Browsing by Author "Rani, B"

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Amelioration of surface and subsoil acidity in the laterite soils (ULTISOLS) of central and southern Kerala
(Department of Soil Science and Agriculture Chemistry, College of Agriculture, Vellayani, 2024-12-31) Akhila Merin Mathew.; Rani, B
The study entitled “Amelioration of surface and subsoil acidity in the laterite soils (Ultisols) of central and southern Kerala” was undertaken with the objectives of characterization and mapping of spatial variation of surface and subsoil acidity in the laterite soils (Ultisols) of central and southern Kerala - AEU 8, 9 and 10, evaluation of inorganic and organic amendments for amelioration of surface and subsoil acidity and the analysis of their effect on crop production using fodder sorghum as test crop. A survey was carried out and geo-referenced surface and subsurface soil samples were collected from 30 locations in AEU 8 (Southern laterites), 9 (South central laterites) and 10 (North central laterites) of Kerala from five depths viz. 0 20 cm, 20-40 cm, 40-60 cm, 60-80 cm and 80-100 cm. The samples were characterized for soil acidity parameters, EC, organic carbon and available nutrients. Soil acidity attributes except pH were classified using natural breaks or Jenks optimization method and graduated symbol maps were generated using ArcGIS pro 3.3.1. Soil pH maps were generated based on the existing classification. The results showed that soils of Vellayani and Balaramapuram in AEU 8, Kalluvathukal, Kottarakara and Kozhuvanal in AEU 9 and Madakkathara and Chalavara in AEU 10 displayed higher levels of surface and sub soil acidity. Among the sampling locations, soils of Vellayani which registered the lowest pH at 0-20 and 40-60 cm depths, highest exchangeable H+ at all depths and highest exchangeable Al3+ at 20-100 cm depth was selected for column incubation study and field validation. Soil samples were collected up to a depth of 90 cm from CoA, Vellayani for setting up the column incubation experiment for a period of 16 weeks. The soil columns were maintained at field capacity and treatments consisting of liming materials @ lime requirement (LR), liming materials @ lime requirement (LR) + co composted biochar (CCB) (5t/ha), and CCB (5t/ha) alone were applied to the top 15 cm. The soil columns were subjected to periodic leaching and destructive sampling through 0-15, 15-30, 30-60 and 60-100 cm depths at 4, 8, 12 and 16 weeks of incubation. The leached soil and leachate samples were characterized to elucidate Al replacement, nutrient retention and downward movement of Ca and Mg. The CCB-liming material combinations demonstrated better alleviation of soil acidity especially in the subsoil (15-90 cm) throughout the incubation experiment. Among the CCB- liming material combinations, combinations of burnt lime (BL) or dolomite (DL) with phosphogypsum (PG) alone or PG + magnesium sulphate (MS) showcased superior performance with lower exchangeable H+, Al3+ exchangeable, potential and pH dependent acidities, extractable, free and total Al and higher pH and Ca fractions at different depths. These treatments also displayed higher concentrations of Ca, Mg and Al in leachate indicating swift downward movement of Ca and Mg and removal of toxic levels of Al from the columns. The treatments ½ LR as BL + ½ as PG + CCB (5t/ha), ½ LR as DL + ½ as PG + CCB (5t/ha) and ½ LR as BL + ½ as PG & MS + CCB (5t/ha) showing higher potential for ameliorating soil acidity at different depths were selected for field validation. The field experiment was carried out using fodder sorghum as the test crop with the best three treatments selected from the soil column incubation experiment, each at 100 per cent LR and 75 per cent LR. The analysis of soil from different depths at the end of the field experiment showed that the application of ½ LR as BL + ½ LR as PG + CCB (5t/ha) @ 100 per cent LR displayed highest pH of 5.74 at 0-15 cm, 5.53 at 15-30 cm, 5.45 at 30-60 cm and 5.28 at 60-90 cm respectively. The pH values at different depths for this treatment was significantly higher than the other treatments except at 0-15 cm (5.74) where it was on par with ½ LR as BL + ½ as PG & Magnesium sulphate (MS) + CCB (5t/ha) @ 75 per cent LR (5.62). The treatment ½ LR as BL + ½ LR as PG + CCB (5t/ha) @ 100 per cent LR also recorded the lowest exchangeable H+ of 0.123 meq 100 g-1 at 0-15 cm, 0.213 meq 100 g-1 at 15-30 cm, 0.433 meq 100 g-1 at 30-60 cm and 0.490 meq 100 g-1 at 60-90 cm, respectively which was comparable with 1/2 LR as BL + 1/2 as PG & MS (3:2) + CCB (5t/ha) @ 100 per cent LR (0.133 meq 100 g-1) at 0-15 cm and with 1/2 LR as DL + 1/2 as PG + CCB (5t/ha) @ 100 per cent LR (0.437 meq 100 g-1), 1/2 LR as BL + 1/2 as PG & MS (3:2) + CCB (5t/ha) @ 100 per cent LR (0.443 meq 100 g-1) and ½ LR as BL + ½ as PG & Magnesium sulphate (MS) + CCB (5t/ha) @ 75 per cent LR (0.457 meq 100 g-1) at 30-60 cm. The treatment ½ LR as BL + ½ as PG & MS (3:2) + CCB (5t/ha) @ 100 per cent LR itself registered the lowest exchangeable Al3+ values of 0.073 meq 100g-1, 0.440 meq 100g-1 and 0.563 meq 100g-1, respectively at 0-15, 30-60 and 60-90 cm depths. At 0-15 cm depth, this was comparable with ½ LR as BL + ½ LR as PG + CCB (5t/ha) @ 100 per cent LR (0.083 meq 100g-1 ) and ½ LR as BL + ½ as PG & magnesium sulphate (MS) + CCB (5t/ha) @ 75 per cent LR (0.113 meq 100g-1), respectively whereas at 30-60 cm depth it was on par with 1/2 LR as DL + 1/2 as PG + CCB (5t/ha) @ 100 per cent LR (0.440 meq 100g-1 ), ½ LR as BL + ½ LR as PG + CCB (5t/ha) @ 100 per cent LR (0.44 meq 100g-1 ) and ½ LR as BL + ½ as PG & magnesium sulphate (MS) + CCB (5t/ha) @ 75 per cent LR (0.46 meq 100g 1), respectively. At 60-90 cm depth, ½ LR as BL + ½ as PG & MS (3:2) + CCB (5t/ha) @ 100 per cent LR was comparable with ½ LR as BL + ½ as PG + CCB (5t/ha) @ 100 per cent LR (0.567 meq 100g-1 ), 1/2 LR as DL + 1/2 as PG + CCB (5t/ha) @ 100 per cent LR (0.587 meq 100g-1 ) and ½ LR as BL + ½ as PG & Magnesium sulphate (MS) + CCB (5t/ha) @ 75 per cent LR (0.630 meq 100g-1), respectively. At 15-30 cm, ½ LR as BL + ½ as PG + CCB (5t/ha) @ 100 per cent LR displayed the lowest exchangeable Al3+ (0.163 meq 100g-1) which exhibited remarkable variation from other treatments. Similar results were observed for exchangeable, potential and pH dependent acidities, Al saturation and base saturation. The highest green fodder yield (86.7 t ha-1), dry matter yield (66.2 t ha-1), crude protein (9.14%), plant height (3.50m), root length (60.1 cm) and Ca uptake (188 kg ha-1) was also observed for ½ LR as BL + ½ as PG + CCB (5t/ha) @ 100 per cent LR. The study showed that an integrated approach utilizing organic and inorganic amendments is the most feasible option for the simultaneous alleviation of surface and subsoil acidity. The results of the incubation and field experiments suggests that the application of ½ LR as BL + ½ as PG + CCB (5t/ha) (546.6 kg BL per ha + 1161.8 kg PG per ha + CCB (5t ha-1)) has remarkable potential in alleviating surface and subsoil acidity, lowering Al saturation and improving soil reaction, base saturation and nutrient availability in the laterite soils of Kerala while ensuring higher crop productivity.
Assessment if soil quality in the post flood scenario of AEU 12 in Pathanamthitta district of Kerala and generation of GIS maps
(Department of soil science and agricultural chemistry, College of Agriculture, Vellayani, 2020) Akhila Merin Mathew; Rani, B
Biochar for carbon sequestration, soil health and crop productivity
(Department of Soil Science and Agricultural Chemistry, College of Agriculture, Vellayani, 2022-11-21) Nhala Jabin P P.; Rani, B
Boron Nutrition of wetland rice ( Oryza sativa L. )
(Department of Soil Science and Agricultural Chemistry, College of Agriculture, Vellayani, 2016) Reshma Remesh; Rani, B
Dynamics of potassium, magnesium and sulphur in plant and soil with special reference to the application of langbeinite
(Department Of Soil Science And Agricultural Chemistry,College Of Horticulture, Vellanikkara, 2000) Rani, B; Jose, A I
Impact of long term integrated nutrient management system on soil health and rice productivity
(Department of Soil Science and Agricultural Chemistry, College of Agriculture, Vellayani, 2017) Rakhi, R; Rani, B
Nutrient release pattern and performance of biochar blended N and K fertilizers in laterite and sandy soils
(Nutrient release pattern and performance of biochar blended N and K fertilizers in laterite and sandy soils,Vellayani, 2024-01-24) Kavya, S R; Rani, B
Organic and inorganic amendments for surface and subsoil acidity amelioration in southern laterites of Kerala
(Department of Soil Science and Agricultural Chemistry, College of Agriculture,Vellayani, 2024-02-12) Fida Banu, M R; Rani, B
The study entitled Organic and inorganic amendments for surface and subsoil acidity amelioration in southern laterites of Kerala was conducted in the Department of Soil Science and Agricultural Chemistry, College of Agriculture, Vellayani during 2021-2023 with the objectives to evaluate various organic amendments and liming materials for amelioration of surface and subsoil acidity in the southern laterite soils (AEU -8) of Kerala and assessment of the effect on crop production using tomato as test crop. The experiment comprised of two parts viz. column incubation experiment and field validation of amendments for soil acidity. A column incubation study was conducted under laboratory conditions for 12 weeks using the southern laterite soils (AEU-8) of College of Agriculture, Vellayani, to elucidate the acid neutralization capacity of organic and inorganic amendments applied to the soil and to monitor the amelioration of surface and sub soil acidity. Soil samples were collected to a depth of 60 cm from the experiment site and filled in polyvinyl chloride (PVC) tubes of 10 cm diameter and 60 cm length and with facility to collect the leachate in such a manner as to attain the same bulk density as that of the field. Treatments were applied to the top 15 cm soil on weight basis and thoroughly mixed. The soil columns were maintained at field capacity. There were 17 treatments which included farmyard manure (FYM) @ 20 t ha-1 , humic acid (HA) @ 10 kg ha-1 , poultry manure (PM) @ 1 t ha-1 and coconut frond biochar (CFB) @ 10 t ha-1 along with lime or dolomite or calcium silicate (CS) or phosphogypsum (PG) at lime requirement (LR) and soil alone. Biochar produced from coconut frond by the process of slow pyrolysis and other organic amendments, were analysed for various physical and chemical properties using standard procedures. Humic acid recorded the highest bulk density (0.51 Mg m-3 ) while the lowest was for CFB (0.36 Mg m-3 ). The highest pH was for CFB (10.70) followed by HA (9.84). The TOC (41.11%), P (0.95%), K (0.91%), Ca (0.56%), Mg (0.45%), S (0.25%) and B (6.28%) were highest for CFB while the highest value of N (2.97%) was for PM. Fe (813.30 mg kg-1 ), Mn (94.50 mg kg-1 ), Zn (40.12 mg kg-1 ) and Cu (5.13 mg kg-1 ) were highest for FYM. CCE of lime, dolomite, PG and CS were 123.5%, 124 %, 58.1% and 58.06% respectively. The highest concentration of total Ca was observed for lime (37.10%) and for total Mg, was for dolomite (16.03%). Three leching events were performed in the prepared soil columns at 4, 8 and 12 weeks of incubation by adding double the pore volume of water. Leachate was acidic in pH for all the treatments and showed an increase up to 12th week of incubation. The EC, total OC, P, K, Ca, S, Mg and B contents in the leachate decreased from the 4 th week to 12th week. Total N content showed a general decrease from the 4 th week to 8th week and an increase at 12 weeks except for the treatment supplied with CFB along with either lime, dolomite, PG or CS which showed a gradual increase. The cumulative contents of total Fe, Mn, Zn and Cu were significantly highest for the control treatment. pH of leached soils showed significant increase at all depths after the incubation period compared to control and it decreased as depth increased from 0-15 cm to 30-60. CFB @ 10 t ha-1 with lime as per LR showed the highest value for pH at 0-15 cm depth of soil and it was on par with PM @ 1 t ha-1 with lime as per LR and CFB @ 10 t ha-1 with CS as per LR. Significantly highest pH was noticed for FYM @ 20 t ha-1 with CS as per LR at 15-30 cm depth of soil. At 30-60 cm depth of soil significantly highest value for soil pH was observed for CFB @ 10 t ha-1 with PG as per LR. Significantly lower mean values for exchangeable Al3+ and H+ at different depths were observed for the treatment combination CFB @ 10 t ha-1 with CS as per LR. The exchangeable Ca content increased significantly at all depths of soil compared to the control. The higher mean values for exchangeable Ca were recorded by CFB @ 10 t ha-1 with CS as per LR treatment at 0-15, 15-30 and 30-60 cm depths of soil. Significantly highest value for exchangeable Mg was recorded by the treatment supplied with CFB @ 10 t ha-1 with dolomite as per LR at all the depths of soil. Available N was significantly higher for the treatment receiving PM @ 1 t ha-1 with lime as per LR which was on par with dolomite or PG or CS as per LR and with FYM @ 20 t ha-1 + PG as per LR. Available P showed the maximum value for treatment supplied with FYM @ 20 t ha-1 + CS as per LR which was on par with CFB @ 10 t ha-1 with CS as per LR. The treatments receiving CFB @ 10 t ha-1 with lime as per LR gave the maximum value which was on par with CS or PG or dolomite as per LR. The available S content was highest for CFB @ 10 t ha-1 with PG as per which was on par with all the treatments receiving PG as per LR with FYM @ 20 t ha-1 or HA @ 10 kg ha-1 or PM @ 1 t ha-1 . Available Fe, Mn, Zn and Cu were recorded highest for the control treatment. Based on the acidity amelioration ability, best five treatments from the column incubation experiment viz. CFB @ 10 t ha-1 with dolomite as per LR, FYM @ 20 t ha-1 with PG as per LR, FYM @ 20 t ha-1 with CS as per LR, HA @ 10 kg ha-1 with CS as per LR and CFB @ 10 t ha-1 with CS per LR each along with NPK as per POP were selected for field validation using tomato as the test crop including KAU POP, KAU organic POP and absolute control. The physical properties of soil such as bulk density, porosity, water holding capacity and aggregate stability were significantly improved by the application of CFB @ 10 t ha-1 along with CS or dolomite as per LR, compared to other treatments. The surface and subsoil acidity were significantly reduced by the application of treatments compared to the control. Treatments receiving CFB @ 10 t ha-1 with dolomite or CS as per LR showed significant improvement for pH, exchangeable Al3+ and H+ , and exchangeable Ca and Mg compared to other treatment combinations. CFB@ 10 t ha-1 with CS as per LR recorded the highest value for available OC, N, K and B and it was on par with CFB @ 10 t ha -1 with dolomite as per LR. FYM @ 20 t ha-1 with PG as per LR showed highest value for available P and S which was on par with the treatment receiving CFB @ 10 t ha-1 with dolomite or CS as per LR. Plant height, number of branches per plant, root length and volume, fresh weight of shoot and root, dry matter production, number of fruits per plant and yield were highest for the treatment receiving CFB @ 10 t ha-1 with CS as per LR which was on par with CFB@ 10 t ha-1 with dolomite as per LR. The higher mean values for uptake of N, P, K, Ca, S and B by tomato was for CFB @ 10 t ha-1 with CS as per LR. Significantly higher mean values for uptake of Mg, Mn and Zn by tomato was significantly higher for CFB@ 10 t ha-1 with dolomite as per LR, while FYM @ 20 t ha-1 with CS as per LR showed the highest improvement for total uptake of Fe and Cu by tomato. The quality parameters of tomato fruit such as vitamin C and lycopene content were significantly improved by the application of treatments and the higher mean values was observed for FYM @ 20 t ha-1 with PG as per LR and CFB @ 10 t ha1 with CS as per LR, respectively. It may be inferred that there was significant movement of exchangeable calcium and magnesium through the depth in all treatments. Exchangeable H+ and Al3+ were significantly reduced by the combined application of organic and inorganic amendments. The highest acidity amelioration capacity in both incubation and field study was recorded by CFB @ 10 t ha-1 with CS as per LR. The treatment combinations CFB @ 10 t ha-1 with dolomite or CS as per LR, FYM @ 20 t ha-1 with CS or PG as per LR, and HA @ 10 kg ha-1 with CS as per LR were superior to other treatment combinations in reducing pH, exchangeable Al3+, and H+ and improving exchangeable Ca and Mg of the soil during the incubation study. Application of CFB @ 10 t ha-1 with dolomite or CS as per LR showed the highest reduction in acidity parameters and improved the content and uptake of nutrients during the field study. Application of CFB @ 10 t ha-1 with dolomite or CS as per LR and NPK as per POP increased the fruit yield by 26 % and 37 % compared to KAU POP. From the study, it can be concluded that CFB @ 10 t ha-1 along with dolomite as per LR is the economically viable and best treatment for amelioration of surface and subsoil acidity
Secondary and micronutrient management for enhancing soil health and productivity in upland rice
(Department of Soil Science & Agricultural Chemistry, College of Agriculture, Vellayani, 2018) Shamsida, P; Rani, B
An experiment entitled " Secondary and micronutrient management for soil health and productivity in upland rice " was conducted with medium duration rice variety Uma, to investigate the effect of secondary and micronutrient application under organic and integrated nutrient management practices, on nutrient uptake, soil health and productivity of upland rice. The field experiment was carried out at farmer‟s field, Venganoor, Thiruvananthapuram, during Virippu, 2017-„18. The experiment was laid out in a randomized block design with three replications and ten treatments viz. absolute control (T1), KAU PoP + lime (T2), KAU PoP + dolomite (T3), KAU PoP for organic farming (T4), foliar application of micronutrient solution or KAU sampoorna multimix along with lime (T5 and T6), dolomite (T7 and T8) and organic farming treatment (T9 and T10). Foliar sprays of 0.5 % micronutrient solution (containing FeSO4.7H2O 0.1%, ZnSO4.7H2O 0.25%, borax 0.1%, MnSO4. H2O 0.025%, and CuSO4. 5H2O 0.025%) and 1 % KAU sampoorna multimix (containing Zn 7%, B 4.5%, Cu 0.5%, Fe 0.2%, Mn 0.2% and Mo 0.02%) were given during the critical growth stages viz. active tillering, panicle initiation and one week after flowering. The soil of the experimental site before the crop was very strongly acidic with normal EC, sandy clay loam in texture, medium in organic carbon and available N, high in available P and K, sufficient in available Fe, Mn, Cu, Zn, exchangeable Ca and Mg and deficient in available B. The results of the study revealed that foliar application of micronutrient solution or sampoorna multimix along with KAU PoP (dolomite or lime) significantly increased the total and productive tillers per m2 with T7 giving the highest value. Root length, dry weight and volume were highest for all the organic farming treatments. Foliar application of micronutrients produced significant increase in yield and yield attributes with T8 recording the highest value for panicle weight (2.41 g), length of panicle (23.43 cm), per cent filled grains (87.17 %) and thousand grain weight (23.53 g) resulting in the highest grain yield (4158 kg ha-1). T8 was on par with treatments T5, T6 and T7. Highest straw yield was recorded by T5 (4897 kg ha-1) which was on par with the other micronutrient applied treatments (T6 to T8) and KAU PoP receiving lime or dolomite alone. Application of liming materials alone or along with foliar micronutrients gave significantly higher contents of N, P and K in index leaf at panicle initiation stage with T6 giving the highest value for N and P and T7 for K. Treatment T2 gave the highest Ca content of index leaf, which was also on par with all the micronutrient applied treatments. Mg content was highest in the dolomite applied treatments and was on par with the lime applied ones. Fe, Mn, Cu, Zn and B contents in index leaf were also found to be higher for the treatment receiving foliar micronutrients along with KAU PoP (dolomite or lime), with the highest values recorded by T5 for Fe, T7 for Mn and Zn, T6 for Cu and T8 for B. Higher N, P and K content in straw and grain were observed for treatments T5 to T8 which were on par with KAU PoP (lime or dolomite). Ca content of straw was highest for T2 and was on par with all the treatments except T4 and T1. Highest grain Ca was observed for T5 which also gave significantly higher Mg content in grain and straw compared to absolute control and the organic treatments. Uptake of N, P, K, Ca, Mg, Fe, Mn, Cu, Zn and B by straw and grain was also found to be the highest for the treatments receiving micronutrients along with KAU PoP (lime or dolomite). Soil available N and K were on par for all the treatments except organic treatments and absolute control. Available P was on par for all the treatments except T1. The increase in organic carbon due to integrated nutrient management was not significant. Liming materials significantly increased the soil Ca level whereas soil Mg was increased by the application of dolomite. Integrated or organic management increased the soil Fe, Mn and Zn levels. In general organic treatments gave significantly lower values for Cu and B. Foliar application of micronutrients along with KAU PoP (dolomite or lime) was more economical, resulting in significantly higher B: C ratio with the highest value (1.43) given by T8. Based on the study, it can be concluded that foliar micronutrient application (sampoorna multimix or micronutrient solution) along with KAU PoP (lime or dolomite) significantly enhanced the growth, yield and nutrient uptake in upland rice.
Toxic hazards of the industrial atmospheric pollutant, SO2,on tree crops
(Department of soil science and agricultural chemistry, College of Agriculture, Vellayani, 1993) Rani, B; Babukutty, K
A study was conducted to assess the effects of the industrial atmospheric pollutant, sulphur dioxide, on tree crops. The Veli area in Thiruvananthapuram district, Kerala which has been established as a polluted zone, due to the working of the Travancore Titanium products, was selected as the experimental site. Since coconut dominates the tree crops in the area, and due to its added importance as an oilseed, the study was conducted on coconut palms near the factory. Influence of sulphur dioxide pollution on plant parameters like sulphur content of foliage, pigment concentration, macro and micro nutrients, plant metabolites like glucose and ascorbic acid, catalase activity and the copra and oil contents of nuts were studied. Leaf and nut samples were taken at distances of 250, 500, 1000, 1500, 2000 and 5000 m, with the samples at 5000m taken as control. Visual observations, detailed chemical analysis of leaf samples and study of nut characters were conducted on the sampled palms. Visual observations revealed a high degree of chlorosis and necrosis of palms near the factory. As distance from the pollution source increased, the intensity of damage decreased, with the control palms at 5000 m showing no signs of visible injury. Data from Chemical analyses showed significantly higher concentration of total sulphur and sulphate sulphur in palms near the Titanium factory (1.731 and 0.364 per cent respectively). A drastic reduction was noticed in the plant nutrients like nitrogen, phosphorus, potassium and calcium in palms exposed to higher sulphur dioxide concentrations. Magnesium content was not affected significantly though in palms near the factory, there was a decrease in concentration. Among the micronutrients analysed, iron, copper and boron were affected, with the contents of iron and copper increasing with increased sulphur dioxide pollution and boron showing a decrease. Sulphur dioxide had no effect on the zinc, molybdenum and manganese contents while sodium and chlorine contents was reduced. The contents of aluminium was increased significantly in palms near the pollution source. Plant metabolites like ascorbic acid and glucose were decreased but the activity of catalase enzyme in leaf remained unaffected. The plant pigments like chlorophyll and carotenoids were also reduced in quantity, which may either be due to their degradation or decreased production. Among the nut characters studied, the contents of copra and oil were drastically reduced. The adverse effects of increased sulphur dioxide content in the atmosphere was high upto 1 km from the source and gradually decreased with the effect not felt at 5 km. These findings reveal that concentrations of sulphur dioxide higher than normal in the atmosphere can lead to plant injury in the surrounding area, in addition to the effects on human beings. The establishment of new industries and thermal power stations pose a new treat to the cultivated and native plants in that area. Since industrialization is the forerunner of development, the contribution of industries to toxic gases should be reduced by the adoption of suitable pollution control measures, if plant life in nature should proceed unhindered.