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ThesisItem Open Access Carbon pools in Lateritic soil amended with coirpith-vermicompost and its effect on Tomato (Solanum lycopersicum L.)(Department of Soil Science and Agricultural Chemistry, College of Horticulture, Vellanikkara, 2019) Aiswarya, R; KAU; Jayasree Sankar, SSoil organic carbon (SOC) is considered as the key indicator of soil quality and agricultural sustainability. Among the different management practices that are being followed, application of chemical fertilizers and manures has been recognized as the most systematic and effective means to either enhance soil organic carbon accumulation or reduce the rate of SOC loss. Hence, for studying the effect of coirpith based vermicompost on dynamics of carbon in a lateritic soil, a field experiment was laid out during October 2018 – February 2019, in RBD with 12 treatments replicated thrice, with tomato, variety Manulakshmi, as the test crop. The plot size was 3 x 3 m and plant spacing was 60 x 60 cm. The treatments consisted of an absolute control (T1), coirpith compost at 10 t ha-1 (T2), coirpith based vermicompost at 10 t ha-1 (T3), Coirpith based vermicompost at 10 t ha-1 + soil test based KAU POP (T4), , FYM at 20 t ha-1 + soil test based KAU POP(T5), T3 + 25 % of soil test based KAU POP (T6), T3 + 50 % of soil test based KAU POP (T7), T3 + 75 % of soil test based KAU POP (T8), FYM at 20 t ha1 + 25 % of soil test based KAU POP (T9), FYM at 20 t ha-1 + 50 % of soil test based KAU POP (T10), FYM at 20 t ha-1 + 75 % of soil test based KAU POP (T11), Adhoc KAU organic POP (T12). Raw coirpith was converted into compost using vermitechnology employing the compost worm Eisenia foetida .The composting process got completed within 64 days time span. Coirpith in the raw stage and after composting was characterized for physical, electro-chemical and chemical properties. Advantages of vermicomposting coirpith included a reduction in the content of lignin (32 to 16.7 %), cellulose (25.2 to 10.2 %), C: N ratio (113:1 to 20.5:1) and EC (0.98 to 0.51 dS m-1) and an increase in pH and total nutrients. Soil analysis after the experiment revealed the significance of treatments on electro-chemical and chemical properties as against the control. Significantly higher available K (281.0 kg ha-1) and Mn (75.33 mg kg-1) was obtained in coirpith based vermicompost at 10 t ha-1 + soil test based KAU POP (T4). In case of N, P, Ca and Fe the effect of the treatments T4, T5 (FYM + soil test based POP) and T8 (Coirpith vermicompost + 75 % soil test based POP) were comparable. The labile C fractions viz. water soluble carbon (WSC), hot water soluble carbon (HWSC), permanganate oxidizable carbon (POXC) and microbial biomass carbon (MBC) were also significantly influenced by the treatments and it followed the order POXC > HWSC > MBC = WSC. Further analysis revealed that the treatments T4, T5, T6 (Coirpith vermicompost + 25 % soil test based POP), T8 and T11 (FYM + 75 % soil test based POP) were comparable in influencing WSC, whereas T4 and T5 were similar in deciding HWSC and T4 and T8 in case of MBC. Significantly higher total C was registered by coirpith vermicompost + 75 per cent soil test based KAU POP. Dehydrogenase activity which is considered as an index of microbial activity in soil was significantly higher (146.3 µg TPF g-1soil 24hr-1) in coirpith based vermicompost at 10 t ha-1 + soil test based KAU POP. Integration of chemical fertilizers at different levels with organics, either coir pith vermicompost or FYM, increased microbial population which followed the order bacteria > fungi > actinomycetes. However, the impact of treatments was more pronounced in enhancing bacterial population due to the shift in pH towards neutral value. On considering biometric observations, it was seen that the plant height (104.7 cm), number of fruits per plant and fruit yield (1.84 kg/plant) were significantly higher for the treatment coirpith based vermicompost at 10 t ha-1 + soil test based KAU POP. The effect of coirpith based vermicompost and FYM along with fertilizers at different levels were comparable in determining fruit quality parameters like total soluble solids, ascorbic acid, lycopene and titrable acidity. Applying coirpith based vermicompost at 10 t ha-1 + soil test based KAU POP registered a higher B: C ratio of 2.43 in contrast to 1.57 recorded in the absolute control.ThesisItem Open Access Assessment of soil degradation and water quality in areas of small scale brick production and management of the degraded soil(Department of Soil Science and Agricultural Chemistry, College of Horticulture, Vellanikkara, 2019) Sophia, Baby; KAU; Betty, BastinThe utilization of clay for construction of habitations and buildings dates back to the period of ancient civilizations. Even though centuries had passed and civilizations changed, the basic raw material for brick production remained the same. Brick production requires fine clayey loam soil with plenty of water supply. With the increasing demand for construction material, clay mining had shifted from river banks to fertile agricultural lands. This change in land use had resulted in the deterioration of soil health and decrease in crop production. The entry of large number of small scale brick production units is causing irreversible damages to the soil, hydrology and ecosystem. Hence, this study was taken up to characterise the desurfaced (mined) soils and water resources and to identify suitable management methods of these soils. A comprehensive survey was conducted at Alathur Taluk of Palakkad District to identify locations with resurfaced soils. Soil and water samples were collected from 11 locations including a control location without mining activities during August to September, 2017. A total of 88 soil samples (eight samples per location) and 11 water samples (one sample per location) were collected for the study. Both soil and water samples were analysed for various physico- chemical properties. Biological properties of soil samples were also analysed. The physical properties of soil such as temperature and bulk density were found to be higher in desurfaced soils when compared to control. The water holding capacity, porosity and moisture content were found to be reduced in desurfaced soils. The texture of the soil changed from clay loam to sandy loam. The organic carbon content of desurfaced soils were in the range of 0.08 – 0.46 per cent with a reduction of 61 per cent when compared with control soil. The content of available nitrogen, phosphorus and potassium were also reduced to the extent of 43.70, 74.50 and 43.36 per cent respectively. The available magnesium content was found to be lower in desurfaced soils (55.6 per cent reduction). The content of plant available micronutrients (Fe, Mn, Cu and Zn) and heavy metals (Ni, Cr and Pb) were high in desurfaced soils. The presence of earthworms (13 nos. per m2) and termite mound were observed only in the xi control soil. The microbial biomass carbon and dehydrogenase enzyme activity were highly reduced in desurfaced soils. Water samples were also affected by small scale topsoil mining activity. The pH, electrical conductivity and TDS were in the safer limits for all water samples. The concentrations of sodium (W1 andW10) and calcium (W1 andW5) in certain water samples collected from mined areas were high and they were above safe limits to be used for irrigation purposes. Similarly the higher levels of nitrate, phosphate, bicarbonate and chloride in water samples from mined areas denote the possibility of the water bodies being polluted by mining activities. Based on the status of organic carbon and major nutrients, the soil with the lowest nutrient status (S5) was selected for pot culture study. The pot culture study was conducted with chilli (var. Anugraha) as the test crop. The effect of various organic and inorganic amendments on the properties of desurfaced soils were evaluated in this experiment. The treatment T2 (soil test based NPK + poultry manure) recorded the highest plant height (50.42 cm), number of leaves (221.78) and number of branches (6.11) at 60 days after transplanting. The yield attributes such as total number of flowers (95.33), total number of fruits (31.33) and per cent fruit set (32.95 per cent) were found to be higher for the same. The highest yield was obtained for the treatment T2 (soil test based NPK + poultry manure). The soils were also analysed after the harvest of the crop. The bulk density of soil after harvest was the lowest in treatment T3 (soil test based NPK + vermicompost) and was on par with T4 (soil test based NPK + coirpith compost). The content of organic carbon, available nitrogen, phosphorus and potassium recorded higher values in treatment T2 (soil test based NPK + poultry manure) than the other treatments. The biological properties such as microbial biomass carbon (374.133 μg g-1 soil) and dehydrogenase activity (3.630 μg TPF g-1 day-1) were the highest in treatment T2 (soil test based NPK + poultry manure) and T4 (soil test based NPK + coirpith compost) respectively. The study revealed that top soil mining for brick production predominantly affected bulk density, soil temperature and water holding capacity of the soils. The content of organic carbon and available nutrients such as N, P and K were also reduced. The biological properties like dehydrogenase enzyme activity and microbial biomass xii carbon reduced to a greater extent. Water samples from mined areas were polluted by cations like sodium and calcium and anions like nitrate, phosphate, bicarbonate and chloride to limited extent. Poultry manure application as an integrated nutrient management technique, followed by vermicompost application were found to be beneficial for the management of such desurfaced soils.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 Performance of Non-Conventional soil Ameliorants in Banana (Musa spp) var. Nendran(Department of Soil Science and Agricultural Chemistry, College of Agriculture,Padannakkad, 2019) Amalendu, M V; KAU; Jayaraj, PAn investigation entitled “Performance of non-conventional soil ameliorants in banana (Musa spp) var. Nendran” was carried out at College of Agriculture Padannakad and Regional Agricultural Research Station (RARS) farm Nileshwar from 2017 to 2019. The objective was to study the performance of banana (Musa spp) var. Nendran in initial period with respect to the different non-conventional ameliorants and a subsequent field trial to confirm the importance of these ameliorants throughout the growing period in improving plant health and yield Pot culture study was carried out to evaluate the efficiency of different soil ameliorants in improving soil health as well as crop health with respect to availability of nutrients upto 4 months. The experiment was conducted in Completely Randomized Design (CRD) consisting of 5 treatments and 4 replications with the following treatments; T1 (basal application of Calcium silicate), T2 (Basal application of lime+ silica), T3 (Basal application of dolomite + silica), T4 (Basal application of Gypsum+ silica), control T5 (Basal application of lime as per KAU POP 2016). The biometric observations like the plant height, number of leaves, root length, root diameter and root CEC were periodically recorded. Considering the plant height, pseudostem girth and number of leaves T4 showed superior results. The root characters like root length, root thickness and root CEC were found superior in T4. The field experiment was carried out at Regional Agricultural Research Station (RARS) farm Nileshwar to study the effect of ameliorants on yield and quality of tissue culture banana var. Nendran. It was conducted in randomized block design comprising of 11 treatments and 3 replications. The treatments used in pot culture experiment were used in split doses to manage the soil acidity throughout the growing period of crop. Treatments were T1( Basal application of Calcium silicate), T2 (Basal application of lime + silica), T3 (Basal application of dolomite +silica), T4 (Basal application of Gypsum + silica), T5 (Lime+ silica in 2 splits at 1st and 2nd month after planting), T6 (Dolomite + silica in 2 splits at 1st and 2nd month 140 after planting), T7 (Gypsum + silica in 2 splits at 1st and 2nd month after planting, T8 (Lime+ silica in 3 split doses at 1st month, 2nd month and 4th month after planting),T9 (Dolomite + silica in 3 split doses at 1st month, 2nd month and 4th month after planting), T10 (Gypsum + silica in 3 split doses at 1st month, 2nd month and 4th month after planting), T11 (Application of lime as per KAU POP 2016) as the control. Biometric observations were recorded periodically. Soil and leaf analysis were also carried out at specific intervals of the experiment. The results of the field experiment revealed that among the vegetative characters, plant height, pseudostem girth at 90 cm height, number of leaves, number of functional leaves and number of suckers were superior for T10. Considering the yield attributes like number of hands per bunch (6.33) and number of fingers per hand (8.66) T10 recorded superior results. Treatment T10 recorded the highest bunch weight of 11.24 kg. Among the finger characteristics, average finger breadth (16.00 cm) and average weight of the fingers (225.00 g) is superior in T9 and the finger length (21.30 cm) is superior in T10. Among the treatments T10 recorded minimum days for bunch emergence (186 days), days to harvest (277 days) and days to ripening (4.33 days). Fruit characters like total soluble solids (29.90 0 brix), titrable acidity (0.27 %), reducing sugar (19.00 %), non reducing sugar (4.89 %), shelf life (4.40 days) were found superior in T10. Studies on the soil nutrient status was conducted at 3 months after planting, 6 month after planting and at harvest of the crop. It was revealed that T10 recorded superior results for soil pH and electrical conductivity. Considering the organic carbon content and cation exchange capacity T10 recorded superior results. Available nitrogen, potassium, phosphorus, calcium and sulphur, copper, zinc and silicon was found superior in T10 whereas highest available magnesium content was recorded in T9. In case of available Iron, manganese and exchangeable aluminium T10 gave superior results. Leaf analysis was carried out at bunching and at harvest of the crop and the following results were obtained. Nitrogen, potassium, phosphorus content in the leaf was found superior for T10. The calcium and sulphur content in the leaf was 141 superior for T10 while treatment T9 recorded the highest magnesium uptake. Uptake of micronutrients like zinc, copper and silicon were found superior in T10. Lowest concentration of iron and manganese were recorded in T10. The results from the investigation revealed that the application of non-conventional soil ameliorants increased the nutrient availability in soil thereby increasing the yield and quality of banana. Among them application of gypsum + silica in 3 splits dosses performed well and produced superior results in northern lateritic soils.ThesisItem Open Access Bio fortification of rice (Oryza sativa) with zinc under organic and integrated nutrient management practices(Department of Soil Science and Agricultural Chemistry, College of Agriculture, Padannakkad, 2019) Wayoolang Talang; KAU; Suresh, P RAn investigation entitled “Biofortification of rice (Oryza sativa) with zinc under organic and integrated nutrient management practices” was carried out in Regional Agricultural Research Station (RARS), Pilicode during June to October 2018. The study was conducted in rice variety Uma (MO 16). The main objective of this research was to check the zinc nutrient content under organic and integrated nutrient management practices (INM). The field experiment was laid out under Randomized Block Design (RBD) with nine treatments and one control each replicated three times. The treatments consisted of soil application of Zn and combined soil and foliar application of Zn under organic (Organic Package Of Practice) and INM practices (Package Of Practice Kerala Agricultural University). Zn was applied as zinc sulphate (ZnSO4) at the rate of 1 per cent and 20 kg ha-1 as foliar application and soil application respectively. Foliar application of ZnSO4 was done at three growth stages of rice viz tillering, panicle initiation and flowering stage. Single foliar application of Zn was done at only tillering stage. Double foliar application of Zn was done at tillering and panicle initiation stages and triple foliar application of Zn was done at all the three growth stages. The effect of different treatments significantly influenced plant growth attributes like plant height, number of tillers per hill and panicles per hill. At harvest stage, the highest plant height (99.9 cm) was recorded in T8 (POP KAU + soil application of Zn + triple foliar spray of Zn) which was on par with T7. The minimum plant height was recorded in control (92.3 cm). Similarly, the maximum number of tillers per hill (15.5) and maximum number of panicles per hill (15.5) was recorded in T8 at harvest stage. Soil and foliar application of Zn along with soil application of NPK fertilizers as per POP KAU significantly improved the grain yield and other crop yield attributes. The treatment that recorded the highest grain yield was T8 (6.7 t ha-1) which was superior as compared to other treatments. The treatments that recorded the highest straw yield (6.5 t ha-1) and highest 1000 grain weight (27.1g) was with treatment T7. 127 The nutrient content in the plant samples (shoot and straw) analyzed at different growth stages of paddy was studied. The results revealed that nutrient content of N, K and Zn was highly improved in treatments under INM practices. At the harvest stage, treatments T7 recorded the highest N (0.62 %) and K (1.9 %) whereas Zn (85.7 mg kg-1) content in straw was highest with treatment T8. However, the nutrient content of P in plant samples declined with the increase in the number of foliar application of Zn. The treatment that recorded the lowest P content (0.19 %) in the straw at harvest was T5 (Organic POP + soil application of Zn + triple foliar application of Zn). The effect of treatments on Zn and P content in rice grains were also studied. Grain analysis results revealed that the treatment that recorded the highest Zn content (55.8 mg kg-1) was in T8 and the lowest Zn content (18.2 mg kg-1) was recorded in T10 (control). Similarly, P content was also analyzed in rice grains to study the interaction between Zn and P. The treatment that recorded the highest P content (0.61 %) in the grain was T2 and lowest P content (0.44%) was recorded in T5.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 Effect of zinc fertilization on major plant and soil enzymes in southern laterites(Department of Soil Science and Agricultural Chemistry, College of Agriculture, Vellayani, 2019) Aswathy, U A; KAU; Aparna, BThe study entitled “Effect of zinc fertilization on major plant and soil enzymes in southern laterites” was carried out in the Department of Soil Science and Agricultural Chemistry, College of Agriculture, Vellayani during the period 2017-19. The study was envisaged to assess the effect of various sources and methods of application of zinc on the activities of major plant and soil enzymes, biochemical and microbial parameters in laterite soils using tomato (Solanum lycopersicum var. Anagha) as a test crop. From the soil test database developed by the Department of Soil Science & Agricultural Chemistry under the project RF-Soil Testing Lab, laterite soils in Neyyatinkkara series with Zn deficiency were identified. Soil samples were collected from these locations and analysed for confirming Zn deficiency. Soil with low Zn status (0.506 ppm) was selected for the study. The second part of the experiment was a field study aimed at evaluating the efficacy of different sources of Zn using tomato (var. Anagha) as the test crop. The study was laid out in Randomized Block Design with eight treatments replicated thrice. The treatments were Absolute control (T1), N, P, K as per POP- 75:45:25 kg ha-1 (T2), N, P, K+ Soil application of Zn as ZnSO4- 10 kg ha-1 (T3), N, P, K+ Foliar application of Zn as 0.5 per cent ZnSO4 (T4), N, P, K+ Zn as Zn EDTA-18 kg ha-1 (T5), N, P, K+ Zn solubilizer -5 per cent (T6), N, P, K+ Zn Humate- 44 kg ha-1 (T7), N, P, K+ K solubilizer 5 per cent (T8). From the study, it was observed that the treatment T7 with the application of N, P, K+ Zn Humate (44 kg ha-1) recorded the highest plant growth and yield attributes such as number of branches per plant (8.3), days to first flowering (31.7), fruits per plant (46.7), fruit length (3.5 cm), total fruit yield (35833.36 kg ha-1) (1.29 kg plant -1) and total dry matter production (0.108 kg plant -1). The same treatment reported the highest value for enzymes such as carbonic anhydrase, peroxidase and catalase viz., 910 EU g-1, 48.17 activity min-1 g-1 and 27.06x103 units ml-1 respectively. The results of indole 3- acetic acid (IAA) (217.83 μg g-1) and lycopene analysis (26.11 μg g-1) also revealed that the same treatment T7 recorded the highest values. It was observed that the treatments did not have a significant effect on plant pigments chlorophyll a and b. The results of post harvest soil analysis revealed a marginal increase in available nutrient content compared to initial status. The treatment T7 with the application of N, P, K+ Zn Humate (44 kg ha-1) recorded the highest mean value for electrical conductivity (EC) (0.172 dS m-1), exchangeable Ca (436.67 ppm) and Mg (166 ppm), available B (0.221 ppm), soil respiration rate (177.14 mg CO2 100 g-1 d-1), microbial biomass carbon (186.67 μg g-1) and enzymatic activities (dehydrogenase and β- glucosidase). Similarly, T7 with the application of N, P, K+ Zn Humate (44 kg ha-1) recorded the highest value for available Zn (5.123 ppm) which was on par with treatment T5 (4.860 ppm).The uptake analysis revealed that the nutrient uptake varied significantly with the treatments. The treatment T7 registered the highest plant uptake of N, Mg, Zn and B (87.87, 75.29, 0.187 and 0.57 kg ha-1 respectively). An incubation study was conducted to monitor the pattern of activity of enzymes such as dehydrogenase, peroxidase and carbonic anhydrase and to evaluate their kinetic parameters for a period of three months. The study was carried with five treatments each replicated four times in CRD pattern. The treatments included were Soil alone (T1), Soil + Zn as 0.5 ppm ZnSO4 (T2), Soil + Zn as 1 ppm ZnSO4 (T3), Soil + Zn as 1.5 ppm ZnSO4 (T4) and Soil + Zn as 2 ppm ZnSO4 (T5). It was observed that the activity of enzymes were significantly influenced by the treatments. The enzymes peroxidase and carbonic anhydrase showed an increasing trend in activity while peroxidase registered a decreasing trend. Treatment T4 with the application of Soil + Zn as 1.5 ppm ZnSO4 registered the highest value for peroxidase (11.98 activity min-1 g-1) and carbonic anhydrase activity (385 EU g-1). The enzyme kinetics study revealed that the lowest km value was noticed for peroxidase (0.17 activity min-1 g-1) and dehydrogenase (0.77μg TPF g-1 24 h-1) on the 84th day. The peak value for Vmax was observed on the 28th day for enzyme dehydrogenase (75.23 μg TPF g-1 24 h-1) and peroxidase (59.43x103activity min-1 g-1). The treatment T5 corresponding with the application of Soil + Zn as 2 ppm ZnSO4 registered the lowest value of Km for carbonic anhydrase (0.89 EU g-1) and dehydrogenase (0.77μg TPF g-1 24 h-1), and the highest Vmax values for peroxidase. A significant positive correlation between soil enzyme (dehydrogenase), plant enzymes (peroxidase and catalase) and Zn with correlation coefficients 0.942**, 0.950** and 0.726** respectively was noticed. Similarly, in the case of regression analysis, the plant enzymes (peroxidase and catalase) and soil enzyme dehydrogenase were dependent on zinc with coefficients (0.001*, 0.001* and 0.041* respectively). From the study it was observed that treatment T7 with the application of N, P, K+ Zn Humate (44 kg ha-1) registered the highest values for soil parameters (EC, available nutrients and soil enzymes) and plant parameters viz., growth, yield and uptake. Similarly it was also observed to be the best source for available Zn followed by T5- N, P, K+ Zn as Zn EDTA (18 kg ha-1). The incubation study revealed that for highest activity of peroxidase and carbonic anhydrase, the rate of Zn application is 1.5 ppm. In enzyme kinetics study, the treatment T5 with the application of Soil + Zn as 2 ppm ZnSO4 was found to be superior than all other treatments. Hence it can be concluded from the present study that the most efficient source of Zn was Zn Humate with an ideal rate of 44 kg ha-1 along with the recommended levels of N, P, K nutrients.ThesisItem Open Access Development of multinutrient fertilizer tablet and its evaluation in tomato(Department of Soil Science and Agricultural Chemistry, College of Agriculture, Vellayani, 2019) Navya, M P; KAU; Gladis, RThe study entitled “Development of multinutrient fertilizer tablet and its evaluation in tomato”was conducted from 2017 to 2019 in the Department of Soil Science and Agricultural Chemistry, College of Agriculture, Vellayani. The objectives of the study were to develop multi nutrient fertilizer tablet containing major, secondary and micronutrients and to evaluate its effect on nutrient use efficiency, yield and quality of tomato. The study consisted of three parts namely development of multinutrient fertilizer tablets, an incubation study to assess the nutrient release pattern of multi nutrient tablets and a pot culture experiment to evaluate the multi nutrient tablets in tomato. Multinutrient fertilizer tablets were developed using three fertilizer combinations and three binding agents which constitute the 9 treatments and are replicated thrice in CRD. The treatments were T1- urea, dicalcium phosphate, potassium sulphate, calcium sulphate, magnesium oxide, zinc EDTA, boric acid and binding agent methyl cellulose, T2- fertilizer materials as in T1 and binding agent gelatin, T3 – fertilizer materials as in T1 and binding agent polyvinyl pyrrolidone, T4 – urea, diammonium phosphate, muriate of potash, calcium sulphate, magnesium sulphate, zinc EDTA, borax and binding agent methyl cellulose, T5 – fertilizer materials as in T4 and binding agent gelatin, T6 – fertilizer materials as in T4 and binding agent polyvinyl pyrrolidone, T7 – neem coated urea, factomphos, muriate of potash, magnesium oxide, phosphogypsum, zinc sulphate, borax and binding agent methyl cellulose, T8 – fertilizer materials as in T7 and binding agent gelatin and T9 – fertilizer materials as in T7 and binding agent polyvinyl pyrrolidone. Compatibility test of multinutrient fertilizer blends revealed that tablets T3, T4, T5 and T7 were non hygroscopic and no caking or colour change were observed. Whereas T8 and T9 were hygroscopic. Caking was observed in tablet T2 and T6 and colour change was noticed in tablets T6, T8 and T9. Analysis of physical and chemical properties of tablets revealed that tablets T3, T4, T5, T7, T8 and T9 were stable, disintegration time ranged from 10 to 12 hours, moisture content ranged from 6.46 to 9.24% and EC ranged between 9.75 and 29.1 dS m-1. The pH of tablets T1, T2 and T3 were slightly alkaline while T4, T5, T6, T7, T8 and T9 were slightly acidic. The nutrient content in tablets ranged from 7.69 to 8.69 % nitrogen, 4.43 to 4.82 % phosphorus, 2.1 to 3.2 % potassium, 5.81 to 6.45 % calcium, 0.65 to 0.68 % magnesium, 2.37 to 3.27 % sulphur, 0.21 to 0.22 % boron and 0.21 to 0.25 % zinc. An incubation study was conducted for a period of three months to determine the nutrient release pattern of tablets in CRD with 9 treatments and 3 replications. Soil samples were drawn at 15 days interval and analyzed for major, secondary and micronutrients. The results revealed that the tablets T3, T4, T5 and T7 were found to be the best with respect to the release of nutrients N, P, K, Ca, Mg, S, Zn and B throughout the incubation period and were selected for evaluation in the pot culture experiment. A pot culture experiment was conducted to evaluate the effect of the selected multinutrient tablets on yield and quality of tomato variety vellayani vijay in a completely randomized design with 11 treatments and 3 replications. The treatments T1 to T8 consisted of two levels (75% and 100 %) of recommended dose of fertilizers applied as the seleced 4 tablets, T9 was soil test based POP recommendation, T10 was T9 + secondary and micronutrient mixture and T11 was absolute control. The results revealed that the treatment T7 which received 75 % recommended dose of fertilizers as tablet 4 containing neem coated urea, factomphos, muriate of potash, magnesium oxide, phosphogypsum, zinc sulphate, borax and binding agent methyl cellulose recorded the maximum plant height (63 cm), number of branches per plant (6.67) and number of fruits per plant (16). Fruit weight was maximum in T7 (33.77 g) which was on par with T8 (32.27 g). Fruit yield was the highest in T7 (502.02 g plant-1) which was on par with T8 (495.66 g plant-1). Early flowering and fruiting were observed in T9. Lycopene content was also found to be the highest in T7 (16.73 μg g-1) whereas no significant difference was observed with respect to TSS and ascorbic acid. The analysis of post harvest soil revealed that electrical conductivity and available nutrients were significantly influenced by different treatments whereas pH and organic carbon content were found to be nonsignificant. The available nitrogen (321.96 kg ha-1), phosphorus (88.18 kg ha-1), potassium (216.53 kg ha-1), calcium (342.56 mg kg-1), zinc (0.34 mg kg-1) and boron (4.21 mg kg-1) were the highest in T8 and was found to be on par with T7. With respect to magnesium (107 mg kg-1) and sulphur (8.35 mg kg-1) T6 recorded the highest value. The content and uptake of nutrients in plant and fruit were found to be significantly influenced by different treatments. The treatment T7 recorded the highest content and uptake of N, P, K, Ca, Mg, S, B and Zn. The highest NUE of nitrogen (58.77 g g-1), phosphorus (55.10 g g-1) and potassium (79.35 g g-1) was observed in treatment T7 followed by T8. It can be concluded that multinutrient tablets containing macro, secondary and micro nutrients can be prepared using compatible fertilizer materials and binding agents. The multinutrient tablets T3, T4, T5 and T7 were found to be superior with respect to stability, disintegration time and release of nutrients. Application of multinutrient tablet containing neem coated urea, factomphos, muriate of potash, magnesium oxide, phosphogypsum, zinc sulphate, borax and binding agent methyl cellulose (T7) at 75 % of recommended dose of fertilizers was able to significantly increase the yield, uptake of nutrients, nutrient use efficiency and quality of tomato.ThesisItem Open Access Sorption and movement of flupyradifurone in sandy loam soils with and without organic amendment(Department of Soil Science and Agricultural Chemistry, College of Agriculture, Vellayani, 2019) Reshma, V; KAU; Thomas GeorgeThe study entitled “Sorption and movement of flupyradifurone in sandy loam soils with and without organic amendment” was conducted in Department of Soil Science and Agricultural Chemistry and the laboratory attached to the All India Network Project (AINP) on Pesticide Residues, College of Agriculture, Vellayani, Thiruvananthapuram, Kerala during 2017-19. The main objectives of the experiment were to study the adsorption, desorption, persistence and leaching of flupyradifurone in sandy loam soils with and without addition of organic amendment at the rate of 0.5 per cent farmyard manure. The soil was collected from the sandy belts of Kazhakkoottam, Thiruvananthapuram. The physical and chemical analysis of the soil revealed that the soil was acidic with 0.84 per cent organic matter content. Among the major nutrients, phosphorus content was found to be high; potassium was medium while other nutrients were low. The method for estimation of flupyradifurone residues from the soil was validated at 0.1, 0.5 and 1 µg g-1 level of flupyradifurone. Modified QuEChERS method with acetonitrile as the extracting solvent and Primary Secondary Amine (PSA) sorbent for cleanup was found to be suitable for the estimation of flupyradifurone and its metabolites from the soil. The method validation for estimation of flupyradifurone residues from water was done by liquid- liquid partitioning using dichloromethane, concentrated and made up in HPLC grade methanol for LC- MS/ MS analysis. The adsorption- desorption studies were carried out at 5 concentrations of 20, 40, 60, 80 and 100 μg levels each both in soil and 0.5 per cent FYM amended soil in completely randomized design (ten treatments and three replications) . The study was also conducted under direct spiking of flupyradifurone at 3 levels viz., 20, 40 and 60 μg in 10g soil. The adsorption and desorption data fitted well in isotherms. The distribution coefficient Kd (mean value) was found high in the soil amended with FYM (2.58) than soil without amendment (2.41) which indicated increased sorption in both systems at all levels. The kf values (adsorption coefficient) were 2.57 and 2.46 for amended and soil without amendment respectively, indicating a high sorption capacity for the amended soil. The desorption was carried out in three cycles, the percentage desorption decreasing in each consecutive cycle. The desorption percentages were found in the range of 15.68, 17.14 , 20.74 , 23.69 and 27.77 per cent for the initial concentrations of 20, 40, 60, 80 and 100 µg, respectively and was found reduced in FYM amended soil viz., 14.39, 15.99, 19.29 , 22.74 and 26 percent for each of the concentrations. In all levels of concentration, hysteresis effect (ndes/nads) was noticed indicating desorption was slower than adsorption. In the soil samples directly spiked with flupyradifurone done in completely randomized design with six treatments and three replications, the desorption percentages were found lower and a still higher hysteresis was observed. Mobility of flupyradifurone was assessed in completely randomized design with eighteen treatments and three replications i.e by loading 3 levels viz., 25, 50 and 75 µg formulation of flupyradifurone, separately on top of 200g soil columns loaded in PVC pipes and followed by eluting with 40, 80 and 160 mL of water @ 0.4ml min-1. In the sandy loam soil without amendment, flupyradifurone moved down the soil column which resulted in residue levels ranging from 13.84-9.56, 26.38- 19.08 and 34.30- 23.17 µg at 25, 50 and 75 µg levels, respectively when eluted with different volumes of water. In the soil amended with 0.5 per cent FYM, the corresponding residues ranged from 15.48- 11.79, 34.96- 22.00 and 36.62- 29.78 µg at 25, 50 and 75 µg levels indicating a higher retention in soil. The residue present in the leachate was found below detectable level for both amended soil and soil without amendment. The persistence of flupyradifurone in sandy loam soil and 0.5 per cent FYM amended soil under three soil moisture conditions was studied using the formulation of flupyradifurone added at the rate of 1, 2 and 4 mg kg-1 in completely randomized design with eighteen treatments and three replications. The half- life of flupyradifurone in air dry soil when applied 1, 2 and 4 mg kg-1 levels were 19.38, 20.87, 22.47 days respectively and they were 20.41, 21.79 and 22.94 days, respectively in amended soil. For the soil at the field capacity level, application at 1, 2 and 4 mg kg-1 levels resulted in half- life of 11.14, 13.08 and 13.21 days for normal soil and 9.51, 14.59 and 15.74 days for amended soil, respectively. Under saturated soil conditions, the half- life were 9.08, 9.12 and 9.85 days in soil without amendment and 10.02, 10.12 and 10.28 days for the amended soil at 1, 2 and 4 mg kg-1 levels of application respectively. In the persistence study, no metabolites of flupyradifurone were detected. Soil under the study was acidic, low in organic matter with 10.80 per cent clay, 20.50 per cent silt and 68.70 per cent sand. Extraction using acetonitrile followed by dispersive solid phase clean up using MgSO4-PSA was ideal for extraction of flupyradifurone. The estimation was done using LC-MS/ MS with retention time for flupyradifurone, 6-chloronicotinic acid and difluro ethyl amino furanone as 4.65, 4.22 and 1.34 respectively. The study concluded that the adsorption coefficient was higher in FYM amended soil indicating stronger adsorption than soil without amendment and the desorption percentages were reduced in the same. Hysteresis effect was noticed in all the treatments indicating slower desorption than adsorption. The mobility of flupyradifurone was found to be slightly higher in soil without amendment compared to the 0.5 per cent FYM amended soil. The dissipation was found to be the fastest under submerged condition followed by field capacity and dry moisture conditions.
