18 research outputs found
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Not AvailableThe rainfed lowland rice ecosystem is affected by not only water deficit but also excess water. Although
the rice plant is well adapted to aquatic environments, itis unable to survive if it is completely submerged
in water for an extended period. The impact of submergence on survival, chlorophyll, photosynthesis,
post-recovery growth and anti-oxidant capacities in four rice cultivars namely IR 64, IR 64-Sub1, Swarna
and Swarna-Sub1 having differential response to potassium application were examined. All the cultivars
showed inhibition of photosynthesis, this was accompanied with decrease in stomatal conductance,
chlorophyll and carbohydrate contents; the decrease was more pronounced in non-sub1 cultivars. The
activity of anti-oxidants was found to be significantly high and lipid peroxidation was low in
sub1 cultivars. Potassium application improved the survival mainly because of maintenance of
carbohydrates, chlorophyll and contributing to less lodging and leaf senescence. Furthermore, K
application resulted in inhibition of lipid peroxidation and increase in catalase and Peroxidase activities.
Potassium at higher levels was more beneficial in terms of improving survival, photosynthesis and
growth after recovery. The germplasm improvement is beneficial if provided with best management
practices, modification in plant nutrition by K application enhance the survival, recovery and growth of
rice during complete submergence.ICA
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Not AvailableEffects of different fertilizers and manure on dynamics of soil organic carbon (SOC) and nitrogen fractions and their stock changes remains unclear under intensively cultivated rice soil profile. Profile soil samples in six treatments viz. control, nitrogen (N), nitrogen-phosphorus-potassium (NPK), farm yard manure (FYM), N + FYM and NPK + FYM were collected from a long term fertilizer experiment continuing since 1969 at ICAR-NRRI, Cuttack, India to study the soil organic carbon and nitrogen fractions (particulate organic carbon, POC; microbial biomass carbon, MBC; particulate organic nitrogen, PON; and microbial biomass nitrogen, MBN) and SOC sequestration. Results from the study revealed that in the control treatment, where no manure or chemical fertilizer was applied,the bulk density was highest. Balanced fertilization and combined use of chemical fertilizers and manure for 41 years increased the SOC in all the plots except the unfertilized control as compared with the initial value (6.6 g/kg). Balanced fertilization (NPK) and integrated fertilization (NPK + FYM) resulted in similar increases in particulate organic carbon, carbon mineralization and microbial biomass carbon, whereas particulate organic nitrogen, nitrogen mineralization and microbial biomass nitrogen were more in integrated fertilization (NPK + FYM) compared with control treatment. Soil organic C and nitrogen stocks changed positively across the fertilizer and manure treatments over the control. In the control plot, at 0–15 cm depth the soil carbon and nitrogen stock was 15.1 and 1.77 Mg ha−1, respectively which increased to the 19.5 Mg ha−1 in NPK + FYM for carbon and 2.25 Mg ha−1 in N + FYM for nitrogen. As compared to the initial (13.7 Mg ha−1), the SOC stock in 0–15 cm depth increased under all the fertilized treatments during 41 year period in the order: NPK + FYM > N + FYM > NPK > FYM > N > control. The rate of increase in SOC (carbon sequestration) due to fertilizer application alone varied between 57 and 89 kg ha−1 yr−1, while for FYM addition the rate of increase was 61 to 138 kg ha−1 yr−1, highest being in NPK + FYM. Correlation coefficients between different soil organic C and N fractions indicate differential accumulation pattern of organic C and nitrogen in different depths. Based on crop yield and C storage, integrated fertilization of chemical fertilizers and manure proved to be the best for improving crop productivity and SOC sequestration.ICA
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Not AvailableIn this paper an attempt has been made to quantify and test whether rice cultivation in adjoining areas
of mangrove forest by cutting forest tress has brought about significant changes in physicochemical,
microbial and enzymatic properties of soils of the mangrove ecosystem. We collected 48 soil samples
(24 pairs). We collected paired soil samples from each location, i.e., one soil sample from mangrove
forest and its paired soil sample from adjacent rice fields. Various soil physicochemical, microbial and
enzymatic properties were analyzed. Total soil organic carbon (TOC), available potassium and Bray P
were significantly higher in soils of mangrove forest than soils of cultivated rice fields. Soil pH was in
the acidic range at all locations, but was moderated towards neutral in mangrove soils. DTPA extractable
concentrations of soil micronutrients (Zn, Mn) were significantly higher under the soils of mangrove
than soils under cultivated rice fields. Enzymatic activities (Dehydrogenase, Urease, FDA hydrolysis, Acid
Phosphatase) in soils of mangrove forests exceeded than under cultivated rice fields except for acid
phosphatase activity which had higher activity in soils of cultivated rice fields. Populations of ammonium
oxidizer and nitrite oxidizer were higher in mangrove soils, whereas populations of aerobic hetreotrophs
were higher in cultivated rice fields compared to mangrove soils. The study provides a soil quality index
based on soil physico-chemical and microbiological properties. This index is a function of the eight soil
parameters, which showed the greatest weight in the factorial analysis made with all the parameters
analysed. The value of the soil quality index was higher in mangrove soils compared to soils of rice fields
at all the four locations of sampling indicating the adverse effect of rice cultivation around the mangrove
forests.ICA
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Not AvailableThe stability of enzymes in soil has been attributed to enzyme association with organic matter and the
protection provided within soil aggregates. Enzymes namely urease, amidase and protease significantly
affects nitrogen (N) mineralization and their assessment is crucial to study the nutrient cycling. Therefore,
the objective of this study was to evaluate the hypothesis that the long-term application of farmyard manure
(FYM) and inorganic fertilizers (N-nitrogen; P-phosphorus; K-potassium) impact the distribution pattern of
enzymes namely, urease, amidase and protease in different fractions of water stable soil aggregates, and
whole soil at 0-15 cm and 15-30 cm soil depth. The treatments comprised of unfertilized control and
different combinations of inorganic fertilizers and FYM viz. control, N, NP, NK, NPK, FYM, FYM+N,
FYM+NP, FYM+NK and FYM+NPK. A significant difference in soil aggregate size distribution was
observed at two sampling depths. Total water stable aggregates (WSA) ranged between 69.8-91.2% in
which 0.1-0.053 mm aggregate fraction contributed (2.11-3.87%), whereas 0.25-0.5 mm aggregate fraction
was having the highest (27.3-32.6%) contribution. The activities of three enzymes in whole soil as well in
aggregate fractions were lowest in control and highest in FYM+NPK except for amidase, which was having
highest activity in FYM alone treatment. Activities of all the three enzymes were highest in aggregate
fraction of 5-2 mm. Activities of three enzymes in whole soil as well as in aggregate fractions were lower
at 15-30 cm compared to 0-15 cm soil depth. It may be concluded from this study that long-term addition of
FYM alone or in combination with inorganic fertilizer increases the macroaggregate (5-2 mm) and hence
the overall activities of N mineralization enzymes.ICA
Not Available
Not AvailableThe stability of enzymes in soil has been attributed to enzyme association with organic matter and the protection provided within soil aggregates. Enzymes namely urease, amidase and protease significantly affects nitrogen (N) mineralization and their assessment is crucial to study the nutrient cycling. Therefore, the objective of this study was to evaluate the hypothesis that the long-term application of farmyard manure (FYM) and inorganic fertilizers (N-nitrogen; P-phosphorus; K-potassium) impact the distribution pattern of enzymes namely, urease, amidase and protease in different fractions of water stable soil aggregates, and whole soil at 0–15 cm and 15–30 cm soil depth. The treatments comprised of unfertilized control and different combinations of inorganic fertilizers and FYM viz. control, N, NP, NK, NPK, FYM, FYM+N, FYM+NP, FYM+NK and FYM+NPK. A significant difference in soil aggregate size distribution was observed at two sampling depths. Total water stable aggregates (WSA) ranged between 69.8–91.2% in which 0.1–0.053 mm aggregate fraction contributed (2.11–3.87%), whereas 0.25–0.5 mm aggregate fraction was having the highest (27.3–32.6%) contribution. The activities of three enzymes in whole soil as well in aggregate fractions were lowest in control and highest in FYM+NPK except for amidase, which was having highest activity in FYM alone treatment. Activities of all the three enzymes were highest in aggregate fraction of 5–2 mm. Activities of three enzymes in whole soil as well as in aggregate fractions were lower at 15–30 cm compared to 0–15 cm soil depth. It may be concluded from this study that long-term addition of FYM alone or in combination with inorganic fertilizer increases the macroaggregate (5–2 mm) and hence the overall activities of N mineralization enzymes.ICA
Evaluation of Digital Auscultation to Diagnose Pneumonia in Children 2 to 35 Months of Age in a Clinical Setting in Kathmandu, Nepal: A Prospective Case-Control Study
Objective The objective of this study was to determine the diagnostic validity of digital chest auscultation to improve the differentiation of chest sounds associated with pneumonia in children. Methods This is a prospective case-control study at two hospitals in Nepal. Cases had World Health Organization-defined pneumonia and were classified as radiologically confirmed or nonconfirmed based on radiographic findings. Controls had no respiratory complaints. The presence of crepitations in recorded lung sounds defined pneumonia. Radiologically confirmed pneumonia was the reference standard. Results Sensitivity and specificity of digital auscultation were 56% (95% confidence interval [CI], 40-70%) and 73% (95% CI, 70-76%), respectively. Conclusion Digital auscultation in conjunction with standardized grading of digital lung sounds has the potential to improve the specificity of pneumonia diagnosis, but further development of objective interpretation of lung sounds is needed