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  • ThesisItemOpen Access
    Availability indices for stressed nutrients for coconut (Cocos nucifera L) in an ultisol
    (Department of Soil Science and Agricultural Chemistry, College of Horticulture, Vellanikkara, 2003) Priya, P; KAU; Sureshkumar, P
    The present study was conducted with an objective to analyse the soil-plant system, the levels and interactions of nutrient ions in soil, soil solution and plant thereby / finding out the contributing factors to yield. The importance of the term relative intensity lies in the fact that the contribution of mineral elements to growth and yield of plants depend much on the relative amount of one element with respect to the others rather than the absolute content of individual elements. To study the ionic interactions and to unravel the role of Net Ionic Equilibrium based on Ratio Law on soil plant system, a sample of fifty phenotypically identical palms varying in yield from 14.4 to 84.4 nuts palm" year"! grown under an Ultisol were selected. Index leaf samples were collected during pre and post monsoon seasons from 25 palms each from high yielding and low yielding groups. Soil samples were also collected from the basins of these palms during the same seasons at 30 cm (surface) arid 60 cm (subsurface) depths. Soil solutions at saturation point were extracted from the surface samples by centrifugation technique. These leaf, soil and solution samples were analysed / . for different nutrient ions, and the NIE ratios in these three phases were worked out with respect to K and Na. The soil samples were acidic in nature and the variation in rhizosphere pH must have definitely influenced the solubility as well as absorption of different nutrient ions. In the case of available nutrients, the micro nutrients showed significant direct relation with yield both for high and low yielding populations. This might be due to their restricted availability due to aerobic oxidised condition where Fe and Mn might have been precipitated and got into unavailable forms. The BaCh exchangeable ions and the CEC derived from summing up of these exchangeable ions influenced yield directly. Exchangeable K had got a significant dominance in deciding the NIE ratio in soil, solution and in index leaves. Exchangeable K controlled the soil solution concentration of K which in turn controlled the NIE ratio in solution and the ratios in plant. Exchangeable K directly controlled the plant K content and plant K was positively and significantly correlated with the NIE ratios in plant and these ratios were positively and significantly correlated with yield. The negative significant correlation of exchangeable K with plant Mn and Zn revealed the antagonistic effect of exchangeable K in restricting the absorption of Mn and Zn by plants. Among the ionic concentrations in soil solution, Fe was positively and significantly correlated with yield in both the seasons. Soil solution concentrations of Ca and Mg were antagonistically and significantly related with plant Mn content. Potassium content and the NIE ratio in index leaves were found to have a significant direct relation with yield in the pre-monsoon season. Potassium, Ca and Mg were the dominant cations in plant deciding the total cation concentration in index leaves. The NIE ratios between the exchangeable ions, the ions in soil solution and the ions in index leaf samples were mutually, .positively and significantly correlated among themselves. This lead to the conclusion that there exists a constancy in the relative proportion of nutrient ions in the entire soil-plant system which followed Ratio Law. The study lead to the conclusion that the soil test values of the individual ions alone or the plant content of individual ions alone can't give a clear picture of optimum nutrient requirements for the plant. The relative concentration of K in soil through the ~ concentration in soil solution was found to govern the relative concentration in plant which in turn influenced the yield.
  • ThesisItemOpen 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, S
    Soil 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.
  • ThesisItemOpen 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, Bastin
    The 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.
  • ThesisItemOpen Access
    Taxonomy and organic carbon-nutrient interactions in selected wetland soils of Kerala
    (Department of Soil Science and Agricultural Chemistry, College of Horticulture, Vellanikkara, 2019) Nideesh, P; KAU; Sreelatha, A K
    A study was undertaken with the objective to classify wet land soils in the agro ecological units AEU 10 (north central laterite), AEU 5 (Kole lands) and AEU 6 (Pokkali lands) of Kerala and to assess the organic carbon stocks and CNPS stoichiometry. The study also aimed in finding out the organic carbon - nutrient interactions and to predict the organic carbon turnover in these soils. Extensive field traverse was conducted to select sites for profile excavation in the lateritic, Kole and Pokkali wetlands. The excavated profiles were studied for their morphological, physical and chemical properties. Based on the results of the study, soils of lateritic wetlands were classified as fine loamy, mixed, super active, acid isohyperthermic, Fluventic Dystrustepts. Soils of Kole lands were classified as loamy, mixed, euic, isohyperthermic, Terric Sulfihemists and Pokkali soils as coarse loamy over sandy, mixed, active, isohyperthermic, Typic Sulfaquepts. Total soil organic carbon (SOC) stock in the north central laterite region (Fluventic Dystrustepts) was 218 Mg ha-1 up to the depth of 120 cm of which maximum amount was stored in the surface 30 cm (86 Mg ha-1). In the Kole land soil (Terric Sulfihemists) maximum SOC was stored in the 90-120 cm layer (1016 Mg ha-1) and a total SOC of 2261 Mg ha-1 was stored up to 120 cm depth. Pokkali soils (Typic Sulfaquepts) stored 209 Mg ha-1 SOC up to 120 cm depth which was almost uniformly distributed in the entire profile. The C/N, C/P and C/S ratios decreased with depth in lateritic soil profile, whereas in the Kole land soil these ratios except C/S ratio increased significantly in the sub surface horizons. In the Pokkali soils the CNPS stoichiometry suffered irregular variation with depth. An incubation experiment was conducted to study the organic carbon nutrient interactions in the three wetland soils. Treatments included control (T1), POP based fertiliser and lime application (T2), soil test based fertiliser and lime application (T3), FYM substituting nitrogen in the T3 treatment (T4) and soil test based fertiliser and dolomite application (T5). In the lateritic soils. the active carbon and organic reserves of N, P and S were high in T3 treatment. The organic N, P and S pools increased in treatment T5 whereas organic P and inorganic S increased in treatment T4. In the Kole land soils, active carbon, organic nitrogen, inorganic P, organic S and inorganic S increased in T3; inorganic N and organic P increased in T4 and organic P and S pools increased in T5. In the Pokkali soils, active carbon content was high in T2 compared to other treatments while active carbon, organic N and inorganic N decreased in treatment T3. Liming decreased organic P in Pokkali soils due to conversion to available forms and higher utilisation. Application of FYM increased organic S in Pokkali soils and inorganic S in all soils. Temporal variation of the nutrient content (mg kg-1 soil) per organic carbon content (g kg-1 of soil) indicates the change in nutrient supply per unit change of organic carbon content. Treatment T1 favoured higher inorganic nitrogen per carbon content in laterite and Pokkali soils, where as in in Kole soils it was increased in T4. Inorganic phosphorus content per carbon was highest in laterite and lowest in Kole soil in control (T1). Inorganic sulphur per carbon content was highest in T4 for laterite, Kole and Pokkali soils. Organic nitrogen per carbon content was highest in the Kole land and minimum in the Pokkali land in the T3 treatment. Organic phosphorus per carbon content was maximum in FYM treatment in Kole and Pokkali soils and was minimum in T2 treatment in laterite and Pokkali soils. Treatment T3 had the highest organic sulphur per carbon content in the laterite and Kole soils and the treatment T1 gave the highest content in Pokkali soil. Wetland DNDC model was used to simulate the organic carbon turn over in the three wetland systems using the climatic data predicted by MarkSIM software. The results of modelling simulated for the year 2050 indicated that application of 100 per cent NPK along with FYM @ 5t ha-1 will ensure maximum organic carbon content in the Kole, Pokkali and lateritic wetlands. Fertiliser application improves the organic carbon storage in lateritic and Kole land soils. But in the Pokkali soils, fertiliser addition will not cause change in the organic carbon turn over processes whereas FYM application can improve the carbon content. Results of the study indicate that cultivation without any fertiliser and lime application causes gradual depletion of all organic and inorganic pools of nutrients in Kole land and lateritic wetland soils. Soil test based fertiliser and lime application along with FYM @ 5t ha-1 is appropriate in these soils for increased sustainability. The Pokkali soils are self-sufficient and can sustain its fertility status without any fertiliser application. However liming and FYM application may be considered as management options to improve sulphur availability and organic carbon turn over processes in these soils.
  • ThesisItemOpen 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, S
    The 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 apple
  • ThesisItemOpen Access
    Utilisation of dairy industry solid waste as an organic source in soil productivity
    (Department of soil science and agricultural chemistry, College of Agriculture, Vellayani, 2004) Indu, B; KAU; Usha, Mathew
    An investigation entitled ‘Utilization of dairy industry solid waste as an organic waste in soil productivity’ was carried out at College of Agriculture, Vellayani to study the feasibility of using dairy industry solid waste (dsw) as an organic source for improving soil productivity. The experiment consisted of four parts viz., characterization of dsw, vermicomposting of dsw, incubation study to monitor the changes in physical property, nutrient availability and microbial population in soil and pot culture experiment to study the influence of cdsw on amaranthus. The dairy waste collected from TRCMPU Ltd. at Ambalathara, Thiruvananthapuram was used in the present study. The physico-chemical and microbial analysis of dsw were done using suitable analytical procedures. Vermicomposting was carried out in pits of size 1 m x 0.5 m x 0.5 m using vegetable wastes, ground dsw and cowdung in the ratio 5:3:1 by the activity of earthworm Eudrillus eugeniae. Vermicompost was prepared according to package of practices recommendations of Kerala Agricultural University. Incubation study was conducted at the laboratory to monitor the nutrient release pattern and changes in physical properties and microbial population in soil. Two kg of soil was taken in plastic containers of uniform size and incubated at 60 per cent field capacity for three months after application of treatments. The experiment was laid out in CRD with seven treatments viz., T0 - absolute control, T1 – soil + 25 g fym, T2 – soil + 25 g dsw, T3 – soil + 12 ½ g fym + 12 ½ g dsw, T4 – soil 12 ½ g fym + 6 ¼ g dsw, T5 – soil + 12 ½ g cdsw, T6 –soil+ 6 ¼ g cdsw. Physico-chemical and microbilogical properties of soil were analysed at an interval of 1, 2, 4, 6, 8 and 12 weeks. The pot culture experiment was conducted to study the influence of dsw on growth, yield and quality of amaranthus. It was laid out in CRD with a treatments viz., T0 – absolute control, T1 – fertilizers and fym as per POP, T2 – POP fertilizers and 50 t ha-1 cdsw, T3 – POP fertilizers + fym 25 t ha-1 and cdsw 25 t ha-1, T4 – POP fertilizers and fym 25 t ha-1 and cdsw 12 ½ t ha-1, T5 – 2/3 N + full NPK of POP + fym 25 t ha-1 and cdsw 25 t ha-1, T6 – 2/3 N + full PK of POP and fym 25 t ha-1 + cdsw 12 ½ t ha-1, T7 – ½ N + full PK of POP + fym 25 t ha-1 + cdsw 25 t ha-1, T8 – ½ N + full PK of POP and fym 25 t ha-1 and cdsw 12 ½ t ha-1. Observations on various biometric and yield parameters have been recorded and analysis of plant sample were done at three stages of growth of plant viz., 30, 45 and 60 days after transplanting. The nutrient status of soil after the experiment was also analysed. Analysis of physico-chemical and microbial properties of dsw revealed that it had a near neutral pH (6.5) and it contained 37.5 per cent organic carbon, 5.80 per cent N, 2.04 per cent P, 0.71 per cent K, 1.69 per cent Ca, 1.58 per cent Mg, 1.71 per cent Fe, 159 mg kg 1 Mn and 1084 mg kg 1 Zn. Population of bacteria, fungi and actinomycetes in dsw were 13.3 x 106, 11.6 x 104 and 1.3 x 104 respectively. The results of the study revealed that vermicomposting can be successfully done in dsw using Eudrillus eugeniae. Vermicompost with a C : N ratio of 11.12 was obtained after 60 days of composting. The final compost contained 3.12 per cent N, 1.97 per cent P, 1.81 per cent K, 2.05 per cent Ca, 3.55 per cent Mg, 0.80 per cent Fe, 230 mg kg-1 Mn, 408 mg kg-1 Zn and 44 mg kg¬-1 Cu. Number of bacteria, fungi and actinomycetes in the compost at maturity stage were 42.6 x 106, 38.6 x 104 and 21.3 x 104 respectively. From the incubation study, it can be seen that nutrient content of soil increased upto 6-8 weeks in all treatments except T0 followed by a gradual decline. All nutrients except Cu were more on cdsw applied treatment in the initial period. Cu content was more in fym applied treatment. Nutrient availability was more from fym applied treatments during later periods of incubation. Bulk density of soil decreased in all treatments except T0 upto six weeks of incubation followed by a gradual increase in 8 and 12 weeks. Treatment in which cdsw was applied at higher dose showed the lowest bulk density. Upto six weeks the highest water holding capacity was noticed in cdsw applied treatments, after that fym applied treatments showed highest water holding capacity. Bacterial and fungal population reached the peak in sixth week and then declined. Upto eight weeks the effect of treatments was non significant with respect to actinomycete population. The pot culture experiment indicated the influence of cdsw on growth, yield and quality of amaranthus. Biometric and yield observation have proved the superiority of cdsw over fym. Beta-carotene content was more in cdsw applied treatments. Total yield and B:C ratio were the highest when cdsw was used as a partial substitute for fym. Physico-chemical properties of soil after the pot culture experiment revealed that pH, EC, organic carbon and available nutrients increased in all treatment except in T0 compared to the initial soil. pH, EC, organic carbon, available P, Ca and Fe were the highest in T2 which received cdsw at higher dose while the available N, K, Mg, Mn, Zn and Cu were the highest in T1 which received fym. From the results it can be concluded that effective biomanagement of dsw can be carried out using Eudrillus eugeniae. Better availability of nutrients especially nitrogen from cdsw compared to fym immediately after application as evidenced by incubation study is advantageous for short duration leafy vegetables. Use of cdsw can reduce the use of fym partially or fully in amaranthus. Fertilizer N can also be reduced to the extent of 1/3 of POP recommendation.
  • ThesisItemOpen Access
    Soil test crop response studies on groundnut in laterite soils of Kerala
    (Department of Soil Science and Agricultural Chemistry, College of Horticulture, Vellanikkara, 2005) Sidha, P S; KAU; Betty, Bastin
    The investigation entitled “STCR studies on groundnut (Arachis hypogaea L.) in laterite soils of Kerala” was conducted during 2003-2004 in the farm attached to College of Horticulture, Vellanikkara. Objectives of the study were to develop soil test based balanced fertilizer recommendation for specific yield targets to groundnut in laterite soils of Kerala, and to develop a basis for fertilizer recommendation for maximum and economic pod yield at varying STVs. The experiment consisted of FGE and STCR experiment. The aim of FGE was to create desired gradient in soil fertility in one and the same field by applying graded doses of N, P and K fertilizers and raising an exhaustive crop, fodder maize Co-1. After development of fertility gradient, the STCR experiment was conducted in the same field with the test crop groundnut variety TAG-24. The soil nutrient status before and after the experiment were analysed for both FGE and STCR. The nutrient requirements of groundnut variety TAG-24 were estimated as 49.46, 4.25 and 19.52 kg ha-1 N, P and K respectively to produce one tonne of pod. The soil efficiencies were worked out as 28.11, 7.70, 6.88 per cent for N, P and K respectively for groundnut in laterite soil. The contribution of nutrients from fertilizers were estimated as 45.61, 11.18 and 27.33 per cent for N, P and K respectively and the contribution from organic manure were 49.46, 4.25 and 19.52 per cent N, P and K respectively to produce one tonne of pod. Fertilizer prescription equations for specific yield targets of groundnut variety TAG-24 were derived by using the above basic data and the equations were as follows: Without FYM FN = 108.44 T - 0.616 SN FP = 38.01 T - 1.577 SP FK = 71.43 T - 0.305 SK With FYM FN = 108.44 T - 0.616 SN - 1.59 OM FP = 38.01 T - 1.577 SP - 1.87 OP FK = 71.43 T - 0.305 SK - 1.85 OK Multiple regression models were calibrated with yield as dependent variable and soil available and applied nutrients as independent variables. Among the three nutrients, P and K showed normal type (+, -, -) of response in both models with 15 and 17 variables. So equations were calibrated for these two nutrients. The equations were as follows: With 15 variables FP = 32.47 - 0.709 SP FK = 321.36 - 0.429 SK With 17 variables FP = 76.27 - 2.645 SP FK = 312.37 - 0.413 SK Simple correlation coefficient was worked out for nutrient uptake with yield, nutrient uptake and yield with available and applied nutrients and major plant nutrient content with yield. The study is useful to adjust fertilizer doses based on the specific objective and available resources of groundnut farmers of the state.
  • ThesisItemOpen Access
    Sulphur and boron nutrition and their foliar diagnosis in sesame
    (Department of Soil Science and Agricultural Chemistry,College of Agriculture, Vellayani, 2010) Jeena, Mathew; KAU; Sumam, George
    A laboratory cum field experiment was conducted to study the effect of S and B on the growth, yield and quality of sesame var. Thilarani and to standardize the foliar diagnosis of these elements in Onattukara sandy loam soil. The study included an incubation study and two field experiments. The treatments comprising the different levels of S and B laid out in 42factorial RBD. The treatments were T1(S0B0), T2(S0B1), T3(S0B2), T4(S0B3), T5(S1B0), T6(S1B1), T7(S1B2), T8(S1B3), T9(S2B0), T10(S2B1), T11(S2B2), T12(S2B3), T13(S3B0), T14(S3B1), T15(S3B2), T16(S3B3). The different levels of S were S0 (0 kg ha-1), S1 (7.5 kg ha-1), S2, (15 kg ha-1) and S3 (30 kg ha-1) and B0 (0 kg ha-1), B1(2.5 kg ha- 1), B2 (5 kg ha-1) and B3 (7.5 kg ha-1). The incubation study was conducted at College of Agriculture, Vellayani to understand the dissolution and release pattern of S and B from their sources gypsum and borax respectively in Onattukara sandy soil. The results revealed that the release of S and B was maximum at the 30th DOI. Increasing levels of S and B has a positive influence on the S content of the soil. T16 (S3B3) recorded the highest value at all the sampling stages for S whereas in the case of B, the treatment combinations which received B at the highest levels in combination with S3 or S2 showed the highest value. The field experiments were laid out at ORARS, Kayamkulam in 42 factorial RBD having two replications using Thilarani as the test crop. It was observed that application of S and B favourably influenced the yield and yield attributes of sesame. T16 was found to be the treatment which gave the highest grain yield and oil yield in both the years and was found to be on par with T14 (S3B1). S3 was the superior S level. As for the different levels of B, B1 can be inferred as the best level. The content of saturated fatty acids such as palmatic and stearic acid showed a decreasing trend with increasing levels of S and B whereas the content of the unsaturated fatty acids showed an increasing trend. The quality attributes of oil such as acid value, iodine value and saponification value was also studied and it was found that there is a decreasing trend with regard to acid and saponification value and an increasing trend for iodine number. The grain protein content also showed an increasing trend with the increase in rate of application of S and B. Regarding the content and uptake of N, P, K, S, B, Fe, Mn, Cu and Zn, a favourable influence for the different levels of S and B was recorded. Results regarding the S and B use efficiency and their apparent recovery showed that with increase in levels of S, an increasing trend was observed for S. In the case of B, increase was noticed up to B1 (2.5 kg ha-1) and there after showed a decreasing trend. This positive influence was also reflected on the available nutrient status of the soil such as organic carbon content, available N, P, K, S, B and DTPA extractable micronutrients. Correlation studies conducted to standardize the part and stage of sampling for the foliar diagnosis of sesame showed petiole at 30 DAS and 20 DAS in the case of S and B respectively. The same stages were found for the soil sampling also for both the nutrients. The critical nutrient level in the part standardised for these two nutrients were standardized using the graphical method proposed by Cate and Nelson (1965). In the case of S, it had been standardized as 0.088 per cent and for B, it had been found to be 28 mg kg-1. The critical nutrient level in soil was also estimated using the scatter diagram technique and was found to be 23 kg ha-1 at 30 DAS for S and 1.4 ppm at 20 DAS for B. Hence the application of S @ 30 kg ha-1 and B @ 2.5 kg ha-1 could faourably enhance growth of sesame with regard to the growth characters, yield and yield attributes and the quality aspects. Moreover, analysis of the plant and soil samples at the critical stages fixed for the respective nutrients will provide the necessary data for the sustainable management of the crop in Onattukara sandy loam soil.
  • ThesisItemOpen 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 R
    Site 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.