Browsing by Author "Mini, V"

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Assessment and management of micronutrient deficiencies in Onattukara
(Department of soil science and agricultural chemistry, College of agriculture, Vellayani, 2015) Mini, V; Usha Mathew
Assessment of soil quality in the post flood scenario of AEU 3 in Alappuzha district of Kerala and generations of GIS maps
(Department of soil science and agricultural chemistry, College of Agriculture, Vellayani, 2020) Mariya, Denny; Mini, V
A study entitled “Assessment of soil quality in the post-flood scenario of AEU 3 in Alappuzha district of Kerala and generation of GIS maps” was carried out with objectives to evaluate the soil quality of the flood affected areas of AEU 3, to work out the soil quality index and to map the various soil attributes and quality using the GIS techniques. A survey was conducted to identify the flood affected areas in the AEU 3 and identified Chunakkara, Veeyapuram, Palamel, Chettikulangara, Nooranadu, Pathiyoor and Chennithala panchayths as the major flood affected areas. The major land uses in the AEU 3 were rice, coconut, banana and vegetables. Majority of the farmers were marginal (91.5 per cent) and a few were small farmers. 28.6 per cent of farmers followed organic practices and the rest followed inorganic/ INM practices. Seventy geo-referenced surface soil samples were collected from seven flood affected panchayaths and characterized for various physical (texture, bulk density, particle density, porosity, aggregate analysis, soil moisture, WHC and the depth of silt/sand/clay deposition), chemical (pH, EC, organic carbon, available macro and micronutrients and heavy metal contents (Pb, Ni, Cd, Cr) and biological attributes (acid phosphatase and dehydrogenase activity). Principal component analysis was used to set up the minimum data set of the indicators to compute the soil quality index. Seven principal components were extracted from which nine indicators that highly influenced the soil quality were identified, viz. sand per cent, available P, available Ca, available Mg, bulk density, per cent of water stable aggregates, organic carbon, available Zn and available B. Scores and weights were assigned to each indicator, and they were aggregated to compute the soil quality index. The relative soil quality index of the soils were also found. GIS techniques were used to prepare thematic maps of various soil attributes and relative soil quality indices of the flood affected areas of the AEU 3. Correlations were worked out among the various analysed parameters. The acidity of the flood affected areas increased in comparison with the pre flood scenario. Depletion of nutrients like nitrogen, potassium, magnesium, sulphur, copper, and boron were also noticed in the post-flood soils. Available P content of the soil came down slightly from the very high status, but still continues to be high. Mg, S, Cu and B were deficient in 100 per cent of the samples, whereas, Fe and Mn remained sufficient. Ca and Zn exhibited 27.1 and 14.3 per cent deficiency, respectively. Heavy metals like Pb, Ni and Cr were detected (below critical limit) in the analysed samples, with relatively higher content in Veeyapuram. Physical properties like MWD, per cent WSA, soil moisture and WHC and biological attributes were positively correlated with the organic carbon content. Nutrient indices of nitrogen and potassium were low in most of the areas where as nutrient index of phosphorus was high throughout the AEU. 91.4 per cent samples fell into very low land quality and 8.6 per cent into the low land quality. Majority of the soils belonged to medium soil quality (78.6 per cent), followed by poor (12.8 per cent) and good (8.6 per cent) quality. The soils of Nooranad panchayath recorded the highest soil quality index and that of Chettikulangara panchayath, recorded the lowest. The increase in the acidity of the post flood soils, demands the application of adequate liming materials. Addition of more organic inputs can minimise the physical constraints of Onattukara soils. Split application of N and K fertilizers can reduce the leaching losses. Dose of P fertilizer has to be modified in the light of high P status in the AEU. Monitoring of secondary and micronutrients on regular basis is also required. Site specific and crop specific nutrient management is required to restore the soil health in the post-flood soils of AEU 3.
Effect of long term fertilization on soil carbon dynamics in rice-rice cropping sequence of Onattukara
(Department of Soil Science and Agricultural Chemistry , Vellayani, 2021-11-21) Kavyasree, G; Mini, V
A study entitled “Effect of long term fertilization on soil carbon dynamics in rice-rice cropping sequence of Onattukara” was carried out with the objective of studying the effect of long term fertilization on soil carbon dynamics and to explain the relationship between different active pools of soil organic carbon and rice yield. The study was conducted at the permanent manurial trial (PMT) plot at Onattukara Regional Agricultural Research Station, Kayamkulam, during 2019-21. The experiment comprised of field experiment during Virippu and Mundakan season, soil analysis and computation of various indices like Carbon pool index (CPI), Carbon lability index (CLI), Carbon management index (CMI), sensitivity index (SI), critical carbon input, carbon budgeting and plant analysis. Field experiment comprised of 8 treatments viz., T 1 (80 kg N ha -1 as FYM), T 2 (80 kg N ha -1 as Ammonium Sulphate), T 3 (80 kg N ha -1 as A.S + 40 kg P 2 O 5 ha -1 as Rajphos), T 4 (80 kg N ha -1 as A.S + 40 kg K 2 O ha -1 as MOP), T 5 (40 kg P 2 O 5 ha -1 as Rajphos + 40 kg K 2 O ha -1 as MOP), T 6 (80 kg N ha -1 as A.S + 40 kg P 2 O 5 ha -1 as Rajphos + 40 kg K 2 O ha -1 as MOP), T 7 (80 kg N ha -1 (20 kg as FYM and 60 kg as A.S.) + 40 kg P 2 O 5 ha -1 as Rajphos + 40 kg K 2 O ha -1 as MOP) and T 8 (Absolute control) replicated thrice using rice variety Jaya. Treatment receiving 80 kg N ha -1 (20 kg as FYM and 60 kg as A.S.) + 40 kg P 2 O 5 ha -1 as Rajphos + 40 kg K 2 O ha -1 as MOP (T 7 ) recorded the highest growth and yield. Soil samples were drawn from 3 different depths at 15 cm interval viz., 0-15 cm, 15-30 cm and 30-45 cm and analysed for physical, chemical and biological properties. There was no textural variation and the texture of the soil remained as sandy loam in all the treatments during both the seasons. An improved physical condition was noticed in T 7 with low BD (1.32 Mg C ha -1 ), high WHC (33%) and hydraulic conductivity (1.25 cm h -1 ). The soil acidity varied from very strongly acidic to strongly acidic. The highest content of available N, P, K and S was recorded in T 7 during both the seasons, while T 1 (FYM) recorded the highest content of Ca and Mg. The highest content of Zn, Cu and B were recorded in T 7 whereas Fe and Mn recorded the highest values under T 2 (Ammonium sulphate). Deficiencies of Ca, Mg, S and B were recorded in all the treatments. Generally all the parameters showed a decreasing trend with increasing depth except BD and pH. The highest nutrient content in grain and straw were also recorded in T 7 . Highest BC ratio (1.61 and 1.64) was recorded in T 7 during both the seasons. 244SOC, SMBC, SMBN, SMBP, WSC, water soluble carbohydrates and dehydrogenase activity were the highest under T 7 . T 7 recorded the highest TOC, very labile, labile, less labile and non labile C fractions and in all the treatments active C pool dominated the passive C pool. The contribution of active C pool to TOC accounted for 55-66%. Computed indices viz., CPI (1.56), CLI (1.34) and CMI (209.04) were found to be the highest in T 7 . Sensitivity Index (SI) was worked out to determine the sensitivity of each fraction to management practices and observed that active pool, SOC, water soluble carbon and water soluble carbohydrates were the most sensitive fractions while TOC and passive C pool were the least sensitive to management practices. Critical carbon input to maintain the initial level of SOC stock in soil was worked out. All the treatments recorded a positive critical carbon input which indicates that additional C has to be given inorder to sustain the present level of SOC stock. Among the treatments T 7 recorded the highest critical carbon input (0.470 Mg C ha -1 ) and it was due to initial high SOC stock. Carbon budgeting was done by computing SOC stock, C build up per cent, C build up rate and C sequestered and were the highest in T 7 followed by T 1 . Significant positive correlation was observed between different C pools, C pools and nutrient availability, C pools and biological activity and C pools and yield. Present study provided an insight on how management practices affect soil C buildup and C sequestration in rice-rice cropping sequence of Onattukara. Integrated nutrient management (T 7 ) with application of 20 kg N ha -1 as FYM and 60 kg N ha -1 as Ammonium sulphate along with 40 kg P 2 O 5 ha -1 as Rajphos and 40 kg K 2 O ha -1 as MOP significantly improved TOC, C fractions, CPI, CLI, CMI, C buildup rate and yield. Application of FYM @ 8t ha -1 (T 1 ) also improved the above mentioned parameters but the BC ratio was less (1.19 and 1.21) compared to T 7 . Increased soil acidity and deficiencies of secondary and micronutrients were also observed in all the treatments under study. Hence along with integrated nutrient management practices, soil test based fertilizer and lime application including secondary and micronutrients should be given importance to sustain the soil fertility in rice-rice cropping sequence of Onattukara.
Effect of soil amelioration and supplementary foliar nutrition on rice yield in kuttanad
(Department of Soil Science & Agricultural Chemistry, College of Agriculture, Vellayani, 2018) Lekshmi, S; Mini, V
Humic acid as a biostimulant and chelating agent for improving rice productivity in the Onattukara sandy soils
(Department of Soil Science and Agricultural Chemistry, College of Agriculture, Vellayani, 2025-03-04) Akhila Ashokan.; Mini, V
The study entitled ‘Humic acid as a biostimulant and chelating agent for improving rice productivity in the Onattukara sandy soils’ was carried out at the Department of Soil Science and Agricultural Chemistry, College of Agriculture, Vellayani during 2021- 2024. The major objective of the study was to assess the effect of humic acid (HA) as a biostimulant, biosurfactant and as an iron chelating agent for improving nutrient use efficiency and rice productivity in the Onattukara sandy soil (AEU 3). The research work comprised of four parts viz., characterization of HAs, incubation study for assessing iron chelating property, incubation study for assessing biosurfactant property of HA and evaluation of the effect of HA on improving rice productivity. The salient research findings emanated from the experiments are summarized below. Humic acid (HA) used in the study (HA solid formulation and HA liquid formulation) was initially characterized based on physical observation, elemental composition and spectrometric studies. The HA (solid) and HA (liquid) had a pH of 9.58 and 9.2, EC value of 1.04 dSm-1 and 0.46 dSm-1, respectively. Analysis of C, H, N and S revealed that the HA (solid) and HA (liquid) contains 36.18 per cent and 1.79 per cent of C, 2.56 per cent and 11.47 per cent H, 0.76 per cent and 0.12 per cent of N, and 0.35 per cent and 0.06 per cent S, respectively. The CEC value of solid HA and liquid HA was 181.40 cmol (+) kg-1 and 35.40 cmol (+) kg-1, respectively. The C:N ratios of solid and liquid HA formulations was 47.61 and 14.92, while the E4/ E6 ratio was observed to be 3.69 and 4.82, respectively. The solid HA was used for soil application and the liquid formulation was applied as foliar spray. The incubation study for assessing iron chelating properties of HA was carried out at submerged condition for 6 weeks and sampling was done at weekly intervals. The analysis after 4th week of incubation revealed a significant decreasing trend in Fe availability ranging from 229.3 mg kg-1 to 179.3 mg kg-1 with an increase in HA application levels from 2.5 kg ha-1 (T1) to 15 kg ha-1 (T4). A similar trend continued in the 5th week and 6th week and the treatment T4 (15 kg ha-1 of HA) could efficiently chelate Fe resulting in a lower available Fe content of 103.6 mg kg-1 in the soil. Compared to initial value (278.0 mg kg-1), T4 and T3 showed a decrease of 62.72 per cent and 54.32 per cent in available Fe content in soil, respectively. The treatments in the study significantly influence Fe fractions such as water soluble Fe, exchangeable Fe and organic matter bound Fe. The value of Fe fractions viz., water soluble Fe, exchangeable Fe, carbonate bound Fe, iron-manganese oxides bound Fe, organic matter bound Fe, residual fractions and total Fe under the treatment combinations ranged from 3.41 mg kg-1 to 3.92 mg kg-1, 67.52 mg kg-1 to 87.11 mg kg-1, 23.54 mg kg-1 to 34.30 mg kg-1, 2373 mg kg-1 to 2569 mg kg-1, 281.7 mg kg-1 to 311.4 mg kg-1, 7300 mg kg-1 to 7676 mg kg-1 and 10331 mg kg-1 to 10462 mg kg-1, respectively. A significant positive correlation was observed for available Fe with water soluble Fe, exchangeable Fe and carbonate bound Fe whereas, it was negatively correlated with organic matter bound Fe and iron-manganese oxides bound Fe. The incubation study could identify that HA application @ 15 kg ha-1 was the most effective in chelating Fe, followed by T3 (HA @ 10 kg ha-1). A second incubation study was carried out to assess the biosurfactant properties of HA under field capacity. Water stable aggregates, water holding capacity, bulk density and porosity ranged from 47.48 per cent to 52.74 per cent, 22.54 per cent to 26.59 per cent, 1.41 Mg m-3 to 1.51 Mg m-3 and 38.03 per cent to 41.31 per cent, respectively. Similarly, clay dispersion ratio and dispersion ratio ranged between 31.24 per cent to 44.05 per cent and 39.52 per cent to 46.14 per cent, respectively. Soil physical properties like water stable aggregates, water holding capacity and porosity were significantly improved by the application of HA @ 15kg ha-1 followed by HA @ 10 kg ha-1. The field experiment was conducted in two seasons to evaluate the effectiveness of various doses of HA identified from the incubation studies, in combination with chemical fertilizers, lime and FYM on productivity of rice crop (var. Bhagya). The experiment was carried out at ORARS, Kayamkulam during the Kharif and Rabi seasons (2023-24). Biometric observations like plant height, number of tillers per hill, root length, root dry weight and number of active roots per hill were significantly high in the treatment T5 (soil test based recommended dose of fertilizer (RDF) + FYM + HA @ 15 kg ha-1 + foliar application of 0.2 % fortified HA) during panicle initiation and harvest stage in both Kharif and Rabi seasons. Humic acid supplemented treatments (especially T5, T6 (75% soil test based RDF + FYM + HA @ 15 kg ha-1 + foliar application of 0.2 % fortified HA), T9 (soil test based RDF + 50% FYM + HA @ 15 kg ha-1 + foliar application of 0.2 % fortified HA) and T10 (75% soil test based RDF + 50% FYM+HA @ 15 kg ha-1+foliar application of 0.2 % fortified HA)) could bring about a significant decrease in number of iron coated roots per hill, content of iron coatings and number of decayed roots per hill in comparison with treatments receiving RDF, lime and FYM as per POP (T1) and soil test-based RDF + FYM (T3). Visual scoring of Fe toxicity in rice in each treatments revealed the ability of HA in alleviation of Fe toxicity in rice in both maximum tillering to panicle initiation stages. The Fe toxicity score of zero was observed in T5, T6, T7 (soil test based RDF + FYM + HA @ 10 kg ha-1 + foliar application of 0.2 % fortified HA), T9, T10 and T11 (soil test based RDF + 50% FYM + HA @ 10 kg ha-1+foliar application of 0.2 % fortified HA) at panicle initiation stage of both season crops. With regard to grain yield, the treatment T5 (soil test based RDF + FYM + HA @ 15 kg ha-1 + foliar application of 0.2 % fortified HA) was found to be superior in both Kharif (3.43 t ha-1) and Rabi seasons (3.32 t ha-1) which was followed by the treatment T9 (soil test based RDF + 50 % FYM + HA @ 15 kg ha-1 + foliar application of 0.2 % fortified HA). Straw yield was also observed to be high in the treatment T5 which was on par with T6 and T9 for Kharif crop and the treatment T5 was on par with T6 , T7, T8, T9 and T11 for Rabi crop. Soil analysis data from both seasons revealed that the treatment T5 had the highest pH, EC, primary nutrients, secondary nutrients and B content. Highest values of Fe, Mn, Zn and Cu were recorded in the treatment receiving RDF, lime and FYM as per POP (T1 & T2) and soil test-based RDF + FYM (T3 & T4). The carbon fractions viz; soil organic carbon, total organic carbon, soil microbial biomass carbon, water-soluble carbon, very labile carbon, labile carbon, less labile carbon and non-labile carbon were enhanced in HA applied treatments with the highest value recorded in T5 treatment. The combined application of HA and chemical fertilizers had pronounced effect on various Fe fractions such as water soluble Fe, exchangeable Fe, carbonate bound Fe and organic matter bound Fe. A significant increase in organic matter bound Fe was observed in HA applied treatments, of which T5 registered the highest value. Available Fe in the soil was positively correlated with water soluble Fe, exchangeable Fe, carbonate bound Fe and negatively correlated with organic matter bound Fe and iron manganese oxides bound Fe. Effect of treatments on soil physical properties were statistically on par with each other. However, soil supplemented with treatment T5 had the highest porosity and the lowest bulk density values among all the treatments. Plant analysis of both Kharif and Rabi season crops revealed that significantly higher N, P, K and Mg content in straw and grain was observed in the treatment T5, while the highest Fe, Mn, Zn and Cu were recorded from the treatments receiving RDF, lime and FYM as per POP (T1 and T2) and soil test based RDF + FYM (T3 & T4). The Fe partitioning study on the root, straw, grain and glume also revealed that higher amount of Fe is partitioned and deposited in the roots, followed by shoot. Application of HA in combination with chemical fertilizers and FYM brought about significant changes in microbial parameters. The count of bacteria, fungi and actinomycetes was significantly higher in T5 treatment. Similarly, dehydrogenase activity was also found the highest in T5 followed by T9 treatment. The economic analysis of various treatments considered in the study revealed that the treatment T5 had the highest value for net income followed by T9 treatment. Similar trend was observed in case of benefit-cost ratio also and the highest value of 1.66 (Kharif) and 1.63 (Rabi) were observed in T5 treatment. From the above experiments, it can be concluded that the combined application of soil test based RDF + FYM + HA @ 15 kg ha-1 + foliar application of 0.2 % fortified HA had superior effect on mitigating Fe toxicity, increased nutrient availability and better physical properties. Humic acid has the potential to alleviate Fe toxicity in Onattukara soil, which indirectly leads to improvement of rice productivity is evident from the present study. Supplementing humic acid to the soil has proven to enhance the carbon content, nutrient status, yield attributes in rice and Fe toxicity tolerance. Hence, the application of soil test based RDF + FYM + HA @ 15 kg ha-1 + foliar application of 0.2 % fortified HA can be recommended for alleviating Fe toxicity, augmenting soil fertility and improving rice productivity in the sandy soils of Onattukara.
Induced mutations in cowpea
(Department of Agricultural Botany, College of Agriculture, Vellayani, 1989) Mini, V; Vijayagopal, P D
Seeds of cowpea ( vigna unguiculata) cultivar kuruthola-payar were subjected to induced mutagenesis using four doses of gamma rays (10 to 40 krad) and four doses of EMS (0.5 to 2.0 per cent) and their effects in the M1 and M2 generations were studied. The germination percentage was observed to decrease prgogressively with the increase in dose of both mutagens although the reduction was more drastic with EMS. Reduction in survival percentage was observed with increase in the dose of gamma rays and EMS. The growth of shoot and root and plant height were reduced by both the mutagens, although gamma rays showed greater shoot inhibition and EMS showed greater root inhibition. The pollen fertility as well as seed fertility decreased linearly with increase in doses of both the mutagens. Chlorophyll chimeras were observed only in the 30 krad and 40 krad gamma ray treatments. Morphological variations noticed included plants with alterations in the number, size and shape of leaflets. The chlorophyll mutation frequency estimated on M2 progeny row basis showed an increase with increasing doses of gamma rays, except in the 40 krad treatment, which showed a slight decrease. In the case of EMS, maximum mutants were observed at the lowest dose. The chlorophyll mutation frequency estimated on M2 seedling basis showed dose-dependence. The frequencies of the different types of chrolophyll mutants did not show any dose-relationship. The segregation ratio of chlrophyll mutants was higher for EMS than gamma irradiation. The viable mutation frequencies did not show any definite relationship with the doses in both the mutagen treatments. The mutagenic effectiveness in inducing chlrophyll mutations was high at the lowest dose of both mutagens. On the basis of lethality, 20 krad of gamma rays was the most efficient, while on the basis of injury and sterility, 10 krad was the most efficient. With EMS, the 0.50 per cent treatment was the most effective as well as the most efficient treatment on the basis of lethality, injury and sterility. The mutagenic efficiency in inducing chlorophyll mutations was higher for gamma rays with respact to lethality and injury, while on the basis of sterility, EMS proved to be more effcient than gamma rays.
Matrix based slow release fertilizer for increasing nutrient use efficientcy in the onatukars sandy plains
(Department of Soil Science and Agricultural Chemistry, College of Agriculture, Vellayani, 2019) Adithya G Raj; Mini, V
Productivity enhancement of vegetables through salt stree mitigation in the sandy loam soils of Onattukara
(Department of Soil Science and Agricultural Chemistry, College of Agriculture, Vellayani, 2025-12-14) Salma Nizar.; Mini, V
The study entitled “Productivity enhancement of vegetables through salt stress mitigation in the sandy loam soils of Onattukara” was carried out at the Department of Soil Science and Agricultural Chemistry, College of Agriculture, Vellayani during 2022-2024. The main objective of the study was to evaluate the ameliorative effect of calcium silicate and supplementary foliar nutrition on growth and mineral nutrition of vegetables in the salt stressed areas of Onattukara using tomato as the test crop. The three parts of the study were the development of multinutrient formulation for supplementary foliar nutrition, germination test for identifying the critical level of salinity for tomato and the evaluation of the effect of calcium silicate and supplementary foliar nutrition on growth and mineral nutrition of vegetables under salt stress. The salient research findings emanated from the experiments are summarized below. A multi nutrient formulation containing K, Ca, Mg, N, B and Zn was developed for supplementary foliar nutrition based on general soil status. General soil status of these nutrients was low and literature references and adhoc recommendations for secondary and micronutrient management and information on crop requirement were also used for developing the formulation. Suitable nutrient carriers were used for developing the foliar formulation. The carriers evaluated to prepare the mixture were KNO3, CaNO3, MgSO4. 7H2O, H3BO3, ZnSO4.7H2O, Na2B8O13. 4H2O and Zinc acetate. Humic acid and potassium silicate were used as surfactant and binder materials. Based on the properties like pH, EC and solubility in water and trial on standing crop, the mixture containing KNO3, Ca (NO3)2, MgSO4.7H2O, Boric acid and ZnSO4.7H2O was found to be the best. This formulation had a nutrient composition of K (10%), N (4%), Ca (6%), Mg (2.5%), B (5%) and Zn (2%) and recorded a pH of 6.32 and EC of 0.6dSm-1, which was within the desirable limit for foliar formulations and was 100% soluble. The germination test for identifying the critical level of salinity for tomato was carried out in the laboratory in completely randomized design using seeds of tomato variety Vellayani vijai. Different levels of salinity (10mM, 20mM, 30mM, 40mM of NaCl) was evaluated along with control and critical level of salinity for tomato identified. Observations taken on the 14th day of experiment showed that the germination percentage of tomato seeds reduced from 96.52% to 30.87% , days needed to complete germination increased from 3.70 days to 12.15 days and root shoot dry weight ratio increased from 0.433 to 0.611 with an increase in salinity levels from 0mM NaCl (T1) to 40mM NaCl (T5). The analysis of Na and K content of tomato seedlings also revealed a significant increasing trend in Na+/ K+ ratio of shoot and root with increase in salinity levels. Na+/ K+ ratio of shoot ranged from 2.23 to 4.21 and Na+/ K+ ratio of root ranged from 1.90 to 3.36 with treatments T1 to T5. The germination study could identify the treatment T4 - Hoagland solution containing 30 mM NaCl which recorded a noticeably greater reduction in germination percentage (<80%) as the critical level of salinity for tomato. Hence 30 mM NaCl and 40 mM NaCl were selected for the pot culture experiment. The pot culture experiment was conducted from January to April 2024 at O.R.A.R.S., Kayamkulam using tomato (var. Vellayani vijai) as the test crop to evaluate the effect of various doses of calcium silicate (100 kg ha-1 to 150 kg ha-1) and supplementary foliar nutrition (0.5%) on growth and mineral nutrition of vegetables under salt stress. Biometric observations like plant height, number of branches, fruit set percentage and internodal length were significantly higher in the treatment T7 ( Soil test based POP + CaSiO3 @ 125 kg ha-1 + 0.5 % spray of multi nutrient mixture @ 30 mM salt stress) whereas days to first fruit set, root length, root volume and root dry weight was higher in treatment T8 ( Soil test based POP + CaSiO3 @ 150 kg ha-1 + 0.5 % spray of multi nutrient mixture @ 30 mM salt stress). Treatments containing calcium silicate and supplementary foliar nutrition showed a significant improvement in all of the biometric observations recorded. With regard to the yield attributes such as fruits per plant, fruit weight and yield per plant, the treatment T7 ( Soil test based POP + CaSiO3 @ 125 kg ha-1 + 0.5 % spray of The study entitled “Productivity enhancement of vegetables through salt stress mitigation in the sandy loam soils of Onattukara” was carried out at the Department of Soil Science and Agricultural Chemistry, College of Agriculture, Vellayani during 2022-2024. The main objective of the study was to evaluate the ameliorative effect of calcium silicate and supplementary foliar nutrition on growth and mineral nutrition of vegetables in the salt stressed areas of Onattukara using tomato as the test crop. The three parts of the study were the development of multinutrient formulation for supplementary foliar nutrition, germination test for identifying the critical level of salinity for tomato and the evaluation of the effect of calcium silicate and supplementary foliar nutrition on growth and mineral nutrition of vegetables under salt stress. The salient research findings emanated from the experiments are summarized below. A multi nutrient formulation containing K, Ca, Mg, N, B and Zn was developed for supplementary foliar nutrition based on general soil status. General soil status of these nutrients was low and literature references and adhoc recommendations for secondary and micronutrient management and information on crop requirement were also used for developing the formulation. Suitable nutrient carriers were used for developing the foliar formulation. The carriers evaluated to prepare the mixture were KNO3, CaNO3, MgSO4. 7H2O, H3BO3, ZnSO4.7H2O, Na2B8O13. 4H2O and Zinc acetate. Humic acid and potassium silicate were used as surfactant and binder materials. Based on the properties like pH, EC and solubility in water and trial on standing crop, the mixture containing KNO3, Ca (NO3)2, MgSO4.7H2O, Boric acid and ZnSO4.7H2O was found to be the best. This formulation had a nutrient composition of K (10%), N (4%), Ca (6%), Mg (2.5%), B (5%) and Zn (2%) and recorded a pH of 6.32 and EC of 0.6dSm-1, which was within the desirable limit for foliar formulations and was 100% soluble. The germination test for identifying the critical level of salinity for tomato was carried out in the laboratory in completely randomized design using seeds of tomato variety Vellayani vijai. Different levels of salinity (10mM, 20mM, 30mM, 40mM of NaCl) was evaluated along with control and critical level of salinity for tomato identified. Observations taken on the 14th day of experiment showed that the germination percentage of tomato seeds reduced from 96.52% to 30.87% , days needed to complete germination increased from 3.70 days to 12.15 days and root shoot dry weight ratio increased from 0.433 to 0.611 with an increase in salinity levels from 0mM NaCl (T1) to 40mM NaCl (T5). The analysis of Na and K content of tomato seedlings also revealed a significant increasing trend in Na+/ K+ ratio of shoot and root with increase in salinity levels. Na+/ K+ ratio of shoot ranged from 2.23 to 4.21 and Na+/ K+ ratio of root ranged from 1.90 to 3.36 with treatments T1 to T5. The germination study could identify the treatment T4 - Hoagland solution containing 30 mM NaCl which recorded a noticeably greater reduction in germination percentage (<80%) as the critical level of salinity for tomato. Hence 30 mM NaCl and 40 mM NaCl were selected for the pot culture experiment. The pot culture experiment was conducted from January to April 2024 at O.R.A.R.S., Kayamkulam using tomato (var. Vellayani vijai) as the test crop to evaluate the effect of various doses of calcium silicate (100 kg ha-1 to 150 kg ha-1) and supplementary foliar nutrition (0.5%) on growth and mineral nutrition of vegetables under salt stress. Biometric observations like plant height, number of branches, fruit set percentage and internodal length were significantly higher in the treatment T7 ( Soil test based POP + CaSiO3 @ 125 kg ha-1 + 0.5 % spray of multi nutrient mixture @ 30 mM salt stress) whereas days to first fruit set, root length, root volume and root dry weight was higher in treatment T8 ( Soil test based POP + CaSiO3 @ 150 kg ha-1 + 0.5 % spray of multi nutrient mixture @ 30 mM salt stress). Treatments containing calcium silicate and supplementary foliar nutrition showed a significant improvement in all of the biometric observations recorded.