Browsing by Author "Naveen Leno"

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Assesment of soil quality in the post flood scenario of AEU 14 in Idukki district of Kerala and generation of GIS maps
(Department of soil science and agricultural chemistry, College of Agriculture, Vellayani, 2020) Sreejitha Babu, M; Naveen Leno
Evaluation of a customised organic fertilizer in relation to labile carbon dynamics nutrient release characteristics and productivity of banana
(Department of Soil Science and Agricultural Chemistry, College of Agriculture, Vellayani, 2017) Naveen Leno; Sudharmai Devi, C R
Formulation of custom blended thermochemical organic fertilizer pellests for tomato
(Department of Soil Science and Agricultural Chemistry, College of Agriculture, Vellayani, 2024-08-27) Phurpa Tsering; Naveen Leno
Inter-relationship of potassium with other soil fertility parameters in two major wetland rice soils of Kerala
(Department of Soil Science and Agricultural Chemistry, College of Agriculture, Vellayani, 1997) Naveen Leno; Thomas Varghese
A study was done at the College of Agriculture, Vellayani during 1994-95 to quantify the different forms of potassium and to investigate the inter-relationships of these forms with other soil fertility parameters. Soil samples were collected from ten locations each, of the two major wet land rice soils of Kerala selected for the study viz., lateritic alluvium of Pattambi (brown hydromorphic) and Onattukara sandy soil (greyish Onattukara) of Kayamkulam. Incubation studies were also carried in both soil types, with and without applied potash, for a period of two months. The study revealed that considerable variation existed in the physico-chemical properties of the two soils. The lateritic alluvium of Pattambi was clayey, high in chloride, organic matter, active iron, CEC, ECEC, exchangeable Ca, Mg and sum of bases and was low with respect to coarse sand and available phosphorus contents and was less acidic as compared to the Onattukara sandy soils of Kayamkulam. The latter was loamy sand in texture with a high content of coarse sand fraction, more acidic, high in phosphorus content and low in clay, chloride, organic matter, active iron, CEC, ECEC, exchangeable Ca, Mg and sum of bases in comparison to the former. Fractionation studies revealed that the Pattambi soils had a higher content of total K, HN03K and fixed K as compared to that of Kayamkularn soils. The high positive correlation of exchangeable K with the available K fraction in both the soil types justifies the existence of a dynamic equilibrium between the two fractions. The .negative correlation of exchangeable and available fractions of K with active iron observed in Pattambi soils was contrary to earlier observations in this regard. Though comparatively high in organic matter, the effect of soil reaction on the available K status was not considerable in Pattambi soils as compared to Kayamkulam soils. This led to the conclusion that management of organic matter in tropical soils is important to maintain the available K status for sustainable farming. The positive inter correlation obtained between lattice K and total K indicated that the major portion of soil potassium existed in the lattice form. The positive and significant association of other forms of potassium was indicative of the existence of a dynamic equilibrium between these forms of K. Potassium fixation was found to be a constraint in Pattambi soils especially with the addition of potassic fertilisers. Hence this should be given due consideration while formulating cost-effective and efficient potassium management strategies since the major chunk of potassic fertilisers are imported in our country.
Quantification and depth distribution analysis of carbon, nitrogen, and microbiomes in soils of Miyawaki forests in Kerala
(Department of Soil Science, College of Agriculture, Vellayani, 2024-12-11) Sreelekshmi, M; Naveen Leno
A study entitled “Quantification and depth distribution analysis of carbon, nitrogen and microbiomes in soils of Miyawaki forests in Kerala” was undertaken with the objectives of quantifying the levels of carbon and nitrogen in Miyawaki forest soils in Kerala, analysing the effect of increasing carbon sinks in achieving carbon sequestration and to investigate abundance of microbiomes in these soils. A preliminary survey was conducted to identify the locations where Miyawaki forests were established and is existent in the entire Kerala state. Altogether 58 Miyawaki forests have been established till date in Kerala. Five well established and oldest Miyawaki forests out of these were selected for further study. A survey was conducted during December 2023 in the selected study area and 20 georeferenced soil samples were collected from surface and subsurface layers from five Miyawaki forest and nearby undisturbed plots. The selected sites were located at Puliyarakonam, Peyad, Kanakakkunnu, Vilappilsala and Chalai. The soil samples were characterized for selected physical, chemical and biological attributes, carbon pools and nitrogen fractions. Various carbon indices like carbon pool index (CPI), lability index (CLI) and management index (CMI) were worked out. The carbon sequestration potential of each Miyawaki forest was also calculated. A metagenomic analysis of one sample each from Miyawaki forest and undisturbed plot was also conducted. A minimum data set (MDS) of indicators to assess soil quality index (SQI) was set up using Principal component analysis (PCA). The spatial variation in temperature within the confines of the Miyawaki forest as well as outside were recorded for a period of three months from March 2024 to May 2024 at two locations, viz., Puliyarakonam and Vilappilsala. The soils under study belong to sandy clay loam. The bulk density was found to be the lowest in the Miyawaki forest (1.15 Mg m-3) than the control. Other physical properties like water holding capacity (60.28%), soil moisture content (34.83%) and water stable aggregates (88.48%) were found to be higher in the surface soils of Miyawaki forest than the control plots. The soil acidity (pH 5.40) and EC (0.059 dSm-1) were found to be more in the Miyawaki forest. Soil biological properties like soil enzyme dehydrogenase activity (80.20 mg TPF g-1 soil 24 h-1), bacterial density (7.573 log cfu g-1), fungal count (5.507 log cfu g-1) and actinobacterial count (4.909 log cfu g-1) were also found to be higher in Miyawaki forest and decreased with depth. A higher total organic carbon of 10.31% was recorded in Miyawaki forest, which was observed to decrease with depth. Other carbon fractions like water soluble carbon (21.21 mg kg-1), labile carbon (4.51 mg g-1), particulate organic carbon (1.03%) and microbial biomass carbon (152.69 mg kg-1) were also observed to be higher in the Miyawaki forest when compared to the control plots. Total nitrogen content (0.36%) and available nitrogen (264.26 kg ha-1) was highest in Miyawaki forest. A higher C:N ratio was observed in Miyawaki forest (28.77) and was observed to increase with depth. The soil organic carbon stock (38.08 Mg ha-1) and carbon sequestration rates 9.05 Mg ha-1yr-1 were also found higher in Miyawaki forest soils compared to the control plots. A temperature difference up to 3.93°C and 4.21°C was observed between the mean maximum temperature between the inside and outside of Miyawaki forest during the summer months in Puliyarakonam and Vilappilsala respectively. No significant difference was observed for CPI, CLI, CMI, and SQI. The study on Miyawaki forests in Kerala reveal their substantial contribution to soil carbon storage and nutrient enrichment. The findings indicate that these forests not only enhance soil quality through increased organic carbon and nitrogen levels but also support a diverse microbiome, which is vital for soil health. Miyawaki forests in Kerala exhibit lower bulk density and higher water holding capacity compared to control plots, indicating improved soil structure and moisture retention. Additionally, the significant temperature regulation observed within the forests highlights their role in moderating local microclimates. Overall, the results underscore the potential of Miyawaki forests as effective carbon sinks and valuable ecological assets, advocating for their expansion as a strategy for carbon sequestration and soil restoration in the region. Further research is recommended to explore the long-term ecological impacts and management practices that can optimize these benefits.
Rhizophere dynamics of thermochemical organic fertilizer fortified with nitrogen biosources in amaranthus
(Department of Soil and Agricultural Chemistry, College of Agriculture,Vellayani, 2022-11-21) Ananthu C M; Naveen Leno
A study entitled “Rhizosphere dynamics of thermochemical organic fertiliser fortified with nitrogen biosources in amaranthus” was conducted from December 2020 to August 2021 at the Department of Soil Science and Agricultural Chemistry, College of Agriculture, Vellayani with the objectives of studying the dynamics of physicochemical and biological soil health parameters of the rhizosphere against root free soil consequent to the application of thermochemical organic fertiliser fortified with various organic nitrogen sources with and without arbuscular mycorrhizal fungi (AMF) and evaluation of its influence on the growth and yield of amaranthus. Characterization of farm yard manure (FYM), poultry manure (PM), neem cake (NC), vermicompost (VC), coir pith compost (CPC), organic nano NPK (nano NPK), and thermochemical organic fertiliser (TOF) were carried out. The pH of manures was slightly acidic to neutral, and the EC was within safe ranges. TOF had the highest TOC. PM recorded the highest N and nano NPK recorded significantly higher P and K. Zn, Cu and B were also the highest in nano NPK. TOF had higher Ca, Mg, S, Fe, Mn. Heavy metals (Pb, Cd) were below detectable limits. A pot culture trial of Amaranthus (var. Arun) was done to study the dynamics of the physicochemical and biological soil health parameters of the rhizosphere as against root free soil. Potting mixture was prepared with soil, coir pith (CP) and TOF fortified with nitrogen bio sources so as to provide 1 per cent nitrogen and also fortified with organic nano NPK at 0.1 per cent N in the ratio 1:1:1 on volume basis. TOF was fortified with different organic nitrogen sources for a pot culture study for 30 days in a CRD experiment. The pH of the growing media decreased slightly at harvest, whereas EC increased. Carbon fractions and nitrogen fractions were highest in TOF+PM +AMF while there was a general decrease in both the parameters in all the treatments at the harvest stage compared to the initial. P, K, Ca, S, Zn, B content were higher in TOF+NPK +AMF whereas Mg and Cu were higher in TOF+PM +AMF. Fe and Mn remained significantly different at rhizosphere zone only. In all the treatments rhizosphere soil observed lower soil nutrient content than the bulk soil. Biological properties such as dehydrogenase activity, microbial biomass carbon, 175 indole acetic acid, total organic acids were higher in TOF+PM +AMF. The shoot and root nutrient contents of TOF+NPK+AMF were higher than other treatments. TOF+NPK+AMF was also superior in number of primary branches, shoot weight and shoot dry matter content. Plant height was higher in TOF+FYM+AMF whereas stem girth was higher in TOF+NC. TOF+VC+AMF recorded highest root weight (104.07g plant-1 ), root dry weight (13.01plant-1 ) whereas root volume (63.33cm3 ), total root length (31.66 cm) was highest with TOF+CPC+AMF. Three best treatments from the pot culture study were subjected to field testing in micro plots to evaluate the influence of the fortified TOF on the soil health and growth and yield of amaranthus (var. Arun) for two seasons (C1, C2) in RBD. Field soil had strongly acidic pH, safe EC, medium OC, low N, K, high P, inadequate Ca, Mg, S and B. After the harvest of each crop, the soil pH progressively decreased whereas EC and OC increased. Soil available nitrogen was higher in TOF+NPK+AMF@OPOP100 %. P, K, S, Fe, Cu and B contents were highest in TOF+NPK+AMF@OPOP100 %. Soil available Ca and Mg was on par with TOF+VC@OPOP100 % in C2. Mn and Zn in C2 was higher in TOF+NPK+AMF@OPOP100 %. Plant shoot N, P, K, Ca, Mg, S and micronutrients were the highest in TOF+NPK+AMF@OPOP100 %. At C2 shoot Ca was on par with TOF+VC@OPOP100 %. Root N, P, K, Ca, Mg, S and micronutrients were highest in TOF+NPK+AMF@OPOP100 %. TOF+NC+AMF@OPOP100 % recorded highest root N in C2. TOF+VC@OPOP100 % recorded the highest earthworm number in C1 and C2. Micro arthropod counts were the highest in TOF+NPK+AMF@OPOP100 %. Dehydrogenase activity and microbial biomass carbon (MBC) of TOF+NPK+AMF@OPOP100 % in C1and C2 were significantly higher than other treatments. B:C ratio was highest for TOF+NPK+AMF@OPOP100 % (1.57). TOF fortified with various nitrogen bio-sources enhanced soil organic carbon and possessed comparable fertility value as conventional organic manures and is environmentally safe since heavy metal content is below detectable levels. Fortification of thermochemical organic fertilizer facilitated efficient root dynamic characters coupled with proliferation of rhizospheric microorganisms, which favoured enhanced mineralisation of soil available nutrients and root nutrient acquisition. TOF fortified with nano NPK is an effective and efficient substitute for conventional organic manures and help in realising higher productivity and profitability in amaranthus.
Root phenomics and soil biological acitivity in response to thermochemical organic fertilizer application
(Department of Soil Science and Agricultural Chemistry, College of Agriculture, Vellayani, 2019) Ramesha, G K; Naveen Leno