16 research outputs found
Pedotransfer functions to predict water retention for soils of the humid tropics: a review
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Not AvailableAn experiment was conducted at Meghalaya, during 2006–08 to study the effect of rice straw mulching on growth, yield attributes and yield of different rapeseed (Brassica campestris L.) varieties, namely ‘M 27’, ‘TS 38’ and ‘Sikkim Sarson’. The plant height of rapeseed increased by 7.2% at harvest due to rice straw mulching @ 5.0 tonnes/ha over the non-mulching and it was highest (96.88 cm) in ‘TS 38’. Lower values (–2.9°C) of canopy air temperature difference were recorded in the mulch treatment than under control (–2.3°C). Mulching resulted in storage of 2.0% more soil moisture in the root zone of the crop over the unmulched control, indicating better microclimate for crop growth and development. Leaf area index was higher in ‘TS 38’ and in mulching treatment. Number of siliquae/plant (24.6%), seeds/siliqua (17.6%) and seed yield (35.4%) increased due to mulching over the non-mulching. The varieties differed significantly with respect to 100-seed weight and it was highest (0.37 g) in ‘TS 38’. Highest seed yield was obtained in ‘TS 38’ (1.51 tonnes/ha), followed by ‘M 27’ (1.46 tonnes/ha) and significantly superior over the ‘Sikkim Sarson’ (0.97 tonnes/ha).Not Availabl
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Not AvailableMesh covered pan evaporation was correlated with the estimated values of potential evapotranspiration (PET) and/or consumptive use using Thornthwaite (1948), Blaney-Criddle (1950) and Papadakis (1965) models for the period of 1985-2000 at Umiam, Meghalaya. The results revealed that the Papadakis method was most suitable with least biasness and highest accuracy of prediction. The PET values from Papadakis method were more evenly distributed along the 1:1 line. From the analysis it was also observed that correlation coefficient (r) was not an appropriate measure to determine the accuracy of estimation of PET by different methods for the location under study.Not Availabl
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Not AvailableMorphometric analysis of a hilly watershed was carried out using GIS. The drainage map generated from the Survey of India toposheets was used for morphometric analysis of the watershed in terms of stream order, stream length, bifurcation ratio, relief ratio, drainage density, stream frequency, drainage texture, form factor, circulatory ratio, elongation ratio, infiltration number and ruggedness number. The Um Shipra watershed is a fifth order watershed having dendritic drainage pattern with high drainage density (6.22 km.km-2). The logarithmic plot of the stream length versus stream order showed a linear relationship indicating the watershed has developed over a homogeneous rock material. The mean bifurcation ratio of 1.71 indicated absence of strong structural control on the drainage pattern and that the watershed was structurally less disturbed. The number of streams belonging to the order I, II, III, IV and V were found to be 327, 147, 78, 45 and 46 respectively. Lower values of form factor (0.19), circularity ratio (0.29) and elongation ratio (0.49) suggested that the watershed has elongated shape with lower peak flows for longer duration. The ruggedness number having relatively higher value implied that the area has rugged topography which is prone to soil erosion. Higher values of stream frequency and drainage density indicated that the watershed has high runoff potential despite having lower peak flow creating a good scope for surface water resource development. The results obtained can serve as a useful input for developing soil and water resources conservation and management plan on a watershed basis.Not Availabl
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Not AvailableThe economic feasibility of rainwater harvesting and recycling for winter season vegetable cultivation in the mid hills of Meghalaya was analyzed. The weekly rainfall during November to mid March being less than the weekly evaporation, irrigation becomes necessary. The study revealed that rainwater could be successfully harvested and stored in pond with agrifilm lining, reducing the seepage loss by 94%. Four locally grown high-value vegetables viz. cabbage, cauliflower, pea and lettuce were cultivated during November to mid March. The harvested rainwater was used through sprinkler system to irrigate the crops. The average yield of cabbage, cauliflower, pea and lettuce was 426, 280, 44 and 120 q/ha. respectively. The overall benefit-cost ratio for the whole system for 1 ha vegetable cultivation area was 2.7 over a period of 15 years. A farm of 1 ha area totally under vegetable cultivation can recover the initial investment in two years. The benefit-cost ratio may be further enhanced by utilizing the harvested water for fish production and livestock rearing. Thus, efficient utilization and management of rainwater may help transform the subsistence agriculture into a profit earning enterprise in the region.Not Availabl