Rainwater conservation and recycling by optimal size on-farm reservoir

Hydrologic and economic analysis of the on-farm reservoir (OFR) was carried out in rainfed rice–mustard cropping systems in Eastern India followed by 2 years of field experiments in 1999 and 2000. The average contribution (average of 2 years) of direct rainfall and surface runoff from the diked crop fields contributed, respectively, about 79.5 and 20.5% to the total OFR inflow. The average contribution of evaporation loss, seepage and percolation loss and supplemental irrigation from the OFR contributed, respectively, about 10.0, 31.2 and 58.8% to the total OFR outflow. There was an average increase of rice yield of 44.0% over the rainfed rice because of application of 8.4 cm supplemental irrigation from the OFR. Thus, with an application of 4.5 cm supplemental irrigation from the OFR, 15.40% increase of mustard yield was recorded in 1999. Economic analysis indicated average net profit of Rs. 700 (US$ 1 = Rupees (Rs.) 44.75 in Indian currency) from a farm area of 800 m². Average values of benefit–cost ratio, internal rate of return and pay back period of the OFR irrigation system were evaluated as 1.17, 14.8%, and 16 years, respectively. The study reveals that the OFR irrigation in small landholders is economically feasible system for rainwater harvesting and providing supplemental irrigation in rainfed farming system.     

Renewable energy programmes in India

There is increasing optimism regarding the possible role that renewable energy technologies can play in the coming decade in the energy sector in India. Some recent developments and trends within the renewable energy sector that are responsible for this optimism, and the likely investments of the order of US$1210 million in the next four to five years, are discussed. The paper includes discussion of the recent changes in the implementing institutions, innovation in financing renewable technology investments, and a shift from financial to fiscal incentives. In addition, wind power generation, small hydro, photovoltaic and gasifier programmes are analysed in some detail.     

Impact of crude oil pollution on species number and live standing herbaceous crop biomass

Summary The impact of crude oil spill on the number of plant species and the above-ground live standing crop biomass (AGLSCB) of a herbaceous plant community was assessed. The spillage had a devastating effect on the herbaceous community and especially on the component herbaceous annuals. At least 80–90% of the species were absent in the affected areas in comparison to nearby unaffected areas, most of these being annuals. Perennial species were generally less affected. The total herbaceous production for a period of 12 months in the polluted areas was 885.1 gm^–2 compared with 4860.7 gm^–2 for the unaffected areas. The average monthly production in the polluted areas was 73.8 gm^–2 compared with 405.0 gm^–2 for the unaffected areas.Dr Debojit Baruah is the senior author of this paper and he is a research scholar at Dibrugarh University. Dr Sarada K. Sarma is a Pofessor in the Botany Department of Guwahati University in Assam.     

Water-induced erosion potentiality and vulnerability assessment in Kangsabati river basin,eastern India

Environment, Development and Sustainability - The large-scale water-induced erosion is one of the most determining elements on land degradation in subtropical monsoon-dominated region. From this...     

Toxicity assessment of heavy metals with Nostoc muscorum L

Heavy metals in aquatic ecosystem (Mn, Ni, Zn, Cu) were tested for their toxicity against Nostoc muscorum L., a common fresh water phytoplankton, with respect to chlorophyll, protein, total carbohydrate and starch contents along with growth (OD). Mn showed stimulatory effect up to 1.5 ppm for all the observed parameters. However, Ni, Zn and Cu (0.1, 0.2, 0.3, 0.4 and 0.5 ppm) showed adverse effects even at 0.1 ppm. Chlorophyll was most sensitive parameter followed by carbohydrate, protein and starch. Ni was most toxic to N. muscorum followed by Cu and Zn. The IC50 for Ni was 0.1 ppm for growth, chlorophyll and protein, while total carbohydrate and starch showed IC50 at 0.3 and 0.4 ppm, respectively. The IC50 for Cu was recorded at 0.2 ppm for all the parameters. Zn showed IC50 at 0.3 ppm for growth, chlorophyll, protein and starch at 0.4 ppm for carbohydrate. This study can be applied as bioassay using cyanobacteria for toxicity assessment of various industrial wastes in aquatic ecosystem.     

Heavy metals in water of the rivers Hooghly and Haldi at Haldia and their impact on fish

The paper deals with the measurement of five heavy metals viz., Cd, Cu, Mn, Pb and Zn in water of the rivers Hooghly and Haldi at Haldia during June 1999 to October 2002. The industrial effluent out fall (OF) at Patikhali, Haldia was also taken as sampling site along with above out fall (AOF) and below out fall (BOF) sites. Most of the metals exhibited their least concentration at the sampling site above the Haldia industrial area of river Hooghly. The average concentrations of the studied metals were Cd 2-14, Cu 5-19, Mn 8-88, Pb 17-41 and Zn 22-37 microg l(-1). Comparison of the data with the Criterion Continuous Concentration (CCC) of USA revealed that Cd, Cu and Pb were the pollutants present at alarming level to disturb the aquatic life process in the zone. The effect was found to reflect on the tissue level aberrations in the residential fishes. The other two metals viz., Mn and Zn were probably less harmful to the aquatic ecosystem. In India, necessity is felt to develop the CCC values, which will be more appropriate for protection of aquatic environment than comparing with drinking water standards.     

Changes in life histories of cladocerans (Cladocera) from the rotifer-mediated allelochemicals

ABSTRACT

We hypothesised that at higher densities herbivorous rotifers through their allelochemicals affect the survival and reproduction of cladocerans. To test this, we separately cultured three rotifers (Brachionus calyciflorus, Brachionus havanaensis, and Plationus patulus) and three cladocerans (Ceriodaphnia dubia, Daphnia pulex, and Moina macrocopa). Chlorella vulgaris was used as food and reconstituted moderately hard water was used as medium. The conditioned-medium (CM) obtained from each of rotifer species was used to conduct cohort life table tests of cladocerans. SDS PAGE electrophoresis revealed the molecular weights of proteins present in the rotifer conditioned medium were 55–63?kDa. Compared to C. dubia and D. pulex, Moina was more resistant to rotifer-mediated chemicals. Gross reproductive rate of C. dubia was significantly stimulated by the rotifer-CM. However, gross and net reproductive rates of D. pulex were strongly reduced (72–85%) due to P. patulus-CM but not from the other two rotifer species. The rate of population increase of M. macrocopa was significantly reduced by the rotifer CM. Overall, about 46% (adverse effect: 24%; stimulatory impact: 22%) of the life history variables in controls significantly differed from rotifer-CM treatments, thus proving our hypothesis that rotifer-mediated allelochemicals had some effect on the cladoceran life history variables.