IMPACT OF GRAZING ON BOTANICAL COMPOSITION OF NATURAL HERBAGE AND SOIL CHARACTERISTICS

A long term (6 year) grazing experiment was conducted in a coconut plantation atHakmana, a farming village in the southern Sri Lanka, to observe the impact ofgrazing on botanical composition of natural herbage and soil characteristics. Thetreatments were ungrazed coconut land (UO), continous grazing of naturalherbage under coconut with out straw (0), 0 + rice straw adlibitum (OS) and OS+ supplements (OSS), with a density of 3 anirnals/ha in all the treatments.The changes in botanical composition at the end of the six-year period indicatedthat herbs were dominant in the UO treatment, with an increase of the productionof herbage with time, Euphatorium odoratun, Veronica cinera and Cyperuskyllingia were the most dominant species. The highest decrease in herbageproduction were seen in animals that were not given straw (0) and the declineworsened with time indicating overgrazing and soil erosion. In contrast the initialdecline in herbage yields gradually increased in OSS indicating a possibility of astocking rate greater than 3 animals/ha, considering the subjective observations ofthe ground cover in paddocks as well. Due to the changes in grazing pressure, thepercentage of prostate grass species (Axonopus compressus, axoopus aJJinis etc.)and leguminous species (Desmodium spp.) improved the ground cover in OSthrough ass. Hence straw and more significantly supplemented straw feedingimproved botanical composition and animal production per unit area whileincreasing the potential for soil conservation.Treatments had no significant effect on the soil bulk density up to the end of 6years and the water holding capacity up to the end of 3 years. By the end of 6years grazing cattle significantly increased the water holding capacity of the soilfrom G through OS to ass. Low inputs of resources available to farmers havethus produced increasing benefits with the passage of time and demonstrated thepotentials for the sustainability of a crop livestock integrated system

Staged cost optimization of urban storm drainage systems based on hydraulic performance in a changing environment

International audienceUrban flooding causes large economic losses, property damage and loss of lives. The impact of environmental changes mainly, the urbanization and the climatic change leads to increased runoff and increased peak flows which the drainage system must be able to cope with to overcome possible damage and inconveniences caused by the induced flooding. Allowing for detention storage to compliment the capacity of the drainage system network is one of the approaches to reduce urban floods. The traditional practice was to design systems against stationary environmental forcings ? including design rainfall, landuse, etc. Due to the rapid change in climate-environment, this approach is no longer economically viable and safe, and explicit consideration of changes that gradually take place during the life-time of the drainage system is warranted. In this paper, a staged cost optimization tool based on the hydraulic performance of the drainage system is presented. A one dimensional hydraulic model is used for hydraulic evaluation of the network together with a genetic algorithm based optimization tool to determine optimal intervention timings and amounts throughout the lifespan of the drainage network. The model was applied in a case study area in the city of Porto Alegre, Brazil. It was concluded that considerable financial savings and/or additional level of flood-safety can be achieved by approaching the design problem as a staged plan rather than one-off scheme

Factors associated with the level of inhibitory control in elderly people living in elderly care institutions in Galle District, Sri Lanka

Objectives: The proportion of elderly people living in institutions has increased in Sri Lanka duringthe recent decades as a result of population aging and ongoing sociocultural changes. Cognitivefunctions that are important for goal directed behavior will be increasingly important for independentliving. Inhibitory control of irrelevant information (IC) is such cognitive process vital for this. Hencethis study was conducted to assess the level of inhibitory control and associated factors among elderlypeople living in elderly care institutions in Galle District.Methods: Study was conducted in 190 elderly people living in institutions who are physicallyindependent with Barthel’s index score of more than 90. IC was assessed via computerized stroopinhibitory task. Number of errors was calculated to assess the level of inhibitory control. Groupdifferences were assessed through independent sample t test and significant level was kept at p<0.05.Results: The sample comprised of 69.5% (n=132) females with a mean age of 71.78 years (+6.5). Meannumber of errors of the stroop tasks was 8.88 (+3.99). The number of errors in the stroop inhibitory taskwas significantly lower among females (n=132, p<0.01) who have had above secondary education(n=33, p<0.05), who engaged in group (n=153, p<0.05) and leisure time activities (n=173, p<0.05) andwho were younger than 70 years of age (n=78, p<0.01).Conclusions: IC was significantly associated with age, educational status, gender, engagement in groupand leisure time activities among the study sample

Household willingness-to-pay (WTP) for a better waste management system An empirical investigation in the. Mawanella Pradeshiya Sabha region

The Mawanella Pradeshiya Sabha in the Kegalle district that serves to a population of 100,280 hasintroduced a novel approach to manage its waste under its "Increased Public Awareness &amp; LocalGovernment Capacity Building Program" in 2004. The key feature of this program was, educatingand encouraging households to collect and sort waste at its source, which was facilitated by distributionof plastic bags and waste bins with different colour codes designed for the purpose, and subsequently,treat the waste at specific dumping sites using the principles of recycling to produce marketableproducts. This study assesses the progress of this program, and in particular how much the householdsare WTP for continuation and advancement of the program, because the regulatory authorities insistthat it cannot run the program with taxpayers money for any longer time. A survey was conductedwith a help of a structured questionnaire with 120 households selected randomly to represent 31 %households joined to the pilot program in 2004. The WTP of each household was modeled with anumber of variables, includ ing age, income and education level, amount of waste production, distanceto waste collection centre etc. The Contingent Valuation techniques were employed to estimate thecoefficients of model. The results suggest that all variables, except the level of education. have apositive and significant impact on households' WTP for a better system. it was estimated that ahousehold, in general, would like to pay Rs. 39.05 per month to continue the program. The officialsfrom the Pradheshiya Sabha indicated that this is a rational estimate as it can cover the net operatingcost of about Rs. 25-30 per month per household, and the rest can be used to improve the system

TANNINS IN SOME AGRO FORESTRY SPECIES OF LOCAL INTEREST

Total and condensed tannin contents were determined in six agro forestry species usedby local farmers to feed ruminants. Total and condensed tannins were determined byFolin-Ciocalteu and Butanol-Hcl methods respectively. Total tannin (1T) contentranged from 5.41% for Calliandra calothyrsus to 0.15% for Erythrina indica.Condensed tannins (CT) contents ranged from 6.92% in Acacia auricu/iformis to 0.78%in G/iricidia sepium. The percentages of CT were 6.40%, 4.60%, and 1.58% respectivelyfor Artocarpus heterophy//us, C. ca/othyrsus, and Leucaena le ucoceph ala. Among thesix species tested, E. indica, was free of CT while having traces of IT. On the basis oftheir respective CT contents G. sepium was classified as containing traces of CT «1 %),while L. /eucocepha/a classified as containing low level of CT (1-3%). C. calothyrsuswas classified as containing medium level of CT (4-6%) while A. auriculiformis and A.heterophyl/us classified as containing high level of CT (&gt;6%).In a further study, it was found that tender leaves and stems (0-30 cm from the tip) of C.calothyrsus, and A. auriculiformis contained higher levels of IT and CT as comparedwith mature leaves and stems (30-60 em from the tip) of the same species. In contrasttender leaves and stems of A heterophyllus contained low levels IT as compared withmature leaves and stems.The results suggest that IT and CT contents of tested six species are different due totheir inherent characteristics. It was also evident that tannins are present not only inleguminous species but also in non-leguminous species such as A. heterophyllus. Theincrease in TT and CT contents in tender parts of C. callothyrsus and A. auriculiformismay be associated with the chemical defence mechanisms found in younger plant parts.Further investigations are necessary to verify the effects of tannins on their nutritivevalue of above forages

EFFECT OF GRAZING ON SOME PHYSIOLOGICAL PROPERTIES IN INTEGRATED FARMING SOILS.

The objective of this study was to investigate the effect of grazing on somesoil properties; bulk density (BD), true density, porosity, moisture content(Me) and pH. The effect of long term grazing (&gt;20 yrs) was examined in acoconut - pasture - cattle integrated farming system in Kamburupitiya area.Short term grazing effect was compared with an adjoining coconut plantationpermitting 18 buffaloes to graze for 6 months. Another adjoining ungrazedcoconut farm soil was considered as control. Soil samples were taken fromthe topsoil using a core sampler (v = 98.21 em"). Four replicate samples weretaken three times with 30 days interval and analyzed in triplicates. Data werestatistically analyzed using SAS.Soils collected from the long term integrated farming site had a significantlyhigher (p &lt; 0.05) average pH (5.58) than that of non-integrated sites (4.65).Reduction of acidity may be due to the improvement of soil nutrients viadung, urine and accumulation of litter. It was observed that the soil inintegrated sites were comparatively dark in color. BD of integrated soil(1.15g/cm3) was significantly lower than that of non-integeated soil (21.26%)due to the better ground cover by dominant prostate type herbages comparedto ungrazed soils where erect type herbages were prominent. Soil porosityalso improved due to integration (47.76%) with that of non-integrated soil(43.76%). There was no significant difference observed under the effect ofshort term grazing. A considerable time period may be required to change toimproved soil properties.It is concluded that long term crop-livestock integration could improve thesoil physiochemical properties

EFFECT OF BUFFALO GRAZING ON PLANT SPECIES DIVERSITY IN A COCONUT-PASTURE-CATTLE INTEGRATED SYSTEM

The effects of long and short-term buffalo grazing on plant species diversityunder coconut were examined. 18 Murrah and Surthi pure and crossbredbuffaloes were allowed to graze 3 hours a month for 6 months (short termgrazing). Herbage from an adjoining coconut plantation was taken as thecontrol. Quadrate sampling was adopted to analyze herbage up to specieslevel and four random samples were taken at each event.The Shannon diversity Index (H), species richness and evenness werecalculated for each treatment.Results showed that the diversity index and evenness in the undisturbedhabitat (ungrazed coconut plantation) were 2.176 and 0.6679 respectively andwere much higher than highly disturbed habitat (grazed plantation) where thesame values were 0.4.747 and 0.2160. The short term grazing effect showedan intermediate results. In the ungrazed site there were greater number ofplant species and more equitable the individuals in the community weredistributed. Long term grazed coconut plantation had only 9 species and over80% of the individuals belong to one species; Carpet grass (Axonopus affinis)the most common species in a grazing land. Grazing pressure was favorableto dominate prostate type plants. It was shown that grazing pressure whethershort term or long term changed the abundance of plant species.It is concluded that different levels of disturbance have different effects onplant species diversity

SUITABILITY OF ATTANAGALU OYA AS A DRINKING WATER SOURCE

Attanagalu oya basin is situated between the two major river basins Kelani and Maha Oya .It plays amajor role in national water supply since it contains major national water supply and drainage boardintakes. This study intends to study the quality of water of the Attanagalu Oya and its suitability fordrinking purpose. Because of its significance as a drinking water source it is important to maintain thequality of the water. Samples were collected from ten selected sampling locations along the main riverincluding one near the origin of the river, near the sea outfall, NWS&amp;DB intakes from the main river.Other locations were selected so as to have the similar distance between sampling locations Samplingwas taken during both high and low flow rate conditions. Analysis was done on physical, chemicaland biological parameters.Results showed that records of COD, BOD, DO, pH, nutrient are low during the high flow rate whilethe levels of turbidity, metal iron total coliform and faecal coliform are high during the high flow rate

Extended Kalman filtering with stochastic nonlinearities and multiple missing measurements

Copyright @ 2012 ElsevierIn this paper, the extended Kalman filtering problem is investigated for a class of nonlinear systems with multiple missing measurements over a finite horizon. Both deterministic and stochastic nonlinearities are included in the system model, where the stochastic nonlinearities are described by statistical means that could reflect the multiplicative stochastic disturbances. The phenomenon of measurement missing occurs in a random way and the missing probability for each sensor is governed by an individual random variable satisfying a certain probability distribution over the interval [0,1]. Such a probability distribution is allowed to be any commonly used distribution over the interval [0,1] with known conditional probability. The aim of the addressed filtering problem is to design a filter such that, in the presence of both the stochastic nonlinearities and multiple missing measurements, there exists an upper bound for the filtering error covariance. Subsequently, such an upper bound is minimized by properly designing the filter gain at each sampling instant. It is shown that the desired filter can be obtained in terms of the solutions to two Riccati-like difference equations that are of a form suitable for recursive computation in online applications. An illustrative example is given to demonstrate the effectiveness of the proposed filter design scheme.This work was supported in part by the National 973 Project under Grant 2009CB320600, National Natural Science Foundation of China under Grants 61028008, 61134009 and 60825303, the State Key Laboratory of Integrated Automation for the Process Industry (Northeastern University) of China, the Engineering and Physical Sciences Research Council (EPSRC) of the U.K. under Grant GR/S27658/01, the Royal Society of the U.K., and the Alexander von Humboldt Foundation of Germany