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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 Site specific nutrient management for chilli (Capsicum annum.L) in kalliyoor panchayath of kerala(Department of Soil Science and Agricultural Chemistry,College of Agriculture,Vellayani, 2011) Priya, U K; KAU; Sudharmai Devi C RSite Specific Nutrient management is a technology in precision fanning that offers chance for farmers to achieve the targeted yield taking into consideration the potential yield of the crop by application of apt amount of fertilizers. The technology is farmers' friendly, eco-friendly and also consumer friendly. In Indian scenario wherein farmers are suffering from yield losses up to 40% due to micronutrient deficiency of soils mainly zinc and boron deficiencies are the yield limiting factors of production. Kerala the soils are low in basic ions that are posing serious threat to crop production. The Judicious application of chemical fertilizers along with micronutrients is necessary for sustainable crop production. The present study "Site Specific Nutrient Management in" Chilli (Capsicum annuum.L.) in Kalliyoor Panchayath Of .Kerala" was carried out to satisfy the objectives viz. study the spatial variability of area, to find outtheindigenous nutrient supply via omission trials, fix a target yield based on the potential yield of the crop and formulate a site specific nutrient recommendation to obtain the targeted yield. In order to understand the spatial variability survey was conducted at 25 sites of Kalliyoor panchayath. The results of survey showed that the soils showed wide variation in terms of soil physical and chemical properties. Soil phosphorus status , was high in all cases other nutrient concentration ranged from low to high. The spatial variability necessitated carrying out the omission trials at four different sites that were ranked according to the nutrient status into high, medium first level, medium second level and low fertility soils. From the omission trials the recovery fraction and, indigenous nutrient supply were calculated. Utilising all these parameters in QUEFT model SSNJ\:1.--tre tments were fixed. /' / / - :l.33- The high yield target was fixed at 16 t ha that was 50% of the potential yield. The nutrient recommendation generated for HYT was 104.8: 13.6: 201 kg N, P205 and K20 ha-I. Medium yield target was fixed at 168:51: 230 kg N, P205 and K20 ha- I. Taking into account micronutrient and secondary nutrient deficiencies in the soil. In high yield target soil application of micro nutrients and secondary nutrients along with application of 1 % foliar spray of boron was recommended. Micronutrients for soil application were boron @ 5 kg ha-I in form of borax, zinc @ 20 kg ha-I in form of zinc sulphate. Secondary nutrients applied were calcium @ 30 kg ha-I in form of CaS04, magnesium @ 7.5 kg ha-I in form of MgS04. The requirement of sulphur was met from soil applied zinc sulphate, calcium sulphate and magnesium sulphate. In medium yield target only soil application of micro and secondary nutrients along with the application of QUEFT generated recommendations for the crop; POP + micronutrient recommendations were evaluated. Simultaneously an absolute control was also carried out. Soil analysis was carried out for all the physical and chemical properties of the soil initially before the crop was raised, and after each harvest. So that change in soil properties as a result of application of treatments could be evaluated, since the application of fertilizer coincided with each harvest. The results derived from the experiment proved the superiority of SSNM over other treatments with respect to the yield major nutrient and micronutrient uptake. , Where high yield target registered a cumulative yield of 17. 32 tons, medium yield target registered a cumulative yield of 11.75 tons this was _much superior to POP+SNMN that registered an yield of 9.83 tons, or the package of practice recommendation that registered an yield of only 8.3 tons . Farmers practice registered inferior yield data of only 5.2 tons. The study revealed that the site specific nutrient management is an efficient technology to increase the yield of crops and hence provide additional income to the farmers; this technique also provides a -134 - scope of increasing the yield without over application of fertilizers that would result in deterioration of the soil physical and chemical properties in long run.ThesisItem Open Access Nitrogen and sulphur interaction on their release pattern and use efficiency in ferralitic soils.(Department of Soil Science and Agricultural Chemistry,College of Agriculture, Vellayani, 2011) Mariya Dainy, M S; KAU; Usha, P BAn experiment was carried out at College of Agriculture, Vellayani to investigate the interactive effect of nitrogen and sulphur on their release pattern and use efficiency in ferralitic soils with bhindi as the test crop. The experiment consisted of an incubation study and a field experiment. The incubation study was carried out to understand the release pattern of N and S from their sources viz. urea and gypsum in the soil at different sampling stages (30 and 100 days of incubation) using ferralitic soil kept at field capacity. The treatments consisted of M1N1S1, MINIS2 , M1N1S3 , M1N2S1 , M1N2S2 ,M1N2S3 ,M1N3S1 , M1N3S2 , M1N3S3 , M2N1S1 , M2N1S2 , M2N1S3 , M2N2S1 , M2N2S2 , M2N2S3 , M2N3S1 , M2N3S2 and M2N3S3 and M0N0S0 . Levels of N include N1 (50 kg ha-1), N2 (80 kg ha-1) and N3 (110 kg ha-1). M1 include P2O5 @ 8 kg ha-1+ K2O @ 25kg ha-1 (current POP) and M2 include P2O5 @ 35 kgha-1 + K2O @ 70 kg ha-1(modified POP). Different levels of S are S1 (10 kg ha-1), S2 (15 kg ha-1) and S3 (20 kg ha-1). Soil samples were collected and analyzed for pH, available N and available S content. There was increase in pH value to the neutral range at fifty per cent flowering stage (30 Days of Incubation) and all the treatments showed a decreasing trend in the pH value at 100 Days of Incubation. Available N and available S content increased to some extent at fifty per cent flowering and decreased at the final harvest stage. Application of N up to 110 kg ha-1 significantly increased the available N status of soil and S application up to 20 kg ha-1 increased the soil S status during incubation. The field experiment was laid out in 2×3×3+1 factorial RBD having three replications using bhindi variety Varsha Uphar as the test crop. The treatments were similar to that of the incubation study. S application @15 kg ha-1 significantly reduced the internodal length. N and S interaction N @ 80 kg ha-1 and S @ 15 kg ha-1 showed significant influence on fruit length. The maximum number of fruits and highest yield was obtained when the nutrients were applied @ 80 kg N ha-1 + 8 kg P2O5 ha-1 + 25 kg K2O ha-1 + 15 kg S ha-1. Considering the N and S interaction effects, combined application of N @ 80 kg ha-1 and S @ 20 kg ha-1 increased the number of fruits and yield. Application of N up to 80 kg ha-1 increased the crop yield and above this level, there was reduction in yield. The increase in number of fruits per plant by the application of N and S may be due to the highest uptake and efficient utilization of nutrients. N @ 110 kg ha-1 and S @ 20 kg ha-1 recorded the highest dry matter content. S application @ 15 kg ha-1 showed significant influence on N Use Efficiency (NUE) in bhindi. Application of 80 kg N ha-1 + 8 kg P2O5 ha-1 + 25 kg K2O ha-1 + 15 kg S ha-1 resulted in highest NUE. By the application of urea and gypsum, there was slight increase in the soil pH. After N and S application, there was increase in organic carbon content of the soil. At fifty per cent flowering all the nutrients showed an increase in availability and there was a decrease at the final harvest stage because of crop uptake and various losses. N application @ 110 kg ha-1 significantly increased the available N status in the soil. S application up to 20 kg ha-1 significantly increased the available P K and S content in soil. As the levels S increased, there was increase in the exchangeable calcium in soil. Higher levels of application of N recorded higher N content in both plant and fruit. Application of P and K at M2 (35 kg P2O5 ha-1 + 70 kg K2O ha-1) level significantly increased the content of P, K and Ca in plant and fruit. Increased S application increased the Ca content in plant since gypsum was used as the source of S. S application up to 20 kg ha-1 had significant influence on the fruit Ca and Mg concentration. The interactive effect of N and S was not significant in the case of S content in plant. But, N2S3 (N @ 80 kg ha-1 and S @ 20 kg ha-1) recorded the superior value. N application had got positive influence on the content of P, K, Ca, Mg and S in plant and fruit. By progressive increase in S application up to 20 kg ha-1and N application up to 80 kg ha-1, there was significant reduction in N: S ratio. N and S fertilization had significant influence on leaf chlorophyll content and application of 80 kg N ha-1, 35 kg P2O5 ha-1, 70 kg K2O ha-1 and 15 kg S ha-1 showed the superior value for chlorophyll content. An increasing trend was noticed with higher levels of N up to 80 kg ha-1 and S up to 20 kg ha-1. N and S application significantly enhanced the uptake of nutrients. Uptake of phosphorus, potassium, calcium, magnesium and S were highest when N, P, K and S were applied @ 80 kg N ha-1+ 35 kg P2O5 ha-1+ 70 kg K2O ha-1+ 20 kg S ha-1. N application @ 80 kg ha-1 significantly influenced the B: C ratio. Among the treatments M1N2S2 (80 kg N ha-1 + 8 kg P2O5 ha-1 + 25 kg K2O ha-1 + 15 kg S ha-1) which gave the highest yield showed the highest B: C ratio. Maximum B: C ratio was obtained when N and S were applied @ 80 kg ha-1 and 15 kg ha-1 respectively. As the levels of S increased, B: C ratio also increased. Fertilization of N, P, K and S @ 80 kg ha-1, 35 kg ha-1, 70 kg ha-1 and 15 kg ha-1 respectively recorded the minimum Percentage Disease Incidence (yellow vein mosaic). Among the treatments, yield, number of fruits per plant, N Use Efficiency and B: C ratio were highest for M1N2S2 (80 kg N ha-1 + 8 kg P2O5 ha-1 + 25 kg K2O ha-1 + 15 kg S ha-1) and it can be considered as the best treatment combination. Application of N significantly increased the yield and the yield was highest at N2 level (80 kg N ha-1). There was reduction in yield if we apply N @ 110 kg ha-1. By the application of S along with N increased the NUE and we can reduce the dose of N to 80 kg ha-1 instead of 110 kg N ha-1 for bhindi.ThesisItem 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 Silicon and boron nutrition of rice (Oryza sativa L.) in wet land soils(Department of Soil Science and Agricultural Chemistry, College of Agriculture, Padannakkad, 2014) Sainath Nagula, KAU; Biju JosephThe experiment entitled “Silicon and boron nutrition of rice (Oryza sativa L.) in wet land soils of northern Kerala” was carried out to standardize the dose and method of application of silicon and boron to rice crop in paddy soils, to evaluate its effect on available nutrient status and yield and to study the effect of silicon in alleviating the toxicity of Fe, Mn and Al in laterite derived paddy soils. The treatments were a combination of boron source as borax (soil and foliar application) and silicon sources as calcium silicate (soil application) and potassium silicate (foliar application). Two experiments, a pot culture and a field experiment were conducted with rice variety Aishwarya as the test crop. Application of silicon and boron fertilizers improved the availability of silicon and boron in soil. Soil application of calcium silicate along with borax was superior in maintaining the available silicon and boron status of soil than foliar application of potassium silicate and borax. The study revealed that the application of silicon and boron as soil and foliar application had a synergistic effect on the availability of N, P, K, Ca, Mg, S, Zn and Cu in the soil. Application of silicon as foliar application of potassium silicate 0.5 % along with borax 0.5 % spray was effective in reducing iron toxicity in the soil while the use of calcium silicate 100 kg Si ha-1 and borax 10 kg ha-1 proved to be more effective in reducing manganese and aluminium toxicity in the soil. The content and uptake of N, P, K, Ca, Mg, and S in rice were significantly improved by the application of potassium silicate 0.5 % foliar spray along with borax 0.5 % spray 3 rounds. Foliar application of silicon and boron as potassium silicate 0.5 % spray and borax 0.5 % spray was more efficient on improving the content and uptake of silicon and boron compared to soil application of calcium silicate and borax. 141 Application of potassium silicate @ 0.5 % spray + borax 0.5 % spray 3 rounds was significantly superior with respect to yield and yield attributes of rice. In a nutshell, both the pot and field experiments clearly indicated that application of Si and B significantly improves the available nutrient status of soil, nutrient uptake, grain and straw yield of rice. Foliar application of potassium silicate and borax (0.5 % each) 3 rounds at 15 days interval significantly improved the available nutrient status of soil, yield and yield attributes of rice. It was also effective on alleviating toxicity of Fe, Mn and Al in laterite derived paddy soilsThesisItem 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 Quality assessment of pokkali soils under different land uses(Department of Soil Science and Agricultural Chemistry,College of Horticulture, Vellanikkara, 2014) Chris, Joseph; KAU; Sreelatha, A KThe present study entitled ‘Quality assessment of Pokkali soils under different land uses’ was undertaken to evaluate the soil and water quality of acid saline Pokkali soils under different land uses and to develop geo-referenced database and maps on soil characterization. For this purpose, surface soil samples and water samples were collected from the selected panchayaths representing five land use pattern in the Pokkali tracts. Initial survey was conducted on Pokkali area and five panchayaths were selected from Ernakulam district namely, Kuzhippally, Nayarambalam, Elamkunnappuzha, Edavanakkadu and Kottuvally with all the selected land use patterns. The land use patterns under study were i) paddy alone ii) paddy – shrimp iii) shrimp alone iv) fallow and v) mangroves. The soil samples were analysed for their physical (texture, bulk density, soil moisture constants, aggregate stability), chemical (pH, EC, CEC, base saturation, available N, P, K, Ca, Mg, Fe, Cu, Mn, Zn, S, B) and biological (organic carbon, dehydrogenase activity, microbial biomass carbon) attributes. Water samples were also characterized for parameters like pH, EC, TSS and heavy metals. Measured attributes were analyzed by one-way analysis of variance using statistical package MSTATC to examine the effect of land use type on soil properties. Soil quality evaluation was done by the method described by Andrews et al. (2002). Three main steps of this technique includes, i) selection of minimum data set (MDS), ii) scoring of the MDS indicators based on their performance of soil functions, and iii) integration of the indicator scores into a comparative index of soil quality. Analysis of variance revealed that land uses have significant effect on most of the measured attributes except fine sand percent, base saturation percent, content of Mg, Zn, organic carbon and dehydrogenase activity. The statistical analysis resulted in selection of minimum data set which highly influenced the quality of the soil. Indicators in the MDS included available water content, pH, fine sand percent, aggregate stability, silt percent, available Mg, bulk density, available S, microbial biomass carbon, available Mn, organic carbon, base saturation and EC. The highest soil quality index (4.92) was observed in paddy- shrimp land use system in Nayarambalam panchayath and least value (2.07) was observed in shrimp alone land use pattern in Kottuvally panchayath. The observed soil quality index value was in the order, paddy- shrimp> paddy alone> fallow> mangrove> shrimp alone. Based on the relative soil quality index value, all land uses were categorized into three groups, ie, poor, medium and good. Paddy- shrimp land use system in Nayarambalam panchayath was the only one land use system coming under the ‘good’ category. For all the panchayaths and RRS, Vyttila GIS based soil quality index maps were prepared.ThesisItem Open Access Wet soil analysis for nutrient prescription in paddy soils(Department of Soil Science and Agricultural Chemistry,College of Horticulture, Vellanikkara, 2014) Irene, Elizabeth John; KAU; Sureshkumar, PThree locations from 7 agro ecological units dominated by rice crop were identified namely, Onattukkara sandy soil(AEU 3), Kuttanad(AEU 4), Pokkali(AEU 5), Kole(AEU 6), north central laterite(AEU 10), Palakkad central plains (AEU 22) and Palakkad eastern plains (Black soils )(AEU 23). Geo-referenced soil samples were collected at 3 stages: before cropping season, at active tillering and visual panicle initiation. Plant samples were also collected during the above stages and analyzed for nutrient contents. Initial characterization was done with air dried samples while samples during crop growth period were collected by maintaining the wet anaerobic conditions and analyzed as such as well as after drying. Submergence resulted increase in pH both under wet and dry analysis. The pH on the basis of wet analysis was higher than that by dry analysis. EC decreased during flooding and dry analysis gave higher values than by wet analysis. The (C: N) 1 ratio (based on total carbon and total nitrogen) varied from 9.32 :1 in Onattukarasandy soil to 18:1 in Kuttanad on the basis of wet analysis. Analysis after drying recorded a (C: N) 1 ratio ranging from 10.84 inPalakkad central plains to 22 in Kuttanad. Comparison of wet and dry analysis of other available nutrients indicated that higher values were recorded for P, K, Ca, Mg and Fe in wet analysis while the values for availableS, Mn, Zn and B were higher in dry analysis. Data on analysis after drying, recorded significant negative correlation of pH with organic carbon (0.36**) and available S (-0.37**) due to accumulation of organic acids and SO 42-ions under aerobic condition. Antagonistic interaction of available P with available Ca was attributed to significant negative correlation obtained between them in dry analysis. Wet analysis gave significant positive correlation of pH with available Ca (0.35**) and significant negative correlation with available S (-0.28*). All the C: N ratios computed on the basis of, total carbon and total nitrogen (C: N) 1, total carbon and available nitrogen (C: N) 2, organic carbon and total nitrogen (C: N) 3 and organic carbon and available nitrogen(C: N) 4 were significantly correlated with total and available nitrogen at different stages both under wet and dry analysis. Four soil types namely, Onattukara sandy, Kuttanad, north central laterites and Palakkad eastern plains were used for an incubation study to unravel the pattern of decomposition of added organic matter and to identify the C: N ratio at equilibrium. Changes in pH and redox potential during submergence indicated slight increase in pH after 7 days of submergence and redox potential was constantly decreasing with increasing period of submergence. The (C: N) 1 ratio was found to stabilize at 9.6:1 after 3 months of incubation with organic matter while it was stabilized at 7.6:1 without organic matter in Onattukara soil. In Kuttanad soils it was 18.3:1 and 17:3 respectively. In Chittor soils it stabilized at 10:1. The (C: N) 3 also showed similar trends. However, available nutrient did not give any significant correlationwith the corresponding plant content of the respective nutrient. This focusesto the importance of future studies with more number of samples from eachAEU’s as each of the fertility parameters are highly varying in these units.ThesisItem Open Access Nutrient management for sustainable rice production in the black soils of Kerala.(Department of Soil Science and Agricultural Chemistry,College of Horticulture, Vellanikkara, 2011) Danish, Tamuly; KAU; Betty, BastinA field experiment was carried out to find out the best nutrient management system suited for sustainable rice production in black soils of Chittur, Palakkad district. The study also aimed to know the influence of zinc on the yield of rice in such soils. These black soils though fertile, the nutrient imbalances, as well as the poor physical condition may adversely affect the yield of crop. The soil selected for the study had a mean pH value of 6.4 and electrical conductivity of 0.1dSm-1. The organic carbon content was 0.74%. The status of available N, P and K were 310.5, 5.67 and 154.36 kg ha-1 respectively. It was found that, except for available P and B, all other soil nutrients were present either in the medium level or adequate. The field experiment consisted of eleven treatments and three replications each. The treatments were- Absolute control (T1), farmer’s practice (T2), recommendation of KAU (T3), Soil Test Laboratory recommendation of Kerala (T4), STCR recommendation (T5), STCR + FYM @ 5 t ha-1 (T6), T2 + zinc sulphate @ 25 kg ha-1 (T7), T3 + zinc sulphate @ 25 kg ha-1 (T8), T4 + zinc sulphate @ 25 kg ha-1 (T9), T5+ zinc sulphate @ 25 kg ha-1 (T10) and T6 + zinc sulphate @ 25 kg ha-1 (T11). Soil as well as plant nutrient status were recorded at critical growth stages viz, maximum tillering, panicle initiation, flowering and harvest stage for the content of N, P, K, Ca, Mg, S Na, Si, Fe, Mn, Zn, Cu and B. Biometric parameters such as the height of the plant, number of tillers and number of leaves at critical growth stages were also recorded. Simple correlation co-efficient were worked out for soil nutrients, plant nutrients, grain nutrient and uptake with yield. Among the available soil nutrients, N content was found to be highest followed by available K and P during different growth stages. Available Ca was higher than Mg during all the growth stages. Among micronutrients, available Zn reduced while B increased from maximum tillering to harvest. A sharp decline in soil Fe content was observed with the advancement of growth stages. Available Na increased while, Si remained almost uniform throughout the different growth stages. Among plant nutrients, the content of N decreased from maximum tillering stage to harvest. A higher concentration of Mg compared to Ca was observed during maximum tillering stage. The plant content of Fe showed a sharp decrease from maximum tillering to panicle initiation and thereafter increased. The range varied from 5000 mg kg-1 at maximum tillering stage to 3000 mg kg-1 towards the harvest stage. The plant content of Na increased from panicle initiation to harvest stage while, that of Si declined from flowering to harvest. The number of leaves and tillers were found to be significantly higher for STCR treatments (with or without FYM) and zinc sulphate at the flowering stage. The highest benefit cost ratio was obtained for T1 (absolute control). It was also observed that the yield of both grain and straw reduced on addition of ZnSO4. Positive and significant correlation was observed between uptake of almost all the nutrients with grain and straw yield except Ca, Cu and Si. The uptake of the major nutrients, N and K was found to be significantly and negatively correlated to the contents of Na and Ca in soil. This supports the fact that excess amount of basic cations are hindering the uptake of major nutrients. Prediction of yield based on content of soil, plant and yield attributes could not be obtained from the present study. It can be concluded that black soils of Chittur are fertile. But the productivity of these soils are constrained by factors like high content of basic cations such as calcium and sodium and subsequent low uptake of major nutrients. High plant content of Fe was also observed during the maximum tillering and panicle initiation stage. The content of Si in soil as well as uptake of Si by the crop was also comparatively less. So management practices have to be adopted to reduce the soil content of the basic cations as well as nutrient imbalances in soil and plants by drainage, leaching and incorporation of FYM, crop residues rice husk etc. the interaction between macro and micronutrients have to be examined in detail and further studies have to be conducted for sustainable rice production in these poonthalpadam (black) soils.ThesisItem Open Access Availability indices of boron in major soil groups of Kerala.(Department of Soil Science and Agricultural Chemistry,College of Horticulture, Vellanikkara, 2011) Anu, George; KAU; Suresh, Kumar PRepresentative surface samples (0-20 cm) of eight soil types each from three locations (total 25 samples-including one additional sample from Kuttanad) covering nine agro-ecological units representing the major rice growing tracts of the state were collected for the present study on “Availability indices of boron in major soil groups of Kerala”. The agro-ecological units (AEU) included were Kuttanad (Kuttanad, AEU 4), Kole (Kole lands, AEU 6), Pokkali (Pokkali lands, AEU 5), Black cotton (Palakkad central plains AEU 23 and Palakkad eastern plains, AEU 10), Onattukara (Onattukara sandy plains, AEU 3), Palakkad rice soil (North central laterite, AEU 10), Laterite soils from Kozhikode, Vellanikkara and Pattambi (Midland laterite, AEU 11 and North central laterite, AEU 10)and Wayanad Plateau soils (Northern High hills, AEU 15 and Wayanad central plateau, AEU 20). The soils were characterized with respect to pH, EC, CEC, PBS and exchangeable cations, total sesquioxide and available nutrient status (Organic carbon, available B, P, K, Fe, Mn, Cu and Zn). Among the 25 soils, 15 soils showed acute boron deficiency chances (Critical limit: <0.5 mg kg-1 soil ). Fractionation of soil boron was done to separate the different forms of boron existing in soil viz. nonspecifically adsorbed plus water soluble B (NSA-B), specifically adsorbed B (SPA-B), manganese oxy-hydroxide bound B (MOH-B), B occluded in amorphous Fe-Al oxides (AMO-B), B occluded in crystalline Fe-Al oxides (CRO-B) and residual boron. Amount of boron existed in different fractions was in the following order, Residual > CRO-B > AMO-B > MOH-B > SPA-B > NSA-B. Among these fractions, MOH-B and NSA-B contributed to available B directly as well as indirectly through each other. Electrical conductivity or rather salinity is the single most important factor influencing B availability. Adsorption studies were conducted with all the soils to study the adsorption pattern of B in the above soils. The data obtained from boron adsorption experiments were fitted into different adsorption isotherms like Freundlich, Langmuir and Tempkin isotherms. 22 soils followed Freundlich adsorption pattern where as only one each of Black cotton soils (Black cotton 1) and Onattukara soils (Onattukara 2) fitted with Langmuir and Tempkin as well. Onattukara 1, the soil which recorded the lowest available B of 0.04 mg kg-1 was used to conduct a pot culture experiment using rice as test crop with three levels of B (0,10 and 20 kg ha-1) with and without 5t of FYM per hectare. The data on soil as well as plant analysis at panicle initiation and harvest stages indicated that available B status improved with increasing levels of B. Grain and total DM yield increased with the increase in boron doses without FYM. It was also noted that FYM alone could meet the B requirement. FYM with borax was found to have antagonistic effects with respect to yield as well as the nutrient contents in rice.