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Soil properties from termite mounds (Odontotermes obesus) (TM for termite mound and EROD for the soil eroded from TM) and the soil at different soil depths. Sampling was done in the Mule Hole watershed, Karnataka, India. Soil properties... more
Soil properties from termite mounds (Odontotermes obesus) (TM for termite mound and EROD for the soil eroded from TM) and the soil at different soil depths. Sampling was done in the Mule Hole watershed, Karnataka, India. Soil properties are: % of C, N, clay, silt and sand, CEC, exchangeable cations (Ca, Mg, Na, K, Fe, Al), soil pH, amount of Feo, Fed, SiO2, Al2O3, Fe2O3, Si:Al ratio, Ki (SiO2/Al2O3) and Kr indicators (SiO2/(Al2O3+Fe2O3), clay mineralogy (% of smectite, talc, kaolinite, smectite, interstratified Illite-smectite and illite) and Si pools (Sicc and Siaa).
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The persistence and degradation of propineb was studied in rice plant, straw, grain and soil following application of propineb at two different doses (700 g a.i. ha−1 and 1400 g a.i. ha−1) and at 20 and 30 d after transplanting (DAT). The... more
The persistence and degradation of propineb was studied in rice plant, straw, grain and soil following application of propineb at two different doses (700 g a.i. ha−1 and 1400 g a.i. ha−1) and at 20 and 30 d after transplanting (DAT). The initial deposits of propineb residues ranged from 21.69 to 58.9 μg g−1 and more than 80% of propineb residue was dissipated within 7 d irrespective of dose and crop stage. The dissipation of propineb residues followed first order reaction kinetics. Propineb residues on rice leaves dissipated with a half-life of 2.0 and 2.3 d when applied at 20 DAT and 1.2 and 1.6 d when applied at 30 DAT at the dose rates of 700 and 1400 g a.i. ha−1 respectively. The propineb residues were found below Limit of Quantification (LOQ) of 0.19 μg g−1 in the rice straw, grains, husk and soil samples collected at harvesting time.
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An investigation was conducted to study, the status of cadmium and silicon in rice soils from different agro-climatic zones of Karnataka, variation among rice genotypes in cadmium uptake as influenced by silicon application in soil and... more
An investigation was conducted to study, the status of cadmium and silicon in rice soils from different agro-climatic zones of Karnataka, variation among rice genotypes in cadmium uptake as influenced by silicon application in soil and the effect of silicon and cadmium on growth, yield and uptake in rice and availability in soil. The study revealed that the DTPA extractable cadmium in paddy soil in the eight zones surveyed ranged between 0.006 to 0.088 ppm. Under the influence of silicon, cadmium effect on growth inhibition, shoot cadmium content, and translocation factor was reduced to the maximum extent in IR38064 than in the genotype KRH-2. The cadmium accumulated in the roots of the plants treated with both silicon and cadmium was higher than that in roots of the plants treated with cadmium alone. The translocation factor of cadmium in rice decreased with the application of silicon in soil. The uptake of cadmium by rice in the pots maintained under field capacity moisture regime...
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The persistence of chlorpyrifos in the cured tobacco leaves was studied following foliar applications of chlorpyrifos (40 EC) @ 64 g ai ha−1. The levels of chlorpyrifos residue in cured tobacco leaves increased with increase in the number... more
The persistence of chlorpyrifos in the cured tobacco leaves was studied following foliar applications of chlorpyrifos (40 EC) @ 64 g ai ha−1. The levels of chlorpyrifos residue in cured tobacco leaves increased with increase in the number of foliar applications of chlorpyrifos and pickings performed with closer interval of application. The residues of chlorpyrifos in cured tobacco leaves persisted beyond 47 days for single spray, 33 days for two sprays, 12 days after three sprays of tobacco planting. However, no residues of chlorpyrifos were detected (< 0.005 μg g−1) in the fifth picking except fourth treatment (0.095 μg g−1). The level of chlorpyrifos residues in cured tobacco leaves collected from different auction platforms of Karnataka was below detectable (< 0.01 μg g−1).
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Phytoliths are composed of 66 to 91% SiO2 and 1 to 6% organic carbon (C) known as phytolith occluded carbon (PhytOC). PhytOC is critical for long-term C storage in the agroecosystem. A field experiment was carried out to investigate the... more
Phytoliths are composed of 66 to 91% SiO2 and 1 to 6% organic carbon (C) known as phytolith occluded carbon (PhytOC). PhytOC is critical for long-term C storage in the agroecosystem. A field experiment was carried out to investigate the effect of three different sources of exogenous Si, i.e., diatomaceous earth (DE), silicic acid (SA) and rice husk biochar (RHB) on 1) plant phytolith, C content in phytolith and PhytOC content in different rice organs; 2) relationship between plant phytolith, C content in phytolith, PhytOC content, and soil properties (soil physicochemical properties and readily soluble silicon pools). Different Si sources produced significantly higher phytolith, PhytOC content, and readily soluble Si pools (CCSi, AASi, and ASi) than the control (RDF), with treatment receiving 4 t RHB ha-1 outperforming the other treatments. Phytolith and PhytOC production were found to be significantly correlated to soil organic carbon (OC), available nitrogen (N) and potassium (K),...
Fall armyworm (FAW) Spodoptera frugiperda is currently being considered as a serious insect pest in maize that causes significant yield losses worldwide. Silicon (Si) and plant growth regulators (PGRs) are known to induce resistance... more
Fall armyworm (FAW) Spodoptera frugiperda is currently being considered as a serious insect pest in maize that causes significant yield losses worldwide. Silicon (Si) and plant growth regulators (PGRs) are known to induce resistance against biotic and abiotic stresses thereby enhancing the yield. This study was conducted to determine the influence of Si and PGRs on the incidence and damage of FAW on maize (Zea mays L.) under field condition. The experiment was conducted in both Kharif and Rabi seasons using a randomized complete block design with three replications and treatments. Various combinations of foliar silicic acid (FSA) and two PGRs such as gibberelic acid (GA3) and jasmonic acid (JA) were tested to study their effects on FAW incidence and maize yield. The application of FSA at 2mL/plant + GA3 at 0.5 mg/plant recorded the lowest number of larvae per plant (0.39 larva/plant) with the lowest damage score of 2.55 (Davis scale). The percent infestation was also low for the sam...
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Soil erosion is an inexorable process of land degradation affecting economy and environment of the region. Assessment of soil erosion is important for planning and implementing conservational practice in the affected region. In the... more
Soil erosion is an inexorable process of land degradation affecting economy and environment of the region. Assessment of soil erosion is important for planning and implementing conservational practice in the affected region. In the present study, Revised Universal Soil Loss Equation (RUSLE) integrated with remote sensing (RS) and Geographical Information System (GIS) were employed to estimate soil loss in Chatrigudda, a hillock located near Vani Vilasa Sagara Reservoir (VVS) in the central part of Karnataka, India. The RUSLE factors were obtained through pre-recorded meteorological data and data from field survey as well as from remote sensing. ESRI ArcGIS version 10.2 software was employed to delineate the windmill-established site of Vani Vilasa Sagara reservoir and digital elevation model (DEM) with 30 m resolution raster was used to develop the drainage and contour map through hydrology tool. The soil erosion map was created using the "Kriging method" in the GIS platfo...
Yellow gypsum (YG), a synthetic product from Linz-Donawitz slag containing high iron (Fe) (5.41%), zinc (Zn) (0.37%) and silicon (Si) (3.41%) can be used as a source of these nutrients along with calcium (Ca) and sulphur (S) for groundnut... more
Yellow gypsum (YG), a synthetic product from Linz-Donawitz slag containing high iron (Fe) (5.41%), zinc (Zn) (0.37%) and silicon (Si) (3.41%) can be used as a source of these nutrients along with calcium (Ca) and sulphur (S) for groundnut production. Three field experiments were conducted to know the effect of different rates (500 and 625 kg YG ha−1) and time of application (basal alone and basal + split) of YG on growth, yield and economic returns of groundnut, and micronutrient and Si availability and their uptake in comparison with basal application of 500 kg natural gypsum (NG) ha−1. Basal alone and basal + split application of YG significantly increased the growth, yield and economic returns of groundnut. Further, it increased the soil pH, availability of micronutrients, Si and their uptake by haulm and kernel of groundnut over NG. Irrespective of the location, YG application recorded higher plant available nutrient (PAN) coefficient of micronutrients, while NG application reco...
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Rhizodeposition from rice with or without biochar application
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Although silicon (Si) is not considered essential for growth and development, the addition of this element can enhance growth and increase the yield of rice (Savant et al 1997a, Takahashi 1995). Depletion of plant-available Si in the soil... more
Although silicon (Si) is not considered essential for growth and development, the addition of this element can enhance growth and increase the yield of rice (Savant et al 1997a, Takahashi 1995). Depletion of plant-available Si in the soil where rice is grown may ...
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The foliar nutrition of silicic acid is considered to be a novel approach in enhancing the performance of many crops worldwide. The present study aimed to assess if the foliar application of silicon (Si) could influence the performance of... more
The foliar nutrition of silicic acid is considered to be a novel approach in enhancing the performance of many crops worldwide. The present study aimed to assess if the foliar application of silicon (Si) could influence the performance of soybean varieties with distinct crop duration, MAUS-2 (long duration) and KBS-23 (short duration). Field experiments were conducted in two consecutive years (2016 and 2017) of varied rainfall with foliar application of silicic acid @ 2 and 4 mL L−1 for three and two sprays each. The results showed significant enhancement in the yield, seed quality (protein and oil content), and uptake of nutrients (N, P, K, Ca, Mg, S, and Si) by various parts viz., seed, husk, and haulm of both varieties with foliar nutrition of silicic acid. However, the short duration variety, KBS-23, responded well under low rainfall conditions (2016) with two sprays of foliar silicic acid @ 4 mL L−1 and MAUS-2 variety in the second season under higher rainfall (2017) with three...
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Plants’ ability to take up silicon from the soil, accumulate it within their tissues and then reincorporate it into the soil through litter creates an intricate network of feedback mechanisms in ecosystems. Here, we provide a concise... more
Plants’ ability to take up silicon from the soil, accumulate it within their tissues and then reincorporate it into the soil through litter creates an intricate network of feedback mechanisms in ecosystems. Here, we provide a concise review of silicon’s roles in soil chemistry and physics and in plant physiology and ecology, focusing on the processes that form these feedback mechanisms. Through this review and analysis, we demonstrate how this feedback network drives ecosystem processes and affects ecosystem functioning. Consequently, we show that Si uptake and accumulation by plants is involved in several ecosystem services like soil appropriation, biomass supply, and carbon sequestration. Considering the demand for food of an increasing global population and the challenges of climate change, a detailed understanding of the underlying processes of these ecosystem services is of prime importance. Silicon and its role in ecosystem functioning and services thus should be the main focu...
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Nitrogen (N) is an important component of rice cultivation system, especially where rice is grown under aerobic condition. This study examined the effects of Silicon (Si) and leaf colour chart (LCC) based N management on yield and N use... more
Nitrogen (N) is an important component of rice cultivation system, especially where rice is grown under aerobic condition. This study examined the effects of Silicon (Si) and leaf colour chart (LCC) based N management on yield and N use efficiency in aerobic rice. A field experiment was conducted during wet season 2008 in sandy loam soil at Bangalore-north with split plot design. The treatments consist four main plots viz., control (No N), 60 Kg N ha-1 (No basal + LCC-3), 90 Kg N ha-1 (Urea 30 Kg N ha-1 as basal + LCC-3) and 100 Kg N ha-1 as urea (RDF) and two sub plots viz., with (calcium silicate at 2 t ha-1) and without Si treated plots. Periodical LCC readings were taken and N was applied if the LCC value falls below the prescribed critical value. The results revealed that the highest grain yield was recorded with the application calcium silicate at 2 t ha-1 and with 90 Kg N ha-1 (Urea at 30 Kg N ha-1 as basal + LCC-3) and it was on par with 60 Kg N ha-1 (no basal + LCC-3) compa...
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Rice is the principal cereal crop in Asia, which accounts for about 90 % of the global production and consumption in rice. Aerobic method is a new concept of growing rice. It is a production system, which involves direct seeding and... more
Rice is the principal cereal crop in Asia, which accounts for about 90 % of the global production and consumption in rice. Aerobic method is a new concept of growing rice. It is a production system, which involves direct seeding and irrigation intermittently in contrast to the practices, such as raising nursery, puddling, transplantation and submergence. High grain yields can only be obtained when rice crop assimilates adequate amounts of N in the course of growing season (Bijay Singh et al., 2006). Methodology Field experiments were conducted during Kharif - 2008 and 2009 at eastern dry zone soils of Bengaluru, Karnataka, South India. The objective of the study was to know the effect of real-time nitrogen management by SPAD meter and leaf colour chart in aerobic rice. The soil was sandy loam in texture, slightly acidic (6.6) with medium organic carbon and available N content. Plant available Si content was low during both the seasons. Two seeds per hill of aerobic rice (BI-34) were...
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... Prakash, NB, Nagaraj, H., Guruswamy, KT, Vishwanatha, BN, Narayanaswamy, C., Gowda, NA, Vasuki, N. and Siddaramappa, R. 2007. ... 20. Prakash, NB, Nagaraj, H., Guruswamy, KT,Vishwanatha, BN, Narayanaswamy, C., Gowda, NA, Vasuki, N.... more
... Prakash, NB, Nagaraj, H., Guruswamy, KT, Vishwanatha, BN, Narayanaswamy, C., Gowda, NA, Vasuki, N. and Siddaramappa, R. 2007. ... 20. Prakash, NB, Nagaraj, H., Guruswamy, KT,Vishwanatha, BN, Narayanaswamy, C., Gowda, NA, Vasuki, N. and Siddaramappa, R. 2007. ...
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... Singh, KK, Singh, K., Ragevendra, S., Yogeshwar, S. and Singh, CS 2006. ... In tropical eco-regions of Srilanka and India, indica rice varieties may respond to Si application if Si content in straw is lower than 3.7% (Nair and Aiyer,... more
... Singh, KK, Singh, K., Ragevendra, S., Yogeshwar, S. and Singh, CS 2006. ... In tropical eco-regions of Srilanka and India, indica rice varieties may respond to Si application if Si content in straw is lower than 3.7% (Nair and Aiyer, 196818. Nair, PK and Aiyer, RS 1968. ...