Zonal Agricultural Research Station Research Articles

Effect of Different Levels of Nano Urea on Growth and Yield of Maize (Zea mays L.)

A field experiment was conducted during the kharif season of 2023 at the Zonal Agricultural Research Station, V.C. Farm, Mandya, to investigates the effects of nano urea and conventional urea doses through foliar spraying at different growth stages of the maize crop by establishing a comparative analysis between both treatments. The experiment was followed a Randomized Complete Block Design with ten treatments, replicated thrice. The treatments consisted of 75% and 100% of the recommended nitrogen dose (RDN), supplemented with foliar applications of nano urea (2, 4, and 6 ml l⁻¹) and urea (2%) at 25 and 50 days after sowing. These were compared with the recommended dose of fertilizer (RDF) alone and a control (RDF without nitrogen). The results revealed that the highest plant height (220.33 cm), SPAD readings (48.97 at 90 DAS and 35.97 at harvest), and total dry weight of leaf (55.86 g plant⁻¹) and stem (160.73 g plant⁻¹) were recorded with 100% RDN + nano urea @ 4 ml l⁻¹ foliar spray. This treatment was statistically on par with 75% RDN + nano urea @ 4 ml l⁻¹. Similarly, the highest grain yield (9256 kg ha⁻¹) and stover yield (11474 kg ha⁻¹) were obtained under 100% RDN + nano urea @ 4 ml l⁻¹, with comparable results in the 75% RDN + nano urea @ 4 ml l⁻¹ treatment. These findings suggest that nano urea application allows a reduction in nitrogen fertilizer use without compromising maize productivity, offering a sustainable alternative for nutrient management.

Achieving Yield Sustainability in Small Millets Through Liquid Microbial Consortia-An Eco-friendly Approach

Background: Actually, the millets are grown organically/no manures are applied even under low fertile soils resulted in poor millet production levels and leading to higher price of millets. Hence, there is need for low cost and eco-friendly technologies for getting higher productivity and sustaining the soil health. Methods: The field experiment was conducted to investigate the benefits of liquid microbial consortia and their mode of application on small millets (Proso, Little and Barnyard millet, respectively) at Zonal Agricultural Research Station, V. C. Farm, Mandya from kharif, 2020 to kharif 2022. The experimental design followed was randomized complete block design with three replications using the recommended dose of fertilizers (RDF) at various levels (100%, 85% and 70% RDF, respectively) with different mode of application of liquid microbial consortia as seed treatment, soil application and combination of both. Result: The highest grain and straw yield was realized with treatment receiving 100% RDF+Seed treatment with liquid microbial consortia (5 ml kg-1 seed) followed by soil application of liquid microbial consortia (6.25 litres/ha) mixed with 500 kg farmyard manure (FYM) and applied in furrows during sowing as compared to 100% RDF alone. This might be due to the better growth and yield parameters. The nutrient uptake by grain and straw and microbial population and available soil nutrients at harvest and B:C ratio also followed the similar trend as in case of grain and straw yield.

Carbon stock dynamics in soil as influenced by perennial grass-legume mixtures in southern dry zone of Karnataka

A field experiment was conducted at Zonal Agricultural Research Station, Vishweshwaraiah Canal Farm, Mandya, University of Agricultural Sciences, Bangalore from July 2020 to June 2022 to study the carbon stock dynamics in soil as influenced by different perennial grass-legume mixtures in southern dry zone of Karnataka. The experiment was laid out in a randomized complete block design comprising of twelve treatments and replicated thrice. The data revealed that among different grass-legume mixtures, paired row system of B×N hybrid + Desmanthus (2:5) recorded considerably higher credit of soil organic carbon (0.018%) and carbon sequestration in soil (1.12 Mg ha-1) followed by paired row system of Guinea grass + Desmanthus (2:3) (0.016% and 0.99 Mg ha-1, respectively) at the end of the second year. Further, significantly higher green fodder, dry matter and crude protein yield (1802.7, 355.7 and 41.5 q ha-1 year-1, respectively), gross and net returns (Rs. 3,44,072 and 2,58,752 ha-1 year-1, respectively) as well as benefit cost ratio (4.05) were observed with paired row system of B×N hybrid + Desmanthus (2:5) cropping system on a pooled basis which was on par with paired row system of Guinea grass + Desmanthus (2:3) with respect to crude protein yield (38.3 q ha-1 year-1) and B:C ratio (3.67) as compared to other grass-legume mixtures. Considering these results, B×N hybrid paired row + Desmanthus (2:5) followed by Guinea grass paired row + Desmanthus (2:3) were found as the most promising fodder cropping systems for meeting both farmer needs and soil sustainability.

Trait Association and Genetic Variability Study in Rice MAGIC Lines for Yield Related Traits

The study was aimed to assess genetic variability and associations between grain yield and morphological traits in 50 multi-parent advanced generation intercross (MAGIC) lines generated by single seed descent utilizing eight diverse parents (to impart tolerance to biotic and abiotic stresses) were utilized in the study along with eight checks at Zonal agricultural and horticultural research station, Navile, Shivamogga during kharif 2022. Improvement in grain yield, a quantitative trait is one of the key objective of plant breeders which depends upon the magnitude of genetic variability existing in the genetic material utilized in the breeding programme. The analysis of variance revealed the presence of significant differences were found among lines for all traits. Moderate to high genotypic and phenotypic variation, heritability and genetic advance were recorded for plant height, tillers per plant, filled grains per panicle, test weight and grain yield. Correlation analysis revealed positive associations between grain yield and tillers per plant, panicle length, filled grains per panicle, panicle fertility and test weight. These findings emphasize the importance of indirect selection for these traits to improve grain yield in rice. The results suggest that breeders can utilize these traits as selection criteria to enhance grain yield, ultimately contributing to rice yield improvement programs. Our study provides valuable insights for rice breeders to develop high-yielding rice varieties with improved tolerance to biotic and abiotic stresses.

Genetic Variability and Correlation Studies in Red Rice (Oryza sativa L.) for Yield Related Traits and Grain Zinc, Iron and Protein Content

Aims: Nutrient deficiencies, particularly zinc (Zn), iron (Fe) and protein, pose severe health risks especially in children and lactating women. Red rice is significantly rich in iron, zinc and protein compared to white rice. The present investigation was undertaken in this context to elucidate information on variability and character association in red rice genotypes to identify effective selection criteria for grain yield and quality improvement of red rice genotypes. Study Design: Randomized complete block design with two replications. Place and Duration of Study: Zonal Agricultural and Horticultural Research Station, Brahmavar, Udupi during Kharif 2023. Methodology: A total of 108 red rice genotypes were used in the study and observations were recorded for ten characters. Protein was estimated by Kjeldhal method, zinc and iron content by Atomic absorption spectrophotometer (AAS) method. The data collected was subjected to statistical procedures using R software. Results: Analysis of variance revealed significant variation among the genotypes for all the characters studied. Grain Zn (11.4-44.7ppm), Fe (13.11-37.12ppm) and protein (5.0-11.43%) showed wide range of variability. High genotypic and phenotypic coefficient of variation was observed for Zn, number of productive tillers per plant, Fe, grain yield per plant, number of grains per panicle and plant height. Correlation studies revealed that grain yield per plant exhibited significant positive association with yield component traits. Protein and Fe content had negative association with grain yield. Conclusion: The traits that have high PCV, GCV, heritability and genetic advance as per cent mean are controlled by additive gene action which is very valuable for selection. The traits that are positively correlated with grain yield can be used for indirect selection which aids crop improvement. Karthika, Bilihallga and Shahara genotypes have high protein, iron and zinc respectively, which can be used in the further breeding program to develop nutritionally rich varieties.

Influence of Nano Urea and Nano DAP on Growth and Productivity of Sunflower (Helianthus annuus L.) During kharif season

A two years field experiment was conducted at AICRP on sunflower, Zonal agricultural research station, UASB, GKVK, Bengaluru during kharif, 2022 and 2023 to study the effect of nano urea and nano DAP on growth and productivity of sunflower. The experiment was laid out in Randomized Complete Block Design with thirteen treatments (50 % RDN+ Nano N @ 4 ml, 50 % RDN+ Nano N @ 6 ml, 75 % RDN+ Nano N @ 4 ml, 75 % RDN+ Nano N @ 6 ml, 50 % RDNP + Nano N & P @ 4 ml, 50 % RDNP + Nano N & P @ 6 ml, 75 % RDNP + Nano N & P @ 4 ml, 75 % RDNP + Nano N & P @ 6 ml, RDF + Normal urea spray @ 1%, RDF+ DAP spray @ 1%, RDF+ FYM, RDF and absolute control) each replicated thrice. The results revealed that significantly higher plant height (199.89 cm), number of leaves per plant (30.26), leaf area (5557 cm2 plant-1), leaf area index (3.09), total dry matter production (146.70 g plant-1), capitulum diameter (19.06 cm), no. of seeds per capitulum (1147), seed yield (2026 kg ha-1) and stalk yield (4395 kg ha-1) were recorded with the application of RDF+ FYM and it was found on par with application of 75 % RDN+ Nano N @ 6 ml.

Investigating Different Planting Geometry and Nutrient Management to Enhance Teff Productivity in Eastern Dry Zone of Karnataka, India

A field experiment was conducted at Zonal Agricultural Research Station (ZARS), Gandhi Krishi Vignana Kendra, University of Agricultural Sciences, Bangalore, Karnataka on red sandy loam soil to study the “Investigating different planting geometry and nutrient management to enhance teff productivity”. The experiment was laid out in Factorial Randomized Complete Block Design, consisting two factors viz., Factor 1: Two planting geometry (S1: 30 cm × 10 cm and S2: 45 cm × 10 cm) and Factor 2: Five Nutrient management (N1: 50 % RDF, N2: 75 % RDF, N3: 100 % RDF, N4: 125 % RDF and N5: Absolute control (6 t FYM ha-1 commonly applied to all except control treatments) and replicated thrice. The uptake of nitrogen, phosphorus and potassium was higher under 30 cm × 10 cm spacing (5.74, 1.04 and 3.29 kg ha-1, respectively) and among nutrient levels, application of 125 per cent RDF resulted in statistically higher uptake nitrogen (7.35 kg ha-1), phosphorous (1.33 kg ha-1) and potassium (4.28 kg ha-1). Significantly higher (12.58 %) grain protein content was obtained with application of 125% RDF. Maintaining 30 cm × 10 cm spacing recorded significantly higher grain (2.37 q ha-1) and straw yield (3.65 q ha-1). Application of 125 % RDF resulted in significantly higher straw yield, however significantly higher grain yield (2.73 q ha-1) was obtained under 100% RDF. Application of 100% RDF along with narrow spacing yielding substantially higher gross returns (₹90,776 ha-1), net returns (₹60,021 ha-1), and a commendable B:C ratio of 2.77.

Response of irrigation scheduling with hydrogel under deficit and sufficient irrigation conditions on Indian mustard (Brassica juncea) in semi-arid India

In the Gird Agroclimatic Zone at Rajamata Vijayaraj Scindia Krishi Visva Vidhyalay, Zonal Agricultural Research Station Morena, an experiment was carried out during the Rabi season of 2013–14, 2014–15, and 2015–16. Split plot design was used to set up the experiment, with three hydrogel levels assigned to each sub-plot and four watering schedules assigned to the main plots, all of which were reproduced three times. The growth and yield parameters of mustard (Brassica juncea L.) were significantly higher when irrigation was scheduled at 0.8 IW/CPE. These attributes were plant height, number of primary branches plant-1, number of siliquae plant-1, number of seeds siliqua-1, and seed yield (1803 kg ha-1). In a similar vein, the irrigation schedule at 0.8 IW/CPE across the remaining treatments resulted in better oil yield (781.8 kg ha-1), financial returns, production efficiency (15.1 kg ha-1day-1), and B:C Ratio. When compared to the other treatments, the irrigation schedule with rainfed (no irrigation) had the highest water use efficiency (8.5 kgha-cm). As the hydrogel level was increased to 5.0 kg ha-1, growth metrics, yield attributes, seed yield, and oil production all improved. Higher production efficiency (14.3 kg ha-1 day-1) and water use efficiency (9.5 kg/ha-cm) were also brought about by the increased yield with 5.0 kg ha-1 hydrogel.

Influence of row spacing and organic nutrient management practices on growth, yield and nutrient uptake of chia (Salvia hispanica)

The field experiment was conducted during rainy (kharif) seasons of 2020–21 and 2021–22 at Zonal Agricultural Research Station, Vishweshwaraiah Canal Farm, Mandya, Karnataka, to study the consequences of row spacing and organic nutrient management practices on growth, yield and nutrient uptake of chia (Salvia hispanica L.). The experiment was conducted in a factorial randomized complete block design (Factorial-RCBD), with 12 treatment combinations replicated thrice. The treatments comprised of 2 spacings (45 cm × 15 cm and 60 cm × 15 cm) and 6 organic nutrient management practices [application of 75 and 100% recommended dose of nitrogen (RDN) equivalent compost along with the application of Jeevamrutha at sowing and 30 days after sowing (DAS)]. The pooled mean results of 2-years revealed that row spacing and organic nutrient management practices significantly influenced the performance of chia. Plant height, number of branches/plant, total dry matter production, and yield variables such as spike number and spike length were all significantly greater in 60 cm × 15 cm spacing with the application of 100% RDN equivalent compost + application of Jeevamrutha at sowing and 30 DAS. The same treatment also recorded significantly higher nutrient uptake (66.35, 12.91, and 52.27, NPK kg/ha, respectively). Whereas, significantly higher seed yield (1015.47 kg/ha) and leaf area index (1.72) were gained with 45 cm × 15 cm + 100% RDN equivalent compost + application of Jeevamrutha at sowing and 30 DAS.

Influence of Various Organic Manures on the Growth and Yield of Radish at Different Growth Stages (Raphanus sativus L.)

Influence of Various Organic Manures on the Growth and Yield of Radish at Different Growth Stages (Raphanus sativus L.)

Predictive Modeling of Extreme Weather Forecasting Events: an LSTM Approach

For a variety of industries, including agriculture, water resource management, and flood forecasting, accurate rainfall prediction is crucial. The purpose of this research work is to improve rainfall forecast system by employing the Long Short-Term Memory (LSTM) based system. The LSTM utilized in the aforementioned study made predictions by using meteorological input variables such as temperature, humidity, and rainfall. Numerous elements affect the LSTM network's performance, such as the kind and volume of data, the suitability of the model architecture, and the tuning of hyperparameters. The dataset used for model training spans from January 2015 to December 2021 and includes rainfall data collected from the Zonal Agricultural Research Station (ZARS), Shenda Park, Kolhapur. Prior to model training, the input data undergoes rigorous preprocessing. This preprocessing involves data correction, achieved through moving averages, followed by feature scaling and normalization methods. These steps are crucial to align the dataset with the unique capabilities of the LSTM model. The total dataset has a R squared (R2) value 0.23517 and a mean squared error (MSE) value 92.1839, according to the simulated findings. These metrics affirm the robust performance of the LSTM model, suggesting a high probability of accurate rainfall predictions, particularly in non-linear and complex scenarios. Decision-makers in flood predictions, agriculture, and water resource management will find the knowledge gathered from this study to be useful. They emphasize how crucial it is to use cutting-edge techniques like LSTM to increase rainfall forecast accuracy and guide strategic planning in associated industries.

Effect of Different Liquid Organic Manures on the Nutrient Release Pattern in Radish Grown Soil

The study of nutrient release patterns from various organic manures is critical for ensuring enough nutrient availability to crop plants at the right time and in the right quantity. To assess the nutrient release pattern from several organic manures, including farm yard manure, panchagavya and jeevamrutha, a field experiment was conducted at organic farming block of Zonal Agricultural Research Station, V. C. Farm, Mandya during late Kharif 2020. The experiment consists of 9 treatments including different rates of recommended dose of nitrogen was applied through FYM and one- and two-times application of panchagavya and jeevamrutha in different combinations. The experiment was laid out in a Randomized Block Design with three replications. The release pattern of available nitrogen, phosphorus, potassium, calcium, magnesium, sulphur and micronutrients in soil applied with various organic manures at various days (15, 30, 45 DAS and at harvest). The study revealed that application of various organic manures showed substantial increase in primary (N, P and K) and secondary nutrient (S) release and there were no significant variations found in Ca, Mg, Fe, Mn, Cu and Zn release pattern. Based on the release rate of nutrients, it was found that there was consistent and stable release of N, P, K and S from 75% RDN through FYM + two time application of Panchagavya followed by 75% RDN through FYM + two time application of Jeevamrutha, compared to other treatments.

Studies on Nutrient uptake, Nutrient use Efficiency and Water Productivity of Drip Irrigated Ratoon Sugarcane as Influenced by Water Soluble Fertilizers

A field experiment was conducted at Zonal Agricultural Research Station, V.C. Farm, Mandya during 2020-21 to study the Nutrient content and Uptake of Drip irrigated Ratoon Sugarcane as influenced by water soluble fertilizers. The experimental site was red sandy loam soil with neutral pH, normal electrical conductivity, medium organic carbon, low available nitrogen, medium phosphorus and potassium content. The experiment was laid out in Randomized Complete Block Design with three replications comprising seven treatments with VCF-0517 sugarcane variety. The results revealed that application of 150 per cent RDF through WSF (325.9 kg ha-1 N, 46.5 kg ha-1 P2O5, 338.4 K2O kg ha-1) recorded significantly higher nitrogen, phosphorus and potassium uptake compared to 100 per cent RDF through WSF (287.3 kg ha-1 N, 37.5 kg ha-1 P2O5, 282.6 kg ha-1 K2O) and 75 per cent RDF through WSF (269.9 kg ha-1 N, 33.4 kg ha-1 P2O5, 253.6 kg ha-1 K2O). Application of WSF at 75 per cent RDF resulted in greater NUE in case of nitrogen, phosphorus and potassium (348.3 kg kg-1, 870.7 kg kg-1 and 696.5 kg kg-1 respectively) when compared with other fertigation levels and conventional fertilizer application.

Alterations in the Nutrient Status of Soil and Enzymatic Activity of Finger Millet Cultivated Soil Accompanying to Nano Urea Application

An experiment was conducted at the Zonal Agricultural Research Station, Gandhi Krishi Vigyan Kendra, University of Agricultural Sciences, Bangalore, with the aim of assessing the impact of nano nitrogen on growth, yield, nutrient uptake, nitrogen use efficiency and enzymatic activity in finger millet cultivation. Among different treatments, application of 75% RDN + seed treatment with nano urea + foliar spray of nano urea at 30 and 50 DAS showed significant improvements in various growth and yield parameters of finger millet. At 90 DAS, it resulted in a remarkable increase in the number of leaves hill-1 (36.73), leaf area (982.90 cm2 hill-1) and leaf area index (3.28). The treatment also led to enhanced growth indices viz., absolute growth rate of 0.74 g day-1, a relative growth rate of 0.029 g g-1 day-1 and a crop growth rate of 24.80 g m2 day-1 during 60-90 DAS period. Significantly, it boosted the grain yield of 3,397 kg ha-1 for finger millet over control. Notably, this treatment exhibited higher NPK (86.56, 25.93 and 55.36 kg ha-1 respectively) uptake at harvest. It also demonstrated superior agronomic efficiency, internal utilization efficiency and nutrient increment efficiency of nitrogen (52.57, 39.24 and 1.40 kg kg-1 respectively). These findings underscore the potential of nano nitrogen in enhancing finger millet growth, increasing yield, optimizing nutrient uptake and improving nitrogen use efficiency in finger millet cultivation.

Evaluation of Pigeonpea-based Intercropping System for Growth, Productivity, Economics, Available Nutrient and Nutrient Uptake under Alfisols

An experiment was conducted to the evaluation of pigeonpea-based intercropping system for growth, productivity, economics, available nutrient and nutrient uptake under alfisols of Karnataka during Kharif, 2020 at ‘K’ Block, Zonal Agricultural Research Station, University of Agricultural Sciences, Gandhi Krishi Vigyan Kendra, Bengaluru. The experiment had 15 treatments which were replicated thrice in Randomised Complete Block Design. Treatments consisted of sole crops pigeonpea and different intercrops mixed along with of intercrops (field bean, vegetable soybean and chia) in different row proportions of (1:2, 1:3 and 1:4).The study aimed to assess the growth, yield and economics of pigeonpea comprising planting geometry and different intercrops. The results indicated that the combined effect of paired-row pigeonpea with field bean at 120/60 cm × 30 cm (1:2) spacing recorded the highest seed yield (1770 kg/ha) and stalk yield (4026 kg/ha). Among planting geometry and intercropping systems, higher gross returns, net returns and B:C ratio (Rs. 2,60,591 ha-1, Rs. 2,19,030 ha-1 and 6.27 respectively) was recorded in T7 (paired row pigeonpea with vegetable soybean at 120/60 cm). Among planting geometry and intercropping system highest total nutrient uptake of pigeonpea was recorded in T6 (Paired row - 120/60 cm × 30 cm pigeonpea + field bean (1:2), 76.65, 12.20 and 98.36 kg/ha NPK respectively) compared to rest of intercropping treatments. In available nutrients, among planting geometry and intercropping systems highest total available nitrogen and phosphorous was recorded in T14: Sole vegetable soybean (318.62 and 107.20 kg/ha N & P respectively) and higher total available potassium was recorded in T13: Sole field bean (321.40 kg/ha K respectively), compared to other treatments. The study concludes that the paired row pigeonpea with vegetable soybean at 120/60 cm x 30 cm yield and economics of the intercropping systems.

Influence of Foliar Application of Nano Urea and Urea on Productivity and Nutrient Status of Fodder Maize during Kharif Season

A field-based study was carried out during Kharif season in 2022 at Zonal Agricultural Research Station, V. C. Farm, Mandya, Karnataka, India. The soil was sandy loam in texture, neutral in reaction, low in available nitrogen, and medium in organic carbon, phosphorous and potassium status. The experiment was carried out with fodder Maize in randomized block design with 11 treatments and 3 replications. The treatments include varied levels of recommended dose of N (50, 75 and 100%) along with foliar application of nano urea (0.2% and 0.4%) and urea (2%) spray at 20 and 40 DAS, in comparison with RDF alone and control (RDF without N). The application of 100% recommended dose of N + Urea @ 2% spray recorded significantly higher growth parameters such as leaf area and dry matter accumulation at harvest and was on par with 100% recommended dose of N + Nano urea @ 0.4% spray. Significantly higher green fodder yield, dry fodder yield and nutrient content in fodder maize was recorded in 100% recommended dose of N + Urea @ 2% spray and was on par with 100% recommended dose of N + Nano urea @ 0.4% spray. Higher gross returns, net returns and B:C ratio was observed with application of 100% recommended dose of N + Urea @ 2% spray over rest of the treatments.

Population Dynamics of Cardamom Shoot and Capsule Borer, Conogethes punctiferalis (Guenee) on Cardamom Variety M2 under Hill Zone of Karnataka, India

The experiment was carried out to study the population dynamics of cardamom shoot and capsule borer, Conogethes punctiferalis(Guen.) at the Zonal Agricultural and Horticultural Research Station (ZAHRS), Mudigere during 2022-23. Infestation of borer was present throughout the year, but peak infestation on shoot was recorded in the month of December (56.67%). Whereas, infestation on capsules peaked during first fortnight of December (33.65%). The correlation studies revealed that there was a significant positive correlation with maximum temperature and sunshine hours for shoot infestation. While, morning relative humidity had significantly positive correlation with capsule infestation. However, rainfall had significant negative correlation for both shoot and capsule infestation.

Performance of Chia (Salvia hispanica L.) under Spacing and Nutrient Management Practices in Cauvery Command Area

An investigation was carried out at the Zonal Agricultural Research Station, Vishweshwaraiah Canal Farm, Mandya, Karnataka, spanning from September to December in both 2020 and 2021. The purpose was to analyze how varying spacing and nutrient management practices affect the yield and growth rate of chia plants. The study involved two different spacings (S) and six levels of organic nutrients (N). Employing a 2 × 6 × 3 factorial experiment design within a randomized complete block framework with three replications, the experiment was conducted over a two-year period. The spacing of 60 cm × 15 cm (S2) resulted in notably higher absolute growth rates (1.00 and 1.87 g/day, respectively at 30 – 60 and 60 – 90 DAS) and biomass duration (221.84, 893.45 and 2182.73 days, respectively at 0 – 30, 30 – 60 and 60 – 90 DAS). Conversely, for relative growth rate (1.67 and 1.19 g/g/day × 10-2, respectively at 30 – 60 DAS and 60 – 90 DAS) and leaf area ratio (2180.90, 1967.19 and 1522.35 cm2/g × 10-2, respectively at 30, 60 and 90 DAS), higher values were observed with 45 cm × 15 cm spacing (S1). Among the various organic nutrient levels, the highest absolute growth rate (1.09 and 2.01 g/day, respectively at 30 – 60 and 60 – 90 DAS) and biomass duration (259.18, 1009.48 and 2403.23 days, respectively at 0 – 30, 30 – 60 and 60 – 90 DAS) were recorded with N6, while greater relative growth rate (1.86 and 1.20 g/g/day × 10-2, respectively at 30 – 60 DAS and 60 – 90 DAS) and leaf area ratio (2616.15, 2206.54 and 1723.31 cm2/g × 10-2, respectively at 30, 60 and 90 DAS) were found with N1. The interaction between spacing and organic nutrient levels did not yield any significant differences with respect to absolute growth rate, biomass duration, relative growth rate and leaf area ratio.

Evaluating the Varied Impacts of Conventional Versus Nano Fertilizers on Soil Nutrient Levels, Utilization Efficiency and Biological Activity in Acidic Soil

A two-season field experiment was conducted at zonal agricultural research station, GKVK, Bengaluru during Kharif season in 2021 and 2022 with test a crop sunflower. The soil was sandy loam (Alfisol) in texture and experiment was laid out in RCBD with 3 replications and comprised of 14 treatments. Results revealed that the available soil nutrients like nitrogen (307.25 kg ha-1), sulphur (13.28 mg kg-1) and zinc (1.23 mg kg-1) content differed significantly, with treatment T2 (Package of practice). However, all other major, secondary and micro nutrients did not vary significantly. Nutrients use efficiency of nitrogen (72.01 kg kg-1), phosphorus (26.47 kg kg-1) and potassium (35.29 kg kg-1) were recorded higher with nano fertilizers than conventional one. Urease activity (22.42 µg NH4-N g-1 hr-1) was found to be significantly higher in treatment T2 (Package of practice) and enzyme activity like dehydrogenase activity and acid phosphatase activity not significantly varied, the numerical difference was regulated by pH of soil. Combination of conventional and nano fertilizers can be effectively utilized in enhancing the nutrients use efficiency while sustainably managing the soil properties.

Effect of Chemical Weed Management Practices on Weed Dynamics, Soil Microorganism and Nutrient Uptake in Blackgram [Vigna mungo (L.)

An investigation was carried out at Zonal Agricultural Research Station, Kalaburagi, India, University of Agricultural Sciences, Raichur, Karnataka, India during kharif 2021-22 to study the effect of pre and post emergent application of weedicides on seed yield, weed dynamics, microbial population and nutrient uptake by weeds in blackgram. The results revealed that, significantly lower weed density (grassy weeds, sedges and broad leaf weeds (0.71) and weed dry weight (0.71) was observed with hand weeding at 25-30 DAS and intercultivation at 45 DAS (control) followed by sodium acifluorfen 16.5% + clodinafop propargyl 8% EC @ 1.0 kg a.i. ha-1 at 20-25 DAS [grassy weeds (1.08, 1.26 and 1.83) sedges (1.03, 1.57 and 1.47) and broad leaf weeds (1.72, 2.06 and 2.11 at 25, 50 DAS and at harvest respectively]. Weed control efficiency was significantly higher with sodium acifluorfen 16.5% + clodinafop propargyl 8% EC @ 1.0 kg a.i. ha-1 at 20-25 DAS (89.52, 90.31 and 91.17 at 25, 50 DAS and at harvest respectively) that was on par with hand weeding. Hand weeding at 25-30 DAS and intercultivation at 45 DAS recorded significantly higher population of bacteria, fungi and actinomycetes (13.82, 12.49 and 5.25 cfu x 106 g-1 soil respectively). All chemical weedicides applied either pre-emergent or post-emergent significantly reduced population of total bacteria, fungi, actinomycetes. Significantly higher nutrient uptake by weeds was recorded with weedy check (71.03, 32.00 and 56.67 kg ha-1 nitrogen, phosphorus and potassium respectively). Where as, higher nutrient uptake by blackgram was with hand weeding at 25-30 DAS and intercultivation at 45 DAS (126.25, 28.20 and 109.30 kg ha-1 nitrogen, phosphorus and potassium respectively). After the harvest, soil available nutrients status was higher with hand weeding at 25-30 DAS and intercultivation at 45 DAS (141.38, 42.10 and 298.53 kg ha-1 nitrogen, phosphorus and potassium respectively) and significantly lower nutrients were observed with weedy check (122.93, 30.17 and 220.10 kg ha-1 nitrogen, phosphorus and potassium respectively).