Urea Fertilizer Research Articles

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.

Slow-Release Urea Fertilizer with Water Retention and Photosensitivity Properties Based on Sodium Alginate/Carboxymethyl Starch Sodium/Polydopamine

Using slow-release fertilizer is one of the sustainable strategies to improve the effectiveness of fertilizers and mitigate the environmental pollution caused by excess usage of fertilizer. In this study, a slow-release urea fertilizer with water retention and photosensitivity properties was prepared by a two-step method. It was characterized by Fourier transform infrared spectroscopy, thermogravimetric analysis, scanning electron microscopy and an infrared camera. This fertilizer can prolong the release period of urea, improve water-retention capacity of soil, and carry out photothermal conversion under illumination. Comparing four release kinetics models, the Ritger–Peppas model was the best fitting model for releasing behavior in soil, and diffusion followed the Fickian mechanism. The application of fertilizer on winter wheat was carried out to intuitively evaluate the fertilizer’s effects on promoting plant growth and resisting water stress. Thus, this study provides a new strategy for improving fertilizer utilization rate and maintaining soil moisture, which will be beneficial for sustainable agriculture.

Investigation of Response of Upland Rice (<i>Oryza sativa </i>L.) to Blended NPSB Fertilizer in Fogera and Libo Kemkem Districts of Amhara Region

A field experiment was conducted for three years to evaluate and determine economic optimum rate of NPSB blended + urea fertilizers for upland rice production in Fogera and Libokemkem districts of Amhara Region. Blended NPSB fertilizer rates of 100, 150, 200 and 250 kg ha<sup>-1</sup> were factorially combined with 100, 150, 200 and 250 kg urea ha<sup>-1</sup>. Zero fertilizer as control treatment and recommended NP as a reference treatment were included in the study. The treatments were laid in a randomized complete block design with three replications. The results show that, in Libokemikem district, the maximum grain yield of 4.9 t ha<sup>-1</sup> was obtained from 200 kg NPSB + 250 kg Urea ha<sup>-1</sup>, while the maximum dry biomass yield of 10.2 t ha<sup>-1</sup> was recorded from 250 kg NPSB + 250 kg Urea ha<sup>-1</sup>. In Fogera district, the maximum grain and biomass yields of 6.1 and 15 t ha<sup>-1</sup>, respectively were obtained from 250 kg NPSB + 200 kg Urea ha<sup>-1</sup>. The partial budget analysis of the pooled data indicate that at Libokemikem district, the maximum net economic return (NER) of Ethiopian birr (Birr) 48,529.70 with marginal rate of return (MRR) of 1284.9% was obtained from 200 kg NPSB + 250 kg urea ha<sup>-1</sup>. At Fogera district, the maximum NER of Birr 62,323.60 with MRR of 959.7% was obtained from 100 kg NPSB + 250 kg urea ha<sup>-1</sup>. However, it is not possible to draw conclusions that the significant yield increment recorded was due to the contribution of S and B blends in the NPSB blended fertilizer. Because, there were confounding effects of N and P nutrients in the NPSB blended fertilizer. As it is revealed in the results, the significant yield response recorded, however, was due to the increasing levels of N. Therefore, we recommend further investigation of the response of NERICA-4 (upland rice) to each nutrient (P, S and B) through nutrient omission studies.

IMPACT OF FADAMA III ADDITIONAL FINANCE II ON YIELD AND INCOME OF FARO-44 RICE FARMERS BENEFICIARIES IN TARABA STATE, NIGERIA

The study was carried out to examine the impact of fadama III additional finance II on yield and income of faro-44 rice farmers beneficiaries in Taraba State, Nigeria. A Multi-stage sampling procedure was used to select 500 respondents. Data were analyzed using descriptive statistics (mean, frequency distribution and percentages) and inferential statistics (Gini coefficient). The findings of the study revealed that more days was expended in faro-44 rice weeding days per hectare with mean of 5.0 and 8.0 hours worked/day. The average number of tractors owned by the fadama users’ association (FUA) farmers was 2 with value of N3,129,079.63. The major inputs intervention received by the respondents were 5 kg seeds, wet season = 10 kg seeds all at N10,000/20 kg bag ((dry season), 2 bags of NPK fertilizer and 4 bags of NPK fertilizer at N7,000/50 kg bag in dry and wet season respectively, followed by a bag of Urea fertilizer in dry season and 2 bag of Urea fertilizer at N9,000/50 kg bag in wet season. Similarly, the respondents also received 4 liters of herbicides each in dry season and wet season. The result further revealed that the yield (kg/ha) in dry season increased from 3,675 kg before intervention to 6,156 kg after intervention representing 59.69% increase and with mean difference of 2,481 kg significant at P<0.01. Similarly, yields in wet season by the faro-44 rice farmers has a mean difference of 1,679 kg compared to mean difference of 2,481 yield in dry season. Consequently, income from dry season harvest (N/ha) increased by 40.77% representing Naira value from N787,375.00 to N1,720,400.00 for before and after fadama AF-II intervention. Similarly, income from wet season harvest only increased by 4.63% with wet season mean income difference of N315,189 compared to the dry season mean income difference of N933,025 implying that the respondents realized more income in dry season faro-44 rice farming than wet season in Taraba State, Nigeria. The study concluded that fadama III additional finance II project intervention had positive impact on yield and income of the respondents and faro-44 rice farming yielded more in dry season than wet season. It is recommended that farm inputs at subsidized rate should be made timely available, there should be further collaboration through the State fadama office with National Agricultural Land Development Authority (NALDA) to clear more land, rice promotion programmes like training on modern rice production techniques, new varieties of seeds in order to be technically efficient should also be promoted and farmers should be encouraged to form cooperatives to benefit more from such laudable fadama AF-II intervention and enjoy economies of scale.

Assessment of Land Quality for Siamese Orange (Citrus nobilis var. microcarpa) Development in Pacitan Regency, Indonesia

Siamese oranges are one of the most widely developed horticultural crops in Indonesia. Arjosari and Ngadirojo are some of the sub-districts that produce Siamese orange in Pacitan Regency. One of the factors that can affect the development of citrus is land quality. This study aims to obtain land quality index data and improvement efforts for developing Siamese orange. Soil samples were taken from 25 land mapping units (LMUs) with 87 sample points. The soil sampling points were determined based on area or sampling density. Data analysis used for soil quality assessment includes correlation, principal component analysis (PCA), minimum data set (MDS), and calculation of climate quality index. The parameters used in this study are bulk density, porosity, moisture content, texture, pH, electrical conductivity (EC), cation exchange capacity (CEC), base saturation, total N, available P, available K, soil organic carbon (SOC), microbial biomass carbon (MBC), evapotranspiration, temperature, and solar radiation. Based on the results of soil quality analysis in the study area, it has a value range of 0.28 to 0.37, including low class, while the climate quality index is 1.39 with moderate class. The land quality index has a very low to low class with a value of 0.39 to 0.51. Intrinsic, extrinsic, and anthropogenic factors can influence soil quality. The study area’s limiting factors for developing Siamese oranges are EC, total N, and available P, which can be improved by making furrow ponds, adding organic fertilizer, using urea fertilizer, and SP36 according to the dosage.

"Response of Malt Barley to NPSB and Urea Fertilizers Across Soil Types and Agro-Ecologies, Arsi Zone of Oromia, South-Eastern Ethiopia"

"Response of Malt Barley to NPSB and Urea Fertilizers Across Soil Types and Agro-Ecologies, Arsi Zone of Oromia, South-Eastern Ethiopia"

Urea promoted soil microbial community and reduced the residual ciprofloxacin in soil and its uptake by Chinese flowering cabbage.

Antibiotics in agricultural soil can be accumulated in crops and might pose a potential risk to human health. Nevertheless, there is a lack of knowledge about the impact of nitrogen fertilizers on the dissipation and uptake of antibiotics in soils. Therefore, our aim in this study is to investigate the effects of urea fertilizer on the residues of ciprofloxacin and its uptake by Chinese flowering cabbage (Brassica parachinensis L.) as affected by the associated changes on the soil microbial community. A pot experiment has been conducted using spiked soil with 20 mg ciprofloxacin /kg soil and fertilized with urea at dosages equal to 0, 0.2, 0.4, 0.8 t/ha. Application urea especially at 0.4 t/ha decreased the residue of ciprofloxacin in the soil and its uptake by the roots and its translocation to the shoots of Chinese flowering cabbage. The translocation factors (TFs) for ciprofloxacin were significantly decreased (P < 0.05) only at the treatment of 0.4 t/ha, while no significant difference of bio-concentration factors (BCFs). The average well color development (AWCD) values, Shannon diversity, and richness index were higher in the fertilized than the un-fertilized soils, and all such indicators were greater at the treatment of 0.4 t/ha than at 0.2 and 0.8 t/ha. The carbon substrate utilization of phenolic acids at the treatments of 0.4 t/ha were greater than with other levels of urea fertilizer. In conclusion, moderate urea addition significantly increased soil microbial activity and abundance, which in turn promoted the ciprofloxacin dissipation in soil and plant tissue. The present study provides an economical and operational strategy for the remediation of ciprofloxacin contaminated soils.

Effects of Long-Term Controlled-Release Urea on Soil Greenhouse Gas Emissions in an Open-Field Lettuce System.

Controlled-release urea (CRU) fertilizers are widely used in agricultural production to reduce conventional nitrogen (N) fertilization-induced agricultural greenhouse gas emissions (GHGs) and improve N use efficiency (NUE). However, the long-term effects of different CRU fertilizers on GHGs and crop yields in vegetable fields remain relatively unexplored. This study investigated the variations in GHG emissions at four growth stages of lettuce in the spring and autumn seasons based on a five-year field experiment in the North China Plain. Four treatments were setup: CK (without N application), U (conventional urea-N application), ON (20% reduction in urea-N application), CRU (20% reduction in polyurethane-coated urea without topdressing), and DCRU (20% reduction in polyurethane-coated urea containing dicyandiamide [DCD] without topdressing). The results show that N application treatments significantly increased the GHG emissions and the lettuce yield and net yield, and DCRU exhibited the lowest N2O and CO2 emissions, the highest lettuce yield and net yield, and the highest lettuce N content of the N application treatments. When compared to U, the N2O emission peak under CRU and DCRU treatments was notably decreased and delayed, and their average N2O emission fluxes were significantly reduced by 10.20-20.72% and 17.51-29.35%, respectively, leading to a significant reduction in mean cumulative N2O emissions during the 2017-2021 period. When compared to U, the CO2 fluxes of DCRU significantly decreased by 8.0-16.54% in the seedling period, and mean cumulative CO2 emission decreased by 9.28%. Moreover, compared to U, the global warming potential (GWP) and greenhouse gas intensity (GHGI) of the DCRU treatment was significantly alleviated by 9.02-17.13% and 16.68-20.36%, respectively. Compared to U, the N content of lettuce under DCRU was significantly increased by 6.48-17.25%, and the lettuce net yield was also significantly increased by 5.41-7.71%. These observations indicated that the simple and efficient N management strategy to strike a balance between enhancing lettuce yields and reduce GHG emissions in open-field lettuce fields could be obtained by applying controlled-release urea containing DCD without topdressing.

Bacterial diversity in agricultural drainage ditches shifts with increasing urea-N concentrations.

Urea-based fertilizers applied to crop fields can enter the surface waters of adjacent agricultural drainage ditches and contribute to the nitrogen (N) loading in nearby watersheds. Management practices applied in drainage ditches promote N removal by the bacterial communities, but little is known about the impacts of excess urea fertilizer from crop fields on the bacterial diversity in these ditches. In 2017, sediments from drainage ditches next to corn and soybean fields were sampled to determine if fertilizer application and high urea-N concentrations alters bacterial diversity and urease gene abundances. A mesocosm experiment was paired with a field study to determine which bacterial groups respond to high urea-N concentrations. The bacterial diversity in the ditch next to corn fields was significantly different from the other site. The bacterial orders of Rhizobiales, Bacteroidales, Acidobacteriales, Burkholderiales, and Anaerolineales were most abundant in the ditch next to corn and increased after the addition of urea-N (0.5mg N L-1) during the mesocosm experiment. The results of our study suggests that urea-N concentrations >0.07mg N L-1, which are higher than concentrations associated with downstream harmful algal blooms, can lead to shifts in the bacterial communities of agricultural drainage ditches.

Concentration Weathering of some Agrochemicals in Runoff and Soil Interface on the National Centre for Agricultural Mechanization (NCAM) Farm, Ilorin, Nigeria

Agrochemicals are needed to boost agricultural productivity, but substantial quantities are either transported into surface water through runoff or leached into groundwater, which may eventually lead to environmental degradation and pollution. Although several studies have been carried out on the effects of agrochemicals o soil and water qualities but the rate of dissipation of agrochemicals along their pathways are not fully understood yet. The aim of this study therefore was to investigate the level of dissipation of agrochemical elements and compounds as they moved along the furrow. Four experimental fields - NPK fertilizer, urea fertilizer, pesticides (organochlorine) and herbicides (glyphosate) were prepared for this study. The selected agrochemicals were applied on the experimental field and the concentration of chemical elements (electrical conductivity, pH, nitrogen, phosphorus, manganese, zinc, magnesium, potassium, glyphosate and organochlorine) along the furrow were measured at intervals (1 m on a 20 m row) using standard techniques. The range of electrical conductivity, pH, nitrogen, phosphorus, manganese, zinc, magnesium and potassium concentrations for runoff from NPK fertilizer applied field were: 95.75 - 174.51 µS/cm, 5.72 - 7.54, 0.21 - 0.68%, 0.09 - 0.36%, 0.1 - 0.47 mg L-1, 0.25 - 0.66 mg L-1, 4.63 - 7.88 mg L-1 and 7.28 - 16.15 mg L-1; for runoff from Urea fertilizer applied field, the range were: 176.25 - 186.33 µS/cm, 7.14 - 7.64, 0.21 - 0.48 %, 0.21 - 0.38%, 0.41 - 0.65 mg L-1, 0.23 - 0.49 mg L-1, 5.48 - 7.64 mg L-1and 8. 23 - 10.46 mg L-1. The range of electrical conductivity, pH, nitrogen, phosphorus, manganese, zinc and magnesium concentrations for runoff from glyphosate applied field were: 114.00 - 283.78 µS/cm, 6.49 - 7.82, 0.13 - 0.67 mg/kg, 0.03 - 0.09%, 0.41 - 1.60 mg L-1, 0.45 - 2.59 mg L-1, 8.35 - 12.76 mg L-1; and for runoff from organochloride applied field the range were: 344.37 - 380.48 µS/cm, 6.66 - 7.86, 0.30 - 0.56 mg/kg, 0.05 - 0.18%, 0.68 - 0.91 mg L-1, 0.81 - 1.45 mg L-1 12.48 - 14.68 mg L-1. The concentration of agrochemical elements and compounds disintegrate along the furrows on all agrochemical fields except in the case of pH.

Impact of urea fertilization rates on nitrogen losses, productivity and profitability in East African sugarcane plantations

AbstractFertilizer‐intensive sugarcane plantations are expanding in sub‐Saharan Africa (SSA) amidst increased groundwater pollution and carbon footprint concerns. Yet, the impact of nitrogen (N) levels on N losses, productivity and profitability in these plantations remains unclear. To address this gap, we conducted a completely randomized design experiment in a Ugandan sugarcane plantation using three N fertilization rates (low, standard and high) as treatments. N leaching under the different treatments was determined using the average drainage fluxes across a 1‐m‐layered profile which we estimated with a suite of pedotransfer functions (PTFs) and leachate N concentrations from suction cup lysimeters. Soil nitrous oxide fluxes were determined using static vented chamber bases and gas chromatography. Partial factor crop productivity was estimated from the average field fresh weight under each treatment and the amount of N fertilizer applied, while the return on investment was determined from the factory price of the field fresh weight and the market price of fertilizers. Our findings indicate that three out of five PTFs effectively estimated soil hydraulic properties at our test site, based on the close match between measured and predicted soil matric potential values. Notably, N leaching at low and standard N rates were comparable but significantly lower than at higher‐than‐standard N rates. Additionally, we measured comparable soil nitrous oxide emissions and field fresh weight but partial factor productivity and return on investment declined along the fertilizer intensification gradient. In conclusion, the study demonstrates the promising application of certain PTFs in N‐leaching modelling in the data‐scarce SSA. Furthermore, obtaining comparable field fresh weight with minimal N losses at lower‐than‐standard N rates presents an opportunity to mitigate groundwater pollution and greenhouse gas emissions. However, the potential impact of the switch from standard to low N rates on soil organic carbon stocks and sugarcane yields warrants further investigation.

Bacterial-Coated Urea To Reduce The Use Of Urea Fertilizer In Potato Cultivation

Urea fertilizers and biofertilizers play an important role in potato (Solanum tuberosum L.) cultivation, but urea fertilizers are volatile and leach out easily that reduce their effectiveness. Urea coated with beneficial bacteria-enriched organic matter is expected to increase nitrogen used efficiency. The purpose of the experiment was to determine the ability of bacterial-coated urea (BCU) included Bacillus and Azotobacter to improve the growth, nutrient status and yields of potatoes grown in field; as well as to reduce urea dose. The experiment was setup in randomized block design with five treatments and six replications. The treatments were four combinations of the dose and formulation of BCU; and conventional urea fertilizer as control treatment. Application of both BCU formulation increased plant height as well as N and P uptake particularly when the recommended dose was used. In contrast, the doses and formulation of BCU did not affect chlorophyll content. Application of BCU-A or BCU-B at the rate of 200 kg/ha increased tuber weight by 59% and 81% respectively. Both high and low dose of BCU did not reduce the vegetative growth and yield compared to the plants fertilized with conventional urea. This experiment showed that BCU is considered to reduce the rate of Urea in potatoes cultivation.

Response of Vermicompost and Urea Combination Fertilizer Doses on the Growth and Yield of Scallion Plants (Allium fistulosum L.)

Leeks (Allium fistulosum L.) are short-lived horticultural crops and have great commercial potential. The productivity of leeks in Indonesia, especially in the East Java region, is experiencing fluctuations, this is due to the problem of decreasing soil fertility. The use of inorganic fertilizers is one of the causes of decreasing soil fertility where the use of inorganic fertilizers in Indonesia reached 105.22 kg/ha, being the highest use compared to several countries in Southeast Asia. Therefore, I offer a solution to this problem, namely by combining the use of inorganic fertilizer with organic fertilizer, for this you can use urea fertilizer and vermicompost fertilizer, where vermicompost fertilizer has advantages compared to other compost fertilizers in terms of complete content starting from microorganisms, growth hormones, and nutrients. The aim of the research I conducted was to determine the interaction of applying urea fertilizer and vermicompost on the growth and yield of leek plants (Allium fistulosum L). The research was conducted at the Green House using a Completely Randomized Design (CRD) with 2 factors, each of which had 3 levels and was repeated 3 times to obtain 27 plant units. The first factor was a vermicompost dose of 0 g/polybag, 75 g/polybag, and 150 g/polybag, while the second factor was a urea dose of 0 g/polybag, 1 g/polybag, and 2 g/polybag. The experimental results showed that the best dose for the combined interaction of vermicompost and urea fertilizer treatment was 75 g/polybag vermicompost and 2 g/polybag urea to increase the number of leaves and height of leek plants.

Analysis of production projections and factors that correlated with rice production in Indonesia

Introduction: Meeting rice needs is largely determined by the level of domestic rice production. However, the various dynamics that occur provide encouragement to provide an overview of the conditions for meeting food needs, namely in the form of rice, based on trends in rice production and how independent variables correlate with rice production. The aim of this research is to determine the projected rice production for 2023-2032 and determine the strength of the relationship between the dependent variable (rice production) and the independent variables in the form of harvested area, price of harvested dry grain, price of urea fertilizer and price. Methods: namely a quantitative descriptive method with secondary time series data from 1993-2022. Data analysis techniques for forecasting studies are by using Autoregressive Integrated Moving Average (ARIMA) analysis. Meanwhile, in the correlation analysis of rice production using the Pearson correlation. Results: Projections for rice commodity production in Indonesia from 2023 to 2032 using the MA1 model show a positive trend. Analysis of the relationship between the independent variable and the dependent variable, namely harvest area (X1), rice price (X2), urea fertilizer price (X3), and price of other food commodities, namely corn (X4) shows a significant positive relationship with rice production in Indonesia. Conclusion: Projections for rice commodity production in Indonesia from 2023 to 2032, which were analyzed using the MA 1 model, obtained data with a positive trend which states that based on past data, Indonesian rice production will continue to increase every year in line with domestic food needs.

Urea Fertilization Significantly Promotes Nitrous Oxide Emissions from Agricultural Soils and Is Attributed to the Short-Term Suppression of Nitrite-Oxidizing Bacteria during Urea Hydrolysis.

The application of urea in agricultural soil significantly boosts nitrous oxide (N2O) emissions. However, the reason for nitrite accumulation, the period of nitrite-oxidizing bacteria (NOB) suppression, and the main NOB species for nitrite removal behind urea fertilization have not been thoroughly investigated. In this study, four laboratory microcosm experiments were conducted to simulate urea fertilization in agricultural soils. We found that within 36 h of urea application, nitrite oxidation lagged behind ammonia oxidation, leading to nitrite accumulation and increased N2O emissions. However, after 36 h, NOB activity recovered and then removed nitrite, leading to reduced N2O emissions. Urea use resulted in an N2O emission rate tenfold higher than ammonium. During incubation, Nitrobacter-affiliated NOB growth decreased initially but increased later with urea use, while Nitrospira-affiliated NOB appeared unaffected. Chlorate suppression of NOB lasted longer, increasing N2O emissions. Urease inhibitors effectively reduced N2O emissions by slowing urea hydrolysis and limiting free ammonia production, preventing short-term NOB suppression. In summary, short-term NOB suppression during urea hydrolysis played a crucial role in increasing N2O emissions from agricultural soils. These findings revealed the reasons behind the surge in N2O emissions caused by extensive urea application and provided guidance for reducing N2O emissions in agricultural production processes.