiment were conducted: (1) to describe the effect of enriched rice husk biochar addition on soil total N, soil exchangeable NH4+ and available NO3− and (2) to describe the effect of enriched rice husk biochar on improving N, P, K, Ca, and Mg uptake, use efficiency, and dry matter production of rice plants. The amount of NH3 loss that was considerably reduced by rice husk biochar at 5 and 10 t ha−1 was 34 % lower than the control. The availability of soil total N, exchangeable NH4+, available NO3−, available P, and exchangeable cations was greatly enhanced by the addition of rice husk biochar. Due to the effective nutrient uptake that occurs with an increase in soil nutrient level, the physical growth of the rice plant (height, tiller number, greenness, and panicle number) increeased significantly in treatments supplemented with 5 t ha−1 rice husk biochar. When rice plants were treated with 5 t ha−1 rice husk biochar, their absorption of N, P, and K increased by >80 %, respectively. The production of dry matter in rice plants increased as a result of the increased N intake. The application of 5 t ha−1 of rice husk biochar enhanced the soil nutrients by reducing NH3 loss and augmenting soil nutrients for efficient plant absorption, as demonstrated by the favourable enhancement of soil macro- and micronutrients and biomass of rice plants.

Preparation and characterization of slow-release urea fertilizer encapsulated by a blend of starch derivative and polyvinyl alcohol with desirable biodegradability and availability

In this study, a novel double-layer slow-release fertilizer (SRF) was developed utilizing stearic acid (SA) as a hydrophobic inner coating and a blend of starch phosphate carbamate (abbreviated as SPC) and polyvinyl alcohol (PVA) as a hydrophilic outer coating (designated as SPCP). The mass ratios of SPC and PVA in the SPCP matrices were systematically optimized by comprehensively checking the water absorbency, water contact angle (WCA), water retention property (WR), and mechanical properties such as percentage elongation at break and tensile strength with FTIR, XRD, EDS, and XPS techniques, etc. Moreover, the optimal SPCP/5:5 demonstrated superior water absorbency with an 80.2 % increase for the total mass compared to natural starch/PVA(NSP), along with desirable water retention capacity in the soil, exhibiting a weight loss of only 48 % over 13 d. Relative to pure urea and SA/NSPU/5:5, SA/SPCPU/5:5 released 50.3 % of its nutrient within 15 h, leading to nearly complete release over 25 h in the aqueous phase, while only 46.6 % of urea was released within 20 d in soil, extending to approximately 30 d. The slow release performance of urea reveals that the diffusion rate of urea release shows a significant decrease with an increase in coating layers. Consequently, this work demonstrated a prospective technology for the exploration of environmentally friendly SRF by integrating biodegradable starch derivatives with other polymers.

Effect of sprinkler irrigation method and addition urea fertilizer on wheat plant

Originality/Value: Farmers must use sprinkler irrigation and avoid surface irrigation because it harms the soil and increases its salinity, also represents a waste of water resources.Research limitations: Limited availability of sufficient numbers of sprinkler irrigation devices in Iraq, their high prices, and the lack of experience of farmers to use them.The Purpose of the research is to evaluate the effect of the appropriate irrigation method and the amount of fertilizer specified for urea fertilizer that achieves the best growth for the plant and increase its productivity while avoiding a negative impact on soil properties.Research Method: Two types of irrigation: spraying and flooding, and four mineral fertilization treatments (0. 50.100. 150) kg.ha-1 were used in the work to study the apparent characteristics of wheat and the amount of productivity, using statistical analysis (Gen Stat) and simple correlation coefficient to find strength of association between variables. The experiment was carried out in 2023 at Al-Khatib Farm, located in Al-Numaniyah District, it is bordered to the south by Wasit Governorate, 50 km away, and to the north by Baghdad Governorate,160 km away (Iraq).Results and Discussion. Sprinkler irrigation showed significant differences with the surface irrigation in the length of the spike, number of seed per spike,1000 seed weight, number of spikes per square meter, grain yield kg .ha-1 and the harvest index, while the plant height was not significant. The study also showed that the correlation coefficient between the apparent characteristics of the plants was stronger in the case of using sprinkler irrigation compared to the surface irrigation.

Effect of untreated and stabilized dairy effluent applications on soil fertility and associated health risks

The intensification of dairy production in Uruguay generates increasing volumes of organic waste that are difficult to handle and may entail health risks. Irrigation with farm dairy effluents (DE) is a recommended agricultural practice to improve soil fertility. The objective of this work was to evaluate the effect of the application of raw (RDE) and two-lagoon stabilized effluents (LDE), urea fertilization, or non-amendment to Festuca arundinacea on soil and plant nutrient content, as well as pathogenic bacterial indicators and persistence of antimicrobial resistance genes. In a greenhouse trial, four seasonal applications were made with a total dose equivalent to 200 kg N ha-1. Soil Na content increased after DE applications. There was no increase in the nutrient content of tall fescue caused by DE applications. The persistence of E. coli was low but still detected in soil receiving RDE. Beta-lactam genes blaTEM and blaOXA were detected in both DE, being highest in LDE. However, they were not detected in the soil. DE applications demonstrated effects comparable to those of control and urea fertilization on tall fescue biomass and nutrient content, and slightly altered the soil's chemical status. LDE reduced pathogenic bacteria load to the soil, underlining the safety of its application.

Variation in Nitrogen Utilization and Nutrient Composition across Various Organs under Different Strip Logging Management Models in Moso Bamboo (Phyllostachys edulis) Forest.

The rapid restoration and renewal of the moso bamboo logging zone after strip logging has emerged as a key research area, particularly regarding whether nutrient accumulation and utilization in reserve zones can aid in the restoration and regeneration of the logging zone. In this study, a dynamic 15N isotope tracking experiment was conducted by injecting labeled urea fertilizer into bamboo culms. Logging zones and reserve zones of 6 m, 8 m, and 10 m widths were established. The conventional selective logging treatment served as a control (Con). Measurements were taken in May and October to assess the differences in nitrogen accumulation ability, utilization rates, and nutrient content across different organs in bamboo forests at different growth stages and under different treatments. Principal component analysis was conducted to evaluate and determine the importance of each indicator and strip logging treatment comprehensively. The results showed that various bamboo organs exhibited higher nitrogen accumulation and utilization rates during the peak growth period compared to the late growth period. Leaves had the highest nitrogen accumulation and utilization rates than the other organs. The average C content in various bamboo organs under different logging treatments exhibited subtle differences, irrespective of variation in logging width treatments. Bamboo culm exhibited the highest carbon accumulation. The C content in various bamboo organs was higher during the peak growth period than in the late growth period. The nitrogen content peaked in the leaves during the two growth stages and was significantly higher compared to the other organs. Most bamboo organs in the logging zones exhibited relatively higher nitrogen content than in the reserve zone and Con group. The P content was highest in bamboo leaves compared with other organs across the different strip logging treatments. Principal component analysis revealed relatively high absolute values of the coefficients for the C content, bamboo stump C content, and culm Ndff%. Log8 and Res10 zones had the highest comprehensive evaluation scores, indicating that Log8 and Res10 had the best effect on the promotion of nitrogen utilization and nutrient accumulation in various organs of moso bamboo.

Improving Ammonia Emission Model of Urea Fertilizer Fluidized Bed Granulation System Using Particle Swarm Optimization for Sustainable Fertilizer Manufacturing Practice

Granulation is an important class of production processes in food, chemical and pharmaceutical manufacturing industries. In urea fertilizer manufacturing, fluidized beds are often used for the granulation system. However, the granulation processes release ammonia to the environment. Ammonia gas can contribute to eutrophication, which is an oversupply of nitrogen and acidification to the ecosystems. Eutrophication may cause major disruptions of aquatic ecosystems. It is estimated that global ammonia emissions from urea fertilizer processes are approximately at 10 to 12 Tg N/year, which represents 23% of overall ammonia released globally. Therefore, accurate modeling of the ammonia emission by the urea fertilizer fluidized bed granulation system is important. It allows for the system to be operated efficiently and within sustainable condition. This research attempts to optimize the model of the system using the particle swarm optimization (PSO) algorithm. The model takes pressure (Mpa), binder feed rate (rpm) and inlet temperature (°C) as the manipulated variables. The PSO searches for the model’s optimal coefficients. The accuracy of the model is measured using mean square error (MSE) between the model’s simulated value and the actual data of ammonia released which is collected from an experiment. The proposed method reduces the MSE to 0.09727, indicating that the model can accurately simulate the actual system.

CAN THE APPLICATION OF AGROFORESTRY AT MONOCULTURAL FOOD CROP AREAS SUPPORT MANUFACTURER CHEMICAL FERTILIZER REDUCTION PROGRAMS WITHOUT SACRIFICING FARMERS' INCOME?

In an agroforestry system, nutrients from the subsoil can be made available to food plants through the absorption process by trees with deep roots. However, shade from canopy tree plants can suppress photosynthesis and reduce food crop production and farmer income [INCM]. This antagonism needs to be evaluated when introducing agroforestry programs into monoculture food crop areas to reduce manufactured chemical fertilizers application. This research was carried out from June to August 2023 at Natar District, South Lampung Regency to determine the effect of tree strata (teak, acacia, and albizia), multi-proposed tree species or MPTS (Parkia speciosa, avocado, and jack fruit), shrubs (coffee and cacao), and ground cover (vegetables, peanut, and soybean) to [INCM]. Interviewing forty respondents who were still retaining one or more of these tree strata among food crops including upland rice, corn, and cassava. The OLS (ordinary least square) model was employed at 90% confidence level. To eliminate the model error, the variables ownership of productive assets (upland, cattle, sheep, and cock), fertilizer application (urea, ponska, KCl and liquid fertilizer), compost, and pesticide use were also incorporated in the model. The results suggest the significant effects: (1) that positive ones are acacia, teak, vegetables, peanuts, and, soybeans, respectively USD 86.4 (P=0.000); 88.3 (P=0.000); 109,5 (P=0.000); 114.6 (P =0.000); 145.1 (P=0.000); and (2) which negative were Albizia falcataria, Parkia speciosa, avocado, coffee, and cacao respectively of around USD 31,7 (P=0.002); 57.1 (P=0.000); 43.2 (P=0.003); 62,0 (P=0.000) and 96.37 (P=0.000).

The effects of microalgae use as a biofertilizer on soil and plant before and after its anaerobic (co-)digestion with food waste

The increase in food waste generation has resulted in significant challenges for its sustainable management. Anaerobic digestion coupled with microalgae-based ponds for digestate treatment can be used as a low-cost eco-friendly technology approach. In this case, microalgal biomass harvested from the ponds may be valorized into bioenergy (biogas) and soil conditioner and/or biofertilizers. The aim of the present study was to evaluate the microalgal biomass produced from a food waste digestate treatment ponds as agricultural fertilizer. For this purpose, microalgal biomass was tested before and after anaerobic digestion and co-digestion with food waste, exploring its potential for valorization. The inorganic fertilizer urea and soil with no fertilization were also used as treatments. The experimental design consisted of applying the treatments in pots cultivated with hybrid grass Brachiaria cv. Sabiá and distributed in randomized blocks in a controlled greenhouse. Microalgal biomass was mainly composed by Scenedesmus sp.. The assessed parameters showed comparable results on plant growth (i.e. number of tillers, fresh and dry matter and Chlorophyll content index) for fresh and digested microalgal biomass and inorganic fertilizer. Furthermore, it was observed that fresh microalgae provided the highest Phosphorus content in the leaf (21 %). Additionally, there were increases of 9 % in Nitrogen and 12 % in organic matter in the soil after applying digested microalgae compared to the control group without any fertilization. Finally, experimental data obtained suggests that microalgae-based biofertilizer holds the potential to replace inorganic fertilizer as a nutrient source. Moreover, it contributes to the valorization of by-products from organic waste treatment.

Nitrogen leaching mitigation by tithonia biochar (Tithochar) in urea fertilizer treated sandy soil

Abstract Nitrogenous fertilizer drift from farmlands accelerates nitrogen loads in groundwaters. Biochar potential to mitigate nitrogen leaching in urea treated sandy soil was monitored in a four weeks screenhouse leaching column experiment. The trial was a factorial combination of two biochar types (B1 and B2 applied at 5 t/ha) and two urea treatments (with urea at 120 kg/ha and without urea) laid in completely randomized design with three replications. Control that received neither urea nor biochar was compared. Four weekly leaching events were conducted in each leaching column containing 300 g soil amended with appropriate treatments. Amaranthus hybridus was the test crop. The NH4-N and NO3-N leached were generally highest during the week 2 leaching event such that total NO3-N leached was 427.3 % higher than total NH4-N leached with highest contributions from sole urea treatment. Biochar pretreatment reduced total N leached by 9.5 (B1) and 26.8 % (B2) relative to sole urea. Percentage of N added lost to leaching was highest (34.1 %) in sole urea treatment with B1 and B2 pretreatment reducing the value by 54.5 and 46.9 % respectively. Correlation analysis revealed electrical conductivity of the leachate and soil as dominant indicators for N leached in the soil studied.

Corn 15N uptake and partitioning in response to fertilizer application rate and timing

AbstractNitrogen (N) fertilizer applications near the time of planting are important for upper US Midwest corn (Zea mays L.) production, but wet springs may result in significant N losses. Split applications may circumvent this problem and improve fertilizer uptake and use efficiency, but the relative contribution of N from the soil and fertilizer is poorly understood. A field study with six sites in Minnesota received 15N‐labeled urea fertilizer in the first year and unlabeled urea in the second year to determine the effect of N rate and application timing on corn uptake and accumulation patterns of fertilizer‐derived N (FDN) and soil‐derived N (SDN) over two consecutive growing seasons. Corn responded positively to fertilization. The percentage of total N uptake as FDN was greatest closest to the time of application but decreased over time as SDN became the dominant N source. A split application (45 kg N ha−1 at planting, 90 kg N ha−1 at V4) significantly improved FDN uptake over the 135 kg N ha−1 preplant treatment but did not improve total N uptake in the first year at any site. Fertilizer‐N use efficiency (F15NUE) using the isotopic method was 2.8%–43.3% across all sites at the end of the first year with the majority partitioned to the grain. At the end of the second year, approximately 2.2% of the first‐year applied FDN was recovered in aboveground biomass. Fertilization ensures adequate N availability to the developing crop, but ultimately SDN contributed ≥61% of the total N uptake.

Studies on the Effects of Liming Acidic Soil on Improving Soil Physicochemical Properties and Yield of Crops: A Review

Soil acidity is a major constraint to crop production globally by potentially limiting agricultural productivity and causing environmental challenges, especially in temperate and tropical regions of the world where there is high precipitation. The review article summarizes the works of literature and gathers information on the effects of liming on soil's physicochemical properties and the yield of crops. Soil acidity is caused by natural ways, such as the high amount of precipitation that exceeds evapotranspiration that leaches appreciable amounts of exchangeable bases from the soil surface, weathering, and decomposition of organic matter and by human interference (by the use of nitrogen fertilizer mainly ammonia and urea fertilizers). Application of lime improved soil pH and neutralize the effect of toxic elements. Liming directly improves some physicochemical properties of the soil, such as aggregates, density, and porosity as physical properties and reduction of exchangeable acidity, Al saturation, micronutrients (Cu, Fe, Mn, and Zn) in the soil solutions, from exchange complex to the levels required and increasing soil pH, exchangeable cations (Na+, K+, Ca+2, and Mg+2) as chemical properties. Soil aggregation, density, and porosity of soil undergo changes with the application of lime. The long-term lime application resulted in increased soil chemical properties. Lime application contributed to increased crop productivity and crop quality. The effects of liming can be explained by the flocculation and cementing action of Calcium ions in the short term. In the long term, increases in productivity induced by liming, result in increasing soil pH, available phosphorus, cation exchange capacity, basic cations, microbial activity, organic carbon, total nitrogen, and decreasing leaching of nutrients, exchangeable aluminum, and acidity, all favoring the physical and chemical properties of the soil.

Assessing the Impact of Coated and Prilled Urea Fertilizers on Nitrogen Dynamics and Fodder Maize Yield in Alfisols

The study investigates the impact of different urea fertilizers on nitrogen mineralization, leaching losses, and growth, yield of fodder maize in Alfisols. Nitrogen is vital for plant growth but deficient in soils. Urea, a widespread nitrogen fertilizer, suffers from significant losses, prompting the development of controlled-release urea (CRU) fertilizers. This study assesses various urea formulations with coated urea and prilled urea. Laboratory incubation studies show that coated urea exhibits slower NH4+-N release, reducing losses and improving efficiency compared to uncoated urea. Nitrate content increases steadily periodically with coated urea, potentially enhancing nitrogen availability to plants. Greenhouse experiments reveal significant differences in plant height, leaf number, and leaf area among treatments. Coated urea formulations, chiefly CSPC @3%, demonstrate superior growth parameters (plant height-169.56cm, number of leaves-10.33 and leaf area-1850.59), yield (green fodder-328.25 gplant-1, dry fodder-198.61 gplant-1 and dry matter percentage-54.52) and quality parameters (crude protein-4.03, total ash content-3.82%) compared to prilled urea growth parameters (plant height-113.38cm, number of leaves-8.07 and leaf area-1670.98), yield (green fodder-246.26 gplant-1, dry fodder-116.35 gplant-1 and dry matter percentage-44.32) and quality parameters (crude protein-2.88, total ash content-2.75%), likely due to sustained nitrogen release. Higher nitrogen availability from coated urea leads to increased forage yield and quality. The findings suggest that coated urea fertilizers, specially CSPC @3% advocate improved nitrogen management, enhancing fodder maize productivity and sustainability.

Linear modeling of zonal level crop production in Ethiopia

Accounting for zonal-level variations and identifying factors that have linear effects on crop production help to make better decisions and plan new policies for effective crop production and food security. The main objective of this study is to identify potential subsets of covariates and estimate their linear effects on crop production. A linear mixed effects model (random--intercept) is used on agricultural sample survey data for Meher seasons from 2012/13 to 2019/20 to explore and identify the best variance-covariance structure for the longitudinal data on 90 zones with eight repeated observations and different sampling weights. The minimum, mean, and maximum crop production by farmers across the country are 1.616, 8.693, and 147.843 quintals, respectively, and about 98 % of farmers produced less than 25 quintals. There is a small rate of increase in mean and median crop production by farmers across the years, and the variability between zones is highest in the year 2019/20 and in the Somali region. The histogram, kernel density, and P–P plots suggested a common logarithm transformation on the crop production variable. Results from the data exploration and variance-covariance structure selection methods suggested a heterogeneous compound symmetry (CSH) structure. Covariates region, year, proportion of farmers who practice pure-agriculture and other-agriculture types, proportion of farmers who use any type of fertilizer, farmer's age, area used, farmer association crop production, indigenous seed used, improved seed used, UREA fertilizer used, other fertilizers used, and percentage of crop damaged are significant in linearly explaining/affecting log crop production, and among these area used, farmers association crop production, UREA fertilizer used, and indigenous seed used have relatively highest effect on log crop production. Zones Wolayita, North-Shewa (Am), West-Arsi, West-Welega, Dawro, and Guji are top/good performers while zones Southwest-Shewa, Waghimra, Guraghe, South-Omo, Keffa, North-Wello, South-Wello, and Eastern Tigray are bottom/poor performers in crop production. Model assumptions and influence diagnostics results suggested the linearity of the model and normality of random effects and residuals are not violated, even though some zones have influences on either model parameters, precisions of estimates of these parameters, and predicted values.

Enhancing the use of coated urea fertilizer and assessing its effect on growth and yield performance in grain corn

Use of urea fertilizer is currently increasing to meet the agricultural demand. However, the efficiency and optimization of urea application in agriculture is uncertain. Therefore, this study was conducted to compare the efficacy of slow-release urea and standard urea fertilizer. Reductions in the N rate of the slow release was assessed by measuring the different growth performance and yield at the field. A 25% reduction in N content using coated urea gave similar growth performance and yield compared to standard practice The findings indicated that there was no significant difference in stem diameter, number of leaves and chlorophyll content between the control treatment and slow-release urea. Grain yield and yield components like cob length, number of grains per cob, weight of grain per cob and 1000 grain weight obtained in the field was similar when applying the slow-release urea with the yield and yield components obtained from standard practice as a control. We conclude that this slow-release urea can be used in extensive cropping of corn while promising at least the same yields than standard practices with reducing impact on environment and nitrogen losses in the soil.

Pasture productivity benefits from strategic urease and nitrification inhibitor use are limited in rainfed temperate dairy pastures of southern Australia

Abstract Introduction Urea is the most commonly used nitrogen (N) fertiliser on Australian dairy pastures, but has low N use efficiency due to high loss potential. Urease and nitrification inhibitors can be used to reduce these losses, however, their efficacy is highly variable and the reported impacts on productivity are inconsistent, with assessments often made using a single inhibitor across all seasons. Research question We examined the effectiveness of two commonly used inhibitors, the urease inhibitor N-(n-butyl) thiophosphoric triamide (NBTPT) and the nitrification inhibitor 3,4-Dimethylpyrazole phosphate (DMPP) applied in a strategic program, on pasture responses to urea (U) fertiliser, and fertiliser N use efficiency in a temperate dairy pasture in Southern Australia. Materials and Methods Pasture productivity, N uptake, agronomic N use efficiency (NUAE), 15N fertiliser recovery and soil mineral N were monitored. The nitrogen was applied in the urea form at rates of 160, 320, 480 and 640 kg N ha−1 yr−1 Results and Conclusions The majority of the plant N (64%-85%), assessed over autumn and spring growth periods using 15N, was derived from mineralised soil organic matter (SOM). Neither of the inhibitors significantly altered pasture production or NUAE, most likely because of the major role of SOM in supplying N to plants, and because much of the applied 15N (up to 55%) was retained in the soil (0-40 cm depth) due to microbial immobilisation. Uptake of fertiliser N was highest, up to 29% of applied N, immediately following fertiliser application and then was substantially reduced over subsequent months, reflecting low levels of mineralisation of the previously immobilised N. The total loss of applied 15N was greater following autumn applications of N than spring applications, being 14% - 42% and 2% - 7% respectively and was attributed to volatilisation occurring primarily in autumn, with minimal leaching and denitrification predicted under the experimental conditions.

Response of spring rice (Oryza sativa L.) varieties to different nitrogen application methods at Nawalparasi West, Nepal

Rice (Oryza sativa L.) cultivation necessitates an adequate supply of nitrogen to achieve optimal growth and yield. This study, conducted in Nawalparasi West from February to June 2023, aimed to assess the effects of nitrogen management through a foliar spray of nano urea, compared to need-based nitrogen management using the Leaf Color Chart (LCC) and the Recommended Dose of urea Fertilizer (RDF) application. The experiment followed a Randomized Complete Block Design (RCBD) with three replications, incorporating four nitrogen management levels (Control, RDF through urea fertilizer (120 kg/ha), 25% of RDF through basal urea (30 kg/ha) + nano urea, and 25% of RDF through basal urea (30 kg/ha) + (LCC) and two rice varieties (Chaite-5 and Hardinath-1). The results indicated that the LCC-based treatment produced the highest grain yield at 5.18 mt/ha, statistically similar to the yield of the nano urea-based treatment (5.04 mt/ha). The enhanced yields were attributed to more effective tillers per m² (260.17 tillers/m² and 253.17 tillers/m², respectively), longer panicle length (28.12 cm and 25.99 cm), more filled grains per panicle (210.03 and 215.73), and lower sterility percentage (24.93% and 26.95%). Despite comparable yields, nano urea application proved to be more cost-effective [97,926.10 Nepalese Rupees (NRs)] with a higher benefit-cost ratio (1.78) and greater ease of application for farmers compared to the LCC. Varietal responses varied, with Hardinath-1 exhibiting the highest yield with LCC-based nitrogen application (5.37 mt/ha), and Chaite-5 demonstrating the highest yield (4.778 mt/ha); with nano urea-based nitrogen application (5.31 mt/ha). Chaite-5 displayed a greater effective number of tillers per m² (241.42 tillers/m²) and filled grains per panicle (224.56). Consequently, it is suggested that nano urea-based nitrogen application, particularly in conjunction with a variety of Chaite-5, holds the potential for improved productivity.

Improving The Growth and Yield of Pak Choy (Brassica chinensis L.) Using Cacao Pod Husk Biochar

This work aimed to assess the influence of cacao pod husk biochar treatments combined with the urea fertilizer addition on the growth and yield of pak choy (Brassica chinensis L.). The study used pot trials in a completely randomized design with two factors. The first was the addition of biochar from cacao pod husk, which consisted of 4 levels, namely 0, 62, 125, and 187 g/pot. The second factor was the dosage of urea addition with 4 levels, namely 0, 0.46, 0.93, and 1.40 g/pot. Pak choy was planted in triplicate polybags. Plant parameters included plant height, number of leaves, canopy cover area, fresh yield, water consumption, and water productivity. The results exhibited that adding biochar was significant in terms of parameters. Low dose biochar (62 g/pot) increased plant height, number of leaves, and water productivity, whereas high dose (125 to 187 g/pot) negatively affected pak choy growth and yield. The addition of urea is significant, except for pH and number of leaves. A fertilizer dose of up to 1.40 g/pot positively affected plant growth and yield of the pak choy. The most optimal interaction of the two factors occurred at a biochar dose of 62 g/pot and urea dose of 1.40 g/pot, which produced a maximum crop fresh yield of 111.83 g/plant. This research concluded that biochar from pyrolysis of cacao pod husk can be employed as soil amendment during pak choy cultivation but with controlled doses.

Hydrogel Nanocomposite Based Slow-Release Urea Fertilizer: Formulation, Structure, and Release Behavior

To enhance the nitrogen utilization efficiency of fertilizers, we developed a novel slow-release fertilizer hydrogel through free radical polymerization, incorporating lignin-containing cellulose nanofiber (LCNF), clinoptilolite (CL), urea, and acrylic acid (AA)-co-acrylamide (AAm) polymer. Various analytical techniques were utilized to examine the structure, swelling, and release behaviors of the fabricated hydrogels with varying LCNF concentrations. The results indicated that the addition of 10% LCNF led to a decrease in water absorption from 72.44 g g−1 to 24.04 g g−1. However, re-swelling was significantly enhanced, with a reduction in re-swelling capacity loss from 32.91% to 23.52%. Concurrently, water retention capacity notably increased from 18.03% to 39.20%. The hydrogel containing 10% LCNF exhibited a slower urea release over 30 days. The kinetic studies revealed that the swelling and urea release behaviors align well with the second-order kinetics model and the Peppas-Sahlin model, respectively. In summary, the developed LCNF/CL/(AA-co-AAm)/urea hydrogel nanocomposites present a novel strategy for the future production and utilization of slow-release fertilizers in agricultural and horticultural fields.

Optimization of Urea Fertilization with Various Doses and Applications on the Yield and Quality of the Hazelnut

Optimization of Urea Fertilization with Various Doses and Applications on the Yield and Quality of the Hazelnut

Peculiarity of the early metabolomic response in tomato after urea, ammonium or nitrate supply

Nitrogen (N) is the nutrient most applied in agriculture as fertilizer (as nitrate, Nit; ammonium, A; and/or urea, U, forms) and its availability strongly constrains the crop growth and yield. To investigate the early response (24 h) of N-deficient tomato plants to these three N forms, a physiological and molecular study was performed.In comparison to N-deficient plants, significant changes in the transcriptional, metabolomic and ionomic profiles were observed. As a probable consequence of N mobility in plants, a wide metabolic modulation occurred in old leaves rather than in young leaves. The metabolic profile of U and A-treated plants was more similar than Nit-treated plant profile, which in turn presented the lowest metabolic modulation with respect to N-deficient condition. Urea and A forms induced some changes at the biosynthesis of secondary metabolites, amino acids and phytohormones. Interestingly, a specific up-regulation by U and down-regulation by A of carbon synthesis occurred in roots. Along with the gene expression, data suggest that the specific N form influences the activation of metabolic pathways for its assimilation (cytosolic GS/AS and/or plastidial GS/GOGAT cycle). Urea induced an up-concentration of Cu and Mn in leaves and Zn in whole plant.This study highlights a metabolic reprogramming depending on the N form applied, and it also provide evidence of a direct relationship between urea nutrition and Zn concentration. The understanding of the metabolic pathways activated by the different N forms represents a milestone in improving the efficiency of urea fertilization in crops.