Decomposition of biodegradable packing materials jute, Biopol, BAK and their composites in soil

We investigated the effects of the biodegradable polymers jute, Biopol and BAK 2195 and their composites on the mineralisation activity and biomass of microorganisms in soil and on the fungal component of the microbial community. Two different pre-treatments of jute were used to produce the composites, treatment of the fibres with sodium hydroxide (SH-jute) and co-polymerisation with acrylonitrile (AN-jute). All products tested were highly degradable, as indicated by the increase in CO₂ evolution after amendment. The additional amount of CO₂-C evolved after polymer incorporation into the soil corresponded to between 21% and 34% of the added C after 85 days incubation at 25°C. The extra CO₂-C evolved decreased in the order BAK > jute > Biopol. Composites of AN-jute were less mineralisable than those of SH-jute. Degradation of jute is characterised by a rapid increase, then a slow decline of microbial respiratory activity. In contrast, in the Biopol treatments, and especially in the BAK treatments, maximum CO₂ evolution rates occurred considerably later, indicating that the soil microorganisms needed some time to colonise the polymer particles. All polymers and composites tested increased the soil microbial biomass in the order jute h Biopol < BAK. The net increase in microbial biomass C was 3% of the added polymer C in the jute treatment, an average of 4% in the three Biopol treatments, and 7% in the three BAK treatments. The content of ergosterol, an indicator for fungal biomass, was also increased by all amendments, but the effect on ergosterol content was much more pronounced than on microbial biomass C.     

Nitrate leaching,nitrous oxide emission and N use efficiency of aerobic rice under different N application strategy

A field study was conducted in the sub-humid tropical region of India to examine the effect of different nitrogen (N) management strategies on nitrate leaching, nitrous oxide (N₂O) emission and N use efficiency in aerobic rice. Treatments were: control (no N), 120 kg N ha^?1 applied as prilled urea (PU) in conventional method, 120 kg N ha^?1 applied as neem coated urea (NCU) in conventional method, N applied as PU on the basis of leaf colour chart (LCC) reading, N applied as NCU on the basis of LCC reading, and 120 kg N ha^?1 applied as PU and farm yard manure (FYM) in 1:1 ratio. Results showed that 3.4–16.1 kg NO₃-N ha^?1 was leached below 45 cm depth and 0.61–1.12 kg N₂O-N ha^?1 was emitted from aerobic rice during the growing season. NCU when applied conventionally reduced nitrate-nitrogen (NO₃-N) leaching and N₂O emission by 18.6% and 21.4%, respectively However when applied on the basis of LCC reading NCU reduced NO₃-N leaching by 39.8% as compared to PU applied in conventional method. NCU when applied on the basis of LCC reading synchronized N supply with demand and reduced N loss, which resulted in higher yield and N use efficiency.     

Mechanical and thermal degradation behavior of sisal fiber (SF) reinforced recycled polypropylene (RPP) composites

The present investigation focuses on the effect of fiber surface treatment on the mechanical, thermal and morphological properties of sisal fiber (SF) reinforced recycled polypropylene (RPP) composites. The surface of sisal fiber was modified using different chemicals such as silane, glycidyl methacrylate (GMA) and O-hydroxybenzene diazonium chloride (OBDC) to improve the compatibility between fiber surface and polymer matrix. The experimental results revealed an improvement in the tensile strength to 11 %, 20 % and 31.36 % and impact strength to 78.72 %, 77 % and 81 % for silane, GMA and OBDC treated sisal fiber reinforced recycled polypropylene (RPP/SF) composites respectively as compared to RPP. The thermo gravimetric analysis (TGA), Differential scanning calorimeter (DSC) and heat deflection temperature (HDT) results revealed improved thermal stability as compared with RPP. The morphological analysis through scanning electron micrograph (SEM) supports improves surface interaction between fiber surface and polymer matrix.     

Water budgeting in a carp‐prawn polyculture system: impacts on production performance,water productivity and sediment stack

This study was designed to quantify the total water requirement and consumptive water use in carp‐prawn polyculture system under different water management protocols, using water balance model. Under different water management protocols, treatment‐wise estimated total water use, TWU (×10⁴, m³) was 3.7, 4.6 and 3.9, while the computed consumptive water use index, CWUI (m³ kg^?1 biomass) was 6.62, 9.31 and 7.08, in T₁ (no water exchange), T₂ (periodic water exchange) and T₃ (regulated water exchange) respectively. Significantly higher yield (P < 0.05) in both T₂ and T₃ over T₁, was probably due to water exchange that improved the rearing environment. Although intensity of water exchange was more in T₂, significant variation (P < 0.05) in overall growth and yield was not recorded between T₂ and T₃. Treatment‐wise sediment load ranged between 54.6 and 71.3 m³ t^?1 biomasses. Higher sediment load was recorded at lower intensity of water exchange as well as with higher apparent feed conversion ratio. Higher net total water productivity, net consumptive water productivity and OV‐CC ratio in T₃ infers that regulated water exchange has a distinct edge over the no water exchange protocol. Restricted water use instead of regular/excess water exchange not only improves the production performance and water productivity, but also helps in lessening the operational pumping cost.     

Glacial refugia: hotspots but not melting pots of genetic diversity

Glacial refuge areas are expected to harbor a large fraction of the intraspecific biodiversity of the temperate biota. To test this hypothesis, we studied chloroplast DNA variation in 22 widespread European trees and shrubs sampled in the same forests. Most species had genetically divergent populations in Mediterranean regions, especially those with low seed dispersal abilities. However, the genetically most diverse populations were not located in the south but at intermediate latitudes, a likely consequence of the admixture of divergent lineages colonizing the continent from separate refugia.     

Ethno-medico-biology of Bhadrak district, Odisha, India

We carried out an ethno-medico-biological investigation in the interior of Bhadrak district, Odisha, India to explore the therapeutic use of traditional plants/animals by local inhabitants. The villagers and rural people used plant and animal species as medicine. We recorded therapeutic use of 18 plant species of 13 families and 12 animal species of seven taxonomic categories. Different plant/animal parts like bark, leaf, flower, seed, stem, root, whole plant, oil, blood, milk, urine and flesh were reported as used in raw or cooked form against 17 specific diseases. Prominent diseases treated by plant/animal remedies were asthma, cardiovascular ailments, diabetes, epilepsy, jaundice, malaria, skin disorder and rheumatism. This study provides a better database for future studies.     

Effect of restricted feeding and refeeding on compensatory growth,nutrient utilization and gain,production performance and whole body composition of carp cultured in earthen pond

To assess the compensatory growth, a 10‐month pond experiment was conducted in which three species of Indian major carps, viz. Catla catla, Labeo rohita and Cirrhinus mrigala (1 : 1 : 1), were stocked at 7500 ha^?1 and the fish were subjected to different restricted feeding and refeeding protocols, viz. Control (C): Continuously fed for 10 months; Treatment‐1 (T‐1): Initial supplementary feeding for 2 months+ No supplementary feeding for 1 month + Refeeding for 7 months; Treatment‐2 (T‐2): Initial supplementary feeding for 2 months + No supplementary feeding for 2 months + Refeeding for 6 months; and Treatment‐3 (T‐3): Initial supplementary feeding for 2 months + No supplementary feeding for 3 months + Refeeding for 5 months in triplicate ponds. At the end of experiment, 100% growth compensation was achieved in T‐2 for all the three carp species. Among all treatments, higher weight gain, PER and PPV and lower AFCR were also recorded in T‐2, resulting in maximum fish production. The restricted feeding had significant effect (P < 0.05) on whole body chemical composition of fish. From this study, it is concluded that in 10‐month pond culture of carp in fertilized pond, the T‐2 would be the best and most economic feeding strategy.     

Replacement of by-catch fishmeal with dried chicken viscera meal in extruded feeds: effect on growth,nutrient utilisation and carcass composition of catfish <Emphasis Type="Italic">Clarias batrachus</Emphasis> (Linn.) fingerlings

An 84-day feeding trial was conducted to study the effect of replacing dietary fishmeal with dried chicken viscera meal (CVM) on the growth (net biomass gain, specific growth rate, SGR), feed acceptability, feed conversion ratio (FCR), protein efficiency ratio (PER) and carcass composition of Clarias batrachus fingerlings. Triplicate groups of fingerlings with mean initial body weight of 13.35 g were fed on six iso-nitrogenous and iso-lipidic diets. The control diet (CVM0) used marine by-catch fishmeal as the sole source of animal protein. In the other five diets (CVM100–CVM500), 20–100% of fishmeal was substituted by dried CVM at 20% increments. The highest body weight gain, SGR and PER, and the lowest FCR were observed in fish fed a diet containing 300–500 g CVM kg⁻¹. The fish accumulated increasing quantities of lipids and decreasing levels of ash in their carcasses with increasing levels of dietary CVM.