•Weed shift and diversity response to conservation agriculture was examined. •Tillage influenced weed flora more than crop residues in rainfed conditions. •Density of Cyperus spp decreased in zero ...tillage but Bulbosylis barbata increased. •Higher weed diversity, species richness and evenness index were observed in ZT. •Inter-annual rainfall variability is important factor influencing weed diversity.
Conservation agriculture (CA) is an alternative sustainable production system to conventional tillage system for resource conservation in rainfed agriculture. Weeds are the major constraints for adoption of CA in rainfed regions. A seven years study was done at ICAR- Central Research Institute for Dryland Agriculture (CRIDA), Hyderabad, India, to study the effects of different tillage practices and residue levels on weed shift, diversity and crop yields. It was observed that annual weed species were dominant in conventional tillage (CT) and reduced tillage (RT), whereas a shift towards perennials was observed in zero tillage (ZT). The CT recorded significantly lower weed density and weed biomass (12.89 m−2 and 35.60 g m−2) over RT (17.33 m−2 and 38.37 g m−2) and ZT (36.67 m−2 and 69.58 g m−2) after seven years, respectively. A shift in weed species, higher weed density and weed biomass in dicots (Tridax procumbens L and Euphorbia hirta L. and a marginal decrease in monocots (Bulbostylis barbata, Digitaria sanguinalis L) was observed in ZT. The marginal decrease in monocots was due to higher precipitation immediately after herbicide application which reduced the control of weeds due to leaching. The anchored residues 10 and 30 cm recorded lower monocots and total weed count over No residue. The study suggests that integrated weed management (combination of herbicide and removal of chance weeds) and in RT are efficient strategies to minimise the weed infestation in CA and these methods not only reduce the over reliance on herbicides but also improve the productivity of pigeon pea (Cajanus cajan L.), castor (Ricinus communis) and the environmental performance of CA. ZT and RT recorded the highest Shannon index, Pieloús evenness index and species richness over CT which indicates a higher weed species diversity in ZT as compared to CT. This study helps to improve the understanding of crop–weed communities and in the development of cost effective environmentally sound weed management strategies.
Soil organic matter dynamics in terrestrial ecosystems are controlled by complex interactions between various factors such as climate, soil, and agricultural management practices. We utilized a ...process-based crop model, APSIM, to simulate long-term soil organic carbon (SOC) dynamics for a soybean-wheat cropping system under nitrogen (N) and farmyard manure management (FYM) practices for a 43-year old experimental dataset in India. The APSIM was parameterized and validated to predict grain yield and SOC stock. The validated model was then used to evaluate the impacts of different management practices on SOC dynamics in the top 30 cm of soil through scenario modeling. The results of the APSIM simulations demonstrated that improved N and FYM management practices had great potential to increase SOC sequestration in these Vertisols. The equilibrium SOC concentration under different N management practices increased with a higher N application rate, with the integrated application of N with FYM showing the maximum rate. The optimum N (Nopt) rate for maximum SOC sequestration was estimated to be 155 kg ha−1 for wheat in the studied Vertisol and the time to reach steady-state of the site was 104 years. The Nopt increased SOC by about 28.6% over the initial concentration. We found that the APSIM was robust in predicting long-term changes in SOC stock (Index of agreement = 0.79 and root mean square error = 3.33 Mg ha−1, R2 = 0.92, mean bias error = −1.08) for a Vertisol soil of central India, in this case under a soybean-wheat cropping system. The study results highlighted that balanced fertilization is the key to sustaining SOC stock in the long-term for Vertisols.
•Fortythree years of measured SOC stock was satisfactorily simulated by the APSIM model.•Time to reach steady state of SOC stock varied from 37 to 104 years under different N management.•Maximum SOC saturation value of 48.65 Mg ha−1 was obtained in integrated nutrient management involving farmyard manure.•Optimum N application rate for maximum soil C sequestration was 155 kg N ha−1 for wheat and 20 kg N ha−1 for soybean.
Summary
Objective Warangal district in Andhra Pradesh, southern India, records >1000 pesticide poisoning cases each year and hundreds of deaths. We aimed to describe their frequency and ...distribution, and to assess quality of management and subsequent outcomes from pesticide poisoning in one large hospital in the district.
Methods We reviewed data on all patients admitted with pesticide poisoning to a district government hospital for the years 1997 to 2002. For 2002, details of the particular pesticide ingested and management were ed from the medical files.
Findings During these 6 years, 8040 patients were admitted to the hospital with pesticide poisoning. The overall case fatality ratio was 22.6%. More detailed data from 2002 revealed that two‐thirds of the patients were <30 years old, 57% were male and 96% had intentionally poisoned themselves. Two compounds, monocrotophos and endosulfan, accounted for the majority of deaths with known pesticides in 2002. Low fixed‐dose regimens were used in the majority of cases for the most commonly used antidotes (atropine and pralidoxime). Inappropriate antidotes were also used in some patients.
Conclusions It is likely that these findings reflect the situation in many rural hospitals of the Asia Pacific region. Even without an increase in resources, there appear to be significant opportunities for reducing mortality by better medical management and further restrictions on the most toxic pesticides.
The present work investigates the optimum machining parameters while turning EN 8 steel by employing hybrid Grey relational analysis (GRA) and principal component analysis (PCA) techniques. ...Experiments were designed based on the central composite design (CCD) of the Response surface method (RSM). Experiments were conducted by varying machining parameters such as cutting speed, feed, and depth of cut. In this study, the surface roughness and the material removal rate (MRR) are measured during the experimentation. To determine the influence of cutting parameters, an Analysis of variance (ANOVA) was deployed. The optimal turning parameters are found to be speed 1170 rpm, feed 0.225 mm/rev, and depth of cut 1.238 mm. The results revealed that the optimization through hybrid GRA-PCA enhanced the output quality characteristics.
Structural and elastic properties have been investigated for a series of heat treated Ni
x
Cu
0.1
Zn
0.9−
x
Fe
2
O
4
(
x
= 0.5, 0.6, 0.7) nanoferrite powders which were synthesized using ...co-precipitation method. Rietveld refinement patterns revealed the spinel phase belonging to
fd3m
space group. Lattice parameters of the heat treated samples are in the range of (8.453–8.417 Å). As the substitution level of Ni
2+
increased, the lattice parameter decreased in the samples sintered at 200 °C, but it was randomly varied in the in the samples sintered at 500 °C. The average crystallite size (4.1–10.9 nm) estimated from XRD as well as average particle size (5.5–11.3 nm) estimated from FE-SEM were found to be increased with the increase of Ni
2+
ion concentration in sintered ferrite samples. Sintering process was promoting the growth of nanoparticle size. The spherical nature of ferrite nanoparticles was evident from the FE-SEM micrographs. The vibrational bands observed in the FTIR spectra confirm the cubic spinel phase of ferrite systems. The variation of vibrational bands seems to be dependent on the particular metal ion occupying the spinel structure rather than the changes in bond lengths of Fe
3+
–O
2−
ion complexes. The present values of elastic moduli revealed the mechanical hardness of present heat treated ferrite samples. Interestingly, the elastic moduli depend upon the variation of both inter-atomic distances as well as cation redistribution. The identical value of Poisson’s ratio (0.35) is an authentication of isotropic behaviour of the present ferrite systems.
Nd3+ doped lead alumino silicate glasses with varying concentration of Al2O3 (from 5 to 10mol%) have been synthesized. The IR and Raman spectral studies of these glasses have indicated that there is ...a gradual increase in the depolymerization of the glass network with increase in the concentration of Al2O3. The optical absorption, luminescence spectra and fluorescence decay curves of these glasses were recorded at room temperature. From these studies, the radiative parameters viz., spontaneous emission probability A, the total emission probability, the radiative lifetime τ, the fluorescent branching ratio β of different transitions originated from 4F3/2 level of Nd3+ ions have been evaluated. A clear increase in the quantum efficiency and luminescence emission of the two prominent NIR bands of Nd3+ ions viz., 4F3/2→4I11/2, 13/2, is observed with increase in the concentration of Al2O3. The increase has been attributed to the possible admixing of wavefunctions of opposite parities and due to the declusterization of Nd3+ ions by Al3+ ions in the glass network.
Polyaniline-sulfate salt was used as an efficient catalyst for the preparation of benzodiazepines and 2-phenyl benzimidazoles in excellent yields. This method is applicable for the reaction of ...phenylenediamine with cyclic or acyclic ketones or aromatic aldehydes. The salient features of the present methodology are cheaper process, easy synthesis of stable catalyst, versatility and in addition, the catalyst can be easily recovered after completion of the reaction and reusable without affecting its activity.
•Pure and Ag substituted CoFe2O4 were synthesized successfully.•The crystallite sizes of the synthesized and annealed powders are in the range of 24–41 nm.•The highest value of Ms (60 emu/g) was ...reported for CoFe2O4 with the coercivity value 1358 Oe.•The present cobalt and Ag doped cobalt ferrite nanoparticles are showing good antibacterial activities.
Pure and Ag substituted cobalt ferrite nanoparticles (NPs) having the composition (1−x)CoFe2O4: xAg (x = 0.0, 0.2) were synthesized by a novel honey assisted combustion method in order to investigate their structural and magnetic properties along with their antibacterial activity. XRD patters confirm the spinel phase of CoFe2O4 and the presence of silver (Ag) nanoparticles in the spinel network. The incorporation of Ag in CoFe2O4 spinel structure enhanced the size of the unit cell, resulting to higher value of lattice parameter (a) compared to the pure CoFe2O4. The sintering process promoted the growth of the crystallite sizes (D). The crystallite sizes of the synthesized and annealed powders were found in the range of 24–41 nm. From the EDX studies, it seemed that the distribution of Ag nanoparticles was non-uniform. The saturation magnetization (Ms) and coercivity (Hc) of the powders were influenced by annealing as well as with the substitution of Ag. The highest value of saturation magnetization (60 emu/g) was obtained by the CoFe2O4 nanoparticles with the coercivity value 1358 Oe. The saturation magnetization and coercivity of Ag doped CoFe2O4 were less than that of pure CoFe2O4. The present cobalt ferrite nanoparticles and Ag doped cobalt ferrite nanoparticles have shown good antibacterial activities. But Ag doped cobalt ferrite nanoparticles seems to be the potential candidates for effective antibacterial activity. The structural and magnetic results along with the results of antibacterial activities are reported in the present manuscript.
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