Browsing by Author "Hajilal, M S"

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Design and development of a high capacity Salvinia Harvester
(Department of Irrigation and Drainage Engineering, Kelappaji College of Agricultural Engineering and Technology, Tavanur, 1987) Hajilal, M S; John Thomas, K
Salvlnla molesta locally known as 'African Payal* ia a noxious floating typo aquatic weed in many parts of the humid tropics. Kerala Agricultural university developed a mechanical device to harvest this menacing weed. An investigation on the performance of the prototype Salvinia Harvester was carried out under various conditions. Prototype ejector E1 with secondary flow straight and primary flow inclined at 900 ejectors E2 and E3 with primary flow straight end secondary flow inclined at 400 and 20° respectively and ejector E4 with secondary flow straight and primary flow inclined at 300 were tested along with circular mouth (M1), adjustable rectangular mouth (M2) and elliptical mouth (M3)• Experiments were also conducted to find out the optimum depth of mouth below the water level. The study revealed that clogging was a serious problem for the prototype Salvinia Harvester, where the weed was in the initial stages of third growth phase. Ejectors E1 and E2 showed clogging when tested with all the different feeding mouths. The E4-M2 and E4-M3 combinations yielded almost identical harvesting capacity of 11 t/hr at one metre static lift mad 12 t/hr at 40 cm static lift without any problem due to clogging. All these experiments conducted revealed that the ejectors E3 and E4 can be used under ell conditions of weed growth without clogging along with mouths M2 and M3. The machine is capable of removing weeds at the rate of 16 t/hr where the spread density value was around 16kq/m2 (160 t/ha) like Kuttanadu area. Hence the machine would be capable of Removing the weeds in one hectare in 10 hours. The estimated cost of operation amounted to Rs. 353/- per hectare which compared favourably with the reported costs of Rs.900/- to Rs.2700/- per hectare for manual collection and disposal.
Field testing and evaluation of a two layer soil water balance model
(Department of Irrigation and Drainage Engineering, Kelappaji College of Agricultural Engineering and Technology, Tavanur, 1997) Mohanan, C K; Hajilal, M S
A two layer soil water balance model was tested in the field with bhindi as the test crop. The model considers the dynamics of soil water balance by incorporating an empirical model of root growth and an empirically established result of plant response to available soil water. The input data of the model were daily values of rainfall, irrigation and reference crop evapotranspiration. The model calculated the values of root depth, potential evapotranspiration, actual evapotranspiration, percolation and soil moisture content at the end of each day. The root depth computed by the model was compared with that measured in the field. Maximum root depth of 39.0 cm was attained at 53rd DAS. Total amount of water percolated down the active root zone during the entire crop season was 8.15 mm. The actual evapotranspiration was less than the potential evapotranspiration, whenever the soil moisture content in the active root zone dropped below the critical soil moisture. Totally, AET was less than PET for 6 days durinq the period of study. The computed and observed values of soil moisture content were in close agreement with correlation coefficients 0.976, 0.971 and 0.965 for gravimetric, tensiometer and electrical resistivity methods respectively.
Impact of climate change and watershed development on river basin hydrology using SWAT – a case study
(Department of irrigation and drainage engineering, Kelappaji college of agricultural engineering and technology, Thavanur, 2016) Anu Varughese; Hajilal, M S