Urea Spray Research Articles

Performance of mungbean in Response to zinc and iron through agronomic mechanism of biofortification

A field experiment was conducted at College of Agriculture, Agriculture University, Jodhpur in kharif season during 2020 and 2021 to study the effect of agronomic biofortification of zinc and iron on growth, yield and quality of mungbean (Vigna radiata (L.) Wilczek) varieties. The experiment was laid out in a split plot design, comprised with two varieties namely GM-7 and MH-421 and three treatments of foliar spray of iron (Fe) and urea in main-plots and four treatments included seed inoculation by zinc solubilizing bacteria with soil application of zinc (Zn) in a combinations were assigned to sub-plots. In this way, the experiment had twenty four treatment combinations were replicated thrice. Mung bean variety ‘MH-421’ had performed prominently with respect to all growth and yield parameters, while taller height was recorded under variety ‘GM-7’ during both the years as well as pooled basis of experimentations. Biofortified treatment of iron with urea spray and zinc significantly higher growth and yield attributes were recorded under treatment foliar spray of 0.5% Fe + 2% urea at flower initiation and pod formation stages and seed inoculation with ZSB + soil application of higher dose of zinc sulphate i.e. ZSB (SI) + 25 kg ZnSO4/ha, which remained at par with foliar spray of 0.5% Fe + 2% urea at flower initiation stage and ZSB (SI) + 20 kg ZnSO4/ha at 25, 50 DAS and at harvest stage of mungbean, respectively.

Volatile Oil Yield and its Components of Menthol and Limonene of Peppermint Affected by Foliar Spray and Lighting Intensity

A field experiment was conducted at a research station in the College of Agricultural Engineering Sciences, University of Baghdad, in spring 2021 to study the effects of foliar spraying of yeast extract, urea, and nano-amino acids and two lighting intensities on volatile oil yield and its components, menthol and limonene. The experiment had two factors: ambient type and lighting. The second component was foliar spraying yeast extract at 5 and 7.5 g.L-1, urea at 1000 and 2000 mg.L-1, and nano amino acids at 1 and 1.5 ml.L-1. P, K, and half of nitrogen were supplied to the soil. Randomized Complete Block Design (RCBD) with three replicates was used for the experiment. Plants grown at 100% lighting intensity had the highest percentage and production of aromatic oil, menthol, and limonene (2.24, 45.49, and 3.30%; 20.20, 9.49, and 0.74 kg.ha-1, respectively) compared to 50% lighting intensity (1.77, 31.00, and 1.91%; 11.64, 3.62, 0.24 kg.ha-1). The two treatments of spraying urea (2000mgN.L-1) and nano amino acids (1.5ml.L-1) at 100% lighting intensity yielded the highest percentage and yield of aromatic oil, menthol, and limonene at 3.07, 45.78, 3.99%; 50.23, 4.60%; 32.74, 16.44, 1.50 kg.ha-1, 29.37, 14.32, 1.17 kg.ha-1, respectively.

Combination of seed priming and nutrient foliar application improved physiological attributes, grain yield, and biofortification of rainfed wheat.

Seed priming and foliar application are two crop management practices that can increase grain yield and quality. The research aimed to assess the influence of seed priming and foliar application on rainfed wheat. Two field experiments with two seed priming rates (control and priming) and five foliar applications [control, urea (4%), silicon (4 mM), FeSO4.7H2O (0.6%), and ZnSO4.7H2O (0.4%)] at the anthesis/Z61 stage were conducted. Seeds were primed for 12h at 25 ± 2°C, by soaking in an aerating solution [urea (20g L-1) + FeSO4.7H2O (50 ppm) + ZnSO4.7H2O (50 ppm) + silicon (20 mg L-1)]. Seed weight-to-solution volume ratio was 1:5 (kg L-1). A pot experiment was also conducted to examine the effect of priming on root growth. Overall, combined seed priming and foliar application induced a positive impact on physiological traits and attributes. Maximum chlorophyll a, chlorophyll b, total chlorophyll, and carotenoid concentrations (1.58, 0.669, 2.24, and 0.61 mg g-1 FW), membrane stability index (77.31%), superoxide dismutase and peroxidase activity (0.174 and 0.375 Unit mg-1 protein), 1,000-grain weight (35.30g), biological yield, grain yield (8,061 and 2,456 kg ha-1), and minimum malondialdehyde concentration (3.91 µg g-1 FW) were observed in seed priming combination with ZnSO4 foliar application. The highest glycine betaine concentration (6.90 mg g-1 DW) and proline (972.8 µg g-1 FW) were recorded with the co-application of seed priming and foliar urea spraying. Foliar application of ZnSO4, FeSO4, and urea drastically enhanced grain Zn (29.17%), Fe (19.51%), and protein content (increased from 11.14% in control to 12.46% in urea foliar application), respectively. Compared to control, seed priming increased root length, root volume, and dry mass root by 8.95%, 4.31%, and 9.64%, respectively. It is concluded that adequate Zn, Fe, silicon, and N supply through seed priming and foliar applications of these compounds at the terminal stage of rainfed wheat alleviates drought stress and improves GY and biofortification.

Boosting wheat yield, profitability and NUE with prilled and nano urea in conservation tillage

Rice–wheat production in the Indo-gangetic plains (IGPs) of India faces major concerns such as depleting resources, rice residue burning, excessive fertilizer use, and decreasing nitrogen use efficiency. These issues threaten sustainable crop production in the future. Therefore, a field study was conducted during the winter seasons of 2020–21 and 2021–22 to evaluate the effect of combined conventional and nano fertilizers on nitrogen application just before or after irrigation to improve wheat productivity, profitability and NUE under conservation tillage. The study evaluated eight treatment combinations of nitrogen application through conventionally applied urea (46% N) and foliar applied nano urea (4% N) under zero tillage with rice residue retention. Results revealed that growth, physiological indices, yield, and quality parameters were enhanced with the application of 150 kg N/ha in three equal splits as basal and just before 1st and 2nd irrigation alone (T2) or along with a spray of nano urea (T5) compared to other treatments. T5 recorded 7.2%, 8.5%, and 7.8% more plant dry matter, number of tillers, and grain yield, respectively, over the conventional practice of applying 150 kg N/ha in three equal splits as basal and 7–10 days after 1st and 2nd irrigation (T3, farmers practice). Although, T2 showed similar results to T5, T5 recorded significantly higher gross ($2542/ha) and net returns ($1279/ha) than the other treatments. However, the benefit–cost ratio of T2 and T5 was same (2.01). A significant and positive correlation coefficient between grain yield and physiological parameters such as CCI and NDVI confirmed that increasing the nitrogen dose enhanced the chlorophyll content, greenness, and plant vigor. Based on the results, it can be concluded that applying 150 kg N/ha in three equal splits as basal and just before 1st and 2nd irrigation under conservation agriculture, along with a single spray of nano urea (4% N) at 60–65 days after sowing, can improve growth, yield attributes, wheat yield, and NUE compared to farmers practice (T3) in India.

Influence of Foliar Spray with Urea and GA3 on Some Vegetative Growth Characteristics of Mandarin Saplings cv.Clementine.

The experiment was conducted in the lath house affiliated with the College of Agriculture / University of Anbar to investigate the effect of foliar spray of urea and GA3 on some vegetative growth traits of mandarin saplings cv. Clementine, during the period from April 2021 to December 2021, spraying urea(46% N) included 0(spray with distilled water as control), 4, 8 and 12 g.l-1 ; on the other hand, spraying GA3 included 0(spray distilled water as control), 30 and 60 mg.l-1 . The results showed that urea spray significantly increased all vegetative traits, especially 12 g.l-1 , compared to the control. In the same context, GA3 at 60 mg.l-1 spray increased all vegetative growth characteristics, like plant height, leaves number increment, leaves area, shoot number, shoot length and rootstock diameter increment, compared to the lowest value in control. Keywords: Foliar Spray, Urea, Nitrogen, GA3, Vegetative Growth, Mandarin.

Effect of Nano Urea and Foliar Spray of Urea on Growth and Yield of Wheat (Triticum aestivum L.)

In pursuit of high yield today’s agriculture cultivars put the environment at greater risk by the inputs of chemical fertilizers. Using Nano urea we can minimize the inputs damage upto a certain extent. With this objective, field experiment was carried out during Rabi seasons of 2022-2023 at Crop Research Farm, Department of Agronomy, SHUATS, Prayagraj, Uttar Pradesh on topic “Effect of nano urea and foliar spray of urea on growth and yield of wheat”. The treatment include two factors, Factor- 1 Nitrogen (50 %, 75%, 100%) and Factor- 2 Foliar Spray (2ml/L nano urea, 4 ml/L nano urea, 2% urea) and one control was laid out in Randomized Block Design (RBD) with 10 treatments and three replications. Result revealed that 100% nitrogen along with foliar spray of 4ml/L nano urea recorded significant effect on Growth, yield and yield parameters. Treatment 6 recorded maximum plant height (101.62 cm), dry weight (21.95 g) number of tillers/running row (85.02), number of effective tillers/m2 (340.08), number of grains/spike (54.16), test weight (48.52 g), grain yield (6.30 t/ha) and straw yield (7.98 t/ha).

Effect of Iron and Urea Application on Iron Biofortification of Lentil (Lens culinaris Medik.)

ABSTRACT Agronomic biofortification with iron (Fe) may be a viable approach to combat the widespread deficiency of Fe in humans. Thus, the present study was conducted to examine the effect of Fe and urea foliar application on Fe biofortification in lentil (Lens culinaris Medik.). The field experiments were conducted at two locations viz. Ludhiana and Faridkot, India. Different treatment combinations of foliar spray of sole Fe (0.5% of FeSO4.7 H2O), sole urea (2% urea), and combined application of Fe and urea at flowering, pod formation, and flowering + pod formation stages along with unsprayed control were applied to lentil. The results of the study revealed that the combined foliar application of Fe and urea at flowering + pod formation stages was the most effective in enhancing grain yield, Fe and zinc (Zn) concentration in plants (at flowering as well as pod formation stage), stover and grain (whole and split). The highest Fe concentration in whole (36% higher over control) as well as split (32.9% higher over control) grain and protein content (21% higher over control) was obtained with foliar application of Fe + urea at flowering + pod formation stages. Conclusively, the combined foliar application of 0.5% FeSO4.7 H2O and 2% urea at flowering + pod formation stages may prove to be a feasible option for increasing grain yield and enrichment of lentils with Fe and Zn to combat micronutrient malnutrition in human populations.

Productivity and economic viability of winter niger [Guizotia abyssinica (L.f.) Cass.] under varying nutrient management practices

Results of the field experiments conducted in Vertisols of Jabalpur, Madhya Pradesh on irrigated niger (cv.JNC-1) during winter season for three consecutive years (2008-09 to 2010-11) revealed that application of 40 kgN + 30 kg P2O5 + 20 kg K2O/ha (recommended dose of fertilizer) along with spraying of 2% DAP twice at flowering and capitula formation stage showed higher seed (647 kg/ha); oil yield (198 kg/ha), and net monetary returns (` 7867/ha). This was at par with recommended dose of fertilizer (RDF) along with spraying of 2% urea twice. Application of 75% RDF along with spraying of 2% DAP twice at the same stage was comparable to 100% RDF alone with regard to productivity and economic viability. Numerically,spraying of DAP proved better than spraying of urea in respect of production and profit.

Influence of Nano Urea on Growth and Microbial Population in Paddy Ecosystem

Chemical fertilizer usage has been a long-drawn criticism because of its harmful effects on the environment and on the quality of agricultural produce. Researchers are continually looking for more productive, better solutions while retaining societal wellbeing. Effective use of nano fertilizers in place of chemical fertilizers is essential in reducing fertilizer overuse and also contribute in lowering the pollution and leaching which in turn increase the effectiveness of nutrient consumption and also increase the yield of the crop. An experiment was carried out in paddy to study the influence of Nano urea applications on growth and microbial populations in soil. The field trial used a Randomized Block Design (RBD) with eight treatment combinations and three replications. Results showed that application of STCR based N as Urea (50%) and Nano Urea (2 sprays) and Recommended dosage of N as Urea (50%) and Nano Urea (2 sprays) recorded higher plant height, Leaf Area Index (LAI), Dry matter accumulation in paddy. In addition, applications of Nano urea increased the microbial population including bacteria, fungi and actinomycetes. Combining recommended dosage of fertilisers with nano urea spray at critical stages of paddy crop increases the crop growth and microbial activity.

Effect of Nitrogen Rates and Foliar Spray of Urea Application and Nano Urea on Yield and Economics of rabi Maize (Zea mays L.)

A field experiment was conducted during Rabi 2022 at Crop Research Farm, Department of Agronomy, SHUATS, Prayagraj (U.P) to study the ”Effect of Nitrogen Rates and Foliar Spray of Urea Application and Nano Urea on Yield and Economics of rabi Maize (Zea mays L.)”effect of three nitrogen rates (50%, 75% and 100% RDN ) and three foliar spray of urea viz 20000 PPM (2%) and nano urea viz 2000 PPM (2 ml/L) and 4000 PPM (4ml/L) application on yield and economics of rabi maize (Zea mays L.). The soil of experimental plot was sandy loam texture, nearly neutral in soil reaction (pH 7.1), low in organic carbon (0.28%), available N (225kg/ha), available P (19.50) kg/ha) and available K (92 kg/ha). The experiment consists of 10 treatment, each being replicated thrice and laid out in Randomized Block Design. The results of present investigation revealed that the highest Grain yield (6.41 t/ha), Stover yield (8.65 t/ha), Harvest Index (42.58), Maximum gross return (INR 1,28266.67), Net return (81,682.75) and B:C ration (1.75) under 100% RDN +4000ppm (4 ml/l) spray of nano urea.

Effect of Nitrogen and Foliar Spray of Urea and Nano Urea on Growth and Yield of Rabi Maize (Zea mays L.)

A field experiment was conducted during Rabi 2022 at Crop Research Farm, Department of Agronomy, SHUATS, Prayagraj (U.P) to study the “Effect of nitrogen and foliar spray of urea and nano urea on growth and yield of rabi maize (Zea mays L.)”, to study treatments consisting of three levels of Nitrogen viz. 50% RDN, 75% RDN and 100% RDN and three foliar sprays of nano urea viz. 2000 ppm (2ml/L), 4000ppm (4ml/L), and foliar spray of urea viz., 20000 ppm (2%). The soil of experimental plot was sandy loam in texture, nearly neutral in soil reaction (pH 7.1), low in organic carbon (0.28 %), available N (225 kg/ha), available P (19.50 kg/ha) and available K (92 kg/ha). There were 10 treatments each being replicated thrice and laid out in Randomized Block Design. The results revealed that at 60 DAS, treatment combination 100% RDN + 4000 PPM (4ml/L) spray of Nano Urea recorded significantly higher Plant Height (108.10cm), Plant Dry weight (61.20 g), Crop Growth Rate (14.67 g/m2/day), number of cobs per plant (1.60), number of grains per cob (249.67), Seed index (23.55 g), Grain yield (6.41 t/ha), Stover yield (8.65 t/ha) and Harvest Index (42.58 %) as compared to other treatments.

Effect of Nutrient Management on Crop Moisture Utilization and Water Use Efficiency in Indian Mustard

Improving agricultural water use efficiency is a major concern, particularly in areas affected by drought, as it significantly limits grain production worldwide. Efficient water management techniques are essential for crop production in water-scarce regions. Enhancing crop water use efficiency and drought tolerance through genetic improvement and physiological regulation can contribute to more effective water utilization. A field experiment was conducted during Rabi season 2017-18 at Agriculture Farm, Bhagwant University, Ajmer to study the “Effect of nutrient management on growth, yield and quality of mustard” to evaluate the effect of nutrient management on crop moisture utilization and moisture use efficiency. The experiment comprising of 10 treatments replicated three times, was laid out in randomized block design. The treatments are Control (T1), Water Spray (T2), 2% urea spray (T3), 100% RDF (T4), 50% RDF + 2% urea spray (T5), 50 % RDF + 2% Multiplex spray (T6), 50% RDF + 2% urea + 2% Multiplex spray (T7), 100% RDF + 2% urea spray (T8), 100 % RDF + 2% Multiplex spray (T9), 100% RDF + 2%urea + 2% Multiplex spray (T11). The results indicated that the application of 100% RDF (Recommended Dose of Fertilizer) along with 2% urea and 2% Multiplex spray improved crop moisture utilization and moisture use efficiency.

Influence of Precision Nutrient Management on Dry Matter Accumulation and Partitioning of Rice in Southern Odisha

Background: The nutrient management practices are largely known to influence dry matter accumulation and translocation in rice. However, the role of precision nutrient management in dry matter partitioning to the reproductive parts of rice is still unexplored. Methods: The present trial was conducted during boro season of 2021-22 at PG Experimental Farm, MSSSoA, CUTM, Odisha. The experiment was laid out in randomized block design with 11treatments that were replicated thrice. The treatments examined under the investigation were namely, absolute control, 75% recommended dose of fertilizer (RDF), 100% RDF, 125% RDF, 75% RDF fb nano urea spray @ 2ml/L at panicle initiation, 100% RDF fb nano urea spray @ 2ml/L at panicle initiation, leaf colour chart (LCC) 3 basednitrogen management, LCC 4 based nitrogen management, sufficiency Index (SI)-based N management at a threshold value less than 90%, Nutrient expert (NE) based nutrient recommendation, Rice crop manager (RCM) based nutrient recommendation. Result: The results of the study indicated that SI-based N management at a threshold value less than 90% results in highest allocation, shoot dry matter to the panicle (53.46%); while, absolute control of nutrients resulted in highest percentage allocation of shoot dry matter to culm (23.72%) and leaves (33.88%) during maturity.

Effect of nutrient and pest management on productivity and profitability of pigeonpea (Cajanus cajan)

A field experiment was conducted during the rainy (kharif) season of 2017 and 2018 at the Mahatma Gandhi Chitrakoot Gramodaya Vishwavidyalaya, Chitrakoot, Satna, Madhya Pradesh, India, to study the impact of nutrient and pest management on productivity and profitability of pigeonpea [Cajanus cajan (L) Millsp.]. The experiment consisted 8 treatments of nutrient and pest management, replicated thrice in randomized block design. Pods/plant were found markedly superior in recommended dose of fertilizer (RDF) + multimicronutrient @ 2 ml/L at 50% flowering + indoxacarb spray at flowering + 1 systemic insecticide at 15 days after the first spray. However, 1000-seed weight (65.19 g) was significantly higher in RDF + multimicronutrient @ 2 ml/L at 50% flowering + indoxacarb spray at flowering + 1 systemic insecticide at 15 days after first spray. Grain yield (1.07 t/ha) was significantly superior under RDF + multimicronutrient @ 2 ml/L at 50% flowering + indoxacarb spray at flowering + 1 systemic insecticide at 15 days after the first spray. The stover yield (6.13 t/ha) was recorded significantly higher (17.92%) in RDF + 0.5% borax spray at 50% flowering. Harvest index was estimated significantly superior in RDF + indoxacarb spray at 50% flowering + 1 systemic insecticide (Dimethoate) at 15 days after first spray followed by RDF + multimicronutrinent @ 2 ml/L at 50% flowering + indoxacarb spray at flowering + 1 systemic insecticide at 15 days after the first spray (17.53%). Gross returns (69.3 × 103 `/ha) and net returns (69.3 × 103 `/ha) of pigeonpea were recorded significantly higher under RDF + multimicronutrient @ 2 ml/L at 50% flowering + Indoxacarb spray at flowering + 1 systemic insecticide at 15 days after the first spray, while benefit : cost ratio (3.68; 3.49) was found significantly more in RDF + 2% urea spray at 50% flowering and RDF + 0.5% ZnSO4 spray at 50% flowering than the other treatments.

IoT Based Smart Farming

Abstract: The revolution brought by Internet of Things (IoT) technology has affected every field of common man's life, making everything smart and intelligent. In the past, the ripeness of the soil and crop growth were determined by farmers based on their intuition and suspicions. They were unaware of factors such as humidity, water levels, and especially weather conditions, which negatively impacted farmers. The agricultural sector is being transformed by the Internet of Things (IoT), empowering farmers through a wide range of techniques. In the era of IoT, extensive research is being conducted to develop Smart IoT-based products that facilitate Smart Farming in terms of Crop Management, Pest Management, Agriculture Precision, Agriculture Fields Monitoring through Sensors, and even Drones. The production rate of crops in agriculture depends on various parameters such as temperature, humidity, and rainfall. Therefore, the project aims to make agriculture smart using IoT technologies and the utilization of Unmanned Aerial Vehicles (UAVs), also known as drones, and connected analytics, which have great potential to address and support some of the most pressing issues faced by agriculture in terms of accessing real-time quality data that can be acted upon. The basic purpose and use of drones for spraying plants could allow for the rapid application of plant protection agents on growing areas. Accordingly, this paper presents the applicable types, role, and significance of drone usage in modern agriculture. This paper provides an overview of various technologies used to reduce human efforts in various agricultural operations, such as detecting the presence of pests, spraying of UREA, spraying of fertilizers, crop mapping, and soil analysis, among others

Leaf defoliation and Tabernaemontana rotensis (Asterids: Gentianales: Apocynaceae) flower induction and fruit development

Tabernaemontana rotensis (Kaneh.) P.T. Li is an attractive small tree that is endemic to the islands of Guam and Rota. Conservation efforts of the threatened population are constrained by lack of research. Understanding the ecology of flower and fruit development is fundamental to successful conservation of threatened angiosperms. This study determined the extent of flower induction following tropical cyclone defoliation, tested the efficacy of 10% urea sprays as a defoliant to induce flowering, and quantified the resulting fruit expansion to determine ontogeny traits. A total of 512 inflorescences were observed, half following tropical cyclones and half following defoliation with urea. Fruit length was measured every five to seven days until seed dispersal. The mean length of time between defoliation and initial flower anthesis was 29 days, and did not differ between tropical cyclone defoliation and urea solution aerosol defoliation. Four stages of observable fruit development were identified following anthesis. Linear increases in ovary length occurred for two weeks, maximum ovary length occurred at about day 30, color break from green to orange began at about day 60, and seed dispersal occurred at about day 90. Defoliation treatment did not influence the timing of these stages. The results indicated that tropical cyclone and urea solution defoliation consistently generated mast flowering after about one month with mast seeding about three months later. Conservationists may use this new knowledge to predictably schedule seed harvests at about four months following a natural or anthropogenic defoliation event. Many Tabernaemontana species are exploited for traditional medicine, and the use of defoliation to manipulate phenology of these species may benefit the practitioners of this trade.

Evaluation of the effect of urea foliar application on polyamine content, grain protein content, and the agronomic traits of bread wheat cultivars under dryland and supplemental irrigation conditions

The purpose of the experiment was to investigate the relationship between the accumulation of polyamines during the filling period of wheat grain with yield and grain protein under dryland and supplemental irrigation (SI) conditions and also the effect of foliar spraying of urea on the amount of polyamines in grain a factorial experiment was conducted based on randomized complete block design with three replications during two cropping seasons. The examined treatments included water availability (dryland and SI), wheat cultivars (Homa, Sardari, Rijaw, Ouhadi, and Azar2), and foliar application of urea (control and 4% urea foliar application). The results demonstrated that SI (10%) reduced and urea foliar (12%) application increased the percent of grain protein. SI reduced the contents of three PAs by 24%: spermine, spermidine, and putrescine. But urea foliar application increased the three PAs in the first and second years by 31% and 27% in dryland conditions and 12% and 4% in SI conditions, respectively. These results indicated that there is less need for PAs in SI conditions, and they thus exhibit poorer accumulation in the grain; in dryland conditions, however, their content increases with greater access to foliar nitrogen. Older cultivars Sardari and Azar 2 had more polyamines. According to the observed positive correlation between 1000-grain weight and the three PAs under stress conditions, PAs are probably involved in the improvement of grain filling, and urea foliar application can affect drought tolerance by increasing PA accumulation. Moreover, cadaverine exhibited a different function from the other PAs.

Effect of Nano Urea on growth, yield and nutrient use efficiency of Okra under tropical island ecosystem

The field experiment was conducted during 2021-22 at Garacharma, ICAR-CIARI, Port Blair to study the effect of nano urea (liquid) on the growth and yield of okra under island conditions. The treatment combinations consist of basal applications of fertilizers and foliar spray of nano urea in two concentrations (2 % and 4% concentrations). The results revealed that nano spray resulted in higher okra yield(9.6 %) than NPK addition through chemical fertilizers. While increased concentration of nano spray (4%) had significant impact on the growth and yield parameters due to increased availability of N within the plant system. Though Rs. 600- 1200 respectively were incurred as additional cost on account of application of nano spray (0.2 - 0.4%), the nano spray (N66 PK and 0.4 % Nano urea) contributes to additional okra yield (1.32 t ha-1, 9.6%), additional monetary benefit (Rs.65,561) than only NPK addition through chemical fertilizers (100 % RDF). Further, there is significant difference between Nano spray at 0.2 % and 0.4% spray though higher concentration of (0.4%) nano spray gave 7.5-16 % higher yield and 17- 29 % higher netreturn. Further, the increased efficiency of nano urea resulted in saving of nitrogen fertilizer to the extent of 25-34%. At the same time nano urea had no significant negative impact on soil properties and socio-root micro environment by the accumulation of excess mineral N. Hence, it can be concluded that spraying of nano urea is proved to be beneficial for island ecosystem as it lead to increased yield and saving of chemical fertilizer thereby reducing the accumulation of N in the environment.

Soil type and integrated nitrogen nutrient-rice straw residue management techniques affect soil microbes, enzyme activities and yield of wheat crop

Sporadic burning of rice straw and the particulate air pollution caused consequently have created a pressing need for identification of practical environmentally sound in situ rice residue management methods. However, the agronomic interventions associated with the agri-inputs particularly the type of nitrogen fertilizer source must be worked out for these interventions. In a two-year field study performed at two different locations representing sandy loam and clay loam soil types, zero tillage with application of nitrophosphate (applied as basal dose through drilling) in combination with urea (applied at 1st irrigation + 3 foliar sprays of urea at weekly interval) significantly enhanced the grain and straw yield of wheat. The soil microbial viable cell counts and dehydrogenase and urease enzyme activities were also recorded to be highest in this treatment indicating the occurrence of higher living microbial population. The treatment × response variable Principle component analysis (PCA) biplot depicted relative variation among the residue management treatments/Nitrogen fertilizer sub-treatments and the enzyme activities as response variables. A variation in the soil organic content components was recognized through Fourier transform infra-red spectroscopy (FT-IRS) studies. Irrespective of the soil types under study, the FT-IR spectra exhibited presence of the aromatic carbon functional groups in residue incorporated treatments as compared to the no residue incorporation treatment.

Effect of Added Urea Foliar Spray and Leaf Clipping on Growth and Yield Response of Mungbean

An experiment was conducted at Sher-e-Bangla Agricultural University, Dhaka, during March to May 2018 to study the impact of added urea foliar spray and leaf clipping on growth and yield of mungbean. The experiment was laid out in Split-plot Design with three replications and composed of four levels of urea foliar spray viz. F0 = Recommended Fertilizer (RF) + No Foliar Spray (FS), F1 = RF + 1% Urea FS at Flower Initiation (FI), F2 = RF + 2% Urea FS at FI, F3 = RF + 3% Urea FS at FI and four levels of Leaf clipping viz. C0 = No leaf clipping, C1 = Clipping 1 basal leaf, C 2 = Clipping 2 basal leaves, C3= Clipping total apical leaves having no inflorescence. Results indicated that foliar spray and leaf clipping had significant effect on most of the growth and yield contributing parameters. In case of foliar spray of urea, the maximum plant height, nodules plant-1, highest above ground dry matter plant-1, pods plant-1, pod length, seeds pod-1, 1000 seed weight, seed yield, stover yield and biological yield were recorded from F0. In case of leaf clipping, all growth and yield attributes were recorded highest from C1. Regarding combined effect, the highest growth and yield parameters were recorded from the treatment combination of F0C1. So, F0 along with C1 is suggested for yield improvement in mungbean cultivation.
 Bangladesh Agron. J. 2022, 25(2): 57-65