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Kerala Agricultural University, Thrissur
The history of agricultural education in Kerala can be traced back to the year 1896 when a scheme was evolved in the erstwhile Travancore State to train a few young men in scientific agriculture at the Demonstration Farm, Karamana, Thiruvananthapuram, presently, the Cropping Systems Research Centre under Kerala Agricultural University. Agriculture was introduced as an optional subject in the middle school classes in the State in 1922 when an Agricultural Middle School was started at Aluva, Ernakulam District. The popularity and usefulness of this school led to the starting of similar institutions at Kottarakkara and Konni in 1928 and 1931 respectively.
Agriculture was later introduced as an optional subject for Intermediate Course in 1953. In 1955, the erstwhile Government of Travancore-Cochin started the Agricultural College and Research Institute at Vellayani, Thiruvananthapuram and the College of Veterinary and Animal Sciences at Mannuthy, Thrissur for imparting higher education in agricultural and veterinary sciences, respectively. These institutions were brought under the direct administrative control of the Department of Agriculture and the Department of Animal Husbandry, respectively. With the formation of Kerala State in 1956, these two colleges were affiliated to the University of Kerala. The post-graduate programmes leading to M.Sc. (Ag), M.V.Sc. and Ph.D. degrees were started in 1961, 1962 and 1965 respectively.
On the recommendation of the Second National Education Commission (1964-66) headed by Dr. D.S. Kothari, the then Chairman of the University Grants Commission, one Agricultural University in each State was established. The State Agricultural Universities (SAUs) were established in India as an integral part of the National Agricultural Research System to give the much needed impetus to Agriculture Education and Research in the Country. As a result the Kerala Agricultural University (KAU) was established on 24th February 1971 by virtue of the Act 33 of 1971 and started functioning on 1st February 1972. The Kerala Agricultural University is the 15th in the series of the SAUs.
In accordance with the provisions of KAU Act of 1971, the Agricultural College and Research Institute at Vellayani, and the College of Veterinary and Animal Sciences, Mannuthy, were brought under the Kerala Agricultural University. In addition, twenty one agricultural and animal husbandry research stations were also transferred to the KAU for taking up research and extension programmes on various crops, animals, birds, etc.
During 2011, Kerala Agricultural University was trifurcated into Kerala Veterinary and Animal Sciences University (KVASU), Kerala University of Fisheries and Ocean Studies (KUFOS) and Kerala Agricultural University (KAU).
Now the University has seven colleges (four Agriculture, one Agricultural Engineering, one Forestry, one Co-operation Banking & Management), six RARSs, seven KVKs, 15 Research Stations and 16 Research and Extension Units under the faculties of Agriculture, Agricultural Engineering and Forestry. In addition, one Academy on Climate Change Adaptation and one Institute of Agricultural Technology offering M.Sc. (Integrated) Climate Change Adaptation and Diploma in Agricultural Sciences respectively are also functioning in Kerala Agricultural University.
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ThesisItem Open Access Nutrient dynamics and crop productivity in lowland lateritic soil (aeu 10) under rice residue management practices(Department of Soil Science and Agricultural Chemistry, College of Agriculture, Vellanikkara, 2021) Amritha, K; KAU; Jayasree Sankar, SThe present investigation was undertaken at College of Agriculture Vellanikkara, Kerala Forest Research Institute Peechi, and Agricultural Research Station Mannuthy during 2017-2020. The experiment comprised of characterization of rice residues and their products for physical and chemical properties, an incubation experiment to study the kinetics of carbon mineralization, and a field experiment to evaluate the efficacy of rice residues and their products on lowland rice. Straw and husk, the important residues produced during the cultivation and processing of rice, respectively was procured from farmer’s field and further materials required for the research work viz., vermicomposted rice straw (VRS), vermicomposted rice husk (VRH), rice straw biochar (RSB), and rice husk biochar (RHB) were produced from the straw (RS) and husk (RH) using vermitechnology and pyrolysis. Recovery from vermicomposting was more (74.38 % for VRS and 70.03 % for VRH) than when the residues were converted into biochar through pyrolysis (19.86 % for RSB and 38.00 % for RHB). Vermicomposting and pyrolysis reduced the bulk density of raw materials. Rice residues and their products were alkaline, with biochar exhibiting the highest level of alkalinity (9.24 for RSB and 9.20 for RHB). The electrical conductivity increased both by vermicomposting and pyrolysis. Straw was comparatively superior to the husk in respect of C, N, K, Ca, Mg, Fe, Mn, Cu, and Zn. However, husk was superior in P, S, B, Si, cellulose, and lignin. Vermicomposting helped to concentrate the nutrients viz., N, P, K, Ca, Mg, S, Fe, Mn, Cu, Zn, B, and Si while reducing that of carbon, cellulose and lignin thereby narrowing down the C: N ratio. However, C: N ratio increased upon pyrolysis. Surface morphology of rice residues and their products were studied using scanning electron microscope (SEM). The SEM micrographs of straw and husk exhibited a complex morphology with cell wall composition. SEM micrograph of VRS showed highly fragmented, disaggregated and porous structure which could not be visualised in VRH, may be because the technology of composting using earthworms was more suited to decomposing rice straw than its husk. The SEM analysis showed that the structure of biochar was porous, fragmented and particles gave a broken or distorted appearance thus resembling the plant structure. The structural chemistry of rice residues and their products were analysed using fourier transform infra red spectrometer (FT-IR). Each peak is characteristic of correspondingfunctional group and it clearly explained the presence of C, H, O, N, and Si in the residues and products. Silicon, a major component in the chemical structure of rice material was illustrated by Si-O-Si and Si-H bond in FT-IR spectra. Vermicompost had significant level of nitrogen rich compounds and low level of aliphatic or aromatic carbon compounds compared to biochar, as confirmed by the FT-IR analysis. The FT-IR spectra of RSB and RHB revealed its aromatic and recalcitrant nature. The incubation experiment was conducted for 110 days at 15, 25, 35 and 45 oC to study the kinetics of carbon mineralization in lateritic soil over time, wherein the CO 2 evolution was determined at frequent intervals and the data were used for determination of carbon mineralization and mineralization kinetics. Lateritic soils (100g) collected from Agricultural Research Station Mannuthy, were treated with rice residues and their products (5t ha -1 ), FYM (5 t ha -1 ), and soil test based nutrient recommendation. An absolute control without the addition of organic/inorganic materials was also maintained. Dehydrogenase enzyme assay, enumeration of microbial population, and fractions of carbon were also undertaken at the end of incubation. Results of incubation experiment revealed that the amount of CO 2 –C mineralized during incubation increased with rise in temperature in all the treatments. The VRS treated soils registered higher mineralizable carbon at 15, 25, 35 and 45 oC. The rate of decomposition reaction was highest in soils that are treated with VRS and FYM. The highest activation energy was found in RHB amended soil (12.79 kJ mol -1 ) followed by RSB treated soil (12.71 kJ mol -1 ). Q 10 values represent the temperature dependency of the reaction. The results showed that all treatments had Q 10 values less than one. After incubation experiment, dehydrogenase activity as well as microbial population was found to decrease at 45 oC compared to the values at lower temperature. Comparatively, higher dehydrogenase activity and microbial population was registered in soils treated with VRS. The soils treated with VRS exhibited highest water soluble carbon (WSC), hot water extractable carbon (HWEC), microbial biomass carbon (MBC), and permanganate oxidizable carbon (POXC). However, biochar amended soils (RHB and RSB) registered higher value of total carbon. A field experiment was carried out to evaluate the efficacy of rice residues and their products in lowland with rice variety Uma as the test crop. The experiment consisted of ninetreatments with three replications viz., absolute control (T 1 ), Adhoc KAU organic POP (T 2 ), and treatments T 3 to T 9 comprised of soil test based nutrient recommendation along with FYM (T 3 ), VRH (T 4 ), VRS (T 5 ), RHB (T 6 ), RSB (T 7 ), RH (T 8 ), and RS (T 9 ) at 5t ha -1 . At weekly intervals Eh and pH were monitored. The soil and plant samples were collected at different stages of rice to analyse the effect of treatments on soil physical and chemical properties, fractions of nutrients in soil, nutrient content in plant, soil enzyme activity, and growth, yield and yield attributes of rice. Results of field experiment revealed that the application of residues and its products had a profound influence in lowering redox potential. The alkaline nature of rice residues and their products resulted in higher pH of experimental soil. Physical properties of post-harvest soil was improved by the application of T 6 and T 7 (soil test based nutrient recommendation + RHB and RSB). The application of T 5 (soil test based nutrient recommendation + VRS at 5 t ha -1 ) was superior in increasing the nutrient status of post-harvest soil viz., C, N, P, Ca, Mg, S, Fe, Mn, Zn, and Si. While, K content was superior in T 7 (soil test based nutrient recommendation + RSB at 5 t ha -1 ). Soils receiving combined application of soil test based nutrient recommendation and VRS at 5 t ha -1 (T 5 ) recorded the highest WSC, HWEC, MBC, POXC, inorganic-N and P fractions, fractions of Ca and Mg at all the stages of crop. However, total- C, total hydrolysable-N, organic-P, and Si fractions were higher in biochar amended plots. Soil receiving joint application of soil test based nutrient recommendation +RSB at 5 t ha -1 (T 7 ) was statistically superior in fractions of K at all stages. Enzyme activity (dehydrogenase, urease, and acid phosphatase) was found to be highest in T 5 (soil test based nutrient recommendation + VRS at 5 t ha -1 ), and it followed an increasing trend upto panicle initiation and thereafter it decreased in all treatments. The uptake of N, P, K, Ca, Mg, S, Fe, Mn, Zn, Cu, B and Si were also highest in T 5 . With respect to the growth, yield and yield attributes of rice, application of soil test based nutrient recommendation + VRS at 5 t ha -1 (T 5 ) had superior effect. To conclude, the study has brought out the tremendous potential of rice straw and husk based biochar in improving soil physical properties and in elevating the total carbon content. However, the integration of soil test based nutrient recommendation with vermicompostedrice straw at 5t ha -1 (T 5 ) proved outstanding in augmenting soil fertility and crop productivity in the highly weathered, nutrient poor acidic lateritic soils.ThesisItem Open Access Nutrient dynamics and crop productivity in lowland lateritic soil (aeu 10) under rice residue management practices(Department of Soil Science and Agricultural Chemistry, College of Agriculture, Vellanikkara, 2021) Amritha, K; KAU; Jayasree Sankar, SThe present investigation was undertaken at College of Agriculture Vellanikkara, Kerala Forest Research Institute Peechi, and Agricultural Research Station Mannuthy during 2017-2020. The experiment comprised of characterization of rice residues and their products for physical and chemical properties, an incubation experiment to study the kinetics of carbon mineralization, and a field experiment to evaluate the efficacy of rice residues and their products on lowland rice. Straw and husk, the important residues produced during the cultivation and processing of rice, respectively was procured from farmer’s field and further materials required for the research work viz., vermicomposted rice straw (VRS), vermicomposted rice husk (VRH), rice straw biochar (RSB), and rice husk biochar (RHB) were produced from the straw (RS) and husk (RH) using vermitechnology and pyrolysis. Recovery from vermicomposting was more (74.38 % for VRS and 70.03 % for VRH) than when the residues were converted into biochar through pyrolysis (19.86 % for RSB and 38.00 % for RHB). Vermicomposting and pyrolysis reduced the bulk density of raw materials. Rice residues and their products were alkaline, with biochar exhibiting the highest level of alkalinity (9.24 for RSB and 9.20 for RHB). The electrical conductivity increased both by vermicomposting and pyrolysis. Straw was comparatively superior to the husk in respect of C, N, K, Ca, Mg, Fe, Mn, Cu, and Zn. However, husk was superior in P, S, B, Si, cellulose, and lignin. Vermicomposting helped to concentrate the nutrients viz., N, P, K, Ca, Mg, S, Fe, Mn, Cu, Zn, B, and Si while reducing that of carbon, cellulose and lignin thereby narrowing down the C: N ratio. However, C: N ratio increased upon pyrolysis. Surface morphology of rice residues and their products were studied using scanning electron microscope (SEM). The SEM micrographs of straw and husk exhibited a complex morphology with cell wall composition. SEM micrograph of VRS showed highly fragmented, disaggregated and porous structure which could not be visualised in VRH, may be because the technology of composting using earthworms was more suited to decomposing rice straw than its husk. The SEM analysis showed that the structure of biochar was porous, fragmented and particles gave a broken or distorted appearance thus resembling the plant structure. The structural chemistry of rice residues and their products were analysed using fourier transform infra red spectrometer (FT-IR). Each peak is characteristic of correspondingfunctional group and it clearly explained the presence of C, H, O, N, and Si in the residues and products. Silicon, a major component in the chemical structure of rice material was illustrated by Si-O-Si and Si-H bond in FT-IR spectra. Vermicompost had significant level of nitrogen rich compounds and low level of aliphatic or aromatic carbon compounds compared to biochar, as confirmed by the FT-IR analysis. The FT-IR spectra of RSB and RHB revealed its aromatic and recalcitrant nature. The incubation experiment was conducted for 110 days at 15, 25, 35 and 45 oC to study the kinetics of carbon mineralization in lateritic soil over time, wherein the CO 2 evolution was determined at frequent intervals and the data were used for determination of carbon mineralization and mineralization kinetics. Lateritic soils (100g) collected from Agricultural Research Station Mannuthy, were treated with rice residues and their products (5t ha -1 ), FYM (5 t ha -1 ), and soil test based nutrient recommendation. An absolute control without the addition of organic/inorganic materials was also maintained. Dehydrogenase enzyme assay, enumeration of microbial population, and fractions of carbon were also undertaken at the end of incubation. Results of incubation experiment revealed that the amount of CO 2 –C mineralized during incubation increased with rise in temperature in all the treatments. The VRS treated soils registered higher mineralizable carbon at 15, 25, 35 and 45 oC. The rate of decomposition reaction was highest in soils that are treated with VRS and FYM. The highest activation energy was found in RHB amended soil (12.79 kJ mol -1 ) followed by RSB treated soil (12.71 kJ mol -1 ). Q 10 values represent the temperature dependency of the reaction. The results showed that all treatments had Q 10 values less than one. After incubation experiment, dehydrogenase activity as well as microbial population was found to decrease at 45 oC compared to the values at lower temperature. Comparatively, higher dehydrogenase activity and microbial population was registered in soils treated with VRS. The soils treated with VRS exhibited highest water soluble carbon (WSC), hot water extractable carbon (HWEC), microbial biomass carbon (MBC), and permanganate oxidizable carbon (POXC). However, biochar amended soils (RHB and RSB) registered higher value of total carbon. A field experiment was carried out to evaluate the efficacy of rice residues and their products in lowland with rice variety Uma as the test crop. The experiment consisted of ninetreatments with three replications viz., absolute control (T 1 ), Adhoc KAU organic POP (T 2 ), and treatments T 3 to T 9 comprised of soil test based nutrient recommendation along with FYM (T 3 ), VRH (T 4 ), VRS (T 5 ), RHB (T 6 ), RSB (T 7 ), RH (T 8 ), and RS (T 9 ) at 5t ha -1 . At weekly intervals Eh and pH were monitored. The soil and plant samples were collected at different stages of rice to analyse the effect of treatments on soil physical and chemical properties, fractions of nutrients in soil, nutrient content in plant, soil enzyme activity, and growth, yield and yield attributes of rice. Results of field experiment revealed that the application of residues and its products had a profound influence in lowering redox potential. The alkaline nature of rice residues and their products resulted in higher pH of experimental soil. Physical properties of post-harvest soil was improved by the application of T 6 and T 7 (soil test based nutrient recommendation + RHB and RSB). The application of T 5 (soil test based nutrient recommendation + VRS at 5 t ha -1 ) was superior in increasing the nutrient status of post-harvest soil viz., C, N, P, Ca, Mg, S, Fe, Mn, Zn, and Si. While, K content was superior in T 7 (soil test based nutrient recommendation + RSB at 5 t ha -1 ). Soils receiving combined application of soil test based nutrient recommendation and VRS at 5 t ha -1 (T 5 ) recorded the highest WSC, HWEC, MBC, POXC, inorganic-N and P fractions, fractions of Ca and Mg at all the stages of crop. However, total- C, total hydrolysable-N, organic-P, and Si fractions were higher in biochar amended plots. Soil receiving joint application of soil test based nutrient recommendation +RSB at 5 t ha -1 (T 7 ) was statistically superior in fractions of K at all stages. Enzyme activity (dehydrogenase, urease, and acid phosphatase) was found to be highest in T 5 (soil test based nutrient recommendation + VRS at 5 t ha -1 ), and it followed an increasing trend upto panicle initiation and thereafter it decreased in all treatments. The uptake of N, P, K, Ca, Mg, S, Fe, Mn, Zn, Cu, B and Si were also highest in T 5 . With respect to the growth, yield and yield attributes of rice, application of soil test based nutrient recommendation + VRS at 5 t ha -1 (T 5 ) had superior effect. To conclude, the study has brought out the tremendous potential of rice straw and husk based biochar in improving soil physical properties and in elevating the total carbon content. However, the integration of soil test based nutrient recommendation with vermicompostedrice straw at 5t ha -1 (T 5 ) proved outstanding in augmenting soil fertility and crop productivity in the highly weathered, nutrient poor acidic lateritic soils.ThesisItem Open Access Effect of herbicides and chemical characteristics of soil on microbial biomass carbon and enzyme activity(Department of Soil Science and Agricultural Chemistry, College of Horticulture, Vellanikkara, 2017) Amritha, K; KAU; Durga Devi, K MWeed competition is one of the major factors limiting rice production in the tropics. Due to the scarcity and high cost of labour, weed management with herbicides is widely practiced. The problem associated with herbicides is the persistence of their residues in soil which interact with microorganisms thereby altering the microbial diversity and soil enzyme activity. Hence, the present investigation entitled “Effect of herbicides and chemical characteristics of soil on microbial biomass carbon and enzyme activity” was undertaken at College of Horticulture, Vellanikkara during 2016-2017. The objectives were: (i) to determine the impact of pre and post emergence herbicides on microbial biomass carbon and the soil enzymes namely dehydrogenase, urease, and phosphatase and (ii) to study the influence of chemical characteristics of the soil on microbial biomass carbon and enzyme activity. Representative soil samples were collected during March-April, 2016 from four sites viz., rice field of Agricultural Research Station, Mannuthy (medium organic matter soil with a history of herbicide application: S1 Control), non- cropped area of Agricultural Research Station, Mannuthy (medium organic matter soil without a history of herbicide application: S1 Absolute control), rice field of Kole land, Alappad (high organic matter soil with a history of herbicide application: S2 Control), and non- cropped area of Kole land, Alappad (high organic matter soil without history of herbicide application: S2 Absolute control). Physical, chemical, and biological characterization of the soil samples were done before starting the experiment. Pot culture experiment with rice variety Jyothi was conducted in the kharif season of 2016 with twelve treatments and six replications in factorial CRD (four herbicides under each soil type + four controls). The herbicides included pendimethalin, oxyfluorfen, bispyribac-sodium, and cyhalofop-butyl. Pre emergence herbicides (pendimethalin and oxyfluorfen) were applied at six days after sowing (DAS) and post emergence herbicides (bispyribac-sodium and cyhalofop-butyl) at 16 DAS. Soil samples were analysed at six intervals viz., on the day of herbicide application, but two hour before, then at 7, 15, 30, and 60 days after herbicide application (DAHA) and at harvest so as to evaluate the changes in the chemical and biological properties. Data on analysis of soil samples before the period of experimentation revealed that soils from rice field of Kole land recorded physical, chemical, and biological characteristics which are more favourable for the growth of microflora. The chemical characteristics like pH, electrical conductivity, and organic carbon followed a decreasing trend towards the harvest in all the treatments. Decline in microbial biomass carbon (MBC) was observed upto harvest except on 60 DAHA. Pendimethalin treatment in S1 soil (medium organic matter) registered the highest per cent reduction in MBC with respect to control at different intervals. Percentage reduction in MBC due to herbicide application was comparatively lower in S2 (high organic matter) throughout the period of study. Activity of dehydrogenase, urease, acid phosphatase and alkaline phosphatase was higher in S2 compared to S1. In all cases, the enzyme activity increased upto 60 DAHA with slight variations and declined thereafter registering a peak at 60 DAHA. Among the four enzymes studied, urease recorded maximum increase at 60 DAHA followed by acid phosphatase, dehydrogenase and alkaline phosphatase. All the vegetative and yield parameters of rice were high in S2 (high organic matter soil) irrespective of the treatment combinations. Adverse effects of herbicides on the plant characters were minimal. Whole plant analysis for major nutrients also exhibited appreciably higher values in S2 compared to S1. Out of the five biological parameters analysed, microbial biomass carbon showed the highest variation from control at all the sampling intervals. The adverse effects of herbicides on MBC and enzyme activity followed the order: pendimethalin > bispyribac-sodium > oxyfluorfen > cyhalofop-butyl. Organic carbon had highly significant and positive correlation with all the biotic components viz., MBC, dehydrogenase, urease, acid and alkaline phosphatase activity at different sampling intervals consequent to herbicide application. Further study should be focused on identification of microbial diversity, effect of rhizosphere on biological activity and analysis of biological parameters with respect to crop growth stages consequent to herbicide application.
