Browsing by Author "Manorama Thampatti, K C"

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Characterisation and classification of wetland soils of north Kuttanad
(Kerala Agricultural University, 1997) Manorama Thampatti, K C; Jose, A I
Fifteen profiles representing acid saline soils of North Kuttanad were studied for their characterisation and classification. Soils were light grey to dark brown / black in colour, sticky and plastic, subangular blocky in structure, and sandy to clayey it) texture, with random deposits of lime shells and organic matter. Faint to prominent reddish yellow or brown mottles were observed from surface downwards. Soils were highly acidic (pH 4.0-5.0) and mildly saline (EC 0.33-1.39 dS m'). Both acidity and salinity increased with depth. The soils were high in organic carbon, CEC and ECEC, but base saturation was less than 50 per cent. Taxonomically, 93 per cent of North Kuttanad belongs to the soil order Entisol and seven per cent to Inceptisol. At subgroup level, 78 per cent of the area is occupied by Typic Sulfaquent and seven per cent each by Fluventic Dystropept, Typic Tropofluvent, Typic Fluvaquent and Typic Tropopsamment.
Consumptive use, pattern of soil moisture extraction and water use efficiency of bittergourd (Momordica Charantia L.) under varying irrigation and nitrogen levels
(Kerala Agricultural University, 1993) Manorama Thampatti, K C; Santha Kumari, G; Reena Mathew; Chandrasekharan, P
The influence of graded doses of nitrogen and varying levels of irrigation on consumptive use of water, paltern of soil moisture extraction, water use efficiency and f r u i t yield of biltergourd were evaluated during 1988-89 and 1989-90. The consumptive use of water and lit/Eo values of bittergourd increased progressively with levels of nitrogen and irrigation. At higher moisture regimes the variation in consumptive use and Ht/Eo values did not reflect in crop yield. Wale ruse efficiency of the crop maintained a positive relation with levels of nitrogen and a negative relation with levels of irrigation. The soil moisture extraction paltern was not influenced by nitrogen levels. Major part of water was extracted from upper layers of soil irrespective of treatments.
Effect of thermochemical organic fertilizer on soil carbon pools, nutrient dynamics and crop productivity in ultisols
(Department of Soil Science and Agricultural Chemistry, College of Agriculture, Vellayani, 2021) Amrutha S Ajayan; Manorama Thampatti, K C
A study entitled “Effect of thermochemical organic fertilizer on soil carbon pools, nutrient dynamics and crop productivity in Ultisols” was conducted from 2018 to 2020 at the Department of Soil Science and Agricultural Chemistry, College of Agriculture, Vellayani with the objective to study the effect of thermochemical organic fertilizer on soil carbon pools, nutrient dynamics, their retention and leaching, and crop productivity in comparison with conventional organic fertilizers in Ultisols using tomato - amaranthus cropping sequence. The study includes production and characterization of organic fertilizers, leaching study using soil columns, an incubation experiment and field experiments using tomato - amaranthus cropping sequence. For the leaching study and incubation, the treatments were addition of FYM, ordinary compost (OC), vermicompost (VC), microbial compost (MC), unfortified (TOF) and fortified thermochemical organic fertilizer (F-TOF) @ 50 g per soil column/ pot and an absolute control. For the field experiment on tomato-amaranthus cropping sequence, the treatments were T 1 – FYM + POP recommendation of NPK, T 2 - FYM + soil test based recommendation of NPK (STBR), T 3 - OC + STBR, T 4 - VC + STBR, T 5 - MC + STBR, T 6 - TOF + STBR, T 7 - F-TOF + STBR, T 8 - F-TOF alone and T 9 - absolute control. The organic fertilizers required for the study viz., OC, VC, MC, TOF and F- TOF were produced from bio-waste from vegetable markets and food waste from college hostels and FYM was purchased. The physical and chemical properties of organic fertilizers were in accordance with the standards of FCO. VC, OC, MC and FYM were neutral to slightly alkaline in reaction while TOF and F-TOF were slightly acidic. The lignin content (27.9 %) and the carbon pools viz., TOC (43.90 %), WSOC (1642 mg kg -1 ), labile carbon (1776 mg kg -1 ) and recalcitrant organic carbon (32.45 mg kg -1 ) were highest for TOF followed by F-TOF. The N content was 391highest for MC (2.61 %), P for VC (1.36 %) and K (2.56 %), Ca (1.12 %), Mg (0.78 %), Zn (254 mg kg -1 ) and B (4.64 mg kg -1 ) for F-TOF while S (550 mg kg -1 ), Fe (9580 mg kg -1 ) and Pb (4.16 mg kg -1 ) for FYM. All the organic fertilizers contained Pb, but within permissible limit, while, Cd was not detected in any of them. The soil column study was conducted to assess the extent of leaching loss of nutrients from F-TOF amended soil in comparison with other organic fertilizers and their nutrient retention ability in soil. Soil columns amended with organic fertilizers in the surface layer were subjected to leaching on 1 st , 4 th , 8 th , 12 th , 16 th , 20 th and 24 th weeks with double the pore volume of water. During the leaching, the mineralized nutrients moved downwards and deposited at different depths in the soil column in accordance with their mobility and the rest was lost in leaching water. Leachates from organic fertilizer amended soils showed slightly acidic pH, which decreased up to 8 th week followed by an increase towards 12 th week. EC was highest at first week followed by a decrease towards 24 th week. The highest cumulative loss of N (172.34 mg L -1 ), Ca (273.86 mg L -1 ) and Mn (3.97 mg L -1 ) was from VC while that of P (7.22 mg L -1 ), K (333.36 mg L -1 ), Mg (144.41 mg L -1 ), Cu (0.080 mg L -1 ) and B (0.166 mg L -1 ) was from F-TOF. For S the loss (4.19 mg L -1 ) was highest from FYM, and Fe (4.71 mg L -1 ) and Zn (4.58 mg L -1 ) from OC. The leachate did not contain Pb and Cd. The leached soil in the soil columns maintained a higher level of nutrients compared to the level prior to the addition of organic fertilzers even after leaching for 24 weeks. In the surface soil, highest quantity of total N was retained by MC; P, Mn and Cu by VC and K, Ca, Mg, Zn and B by F-TOF while FYM retained highest quantity of S and Fe. Evaluating the available nutrient status of the leached soil, it was found that F-TOF had highest availability for K, Mg, S, Fe, Zn, Cu and B. Availability of P and Mn was highest in VC amended soil and Ca from MC. Availability of Pb and Cd were not detected in the leached soil. 392The incubation study for a period of 24 weeks revealed the nutrient release pattern of organic fertilizers. The peak release of most of the nutrients from organic fertilizers was from 8 th to 16 th week and for S it extended up to 20 th week. The availability of K, Ca, Mg, Fe, Zn and B was highest from F-TOF amended soil while VC maintained the highest values for P, Mn and Cu and FYM for S. The different fractions of B were highest for F-TOF amended soil and the peak was during 12 th week of incubation. Available Pb and Cd were not detected in the incubated soil. Organic fertilizers amended soil maintained a higher microbial count and exhibited a higher dehydrogenase activity compared to the control and the highest value was observed with F-TOF amended soil. During the field experiments, in the first cropping sequence, VC amended treatment T 4 (VC + STBR) recorded significantly highest fruit yield (40.97 t ha -1 ) for tomato followed by T 7 (F-TOF + STBR) while in the second cropping sequence F- TOF gave the highest yield which was statistically on par with VC. While for amaranthus, F-TOF recorded the highest yield during both the cropping sequences (24.62 t ha -1 and 26.89 t ha -1 , respectively) followed by VC and both the treatments were statistically on par in the second cropping sequence. The quality parameters of tomato and amaranthus were highest for the treatment T 7 (F-TOF + STBR) but was statistically on par with other treatments which received organic fertilizers along with POP or soil test based NPK fertilizers. Evaluating the economic benefits, the performance of VC was the best for the first tomato followed by F-TOF while for second tomato F-TOF was the best. For amaranthus, F-TOF performed best during both the sequences. When the overall B:C ratio for the whole cropping sequence was taken F-TOF was the best followed by VC. Uptake of N, P, K, Ca, Mg, S, Zn and B in tomato was highest for F-TOF while that of Fe, Mn, and Cu was for VC. For amaranthus, the uptake of N, P, K, Mg, Fe, Zn, Cu and B was highest for F-TOF for both the cropping sequences. Among the 393heavy metals tested only Pb was detected in plant parts and that too in roots only. For tomato, it was detected only in FYM treated plants while in amaranthus, all the treatments receiving organic fertilizers showed the presence of Pb. But the Pb content in the root was within the safe limit. The availability of Pb in the post-harvest soil was trace and there was no significant difference between the treatments. Cd was not detected in soil as well as plant samples. The continuous application of organic fertilizers had improved the physical, chemical and biological properties of the soil. At the end of the second cropping sequence, the lowest bulk density and highest water holding capacity was recorded by the treatment receiving F-TOF + STBR. The highest value for TOC, labile carbon, microbial biomass carbon and recalcitrant organic carbon in the post-harvest soil during the cropping sequence was maintained by F-TOF. The N pools, NH 4 -N, NO 3 - N, organic N and total N at the end of second cropping sequence was also highest for F-TOF. In the case of availability of P, S, Fe, Mn and Cu in the post-harvest soil, better performance was showed by VC while F-TOF showed higher availability for K, Ca, Mg, Zn and B. Biological properties are a better indication of soil health and application of VC, MC and F-TOF maintained a higher microbial load in soil. The highest dehydrogenase activity was maintained by F-TOF. Continuous application of F-TOF and TOF increased the carbon stock of surface and sub-surface soil than other organic fertilizers. F-TOF is superior to VC, OC, MC and FYM in terms of increasing carbon pools and carbon stock of the soil. The nutrient release was highest from F-TOF for most of the nutrients compared to other organic fertilizers, which might have resulted more leaching losses. However, the nutrient retention was also highest for F-TOF, even after the leaching for 24 weeks, suggesting a revisit on the rate and mode of fortification for F-TOF, popularly marketed in the trade name “Suchitha”. For crop production, the performance of F-TOF found equally good as that of vermicompost and was superior to FYM, OC and MC.
Evaluation of aquatic pollution and identification of phytoremediators in Vellayani lake
(Department of Soil Science and Agricultural Chemistry, College of Agriculture, Vellayani, 2011) Kavitha, Kamal; Manorama Thampatti, K C
A study entitled “Evaluation of aquatic pollution and identification of phytoremediators in Vellayani lake” has been carried out at the College of Agriculture, Vellayani during the year 2009-2011 to assess the extent of pollution and to identify the phytoremediators in Vellayani lake. Vellayani wetland ecosystem comprising a fresh water lake and surrounding padasekharams, extends through three panchayaths viz., Kalliyoor, Pallichal, Venganoor and two zones of Thiruvananthapuram Corporation namely Nemom and Thiruvallam. It is the sole drinking water source for the above area. Vellayani and adjoining areas is undergoing drastic reduction in area and water quality. Samples of water, sediment and macrophytes found in the lake were collected during pre monsoon, monsoon and post monsoon seasons, from 15 sites within the lake and were subjected to physical, chemical and biological analysis. The physical properties of the lake water viz., colour, turbidity and the amount of suspended solids showed significant variation among seasons and with locations showing higher values during monsoon season. All the chemical properties of lake water were also significantly influenced by the season and location. On evaluating the water as per ISI/WHO criteria, it was found that the chemical characteristics like EC, NO3-N, K, Ca, Mg, S and Zn were within the maximum permissible limits. P and Cu were not detected in water in any of the seasons. pH of the lake water was within safe limits only during the monsoon season and it was highly contaminated with organic load. The NH4-N content of water exceeded the MPL at certain locations during pre and post monsoon seasons. With regard to the heavy metals, one location was contaminated with Fe, six locations with Cd and eight locations with Pb. During monsoon season, the water quality is generally good. Al content of water was always above the safe limits fixed by ISI/WHO. Hence suitable treatments for improving water quality should be advocated for its use as drinking water/ for domestic purposes. With regard to the microbiological properties, the bacterial count was lowest during monsoon and highest during post monsoon season. Regarding the Coliform count, a gradual increase in number from pre monsoon to post monsoon season was observed. Algal population was seen uniformly distributed in all the 15 sites throughout the three seasons. All the chemical properties of lake sediment were significantly influenced by the season and location. Among the chemical characteristics organic carbon, extractable K, Ca, Mg, S, Fe, Cu, Zn and Pb were higher during pre monsoon season while pH and NH4-N were higher during monsoon season. Most of the chemical characteristics like EC, NO3-N, extractable K, S, Fe, Cu, Zn and Pb recorded their lowest values during monsoon season, while organic carbon, extractable Ca, Mg and Cd were at their lowest during post monsoon. NO3-N and extractable Al recorded their highest value during post monsoon season. Carbonates and bicarbonates were not detected in the sediment samples. The texture of sediment ranged from sandy to sandy clay loam. Fourteen species of aquatic macrophytes were found within the lake. Maximum number of plant species (12) was found during pre monsoon and minimum (9) during monsoon season. All the macrophytes showed higher elemental composition in shoot compared to root. Among the macrophytes, Eichhornea crassipes was found to be a good phytoextractor for N, K, S, Al, Fe, Cu and Cd and Pistia stratiotes for N, K, S, Al, Zn, Cu and Pb. Nymphaea odorata was found to phytoextract Cu and Cd and Nymphoides indicus for Cd and Pb. For S, Limnocharis flava and Scirpus grossus can be used as phytoextractors.
Evaluation of thermochemical digest of degradable waste for container cultivation of chilli
(Department of Soil Science and Agricultural Chemistry, College of Agriculture, Vellayani, 2017) Jayakrishna, J; Manorama Thampatti, K C
Exploration on the links between soil carbon storage and root biomass and elucidation of drivers of carbon stabilization
(Department of Soil Science and Agricultural Chemistry, College of Agriculture, Vellayani, 2022) Geethu Jacob; Manorama Thampatti, K C
The study entitled ―Exploration on the links between soil carbon storage and root biomass and elucidation of drivers of carbon stabilization‖ was conducted at the Department of Soil Science and Agricultural Chemistry, College of Agriculture, Vellayani during November 2019 to September 2021 with the objective to study the links between soil carbon storage and root biomass in soils of different agro ecological units and to identify the key drivers of C stabilization and NP fluxes under different management practices. The study area comprised of three Agro ecological units (AEUs) of Southern Kerala viz. Southern and Central Foot Hills (AEU 12), Southern High Hills (AEU 14) and Kumily High Hills (AEU 16). The study was carried out in three parts namely exploration on the links between soil organic C and NP pools with root biomass in soils of different AEUs, assessment of carbon storage under different land use system and identifying the drivers of C stabilization and field experiments to study the effect of management practices on the link between root and shoot biomass C and SOC and NP pools. For the study exploration on the links between soil organic C and NP pools with root biomass in soils of different AEUs, the study area was surveyed and geocoded soil samples from 0-20 cm and 20-60 cm depth were collected using core samplers. The root biomass from the soil samples were separated out and weighed. The soil samples were analyzed for its various physical, chemical and biological properties. For assessment of carbon storage under different land use system and identifying the drivers of C stabilization, the most prominent land use system of each AEU was identified and five samples were collected from each system. The sampling size was one sq.m to a depth of 60 cm. The plants of the same area were uprooted and their shoot and root biomass were recorded. Both the soil and plant samples were collected and analysed for various parameters. The field experiment in split plot design on grain cowpea – fodder maize cropping sequence was laid out with the main plot treatments as m1: conventional tillage, m2: deep tillage (30 cm depth) and m3: no till and sub plot treatments as s1: POP recommendation, s2: soil test based POP, s3: organic nutrient management (TOF-F), s4: POP + AMF, s5: soil test based POP + AMF, s6: TOF-F + AMF and s7: absolute control. After the harvest of grain cowpea, shoot biomass were removed and roots were retained in three replications and in the other three replications total biomass of grain cowpea were added into the soil and left for decomposition. After that fodder maize was raised in the field and the crop and soil samples were collected and analysed for various parameters. The results of the Part I revealed that the physical properties like bulk density (BD) and gravel per cent of all the AEUs showed an increase towards depth while the electrochemical properties showed a decrease. Among the different AEUs, AEU 16 recorded lowest BD (1.22 Mg m-3 ) and gravel per cent (30.53 %) and had a subsoil increase of 12 per cent and 17 per cent for BD and gravel per cent respectively. The different fractions of soil C and N showed a decrease with depth for all AEUs. The soil total organic carbon (TOC-5.94 %) and recalcitrant C (RC-1.64 %) content were highest for AEU 14 with a decrease of 26 per cent and 31 per cent respectively for subsoil. The highest dissolved organic C (DOC-54.63 mg kg -1 ) and labile C (LC- 877.50 mg kg -1 ) content were for AEU 16 with a subsoil decrease of 45 per cent and 27 per cent respectively. AEU 12 recorded lower values for C fractions which may be due to decreased root biomass by 38 per cent and 25 per cent in surface soil and 55 per cent and 70 per cent in subsoil than that of AEU 14 and AEU 16 respectively. The root biomass and soil C fractions were positively and significantly correlated at both sampling depths. The highest correlation coefficients between root biomass and soil C fractions were recorded by DOC (0.976) followed by RC (0.931) and LC (0.975) followed by DOC (0.953) for surface and subsoil respectively. From the regression analysis perfect fit towards linear regression model, expressed as R2 value, was highest for DOC (0.95) and LC (0.94) at sampling depths of 0-20 cm and 20-60 cm respectively. The different fractions of N were highest for AEU 12 and surface soil showed an increase in total nitrogen (TN) by 6 per cent and NH4-N by 20 per cent, NO3 – N by 18 per cent and organic N (ON) by 5 per cent than subsoil. For soil P fractions an increase was observed with depth and AEU 12 recorded highest values for P fractions. Among soil N and P fractions, ON and labile P (LP) were found to be more correlated to root biomass and with higher R2 values at both sampling depths. The MBC (26.89 mg kg -1 ) and DHA (34.94 µg TPF g-1 24 hr-1 ) were highest for AEU 16 and surface soil showed an increase in MBC by 28 per cent and DHA by 30 per cent, than subsoil. For part II, the most prominent land use system of each AEU were identified as rubber plantations for AEU 12 and AEU 14 and cardamom plantations for AEU 16. The rubber plantations of AEU 14 recorded highest C storage (434.0 t ha-1 ) and lowest value was observed for cardamom plantations of AEU 16 (329.9 t ha-1 ). The soil physical properties and electrochemical properties behaved similar to that of Part I. Cardamom plantations of AEU 16 recorded lowest BD (0.97 Mg m-3 ) and gravel content (28 %) while AEU 12 had highest pH (5.61) and lowest EC (0.39 dS m-1 ). Among the different land use systems, rubber plantations of AEU 14 recorded highest values for soil TOC (6.72 %) and DOC (55.16 mg kg-1 ) content while cardamom plantations had highest soil LC (910.91 mg kg-1 ) and surface soil RC (1.92 %) content but subsoil RC content was more for rubber plantations of AEU 14. In rubber plantations the root biomass were correlated to all C fractions and more correlated to RC and TOC and in cardamom plantations root biomass were significantly correlated to TOC (0.98) and DOC (0.95) fractions only. A significant and positive correlation between root lignin and soil C fractions (RC and TOC) was also observed. The different fractions of N and P were highest for cardamom plantations of AEU 16 and surface soil showed an increase in TN by 5 per cent, NH4-N by 14 per cent, NO3– N by 22 per cent and ON by 4 per cent than subsoil and a subsoil increase of TP by 12 per cent, LP by 29 per cent and NLP by 11 per cent were also observed. The shoot biomass were more correlated to soil N and P fractions than root biomass and were more correlated to ON and TN and to TP and NLP among soil N and P fractions respectively. A significant positive correlation between N and P removal and soil NP pools were also obtained. The MBC and DHA were highest for cardamom plantations of AEU 16 and surface soil showed an increase in MBC by 25 per cent and DHA by 23 per cent than subsoil. In the field experiment, among the various nutrient management treatments, soil test based POP + AMF (s5) recorded the highest plant height, shoot biomass and grain yield plant-1 (107.70 g) and TOF-F + AMF (s6) showed highest values for root characteristics and quality parameters for grain cowpea. Similarly for fodder maize grown under both conditions, the treatment soil test based POP + AMF (s5) gave highest shoot biomass, fodder yield and quality parameters while highest root biomass were recorded by the treatment, TOF-F + AMF (s6). Among the tillage levels, the no till treatment (m3) performed best in connection with growth, yield and quality characteristics throughout the cropping period. Tillage and nutrient management had significantly influenced various soil properties. The lowest soil BD and higher WSA per cent and soil pH were reported by the treatment TOF-F + AMF (s6) throughout the cropping sequence. Among tillage levels, deep tillage (m2) remained superior for soil BD and pH and no till treatment (m3) for WSA per cent respectively. The treatment, TOF-F + AMF (s6) remained superior for soil C fractions viz., TOC, LC and RC content, mineralizable N fractions (NH4-N and NO3-N), labile P and MBC content and dehydrogenase activity throughout the cropping sequence. The treatment, soil test based POP +AMF (s5) recorded higher values for NP fractions like TN, ON, TP and non labile P (NLP). Among the tillage levels, the no till treatment (m3) remained superior in connection with soil chemical and biological properties especially towards the end of cropping period. As the cropping sequence advances an improvement in soil physical, chemical and biological properties were observed and this is mainly attributed to the crop residue addition of grain cowpea and more improvement was observed for total residue incorporation than root residue alone addition. The soil C pools were highly linked to root biomass and NP pools to shoot biomass. The root biomass and root lignin were the main drivers of C stabilization. The treatments with AMF remained superior in various soil properties and yield and growth attributes emphasizing the favourable role of AMF in C storage and nutrient cycling in soils. With regard to nutrient management, soil test based POP + AMF recorded the highest yield in cropping sequence while organic nutrition (TOF-F) + AMF contributed more to soil properties indicating the need for further research on nutrient translocation and assimilation under organic nutrition. The no tilled condition with total residue incorporation responded better than root residue alone incorporation, hinting to the fact that more organic matter contributing practices improved the physicochemical and biological conditions of soils favourably.
Feasibility of phosphogypsum as an ameliorant for soil acidity in laterite soil
(Department of Soil Science and Agricultural Chemistry, College of Agriculture, 2003) Jeena Mathew; Manorama Thampatti, K C
Iron and zinc fortification in amaranthus (Amaranthus tricolor) through bioaugmentation
(Department of Soil Science and Agricultural Chemistry,Vellayani, 2013) Amla Sakthidharan; Manorama Thampatti, K C
An investigation entitled “Iron and Zinc fortification in amaranthus (Amaranthus tricolor) through bioaugmentation” has been carried out at the College of Agriculture, Vellayani during May to August 2012. The main objective was to study the effect of Fe and Zn application and bioaugmentation of soil with microbial additives on yield and nutrient composition of amaranthus, particularly with that of Fe and Zn. This was accomplished through a pot culture experiment using laterite soil.The design was Factorial Completely Randomized Design (4 x 4 x 4). The treatments include four methods of bioaugmentation (POP + AMF; POP + P solubilizer; POP + K solubilizer and POP alone), Four levels of iron (Zero; 5 mg kg-1 of soil, 10 mg kg-1 of soil and Foliar application of 1.0 mg kg-1 FeSO4) and Four levels of zinc ( Zero; 5 mg kg-1 of soil; 10 mg kg-1 of soil and Foliar application of 0.5 mg kg-1 ZnSO4).The experiment results revealed that the treatment combination M4F0Z2 (POP x Fe0 x Zn @ 10 mg kg-1 ) recorded the highest shoot biomass and B:C ratio. The above treatment was on par with several treatment combinations of M2 (P solubilizer) and M4 (POP) and with M3F0Z3. Root biomass was also highest for M4F0Z2. The biometric characters like plant height, number of branches per plant, number of leaves per plant, leaf weight, stem weight, leaf: stem ratio, root length and root volume were significantly influenced by the treatments while girth of stem was not significant. Interaction effects of treatment on most of the variable were also significant. Considering the individual effects, among the bioaugmentation methods, M4 (POP) showed highest values for all the above observations except root length and the lowest by M1 (AMF). Levels of iron had shown a negative effect on most of the plant characteristics while zinc maintained a positive significant effect.Treatment effect was significant on concentration of nutrients viz., N, P, K, Ca, Mg, S, Fe, Mn, Zn, and Cu in shoot and root at each harvest. Evaluating the individual effects, it was observed that the microbial additives in general significantly increased N, Ca, Mg, Fe and Zn compared to POP. P solubilizer had significantly increased P and Zn content of the shoot and K solubilizer the K content. Fe @ 5 mg kg-1 alone recorded an increase in Fe content of shoot. Zn maintained a significant positive relation with shoot Zn content and foliar application recorded the significantly highest value. Nutritional parameters like crude protein, β-carotene, nitrate, vitamin C, oxalate and phenol contents were significantly influenced by the treatments. Bioconcentration factor and translocation index were significant only for Zn.Soil characteristics like pH, EC, organic carbon, available N, P, K, Ca, Mg, S, Fe, Mn, Zn and Cu at the time of each harvest were significantly influenced by the treatments. Levels of Zn showed a positive influence on available Zn content. Treatment with microbial additives had favorably influenced the biological parameters like AMF colonization and rhizosphere microbial count.From the above experiment, it can be concluded that the treatment combination POP x Fe @ zero x Zn @ 10 mg kg-1 (M4F0Z2) recorded the highest economic yield and B:C ratio. Considering the nutritional quality and iron and zinc content of economic plant part, the treatment combination K solubilizer x Fe @ zero x Zn as foliar, (M3F0Z3) is the best treatment since it is on par with the above treatment in yield and B:C ratio and at the same time recorded better nutritional quality and iron and zinc content.
Land evaluation and crop suitability rating of the acid sulphate soils of Kuttanad for sustainable land use planning
(Department of soil science and agricultural chemistry, College of Agriculture, Vellayani, 2005) Beena, V I; Manorama Thampatti, K C
An investigation was carried out at College of Agriculture, Vellayani during 2001- 2004 to delineate acid sulphate soils of Kuttanad and to develop sustainable land use plan for the area based on land evaluation and crop suitability rating with the help of GIS technology. The study consists of generation of detailed soil maps of acid sulphate soils of Kuttanad, various thematic maps of acid sulphate soils of Kuttanad, interpretation of soil maps, qualitative and quantitative evaluation of land use systems of the area, and development of a sustainable land use model taking into account the climatology, productivity and socio- economic constraints of the area. Kuttanad is a lowlying deltaic region lying 0.6 to 2.2 m below mean sea level. The reconnaissance soil survey of the area was conducted according to the principles envisaged in IARI (1970). Two profile pits were dug from each series identified and morphological features were described and surface as well as subsurface samples were drawn for detailed laboratory examination. Soil classification was done based on field survey, soil correlation and laboratory investigation and soil map of acid sulphate soils of Kuttanad was prepared based on GIS technique. Land capability classification was done based on inherent soil characteristics, degree of limitations etc. Soil site suitability classificatio~ was done to find the suitability of different crops in the region and fertility capability classification was also done for evolution of sustainable agricultural management. These soils were thoroughly evaluated to study the present land use, its suitability and to suggest alternate land use plan for the area. The morphological and physico- chemical characteristics of the area showed great degree of variation. The soils were deep with a hue of7.5 YR to 10 YR, sticky and plastic, angular blocky to sub angular blocky in structure with textural variation from sandy to clayey with random deposits of lime shells and humus. Presence of faint to prominent reddish yellow or brown mottles in most of the soil layers. Some of the special characteristics observed were partially burned wooden logs and reddish brown root channels. The soils were extremely acidic with high organic carbon content. The CEC, ECEC and available nutrients except phosphorous were high for these soils. Due to P fixation, phosphorous deficiency is widespread. However the base saturation was below 50 per cent. As per USDA classification, the entire study area was classified under the order Entisols, with suborder Aquent, great group Sulfaquent, subgroup Typic Sulfaquent with six soil series viz., Ambalapuzha, Purakkad, Thotapally, Thuravur, Kallara and Thakazhi. As per FAO classification, these soils were included under Thionic Fluvisols. The region enjoys a humid tropical climate. Based on soil mapping of the area it is revealed that acid sulphate soils of Kuttanad cover an area of 14277.51 ha comprising of six soil series. Kallara series occupied the largest area of 6860.17 ha. The soils of the region were deep, poorly drained loamy soils in control section and are very gently sloping with slight erosion. Land capability classification of the area showed five soil senes ViZ., Ambalapuzha, Purakkad, Thuravur, Kallara and Thakazhi covenng an area of 13099.60 ha came under the class IV sw. The Thotapally series was grouped under III sw. While considering the soil site suitability for paddy, Thotapally and Thuravur series come under subclass S2 xf ie these are moderately suitable for paddy cultivation with limitations due to fertility and pH. For coconut cultivation, all the series except Thuravur are grouped under S2 xf. Soil site suitability for mango cultivation revealed that Ambalapuzha, Purakkad and ThotapalJy senes are moderately suitable with limitations due to excess wetness, low pH and fertility limitations. As per Fertility Capability Classification, the soils belong to the units Lgac, Lgac, LCgac, Cgaics, Lgac and LCgaic respectively for Ambalapuzha, Purakkad, Thotapally, Thuravur, Kallara and Thakazhi series. The modifiers that are relevant to the acid sui phate soi I condition are "g" which defi nes wet land soi Is, "a" aluminium toxicity, "i" denotes high P fixation by iron, "c" denotes the acid sulphate soil condition. Socio - economic, cultural and ecological traits were also taken in to account along with land, crop and climatological characteristics of the area for the development of a probable land use model. Based on the study the land use models that can be suggested for the area are rotational farming involving paddy, fish and livestock.
Morphological, physical and chemical characterization of the soils of North Kuttanad
(Department of Soil Science and Agricultural Chemistry, College of Horticulture, Vellanikkara, 1997) Manorama Thampatti, K C; Jose, A J
Phytoremediation of inorganic contaminants in vellayani wetland ecosystem
(Department of Soil Science and Agricultural Chemistry, College of Agriculture, Vellayani, 2017) Meera, A V; Manorama Thampatti, K C
An investigation entitled ―Phytoremediation of inorganic contaminants in Vellayani wetland ecosystem‖ was carried out at the Department of Soil Science and Agricultural Chemistry, College of Agriculture, Vellayani, during 2013-16. The objective of the study was to track the potential sources of contaminants threatening the Vellayani wetland ecosystem and suggest a viable phytoremediation technology. The experiment comprised of four parts. The first part involved a peripatetic survey in the catchment of Vellayani lake along the rivulets that contribute water to Palappoor, Pallichalthodu, Reservoir bund, Arattukadavu RB, Valiyavilagam, Mannamvarambu and Manamukku sites. Three rivulets per site were identified, and geocoded water and sediment samples were drawn from five sampling points under each rivulet during pre and post monsoon seasons of 2014-15. Among the physical properties of water colour, turbidity and suspended solids were above the maximum permissible limit (MPL). Chemical properties viz., pH, EC, NO3-N, NH4-N, P, Fe, Al, Pb, Cd and BOD of water showed significant difference among the sites during both the seasons but COD was significant only for post monsoon. P content and BOD exceeded the MPL and Al the desirable limit. Coliforms were detected at all sites during both seasons and were above the MPL. Texture of the sediment varied from sandy clay to sandy clay loam. EC, OC, NO3-N, NH4-N and P contents of sediment showed a decreasing trend during the post monsoon season. Arattukadavu RB was the most contaminated site followed by Palppoor and Manamukku the least contaminated site preceeded by Mannamvarambu and Valiyavilagam with respect to water and sediment quality. No pesticide residue was detected in water and sediment. The highest plant density was noticed for Cynadon dactylon L. In the second part, potential sources of contaminants were identified as automobile workshops/servicing centres, domestic wastes from hotels/houses and sewage. Out of the 29 species of dominant macrophytes, highest biomass was recorded by Limnocharis flava L. (Buch.). In shoot, the highest concentration for Fe was recorded by M. vaginalis, Panicum repens L. for Aland S. trilobata for Pb and Cd. In root, the highestconcentration for Fe, Al, Pb and Cd was showed by Eichhornea crassipes Mart., Monochoria vaginalis (Burm.f.), Colacasia esculenta L. and Sphagneticola trilobata L. respectively. Sediment from Arattukadavu recorded the highest contents for Fe, Al, Pb and Cd and count for bacteria, fungi and actinomycetes. It was observed from the study that concentration of Fe, Al, Pb and Cd decreased with the distance from the source of contamination. Higher quantities of Fe was extracted by E.crassipes and M.vaginalis; Al by M. vaginalis and L. flava and Pb and Cd by L.flava and E.crassipes from the wetland ecosystem. In the third part, four pot culture experiments were carried out with graded doses of Fe (1000, 2000 and 3000 mg kg-1), Al (750, 1000 and 1250 mg kg-1)and Pb and Cd (50, 75 and 100 mg kg-1) to determine the hyperaccumulation ability of selected macrophytes based on a screening trial. The macrophytes were grown in sediment and water collected from the Vellayani wetland ecosystem for a period of 45 days. From the study it was observed that E. crassipes was the best hyperaccumulator for Fe, M. vaginalis for Al and L. flava for both Pb and Cd and can be identified as the best phytoextractors for the same. Root was the major retention site for all the metals. Among the rhizosphere microbes, fungi maintained a positive relation with levels of of Fe, Al, Pb and Cd and a negative relation by bacteria and actinomycetes. In the fourth part, the macrophytes showing highest hyperaccumulation ability for each metal (based on part III) were raised in pots containing the respective metals (2000 mg Fe kg-1, 1000 mg Al kg-1 and 75 mg Pb /Cd kg-1) for 60 days. The plants were harvested and the biomass was put to different disposal methods viz., composting, vermicomposting, ashing and production of biochar and was used for the pot culture experiments with amaranthus. The treatment effects were significant for biomass production and metal extraction. Among the four disposal methods, vermicomposting had resulted the highest biomass production for all except Pb. Regarding the metal extraction by amaranthus, application of ash (T4) showed the highest removal and the least by the biochar (T5). The metal retention in soil was highest for biochar and least for ash. Loss of metals from the processed materials was also lowest for biochar. Thus the best disposal technique of phytoextractors /hyperaccumulators is conversion to biochar. The viable phytoremediation technology is to raise suitable phytoextractors / hyperaccumulators in the contaminated area and dispose them through biochar production.
Potassium utilization in cassava (Manihot utilissina pohl) as influenced by neem cake - urea blend
(Department of Soil Science and Agricultural Chemistry, College of Horticulture, Vellanikkara, 1985) Manorama Thampatti, K C; Padmaja, P
Potassium utilization in cassava (manihot utilissima pohl.) as influenced by neem cake – urea blend. An investigation was carried out at the College of Horticulture, Vellanikkara, during the year 1983-84, which include a soil column study to understand the dynamics of NH4+- N and K+ ions when applied as urea or urea-neem cake blend either alone or along with muriate of potash. The columns were filled with soil collected from the field surface upto 60 cm depth. Each 15 cm was taken as a separate layer maintaining the same bulk density as observed in the field. Fertilizer treatments comprising, no fertilizer, urea or urea-neem cake blend to supply 100 ppm N and muriate of potash to supply 100 ppm K either alone or in combination were applied to the surface 15 cm soil and mixed thoroughly. The study indicated that under natural conditions NH4+ - N was concentrated more in the lower layers of soil beyond the root zone of cassava whereas potassium was concentrated more in the surface layers of 0-30 cm depth. Application of muriate of potash either alone or in combination with urea-neem cake blend increased potassium in the surface layer within eight hours after fertilizer application. When untreated urea granules were applied along with potassic fertilizer, a major part NH4+ - N was found either concentrated in lower layers, or nitrified and lost. But when urea-neem cake blend was applied along with potassic fertilizer a major part of nitrogen was retained as NH4+ - N in the surface layers upto two weeks and later it moved downwards. There was a drastic reduction of NH4+ - N status in the surface layers upto 45 cm after one week in untreated urea, whereas urea-neem cake blend maintained much of NH4+ - N in the surface 30 cm upto three weeks. Application of muriate of potash maintained highest potassium status followed by urea-neem cake blend along with muriate of potash. The maximum leaching loss of potassium was observed from untreated urea when applied along with muriate of potash. The loss was reduced considerably when potassic fertilizer was applied along with urea-neem cake blend. A field experiment was conducted as a continuation of the study carried out at the College of Agriculture, Vellayani, when urea-neem cake blend at 5:3 ratio increased nitrogen availability, nitrogen uptake and yield. But it had an adverse effect on potassium utilization of the crop resulting in poor quality tubers and the yield increase observed was not significant. The present experiment was planned to tide over this difficulty either by changing the time of application or increasing the rate of potassic fertilizer. Results of the experiment clearly showed that urea-neem cake blend increased nitrogen use efficiency of cassava as evident in higher soil available nitrogen and higher nitrogen uptake by the crop. When muriate of potash was applied one month after application of urea-neem cake blend, the uptake of potassium was not reduced considerably in the initial stages and at the same time uptake was comparatively higher at the sixth month and harvest stages. Potassium at 75 kg K2O ha-1 increased uptake of all nutrients and also produced maximum tuber yield of 21.39 tonnes ha-1, whereas application of potassium one month after application of urea-neem cake blend recorded 19.76 tonnes ha-1 of tuber yield which was on par with the former treatment. Potassium uptake at all major growth stages were significantly correlated with plant dry weight and tuber yield. Maximum benefit per rupee invested was obtained when the rate of potassium was raised from 50 kg K2O ha-1 to 75 kg K2O ha-1 along with 50 kg N as urea-neem cake blend. Changing the time of application of potassic fertilizers to one month and three months after planting also increased the benefit obtained. Both three treatments were on par with each other and significantly superior to others.
Zinc bioinfortification for enhancing yield and quality of yard long bean (Vigna unguiculata subsp.Sesquipedalis (L) Verdcourt) in ferralitic soils
(Department of Soil Science and Agricultural Chemistry, College of Agriculture, Vellayani, 2014) Dhanya, G; Manorama Thampatti, K C