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ThesisItem Open Access Assessment of greenhouse cultivation problems in Kerala(Department of Soil and Water Conservation Engineering, KCAET, Tavanur, 2021) Deepthi S, Nair; KAU; Jinu, AGreenhouses are framed or inflated structure covered with transparent or translucent material large enough to grow crops under partial or fully controlled environmental conditions to get optimum growth and productivity. Greenhouse have many advantages and some limitations also. Due to this farmer are abandoning this cultivation method citing crop failures after the initial phase. Thus, a survey was conducted to explore the reasons of failures of greenhouse farmers in Kerala covering all fourteen districts. Major problem faced by farmers was crop failure due to ageing of cladding material. So that fungal growth and dust deposit over the cladding material reduce the light transmission to the greenhouse which affect its microclimate and growth and yield parameters. To prove this, a field experiment was conducted during the period from April to June 2021 in the instructional farm of KCAET, Tavanur, Kerala. CO-1(Amaranthus green variety) was planted inside both cleaned greenhouse and uncleaned greenhouse (greenhouse without cleaned cladding material) and compared the microclimate and performance of Amaranthus in both conditions. Mean monthly values of light intensity and temperature were higher inside the cleaned greenhouse than the uncleaned one while relative humidity was higher inside the old greenhouse. Thus, crop growth parameters like plant height, number of leaves, number of branches and average yield per plant were higher inside the cleaned greenhouse than the old one whereas the inter nodal length of the plant was higher inside the old greenhouse. From this experiment, it was clear that the aging of cladding material has much influence on crop performance under the greenhouse. Other major problems faced by farmers were a decrease in soil fertility, Fungal/Insect attack inside the greenhouse, high maintenance cost 101 and structural problems of greenhouse, no demand and marketing facility of greenhouse products, etc. From the statistical analysis of survey details, it was clear that farmers are not satisfied with the greenhouse.ThesisItem Open Access Water availability and climatic water balance for a selected cropped area(Department of Irrigation and Drainage Engineering, Kelappaji College of Agricultural Engineering and Technology, Tavanur, 2018) Venkata Sai, K; KAU; Asha JosephRainfall is the main source available for water. The knowledge of the rainfall analysis is crucial for crop planning in a region and designing of water conservation structures. The changes in rainfall, its distribution, probability and trends would influence the spatial and temporal distribution of runoff, soil moisture and groundwater reserves. Crop production in an area has a direct relation with the amount and distribution of rainfall. So correct evaluation of water availability period is an important pre-requisite for crop planning. Climatic water balance is widely used for determining the water surplus, water deficit and water availability period for agricultural planning. Hence in the present research work, the rainfall data of Pattambi was analysed to study the variability, trends and probability of rainfall. A weekly climatic water balance was also assessed to determine the surplus/deficit of rainwater. The rainfall variability analysis showed that the mean annual rainfall of Pattambi region was found 2377.96 mm with a CV of 19.29 % which indicated that the rainfall is highly stable in the region. The South-West monsoon season contributed the highest (74.09 %) amount of rainfall. June and July were the months recorded the highest percentage of rainfall of 25.39 % and 24.06 % respectively. Weekly rainfall variability showed that rainfall was stable during 21st to 45th SMWs as the CV ranges from 90 % to 110 % only. The trend analysis of annual, seasonal and monthly rainfall according to Mann-Kendall test revealed that there was a rising and falling trends. But there was no significant trend observed at 5 % level of significance except in summer season. The Sen’s slope estimator revealed that a rising trend was observed in summer season whereas falling trend was observed in annual, South-West and North-East monsoon season and no trend was observed at winter season. The rainfall probability at different levels of exceedance were found by fitting “Incomplete gamma distribution” using Weather Cock software. The weekly rainfall probability at 75 % level of exceedance varied from 10.3 to 72.6 mm during the weeks 21st to 46th. The highest monthly rainfall at 75 % exceedance occurred during June (471.1 mm) and lowest during January (3.1 mm). The highest seasonal rainfall at 75 % exceedance occurred during South-West monsoon (1466.4 mm) and lowest during winter season (10.8 mm). The annual rainfall at 75 % level of exceedance was found to be 2051.6 mm. Weibull distribution was identified as the best fit for weekly rainfall distribution in the region. The total ETc demand of rice, banana and vegetable crops at 50 % probability levels of ETo was estimated as 469.162 mm, 1124.81 mm and 267.92 mm whereas the rainwater availability at 75 % probability level was 933.85 mm, 1107.53 mm and 59.18 mm respectively. It was observed that there was a surplus of 464.688 mm for rice, deficit of 17.28 mm for banana and deficit of 208.74 mm for vegetable crop. The climatic water balance indicated that water surplus (SUR) and water deficit (DEF) components are significant. The total climatic water surplus and deficit in the region was estimated as 1985.54 mm and 155.08 mm. The Moisture Adequacy Index (MAI) of the region indicated that the most of the weeks were of in good potential for growing crops. The determination of water availability period revealed that 1,4,5,8, 9, 11 and 50th SMWs were in water deficit whereas the remaining weeks were in water surplus.ThesisItem Open Access Soil erosion risk assessment in Kunthippuzha sub-watershed using remote sensing and gis(Department of Soil and Water Conservation Engineering, Kelappaji College of Agricultural Engineering and Technology Tavanur, 2018) Shaheemath Suhara, K K; KAU; Abdul Hakkim, V MThis study mainly focused to identify the erosion prone areas in Kunthippuzha sub-basin using RUSLE as well as MMF model. The effect of spatial and temporal variations of land use-land cover on soil erosion was analysed with the help of NDVI values. The estimation was performed for the year 2000 and 2013. The mean soil erosion estimated for the year 2000 was 18.30 and 20.58 t/ha/y respectively by MMF as well as by RUSLE model. Similarly in the year 2013, it was 32.78 and 35.10 t/ha/y respectively. To find the erosion prone areas in the sub-watershed factorial scoring method was chosen, in which pixel based scoring was done based on mean soil erosion value obtained under each layers of landuse, rainfall, slope and topographic raster. From the study based on the RUSLE model, 0.15% of the area experienced very slight erosion. 40.70% of the area was with slight erosion, 28.76% area was under moderate erosion, 22.61% of the area was under severe range and 6.15% area was under very severe range. According to MMF model, the areal extent observed under slight, moderate, severe and very severe risk categories was 39.02%, 36.94%, 14.92%, 7.50% respectively. NDVI values corresponding to land use were identified, in which negative NDVI values correspond to water pixels whereas higher NDVI values represents the thick vegetation. From the analysis of the temporal variation in land use over the NDVI, it was observed that NDVI value decreased at the points where density of the canopy decreased. The spatial variation of soil erosion varies pixel to pixel according to the landuse pattern. Highest soil erosion risk was observed under built-up plus barren land. Sediment Delivery Ratio (SDR) was calculated for the entire sub- watershed, which shows that most of the eroded sediments get deposited at intermediate location before reaching the outlet. The SDR calculation enhances the importance of adopting GIS technology in soil erosion assessment.
