Loading...
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.
Browse
65 results
Search Results
ThesisItem Open Access Recycling of cashew (Anacardium occidentale L.) leaf litter and cashew apple through vermitechnology(Department of Soil Science and Agricultural Chemistry, College of Horticulture, Vellanikkara, 2016) Indu, V K; KAU; Jayasree Sankar, SThe present study entitled “Recycling of cashew (Anacardium occidentale L.) leaf litter and cashew apple through vermitechnology was undertaken in the Department of Soil Science and Agricultural Chemistry and at Cashew Research Station,Madakkathara during 2012-2014.The objectives were to study the efficacy of different enrichners on the manorial value of vermicompost prepared from cashew leaf litter and cashew apple using compost worm Eisenia foetida, to identify the role of introduced microbes in decreasing compost maturity time and to evaluate enriched vermicompost as a manurial source in the potting mixture for raising cashew grafts. The objectives were achieved through two experiments viz., (1) preparation of enriched vermicompost and (2) adjudging suitability of enriched vermicompost as a component in potting mixture for cashew grafts. Ferro cement tanks of 1m3 dimension, 300 Kg capacity and lined with jute bags were used for producing vermicompost. All the tanks were initially added with basic feed mixture (cashew leaf litter, cashew apple, sawdust and cowdung in 3:3:2:6 ratio on weight basis. Along with the basic feed mixture, different substrates were added according to the treatments. The experiment was carried out in a Completely Randomized Design with three replications with five tanks per replication. Nutrient status of substrates and that of matured compost was recorded initially and after compost maturity. In addition, pH was also recorded before and after composting, pH ranged from 4.5 in cashew leaf litter to 7.6 in cow dungand poultry manure respectively. Organic carbon content varied from 23% in poultry manure to 49% in coconut leaf. C:N ratio was found between 402.5 in sawdust to 22.62 in poultry manure. The biochemical constituents viz, cellulose, phenol, tannin and lignin were highest in cashew leaf litter (45.9, 1.62, 0.62 and 13.4 mg/100 g respectively) as compared to cashew apple. The compost obtained from T9(T1+ glyricidia leaf+ coconut leaf+ poultry manure+ Trichoderma viride + Pleurotus sajarcaju@ 500 mg kg-1 each of substrate+ Bacillus sp @ 2 kg m-3of substrate) on maturity (120 days), recorded a pH of 7.4, OC (28.6%), N (2.9%), C:N ratio (11), P (0.90%), K (2.0%), total Ca and Mg (1834 & 1185 mg kg-1 respectively) which was highest among other treatments. Earthworm population increased from the initial 200 numbers to1935 numbers in T9 as against 972 in T2which contained Eudrilus euginiaeas the facilitating worms. Xv Daily observations on temperature, weekly observations on pH, total microbial count (initial and final stages), days for compost maturity and earth worm count at maturitywere theother important observations studied in the first experiment. Different treatments was found to have significant effect on temperature. It increased in all the treatments with the composting process, reached a peak and then decreased coinciding with maturity or cooling phase. Highest peak was attained for T9 with 32.5OC. pH of compost mixture were also influenced by the treatments. pH value increased in all the treatments with progress in composting and shifted towards a neutral condition. Maximum pH was associated with T9 (7.3). Number of days required for compost maturity was minimum in T9(120Days) whereas it was maximum in T1(135Days) and the count of earthwormpopulation was nearly nine fold in T9whereas it was only six fold in T1. The lowest multiplication level was observed with T2 which contained Eudrilus eugineae as the compost worms. Based on manurial value assessed by high content of major nutrients (2.4%,0.90% and 2.06% NPKrespectively), compost from T9 of experiment I was selected as the best and designated as enriched vermicompost. Its suitability as a component in potting mixture of cashew grafts was assessed in another experiment. The study consisted of four treatments in four replication with five poly bags (25 x 15cm and 300 gauge) per replication in a CRD Design. The scion for grafting was collected from variety ‘Dhana’. Performance of the grafted seedlings was evaluated for a period of three months. Observations included chemical analysis with and without applying vermicompost for OC, available N, P, K,Ca, Mg, Fe, Mn, Zn and Cu.In addition pH was also recorded. Among the four treatments studied,T4 (sand, soil and enriched vermicompost in 1:1:3 ratio) recorded highest nutrient status (2.75, 0.34 and 0.72 g kg-1 of NPK respectively).The number of days for seed germination was minimum in T4 (15) as against 20 days recorded for seed germination for T1. Other biometric observations like plant height (40.37cm), number of leaves (35) and collar girth (5.3cm) were observed maximum in plants grown in T4. Phytotoxicity was not seen in any of the treatments during the three months of evaluation. By employing the epigeic earthworms Eisenia foetida, the enormously available but untreated lignocellulotic solid organic resource, cashew leaf litter and cashew apple, could be effectively converted to nutrient rich vermifertilizer by suitably admering with various organic enrichners. The vermifertilizer thus produced could be efficiently used as a component in the potting mixture for raising cashew plants. Crop performance was the best when the vermifertilizer was mixed at three parts on volume basis with one part each of xvi sand and soil. Based on results vermicomposting could be established as a ecofriendly and ecologically sound method for manure from cashew leaf litter and cashew appleThesisItem Open Access Physico-chemical properties of rain water harvested under different situations in lateritic(Department of soil science and agricultural chemistry, College of horticulture,Vellanikara, 2014) Ibrahim Hassen, Abdu; KAU; Betty BastinRain water harvesting is universally accepted as an important measure of water conservation throughout the world. The quality of irrigation water has become a more serious problem than quantity in different parts of the world. The characterization of quality of water is crucial for assessing the suitability for i rrigation. Hence a study was taken up on “Physico-chemical properties of rain water harvested under different situations in lateritic soil’’ in the main campus of Kerala Agricultural University, Vellanikkara during September, 2012 to August 2013. The objective of the study was to compare the physico-chemical properties of rain water from different water sources in lateritic soil. Water was collected from five sources viz, rainfall (RF), rain water harvesting pond (RWH) , Kotteppadom pond (KP), well water (W) and surface runoff (SR). The experiment for surface runoff study was laid out in an area with a gentle slope between 5 – 10 per cent . Four rain pits were dug in this area with dimensions of 0.5 m x 0.5 m x 0.5 m and lined by polyethene sheet. Water samples were taken from these water sources for one year at monthly intervals and they were analyzed for various physicochemical parameters such as colour, turbidity, pH, EC, TDS, COD, BOD, SAR, RSC, NO 3 - , Cl - and Fe. The amount and distribution of rainfall received as well as the inflow to the rain water harvesting pond were also studied. Soil samples were collected from around rain-pits before and after rains and analyzed for the content of nutrients. The total quantity of rainfall during the study period was 2872.0 mm. The maximum amount of rainfall was observed in June and the minimum in January, 2013. The amount of rain water harvested in pond during the study period was 625.48 m which comes to 63 per cent of its storage capacity. The quality of water from different sources was compared based on the results of physico-chemical analysis. It was found that pH was highest (6.69) for water from Kotteppadom pond during summer and lowest (5.54) for water from rainfall during post monsoon season. The EC and TDS values were maximum for well water during pre- monsoon season and there was significant difference among the different sources. There was no significant difference among the sources of water as regards the content of Cl and NO 3 - over the different seasons. The values for BOD and COD varied significantly over the different sources as also the seasons. Significant difference was observed for SAR and RSC values among the different sources and seasons. Loss of nutrients from soil via surface runoff from a sloppy area was studied. Soil samples were analyzed for various physico-chemical parameters such as pH, EC, OC, 3 available N, P, K, Ca, Mg, Fe, BD, PD and WHC. The different parameters were estimated both before and after receipt of rainfall. The mean values of these parameters and percent changes along with t-value were found out. During summer, after the rains, there were significant changes for the parameters like pH, OC, as well as available nutrients like K, Ca, Mg, Fe, and the percentages of decrease were 1.67, 0.67, 37.94, 25.46, 5.62 and 8.85 respectively. The water holding capacity was also decreased by 4.80 per cent. During monsoon, available nutrients like N, P, K, and WHC decreased to the extent of 23.68, 26.24, 49.32 and 7.29 per cent respectively. In general, it was found that the rainfall and rain water harvested in the water harvesting pond were superior to well water, KP pond water and surface run off water. Salinity was low for water from all the sources. Surface run off in an area with moderate slope (5-10 %) resulted in loss of nutrients like K, P, Mg and Ca. -ThesisItem Open Access Long term effect of field management on soil quality in ultisol(Department of soil science and agricultural chemistry, College of Horticulture,Vellanikkara, 2013) Nithya, A M; KAU; Betty BastinSoil quality is directly related to agricultural sustainability. Assessment of soil quality is essential for determining the sustainability of land management systems. It is generally accepted that intensive agricultural production leads to a decline in soil quality. For this reason, it is highly essential to monitor soil quality to avoid soil degradation and in doing so, preserve the production capabilities of the land and protect environment. The response of soils to management and input depends on soil quality. It is therefore important to identify the soil characteristics responsible for changes in soil quality, which may eventually be considered as soil quality indicators for assessing agricultural sustainability. The present investigation has been undertaken to study the “Long term effect of field management on soil quality in Ultisol”. It was conducted in the main campus of Kerala Agricultural University, Vellanikkara during December, 2012 to June, 2013. The objective of the study was to evaluate the soil quality under different long term field management conditions in an Ultisol (Vellanikkara series) based on physical, chemical and biological indicators. Here, an attempt has been made to evaluate the physical, chemical and biological properties of soil using available soil quality indicators. Five different fields were selected namely, natural forest, rubber plantation, cocoa garden, STCR experimental field and tapioca fields. Soil samples were collected from three depths namely 0-15 cm, 15-30 cm and 30-60 cm. The different sampling sites within each field were selected based on slope percentage. The samples were characterized for soil texture, aggregate size distribution, soil temperature, water holding capacity, single value constants, pH, EC CEC, AEC, SiO2/R2O3, organic carbon , lime requirement, available macronutrients, secondary nutrients, micronutrients, counts of bacteria, fungi and actinomycetes and enzyme activity. The sampling areas were also surveyed and documented for the presence of earthworms and termites. The physical characteristics like water holding capacity, soil aggregate stability and soil temperature showed a decreasing trend with depth in the different fields. Forest ecosystem showed the most conducive physical characteristics followed by cocoa and rubber. The contents of available nutrients, secondary nutrients and micronutrients were found to be the highest in surface samples. The forest ecosystem showed relatively high values for organic carbon, and available nutrients like nitrogen, sulphur, boron, iron, manganese, zinc and copper. Microbial activity was found to be the highest in surface soils in almost all fields. The highest counts of bacteria and actinomycetes were reported in forest ecosystem and lowest in tapioca field. Fungal activity was found to be the highest in cocoa field followed by forest ecosystem. Enzyme activity was also found to be the highest in surface soils in the different fields. Soil quality was evaluated using available soil quality indicators. Based on scoring with the soil quality parameters, the highest scoring was observed for natural forest followed by cocoa field. Correlations between various soil quality parameters of different fields were also worked out. .ThesisItem Open Access Silicon availability of tropical soils with respect to rice nutrition(Department of Soil Science and Agricultrural Chemistry, College of Horticulture,Vellanikkara, 2016) Arya Lekshmi, v; KAU; Jayasree Sankar, sSilicon (Si) is the second most abundant element in soil. The amount of silicon in soil depends on parent material, soil type, pedogenic process and landscape. In soil solution, Si is present as monosilicic acid which is the only form that the plant can absorb from soil. The productivity of rice is comparatively low in soils of Kerala. As a ̳Si – accumulator‘, rice can benefit from Si nutrition. The application of Si can enhance growth and yield of rice. With this background, studies were conducted to categorize major rice growing soils of Kerala according to plant available silicon and to evaluate the efficacy of different sources of silicon including rice straw in wetland rice. The release of silicon from different soils added with various silicon sources under different water regimes was also monitored. Soil samples were collected from five different locations representing major rice growing regions of Kerala viz., Kuttanad, Kole land, Pokkali, sandy and lateritic to categorize them according to plant available silicon. The available Si ranged from 7.70 mg kg -1 (sandy soil) to 34.91 mg kg -1 (Kole land soil) in the order Kole land > Pokkali > lateritic > Kuttanad > sandy soil. All the soils under study were categorized as low in available Si. The available Si had positive correlation with organic carbon, available N, Ca, Mg, Fe, Mn, Zn, exchangeable K, Ca, Mg and CEC and negative correlation with available boron, AEC and silica-sesquioxide ratio. These soils were subjected to fractionation of silicon. The major fractions of Si were mobile, adsorbed, organic, occluded, amorphous and residual Si. The percentage distribution of fractions of Si in these soils were in the order; residual Si > amorphous Si > occluded Si > organic Si > mobile Si > adsorbed Si. Quantity – intensity relationship of five major rice growing soils at two temperatures viz. 25 0 C and 40 0 C were studied. The highest buffer power was indicated by Kuttanad soil followed by Pokkali and sandy soils at 25 0 C. It clearly indicated that these soils have a higher power to retain Si on solid phase and replenish its concentration in soil solution as and when it is depleted through plant uptake or leaching. The equilibrium Si concentration and the amount of Si adsorbed by each soil were used to test the fitness of data to the adsorption isotherms viz., Langmuir, Freundlich and Temkin. The data obtained from the adsorption experiments fitted into Freundlich and Temkin equations, but not to Langmuir equation at 25 0 C. At 40 0 C no adsorption equations were obtained for any soil.An incubation study was conducted to know the extent of release of Si on addition of different sources of silicon such as rice husk ash, biodecomposed rice husk, calcium silicate and sodium silicate in five rice growing soils under submerged water regime (SWR) and field capacity water regime (FCWR). Addition of Si significantly increased the release of available Si in all soils except Kole land soil after a month. Kole land soil showed higher release of available Si after two months. The highest release of available Si was at SWR in case of Kole land and Kuttanad soil, where as Pokkali, sandy and lateritic soils showed more release of available Si at FCWR. Irrespective of soils, treatment with sodium silicate showed higher release of available Si. Total Si showed a decreasing trend over the period of incubation for three months in all the soils. A field experiment was conducted at Agronomic Research Station, Chalakudy to evaluate the efficacy of different sources of silicon including rice straw in wetland rice. Rice husk ash, biodecomposed rice husk, calcium silicate and sodium silicate were used as source of Si along with fertilizers as per package of practice recommendation (NPK alone). The maximum number of panicles per hill, number of spikelets per panicle, thousand grain weights and minimum number of unfilled grains per panicle were recorded in treatment with calcium silicate application. The maximum grain yield of 6.90 t ha -1 was recorded in treatment T 5 (T 2 + Calcium silicate) and significantly superior (fig.54) over all other treatments. This increase in yield may be due to the effect of application of Si on soil fertility, nutrient uptake, and plant growth. The direct effect of Si fertilization on increased number panicle per hill, number of spikelets per panicle, and thousand grain weight and decreased number of unfilled grains per panicle might be the reason for increased grain and straw yield in treatment with calcium silicate. The treatment with POP + sodium silicate showed the highest uptake of Si by grain and straw of rice. The sources of Si had no residual effect on grain and straw yield of succeeding rice crop. In general, sandy soil low in available Si had a high response to applied Si in achieving higher grain yield.ThesisItem Open Access Enzyme Characterization of the acid sulphate soils of Kuttanad(Department of Soil Science and Agricultural Chemistry, college of Agriculture, Vellayani, 2016) Arya Nath V; KAU; Aparna, BRegarding the enzyme status of the acid sulphate soils, the activity of urease was the highest in Thakazhi (L4-75.78 ppm of urea hydrolyzed g-1 soil h-1) in the surface layer. Acid and alkaline phosphatase activities were found to be the highest in Purakkad (L3-57.58 μg pnp released g-1 soil h-1) and Thakazhi series (L4-46.41 μg pnp released g-1 soil h-1) respectively in the surface layers. The highest activity of dehydrogenase was noticed in Thuravur series (L6-115.74 μg of TPF released g-1 soil 24 h-1) in the surface and Kallara series in the subsurface layers (L2-55.39 μg of TPF released g-1 soil 24 h-1). Karappadam and Kayal recorded the values of 145.73 and 114.80 μg of TPF released g-1 soil 24 h-1 for dehydrogenase activity respectively at surface layers. With regard to the microbial population, Thottappalli (L5) recorded the highest total bacterial count and fungal population in both surface and subsurface layers. Thiobacillus spp. recorded the highest population of 9.08 log cfu g-1 of soil at Kallara series (L2) while P solubilizers recorded the highest count at Ambalapuzha series (L1). Thuravur series recorded the highest actinomycetes population in subsurface soils. Micahelis – Menten constant, Km and the maximum velocity Vmax for different enzymes were determined and it was observed that for dehydrogenase Vmax value was found to be the highest in 6th week and for phosphatase only after 12th week of incubation. Thematic maps were prepared based on themes like microflora and enzyme status using GIS (ARC VIEW). Hence the study conclude that, with respect to biological fertility status of the study area, Purakkad recorded the highest enzyme activity number (23.69) at 0-15 cm, while Kallara series recorded the highest enzyme activity number in the subsurface layer and are observed to be biologically sustainable.ThesisItem Open Access Characterization and evaluation of on-farm liquid organic manures on soil health and crop nutrition(Department of Soil Science and Agricultural Chemistry, College of Agriculture, Vellayani, 2017) Sreya, U Parvathi; KAU; Ushakumari, KThe experiment entitled “Characterization and evaluation of on-farm liquid organic manures on soil health and crop nutrition” was undertaken at College of Agriculture, Vellayani during 2014-2017.The study was envisaged to characterize the on-farm liquid organic manures viz., cow urine, panchagavya, fish amino acid, vermiwash and jeevamrutha, to monitor the nutrient release pattern under laboratory conditions and to evaluate the efficacy of soil and foliar applications of these liquid manures on soil health and crop nutrition using bhindi as test crop. The study consisted of three parts. The first part comprised the preparation and characterization of above said on-farm liquid organic manures. These manures were prepared as per standard procedures and characterization study was conducted to determine the physical, chemical, biological and biochemical properties. Physical properties viz., colour and odour of different on-farm liquid organic manures were recorded. Among the liquid organic manures studied, fish amino acid and panchagavya showed acidic pH and other three liquid organic manures viz., cow urine, jeevamrutha and vermiwash recorded neutral pH. Regarding EC, jeevamrutha recorded the lowest value (1.53 dSm-1).The highest OC content (39.96%) was recorded by fish amino acid followed by panchagavya. Among the major nutrients, the highest N content (0.45%) was found in panchgavya followed by fish amino acid. The highest P content was recorded by FAA (0.41%). Maximum K content (0.17%) was recorded in cow urine followed by panchagavya, vermiwash and jeevamrutha. S content of all the liquid organic manures were higher compared to Ca and Mg content. The highest contents of Ca, Mg and S were recorded by fish amino acid. The Fe content (39.92mg L-1) was highest in jeevamrutha and the lowest in fish amino acid. Cow urine was found to be rich in Mn (0.400 mg L-1) and Cu (21.21 mg L-1).The maximum zinc content (2.00 mg L-1), IAA (6.00μg ml-1) and GA (35.00μg ml-1) were found in fish amino acid. Panchagavya was rich in cytokinin (2.82 mg L-1) whereas, ascorbic acid content (37.50 mg 100g-1) was the highest in vermiwash. Fish amino acid was registered the highest enzyme activities, except for dehydrogenase activity which was found to be maximum in cow urine (371.27 μg of TPF g -1soil 24 h-1) followed by fish amino acid (336.98 μg of TPF g -1soil 24 h-1). The maximum population of bacteria was observed in vermiwash and fungal population was presented in all liquid organic manures except cow urine. The highest azotobacter population was observed in fish amino acid. K solubilizers were found to be the highest in vermiwash whereas E.coli, P solubilizers, azospirillum and Pseudomonas sp. were not detected in any of the above liquid organic manures. The second part of the experiment was laboratory incubation study to monitor the nutrient release pattern from soil treated with the on-farm liquid organic manures for a period of two months. The study consisted of 6 treatments which included soil alone and soil treated with 10 per cent dilution of all the liquid organic manures separately and all the treatments were maintained at 60 per cent moisture level. In general increased pH and EC values were observed in all the treatments received diluted liquid organic manures compared to control. Regarding the release of major, secondary and micronutrients, there was significant difference in available nutrient contents between treatments during the periods of incubation. Regarding the release of N and P during incubation study, soil along with FAA 10 per cent recorded the highest release pattern whereas soil along with cow urine 10 per cent recorded the highest K release throughout the incubation period. There was increased release of Ca in the treatments received liquid organic manures. The highest Mg release throughout the incubation period was registered by the treatment received cow urine 10 per cent. Available iron content was higher in T5 (soil 5 kg + jeevamrutha 10 %) compared to other treatments. A significant difference was found among treatments with respect to available Zn content. Initially (0th day of incubation), all the treatments were recorded higher values compared to values recorded on 7th ,15th ,30th , 45th and 60th days of incubation. There was increasing trends in the Cu content of soil from 0th day of incubation to 60th day of incubation except in the case of T3 (soil 5 kg + FAA 10 %). Treatment T1 (soil without treatments) recorded the lowest values for all nutrients throughout the incubation period. The third part of the experiment was to evaluate the efficacy of soil and foliar applications of on-farm liquid organic manures in a pot culture experiment using bhindi as test crop. The treatments included were 75 per cent N as enriched vermicompost along with diluted liquid organic manures separately as soil and foliar applications. Plant height, LAI, dry matter production, number of flowers, number of fruits per plant and total fruit yield were found to be the highest in T5 (75 % N as EVC + panchagavya 3 % foliar application). Chlorophyll a, b and total chlorophyll content were the highest in T10 (75 % N as EVC + jeevamrutha 10 % soil application). T1 (KAU PoP) recorded the highest average fruit weight. T4 (75 % N as EVC + FAA 5 % soil application). registered the highest crude protein content while crude fibre content was lowest in T7 (75 % N as EVC + cow urine 10 % foliar spray). Ascorbic acid content was the highest in T5 (75 % N as EVC + panchagavya 3 % foliar spray) and was on par with T7, T2,T9 and T11. The results of the post harvest analysis of soil revealed that pH, EC, organic carbon and labile carbon contents varied significantly among the treatments. The highest organic carbon content of soil was recorded by T4 (75 % N as EVC + FAA 3 % soil application) and T12 (75% N as EVC + vermiwash 10 % soil application). The maximum labile carbon was recorded by T8. T5 (75 % N as EVC + panchagavya 3 % foliar spray) was rich in available N. Soil enzyme activities were influenced by the application of liquid organic manures. The treatment T5 registered the highest plant uptake of major nutrients. The treatment T3 registered the highest plant uptake of secondary nutrients. The highest value of Fe and Zn uptake was noticed in T11.(75 % N as EVC + vermiwash 10 % foliar spray). The highest value of Cu uptake was noticed in T1 (KAU PoP). The highest value of Mn uptake was noticed in T3 (75 % N as EVC + FAA 5 % foliar spray) . The lowest plant uptake of all nutrients were recorded by T13 (Absolute control). Economics of cultivation of bhindi indicated that cost benefit ratio was found higher for treatment T5, 75 per cent N as EVC + panchagavya 3 per cent foliar application (2.83) followed by T7, 75 per cent N as EVC + cow urine 10 per cent foliar spray (2.09). From the above study, it was concluded that the recommended dose of inorganics (KAU PoP) can be substituted with combined application of enriched vermicompost (enriched with azolla 10 %) to get 75 per cent N and foliar application of 3 per cent panchagavya or soil application of 10 per cent cow urine or 5 per cent fish amino acid at 10 days intervals. Soil health, in terms of physical, chemical, biological and biochemical properties of soil was more enhanced in the treatments received soil application of liquid organic manures. Liquid organic manures viz., cow urine, panchagavya, jeevamrutha, fish amino acid and vermiwash were easily preparable in the farmers’ farm, biodegradable, less expensive, eco-friendly and non-hazardous for human health and environment. From the study it was found that above liquid organic manures were very good organic sources for organic farming and sustainable agriculture.ThesisItem Open Access Sequestration of carbon as influenced by nutrient management practices under long term fertilizer experiments(Department of Soil Science and Agricultural Chemistry, College of Horticulture, Vellanikkara, 2017) Sumayya Sulaiman; KAU; Thulasi, VThe present study entitled “Sequestration of carbon as influenced by nutrient management practices under long term fertilizer experiments” was undertaken at RARS, Pattambi and College of Horticulture, Vellanikkara. The soil samples were collected from the plots of Permanent Manurial Trial (PMT) and AICRP on long term fertilizer experiments (LTFE) at Pattambi after the harvest of rice (Virippu crop), 2016. New Permanent Manurial Trial with dwarf indica rice variety, was started in Virippu, 1973. The AICRP on Long term fertilizer experiment was initiated in Mundakan 1997. The two field experiments where being conducted continuously in the same fields, the present Virippu crops of these experiments being in their, 89th and 39th season respectively. The objectives were set out to study the effect of long term application of fertilizers and manures on soil carbon pools, thermal stability of stored carbon and growth characteristics of plant. The PMT consists of 8 treatments viz.,T1: 90 kg N ha-1 as cattle manure, T2: 90 kg N ha-1 as green leaf manure, T3: 45 kg N ha-1 as cattle manure + 45 kg N ha-1 as green leaf manure, T4: 90 kg N ha-1 as ammonium sulphate, T5: 45 kg N ha-1 as cattle manure + N:P2O5:K2O 45:45:45 kg ha -1, T6: 45 kg N ha-1 as green leaf manure + N:P2O5:K2O 45:45:45 kg ha -1, T7: 22.5 kg N ha-1 as green leaf manure + 22.5 kg N ha-1 as cattle manure + N:P2O5:K2O 45:45:45 kg ha -1 and T8: N:P2O5:K2O 90:45:45kg ha -1. The LTFE consists of 12 treatments viz.,T1: 50 per cent NPK (as per KAU POP recommendation), T2 : 100 per cent NPK, T3 : 150 per cent NPK, T4 : 100 per cent NPK + 600 kg ha -1 CaCO3, T5 : 100 per cent NPK, T6 : 100 per cent NP, T7 : 100 per cent N, T8: 100 per cent NPK + FYM @ 5 t ha -1to the virippu crop only, T9: 50 per cent NPK + FYM @ 5 t ha -1,T10 : 100 per cent NPK + in situ growing of Sesbania aculeata (for Virippu crop only), T11 : 50 per cent NPK + in situ growing of Sesbania aculeata (for Virippu crop only) and T12 : Absolute control (No fertilizers or manures). In PMT, the organic nutrient management (T1) and Integrated Nutrient Management (INM) practice (T5) were equally superior in growth and productivity of the crop. However the dehydrogenase activity and microbial biomass carbon was significantly influenced by the INM practice. The physiological properties of the plant like stomatal conductance and photosynthetic rate, yield attributes such as panicle length, number of panicles per plant and number of filled grains corroborated the trend in yield. The available primary nutrient status of the post harvest soil was higher in T8 (N: P2O5: K2O 90:45:45kg ha -1). However the substitution of 50 per cent mineral N by organic manures under INM treatments improved the available nutrient status suggesting the synergistic role of organic manures. In LTFE, the integrated nutrient package (T8) had significantly higher dehydrogenase activity and microbial biomass carbon in post harvest soil which was positively reflected on yield and yield attributes. Application of FYM had beneficial role over green manures towards organic carbon build up in soil. In LTFE with 20 years history, it was seen that all the carbon pools (active, slow and passive) contributed towards yield whereas in PMT, with 44 years history, it was the slow pool of carbon that showed higher correlation with crop yield. Data on analysis of different carbon pools revealed that slow pool is the most predominant yield determining pool in the long run. The percentage contribution of carbon pool towards total soil organic carbon in paddy soil of the present work can be rated as passive (54%) > slow (36%) > active (10%). An incubation study was conducted at four different temperature regimes (15, 25, 35 and 450C) using the soil collected from the plots of LTFE as well as PMT. The activation energy and the rate constants provided a good insight on decomposability of organic matter. In general, all the treatments in PMT, except T5 (25°C), T6 (15°C) and T8 (35 and 45°C) had comparable amounts of carbon decomposition. Thermal stability studies indicated that the rate of reaction decreased with increase in temperature due to the faster exhaustion of the substrates in initial days of decomposition at higher temperatures. Q10 values were also less than one in both the experiments due to the exhaustion of labile pool available for microbial decomposition. Treatments with inorganics recorded lowest activation energies indicating the instability of even recalcitrant or passive pools. It could be summarized from the results that, the carbon build up in soil was significantly higher under organic nutrient management. But the per cent share of slow carbon pool (Mean Residence Time: 20-40 years) to total carbon was higher under INM. Moreover, the thermal stability of carbon was found to be remarkably higher under INM than sole application of organic manures or inorganic fertilizers. The study fortifies INM as a stable practice to sustain soil organic carbon and crop productivity in the context of rising temperatures. Chemical and physical stability of carbon and its threshold carbon concept in soils of Kerala need to be explored.ThesisItem Open Access Response of tomato to calcium and boron in the onattukara tract of alappuzha district(Department of Soil Science and Agricultural Chemistry, College of Agriculture, Vellayani, 2017) Aswathy Mohan; KAU; Indira, MThe experiment entitled “Response of tomato to calcium and boron in the Onattukara tract of Alappuzha district” was conducted at the ORARS, Kayamkulam during the period from September to December 2016. The objective of the study was to find out the effect of calcium and boron on yield and quality of tomato and to develop a recommendation for these nutrients to optimize the productivity. The experiment was laid out as factorial RBD (42 + 1) with two replications. The treatments included two factors viz. calcium levels and boron levels. The calcium levels were- no calcium (Ca-0), full dose of calcium as basal (Ca-1), half dose of calcium as basal (Ca-2) and one fourth dose of calcium as basal (Ca-3). Calcium was supplied through CaO and the dose of calcium was worked out from lime requirement by SMP (Buffer method by Shoemaker et al.) method. Levels of boron were – no boron (B-0), foliar spray 0.1% (B-1), foliar spray 0.2% (B-2) and foliar spray 0.3% (B-3). Boron was supplied through borax at 50% flowering stage. The Package of Practices Recommendations of KAU (20 t ha-1 FYM and 75:40:25 kg ha-1 NPK) was uniformly followed in all treatments. The control treatment was soil test based application of N, P, K, recommended dose of lime and B. Results of the study revealed that the application of calcium had a significant effect on biometric characters, per cent incidence of physiological disorders, soil pH and plant uptake of nutrients. Application of full dose of calcium as basal (Ca-1) recorded the highest yield. The lowest incidence of blossom end rot and fruit cracking was observed in Ca-1. The highest B : C ratio was also observed in Ca-1. Calcium application did not have any significant effect on available nutrients except calcium. Ca-1 recorded a significant effect on the plant content of calcium. It also contributed to a significant effect on the uptake of nutrients such as N, P, K, Ca, Mg, S, B, Fe, Cu, Mn and Zn. Boron application produced significant effect on biometric characters, per cent incidence of physiological disorders and plant uptake of nutrients. Among various levels, foliar spray of 0.3% boron (B-3) was found to be the best treatment. B-3 has recorded the highest yield and B: C ratio. It also produced the lowest incidence of fruit cracking. Boron application did not have any significant effect on soil available nutrients, soil pH and plant content of nutrients except plant boron. B-3 has also contributed to a significant effect on the uptake of nutrients such as N, P, K, Ca, Mg, S, B, Fe, Cu, Mn and Zn. Among various interactions, application of full dose of calcium as basal along with foliar spray of 0.3% boron (Ca1B3) has contributed to the maximum yield, B: C ratio and the lowest incidence of fruit cracking. Ca1B3 recorded the highest uptake of nutrients such as N, P, K, Ca, Mg, S, Fe, Cu and Mn. None of the interactions were observed to be significant for soil pH, soil available nutrients and plant nutrient content. But the application of Ca and B produced no significant effect on the quality characters such as TSS, lycopene content and ascorbic acid contents. From the results of the study, it can be concluded that higher yield of tomato in Onattukara tract of Alappuzha district can be obtained by the combined application of full dose of calcium as per lime requirement of the soil along with 0.3% foliar spray of boron (Ca1B3) in addition to the blanket recommendations of KAU (20 t ha-1 FYM and 75:40:25 kg ha-1 NPK).ThesisItem Open Access Chemistry and transformations of calcium and magnesium in tropical acid soils of kerala(Department of Soil Science and Agricultural Chemistry, College of Agriculture, Thrissur, 2017) Bhindhu, P S; KAU; Sureshkumar, PCalcium and magnesium are indispensible as secondary nutrients for plant growth. Availability of these nutrients to plants depends on the form and quantity present in soil. Soils of the tropics normally pose the problem of acidity due to high rainfall and leaching of bases causing widespread deficiency of these nutrients. The study aims at characterization of soil samples from 23 agro ecological units of Kerala with respect to supplying power, chemistry, dynamics, transformations and availability indices of calcium and magnesium and also to optimize the level of calcium and magnesium for rice nutrition in lateritic soils. Sixty four representative soil samples from 23 agro ecological units under five agro ecological zones of the state were collected and characterised for physico-chemical properties. Among these soils, ninety two per cent were acidic in reaction, of which sixty three per cent were strongly to very strongly acidic (4.5-5.5). Lowlands of Kuttanad, Pokkali and Kaipad were extremely to ultra acidic. Twenty seven per cent of samples were deficient (< 300 mg kg-1) in available calcium, while sixty seven per cent samples were deficient in available magnesium (< 120 mg kg-1). Deficiency was negligible in soils from Attapady hills (AEU 18 and 19), Palakkad central and eastern plains (AEU 22 and 23) and the lowlands of Kuttanad, Pokkali, and Kaipad (AEU 4, 5 and 7). The availability of calcium and magnesium increased with pH, cation exchange capacity and decreased with increase in exchangeable aluminium. Forty one soil samples from different agro ecological units were subjected to sequential fractionation. The mean per cent contribution of different fractions to total calcium was in the order exchangeable > mineral > acid soluble > water soluble > organic complexed, whereas in the case of magnesium, it was observed as mineral > acid soluble > exchangeable > water soluble > organic-complexed. Exchangeable calcium and water soluble magnesium were the sole forms contributing directly to the available pool. The quantity-intensity relationship of calcium and magnesium in twenty- three soils belonging to different AEUs of Kerala were studied at 25oC and 40oC. Potential buffering capacity or the supplying power of soil had significant positive correlation with CEC and exchangeable cations in soil. The adsorption data of both calcium and magnesium at 25oC and 40oC were best explained by Tempkin adsorption isotherm indicating that the affinity for adsorption decreases linearly with degree of saturation. The change in free energy of adsorption for calcium and magnesium was negative in all the soils studied signifying the spontaneous nature of adsorption. The change in enthalpy (ΔH0) was negative in most of the soils indicating the process to be exothermic. The close correlation of enthalpy change with change in entropy proved that as the enthalpy change becomes more negative, stronger is the bond and more orderly is the adsorption. The incubation experiment conducted to study the effect of organic matter on the adsorption of calcium and magnesium revealed a positive influence of organic matter on availability of calcium and magnesium. The addition of organic matter improved the supplying power with respect to calcium and magnesium either through mineralization or formation of stable soluble complexes especially at higher pH. Two field experiments to optimize the level of calcium and magnesium nutrition for rice in low land of north central laterites (Pattambi) revealed the clear role of calcium and magnesium in improving the yield and yield attributing characters of the crop. Application of dolomite as per ΔpH was found to be effective in increasing the yield and maintaining optimum level of calcium as well as magnesium in soil. Application of lime was not found to influence the in situ soil pH. The response of crop to magnesium showed yield improvement to the tune of 1.18 t ha-1 by application of magnesium sulphate @ 120 kg ha-1. Residual effect of dolomite had significant influence on the yield of rice whereas no residual effect of applied magnesium sulphate was evident. The correlation studies and path analysis clearly indicated that plant absorption of calcium mainly takes place from exchangeable fraction and that of magnesium from water soluble fraction.
