Effects of Phosphorus and Carbofuran on the Growth and Nitrogen Fixation of Azolla pinnata and the Yield of Rice

1988 ◽  
Vol 24 (2) ◽  
pp. 183-189 ◽  
Author(s):  
D. P. Singh ◽  
P. K. Singh
Keyword(s):  
Grain Yield ◽  
Nitrogen Uptake ◽  
Dry Season ◽  
Rice Grain ◽  
Azolla Pinnata ◽  
Wet Season ◽  
Area Index ◽  
Nitrogen Yield ◽  
Matter Production ◽  
Dry Seasons

SUMMARYThe effects of phosphorus fertilizer and the insecticide carbofuran on the growth and N2-fixation of Azolla pinnata and on the growth, grain yield and nitrogen uptake of intercropped rice were examined in a wet and a dry season. Treatment with phosphorus or carbofuran increased the biomass of Azolla and the amount of nitrogen fixed (nitrogen yield) in both seasons, but the response was much better in the dry season. Azolla inoculation at 1.0 t ha−1 resulted in a greater bio mass and nitrogen yield than inoculation at 0.5 t ha−1. In the dry season, a combination of phosphorus and carbofuran enhanced the growth and N2-fixation of Azolla more than either treatment alone. Carbofuran treatment slowed the rate of decomposition of Azolla, particularly in the dry season. The plant height, leaf area index and dry matter production of rice at flowering time were increased in the plots treated with phosphorus or carbofuran in the wet season and these treatments increased rice grain yield and nitrogen uptake in both the wet and dry seasons.

Relative effects of Azolla pinnata and its combination with chemical nitrogen fertilizer on growth, yield and N uptake of rice

1986 ◽  
Vol 106 (1) ◽  
pp. 107-112 ◽  
Author(s):  
D. P. Singh ◽  
P. K. Singh
Keyword(s):  
Grain Yield ◽  
Field Experiments ◽  
N Uptake ◽  
Growth Yield ◽  
Azolla Pinnata ◽  
Wet Season ◽  
Rice Varieties ◽  
Area Index ◽  
Plant Parts ◽  
Matter Production

SUMMARYField experiments conducted during wet and dry seasons with Ratna and Jaya varieties of rice (Oryza sativa Linn.) indicated that the use of Azolla pinnata as fertilizer increased growth in terms of number of tillers, leaf area index, dry-matter production, grain yield, N uptake and its accumulation in different plant parts. Azolla incorporation before planting in addition to 30 kg N/ha produced higher grain yields of both the rice varieties than 60 kg N / h a during the two seasons, while Azolla grown as an intercrop with rice plus 30 kg N/ha was superior to the 60 kg N treatment in grain production of Jaya during the wet season. Azolla incorporation before planting and also once intercropped with rice produced more grain yield than 60 kg N during the wet season. Among Azolla treatments, Azolla twice intercropped with rice produced comparatively lower grain yield. Azolla application increased the number of panicles/m2, number of grains/panicle and reduced sterility during both seasons. The N uptake of the rice crop in the treatments of Azolla incorporation before planting or intercropped once with rice in combination with 30 kg N/ha was similar to that of the 60 kg N/ha whereas the treatment of Azolla incorporation before planting plus once intercropped was similar during the wet season only.

The efficacy of seasonal terrestrial water storage forecasts for predicting vegetation activity over Africa

2021 ◽  
Author(s):  
Benjamin I Cook ◽  
Kimberly Slinski ◽  
Christa Peters-Lidard ◽  
Amy McNally ◽  
Kristi Arsenault ◽  
...  
Keyword(s):  
Regression Model ◽  
Southern Africa ◽  
Water Storage ◽  
Dry Season ◽  
Forecast Skill ◽  
Terrestrial Water Storage ◽  
Wet Season ◽  
Area Index ◽  
Vegetation Activity ◽  
Terrestrial Water

AbstractTerrestrial water storage (TWS) provides important information on terrestrial hydroclimate and may have value for seasonal forecasting because of its strong persistence. We use the NASA Hydrological Forecast and Analysis System (NHyFAS) to investigate TWS forecast skill over Africa and assess its value for predicting vegetation activity from satellite estimates of leaf area index (LAI). Forecast skill is high over East and Southern Africa, extending up to 3–6 months in some cases, with more modest skill over West Africa. Highest skill generally occurs during the dry season or beginning of the wet season when TWS anomalies from the previous wet season are most likely to carry forward in time. In East Africa, this occurs prior to and during the transition into the spring “Long Rains” from January–March, while in Southern Africa this period of highest skill starts at the beginning of the dry season in April and extends through to the start of the wet season in October. TWS is highly and positively correlated with LAI, and a logistic regression model shows high cross-validation skill in predicting above or below normal LAI using TWS. Combining the LAI regression model with the NHyFAS forecasts, 1-month lead LAI predictions have high accuracy over East and Southern Africa, with reduced but significant skill at 3-month leads over smaller sub-regions. This highlights the potential value of TWS as an additional source of information for seasonal forecasts over Africa, with direct applications to some of the most vulnerable agricultural regions on the continent.

scholarly journals Fruiting phenology and consumption by birds in Ficus calyptroceras (Miq.) Miq. (Moraceae)

2002 ◽  
Vol 62 (2) ◽  
pp. 339-346 ◽  
Author(s):  
J. RAGUSA-NETTO
Keyword(s):  
Food Resource ◽  
Bird Species ◽  
Dry Season ◽  
Dry Forest ◽  
Wet Season ◽  
Frugivorous Birds ◽  
Fruiting Phenology ◽  
Dry Seasons ◽  
Seed Dispersers ◽  
Wet And Dry Seasons

Figs are a remarkable food resource to frugivores, mainly in periods of general fruit scarcity. Ficus calyptroceras Miq. (Moraceae) is the only fig species in a type of dry forest in western Brazil. In this study I examined the fruiting pattern as well as fig consumption by birds in F. calyptroceras. Although rainfall was highly seasonal, fruiting was aseasonal, since the monthly proportion of fruiting trees ranged from 4% to 14% (N = 50 trees). I recorded 22 bird species feeding on figs. In the wet season 20 bird species ate figs, while in the dry season 13 did. Parrots were the most important consumers. This group removed 72% and 40% of the figs consumed in the wet and dry seasons, respectively. No bird species increases fig consumption from dry to wet season. However, a group of bird species assumed as seed dispersers largely increases fig consumption from wet to dry season, suggesting the importance of this resource in the period of fruit scarcity. The results of this study points out the remarkable role that F. calyptroceras plays to frugivorous birds, in such a dry forest, since its fruits were widely consumed and were available all year round.

scholarly journals The economics of phosphorus supplementation of beef cattle grazing northern Australian rangelands

2020 ◽  
Vol 60 (5) ◽  
pp. 683
Author(s):  
M. K. Bowen ◽  
F. Chudleigh ◽  
R. M. Dixon ◽  
M. T. Sullivan ◽  
T. Schatz ◽  
...  
Keyword(s):  
Economic Benefits ◽  
Dry Season ◽  
Cattle Herd ◽  
Annual Business ◽  
Northern Australia ◽  
Wet Season ◽  
P Deficiency ◽  
Business Profit ◽  
Dry Seasons ◽  
Land Types

Context Phosphorus (P) deficiency occurs in beef cattle grazing many rangeland regions with low-P soils, including in northern Australia, and may severely reduce cattle productivity in terms of growth, reproductive efficiency and mortality. However, adoption of effective P supplementation by cattle producers in northern Australia is low. This is likely to be due to lack of information and understanding of the profitability of P supplementation where cattle are P-deficient. Aims The profitability of P supplementation was evaluated for two dissimilar regions of northern Australia, namely (1) the Katherine region of the Northern Territory, and (2) the Fitzroy Natural Resource Management (NRM) region of central Queensland. Methods Property-level, regionally relevant herd models were used to determine whole-of-business productivity and profitability over 30 years. The estimated costs and benefits of P supplementation were obtained from collation of experimental data and expert opinion of persons with extensive experience of the industry. The economic consequences of P supplementation at the property level were assessed by comparison of base production without P supplementation with the expected production of P-supplemented herds, and included the implementation phase and changes over time in herd structure. In the Katherine region, it was assumed that the entire cattle herd (breeders and growing cattle) grazed acutely P-deficient land types and the consequences of (1) no P supplementation, or P supplementation during (2) the dry season, or (3) both the wet and dry seasons (i.e. 3 scenarios) were evaluated. In the Fitzroy NRM region, it was assumed that only the breeders grazed P-deficient land types with three categories of P deficiency (marginal, deficient and acutely deficient), each with either (1) no P supplementation, or P supplementation during (2) the wet season, (3) the dry season, or (4) both the wet and dry seasons (i.e. 12 scenarios). Key results In the Katherine region, year-round P supplementation of the entire cattle herd (7400 adult equivalents) grazing acutely P-deficient pasture resulted in a large increase in annual business profit (+AU$500000). Supplementing with P (and N) only in the dry season increased annual business profit by +AU$200000. In the Fitzroy NRM region, P supplementation during any season of the breeder herd grazing deficient or acutely P-deficient pastures increased profit by +AU$2400–AU$45000/annum (total cattle herd 1500 adult equivalents). Importantly, P supplementation during the wet season-only resulted in the greatest increases in profit within each category of P deficiency, comprising +AU$5600, AU$6300 and AU$45000 additional profit per annum for marginal, deficient and acutely P-deficient herds respectively. Conclusions The large economic benefits of P supplementation for northern beef enterprises estimated in the present study substantiate the current industry recommendation that effective P supplementation is highly profitable when cattle are grazing P-deficient land types. Implications The contradiction of large economic benefits of P supplementation and the generally low adoption rates by the cattle industry in northern Australia suggests a need for targeted research and extension to identify the specific constraints to adoption, including potential high initial capital costs.

Effects of seasonal variation and locations on microbial load in sediment and water of a polluted ecosystem

2021 ◽  
Vol 36 (1) ◽  
pp. 93-105
Author(s):  
A.N. Okereke ◽  
J.C. Ike-Obasi
Keyword(s):  
Heterotrophic Bacteria ◽  
Standard Procedure ◽  
Dry Season ◽  
Microbial Load ◽  
Seasonal Effects ◽  
Wet Season ◽  
Different Seasons ◽  
Dry Seasons ◽  
Total Fungi ◽  
Hydrocarbon Utilizing Bacteria

Seasonal effects on microbial load of sediment and water at different locations along Bonny Estuary of Niger Delta was investigated for a period of 12 months. All analyses followed standard procedure. Results revealed that total fungi counts in sediment and water at different locations were not significantly different (p > 0.05) at both wet and dry seasons while hydrocarbon utilizing fungi showed significant differences (p < 0.05) at both seasons in both sediment and water samples. During the wet season, total faecal counts ranged from 5.0 to 10.0 x 105 CFU/g for sediment and 4.0 to 7.0x 105 CFU/g in water. In dry season, the concentration of hydrocarbon utilizing bacteria in the sediment ranged between 0.1 x 105 CFU/ml/g and 8.0 x 105 CFU/ml/g in wet season while in dry season, the concentration in water ranged between 0.1 x 105 CFU/ml/g and 6.0 x 105 CFU/ml/g at Abuloma. At Okwujagu, total heterotrophic bacteria counts in sediment ranged  from 0.1 to 8.0 x 105 CFU/g in dry season. This was higher than the range 0.1 to 6.8.0 x 105 CFU/ recorded in Abuloma, Okwujagu and Slaughter at dry season. The highest vibrio counts in water (11.0 x 105 CFU/ml) for wet and (10.0 x 105 CFU/ml) for dry seasons were recorded at Slaughter. In Oginiba, the feacal count recorded 3.0 x 105 CFU/ml in water during the wet season and 2.0 x 105 CFU/ml for dry season. Generally, there were significant differences (p < 0.05) in the bacterial concentrations in both sediment and water. This showed that different seasons favour the growth of certain microbial types.

Seasonal diet preferences of chital deer in the northern Queensland dry tropics, Australia

2020 ◽  
Vol 42 (3) ◽  
pp. 211
Author(s):  
Kurt Watter ◽  
Greg Baxter ◽  
Michael Brennan ◽  
Tony Pople ◽  
Peter Murray
Keyword(s):  
Dry Season ◽  
Wet Season ◽  
Variable Environment ◽  
Dry Tropics ◽  
Plant Groups ◽  
Axis Axis ◽  
Plant Group ◽  
Diet Preference ◽  
Dry Seasons

Chital deer (Axis axis) were introduced to the Burdekin dry tropics of north Queensland, Australia, in the late 1800s. Here rainfall and plant growth are highly seasonal and a nutritional bottleneck for grazing animals occurs annually before the wet season. This study describes the seasonal changes in diet and diet preference of chital in this seasonally-variable environment. Rumen samples were taken from 162 deer from two sites over the wet and dry seasons of two consecutive years and sorted macroscopically for identification. Relative seasonal availability of plant groups was estimated using step point sampling of areas grazed by chital. Chital alter their diet seasonally according to availability and plant phenology. Chital utilised 42 plant genera including grasses, forbs, subshrubs, shrubs, trees and litter. Grass consumption ranged from 53% of biomass intake during the dry season to 95% during the wet season. The predominance of grass in the wet season diet exceeded relative availability, indicating a strong preference. Although grass contributed more than half of the dry season diet it was the least preferred plant group, given availability, and the least actively growing. Shrubs were the preferred plant type in the dry season, and least subject to seasonal senescence. Composition and quantity of seasonal pastures vary markedly in north Queensland, and chital alter their diet by consuming those plants most actively growing. The increased dry season intake of non-grass forage appears to be a strategy to limit the detriment resulting from the progressive deterioration in the quality of grass.

Diversity, distribution and relative abundance of avifauna at Ansas Dam and surrounding farmland site Debre Berhan Town, Ethiopia

2020 ◽  
pp. 175815592096320
Author(s):  
Alemayehu Shiferaw ◽  
Dereje Yazezew
Keyword(s):  
Relative Abundance ◽  
Bird Species ◽  
Dry Season ◽  
Avian Species ◽  
Ordinal Scale ◽  
Line Transect ◽  
Wet Season ◽  
Debre Berhan ◽  
Dry Seasons ◽  
Wet And Dry Seasons

The diversity, distribution, and relative abundance of avifauna were studied at and Around Ansas Dam, Debre Berhan Town, Ethiopia, from early September 2018 to early February 2019, covering both wet and dry seasons. Line transect technique was employed to study the diversity, abundance and distribution of birds species in the farmland site while total count employed on the dam. Data were collected in both wet and dry seasons from 6:30 to10:00 early morning and 15:30 to 18.00 late afternoon, when birds are more active. The data were analyzed with Shannon-Weiner Index, Simpson Index, Evenness Index, and relative abundance. A total of 45 bird species (35 in the dam and 22 in the farmland) belonging to nine orders and 21 families were recorded during the study period. Order Passeriformes (37.8%) followed by order Charadriformes (24.4%) were represented highest number. From all identified species at Ansas Dam and surrounding farmland, Abyssinian longclaw, Black-headed siskins, White-tailed swallow, Blue-winged goose, and Spot-breasted lapwing were endemic birds to Ethiopia. The highest Shannon diversity (H′ = 2.1) was recorded in dam during the dry season while the lowest (H′ = 1.78) was recorded during wet season in farmland. However, the Simpson diversity Index of avian species indicated relatively higher avian species diversity during the dry season in dam (D = 0.80) than farmland (D = 0.71) habitat. Evenness was highest in the dam (E = 0.65) and lowest in the farmland (E = 0.58) habitat. More avian species similarity (SI = 0.42) at farmland and dam habitat during the wet season but least similarity (SI = 0.2) was observed during the dry season. Most birds had scored rare in the ordinal scale while few species with abundant and uncommon ranks in both habitats and seasons. Conservation of the different charismatic bird species should be taken as an important component of wildlife management plan in the area.

scholarly journals Numerical Assessments of Leaf Area Index in Tropical Savanna Rangelands, South Africa Using Landsat 8 OLI Derived Metrics and In-Situ Measurements

2019 ◽  
Vol 11 (7) ◽  
pp. 829 ◽  
Author(s):  
Timothy Dube ◽  
Santa Pandit ◽  
Cletah Shoko ◽  
Abel Ramoelo ◽  
Dominic Mazvimavi ◽  
...  
Keyword(s):  
South Africa ◽  
Leaf Area Index ◽  
Leaf Area ◽  
National Park ◽  
Dry Season ◽  
Kruger National Park ◽  
Landsat 8 ◽  
Tropical Savanna ◽  
Wet Season ◽  
Area Index

Knowledge on rangeland condition, productivity patterns and possible thresholds of potential concern, as well as the escalation of risks in the face of climate change and variability over savanna grasslands is essential for wildlife/livestock management purposes. The estimation of leaf area index (LAI) in tropical savanna ecosystems is therefore fundamental for the proper planning and management of this natural capital. In this study, we assess the spatio-temporal seasonal LAI dynamics (dry and wet seasons) as a proxy for rangeland condition and productivity in the Kruger National Park (KNP), South Africa. The 30 m Landsat 8 Operational Land Imager (OLI) spectral bands, derived vegetation indices and a non-parametric approach (i.e., random forest, RF) were used to assess dry and wet season LAI condition and variability in the KNP. The results showed that RF optimization enhanced the model performance in estimating LAI. Moderately high accuracies were observed for the dry season (R2 of 0.63–0.72 and average RMSE of 0.60 m2/m2) and wet season (0.62–0.63 and 0.79 m2/m2). Derived thematic maps demonstrated that the park had high LAI estimates during the wet season when compared to the dry season. On average, LAI estimates ranged between 3 and 7 m2/m2 during the wet season, whereas for the dry season most parts of the park had LAI estimates ranging between 0.00 and 3.5 m2/m2. The findings indicate that Kruger National Park had high levels of productivity during the wet season monitoring period. Overall, this work shows the unique potential of Landsat 8-derived metrics in assessing LAI as a proxy for tropical savanna rangelands productivity. The result is relevant for wildlife management and habitat assessment and monitoring.

Incidence of Salmonella on Beef Carcasses Relating to the U.S. Meat and Poultry Inspection Regulations

1999 ◽  
Vol 62 (5) ◽  
pp. 467-473 ◽  
Author(s):  
JOHN N. SOFOS ◽  
SHERRI L. KOCHEVAR ◽  
J. O. REAGAN ◽  
GARY C. SMITH
Keyword(s):  
Correlation Coefficients ◽  
Total Coliform ◽  
Dry Season ◽  
Wet Season ◽  
Regulatory Requirements ◽  
E Coli ◽  
Beef Carcasses ◽  
Plate Counts ◽  
Dry Seasons ◽  
The U.S

This article is part of a major study designed to collect baseline contamination data by sampling beef carcasses in seven slaughtering plants (four steer–heifer and three cow–bull plants) during both a dry season (November to January) and a wet season (May to June). Samples (n = 30) were excised from each of three carcass anatomical sites (brisket, flank, and rump) at each of three points in the slaughtering chain (pre-evisceration, following final carcass washing, after 24-h carcass chilling). A total of 3,780 samples (100 cm2 each) were analyzed for presence of Salmonella; aerobic plate counts, total coliform counts, and Escherichia coli counts were also made. After 24-h chilling, average incidence (expressed as a percentage) of Salmonella in the brisket, flank, and rump samples, respectively, for steer–heifer carcasses was 0.8 ± 1.7, 0, and 2.5 ± 5.0 for the wet season and 0.8 ± 1.7, 0, and 0 for the dry season; the corresponding percentages for cow–bull carcasses were 4.4 ± 2.0, 2.2 ± 3.9, and 1.1 ± 1.9 for the wet season and 2.2 ± 3.9, 1.1 ± 1.9, and 0 for the dry season. Depending on plant and season, ranges of probabilities of chilled steer–heifer carcasses passing the U.S. regulatory requirements for Salmonella contamination were 0.24 to 1.0 for the brisket, 1.0 for the flank, and 0.002 to 1.0 for the rump; the corresponding ranges for the chilled cow–bull carcasses were 0.25 to 1.0, 0.25 to 1.0, and 0.70 to 1.0. When the number of positive brisket, flank, and rump samples were combined, the probabilities of passing the regulatory requirements were 0.242 to 1.0 and 0.772 to 1.0 for the wet and dry seasons, respectively, in steer–heifer plants and 0.368 to 0.974 and 0.865 to 1.0 in cow–bull plants. Correlation coefficients of aerobic plate counts, total coliform counts, and E. coli counts with Salmonella incidence were higher (P ≤ 0.05) for cow–bull samples that had increased incidence of the pathogen when compared to steer–heifer samples.

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