Silica Nanoparticles from Coir Pith Synthesized by Acidic Sol-Gel Method Improve Germination Economics

Lignin is a natural biopolymer. A vibrant and rapid process in the synthesis of silica nanoparticles by consuming the lignin as a soft template was carefully studied. The extracted biopolymer from coir pith was employed as capping and stabilizing agents to fabricate the silica nanoparticles (nSi). The synthesized silica nanoparticles (nSi) were characterized by ultraviolet–visible (UV–Vis) spectrophotometry, X-ray diffraction analysis (XRD), Scanning Electron Microscope (SEM), Energy-Dispersive X-ray Analysis (EDAX), Dynamic Light Scattering (DLS) and Fourier-Transform Infrared Spectroscopy (FTIR). All the results obtained jointly and independently verified the formation of silica nanoparticles. In addition, EDAX analysis confirmed the high purity of the nSi composed only of Si and O, with no other impurities. XRD spectroscopy showed the characteristic diffraction peaks for nSi and confirmed the formation of an amorphous nature. The average size of nSi obtained is 18 nm. The surface charge and stability of nSi were analyzed by using the dynamic light scattering (DLS) and thus revealed that the nSi samples have a negative charge (−20.3 mV). In addition, the seed germination and the shoot and root formation on Vigna unguiculata were investigated by using the nSi. The results revealed that the application of nSi enhanced the germination in V. unguiculata. However, further research studies must be performed in order to determine the toxic effect of biogenic nSi before mass production and use of agricultural applications.

​Allelopathic Chemical Screening of Aqueous Extracts of Coir Pith on Seedling Growth of Black Gram (Vigna mungo L.) and Green Gram (Vigna radiata L.)

Background: Black gram (Vigna mungo L.) and Green gram (Vigna radiata L.) were mostly used as chemical residue indicators for testing the persistence of pesticides, fungicides and herbicides, etc. in the soil. Presently, the coir pith was used as a medium of nursery for many seeds and seedling production. This study evaluated the inhibition effects and screening of allelopathic chemicals from aqueous extracts of coir pith and composting coir pith on the back gram and green gram by response index method and GCMS/MS analysis. Methods: The coir pith and composted coir pith soaked the ratio of 1:10 for 24 hrs, filtered through Whatman No.1 filter paper. The inhibition effect tested for germination and seedling growth of black gram and green gram was sown in poly pots. The carbon: nitrogen ratio and the total organic carbon were analyzed by dry combustion method, Kjeldahl method and GCMS/MS analysis. Result: The phytotoxic substances are present in coir pith, which can be exterminated by composting the coir pith for better growth and development of seedlings. The negative response index (RI), high C: N ratio and chemical compounds like tocopherol, fucoxanthin, tetramethyl heptadeca, dichloroacetamide, tetrazole, hydroxyethyl palmitate, neocurdione and uridine derivations present in raw coir may have the phytotoxic effect and produced yellowing symptoms in young plants compared to composted coir pith. This is exterminated by composting the coir pith for better growth and development of seedlings as well as used for various agricultural and horticultural nurseries.

​Quality Characters of Tannia [Xanthosoma sagittifolium (L.). Schott] as Affected by Tillage, Planting Methods, Plant Nutrition and Application of Soil Conditioners

Background: Tannia is one of the six most important root and tuber crops grown world-wide. Tannia possess good keeping quality compared to other vegetables. The tubers are considered more nutritious than colocasia and potato. But the crop is still under-exploited compared to other tuber crops. Hence the study was undertaken to identify the effect of tillage and nutrition on quality characters of tannia. Methods: A field experiment was conducted at College of Agriculture, Vellayani, Kerala during 2014-15 to study the effect of organic nutrition on quality characters of tannia. The design used was split plot design with four replications. The treatments consisted of tillage and planting methods as main plot treatments (L1- conventional tillage followed by pit system, L2- conventional tillage followed by mound system, L3- deep tillage followed by pit system and L4- deep tillage followed by mound system). The sub plot treatments were combinations of soil conditioners (S1- control, S2- coir pith, S3- rice husk) and two nutrition systems (N1- integrated nutrient management (INM) and N2- organic nutrition). Result: Results of the experiment revealed that the quality characters of tannia was improved by deep tillage to a depth of 30 cm followed by pit system of planting, application of coir pith as soil conditioner @ 500 g plant-1 and organic nutrition (FYM @37.5 t ha-1 + wood ash @ 2 t ha-1).

Carbon fractions of fortified thermochemical organic fertilizers and their response on the yield of okra and tomato

Aim: To study the carbon fractional status of the growing media and to find out the best organic nitrogen source for fortification of thermochemical organic fertilizer, the manurial constituent of growing media for container cultivation of okra and tomato. Methodology: Container cultivation of okra and tomato were done in completely randomised design. Treatments included fortification with farmyard manure, neem cake, groundnut cake, poultry manure, vermicompost, coir pith compost, hatchery waste organic fertilizer, urea and unfortified thermochemical organic fertilizer. Carbon fractions, viz. total organic carbon, permanganate oxidisable labile carbon, microbial biomass carbon and soil respiration of the growing media were analysed. The yield and yield attributes of the crops were determined. Results: Irrespective of the organic source of nitrogen used, the fortified thermochemical organic fertilizer imparted a high status of total organic carbon to the growing media. Fortification with farmyard manure enhanced labile carbon, soil microbial biomass carbon and soil respiration over those fortified with other organic and inorganic sources. Container grown okra in a growing media with thermochemical organic fertilizer fortified with farmyard manure out yielded urea based fortification by 55.96%. Tomato grown in coir pith compost fortified growing media enhanced yield by 27.37% over the groundnut cake fortified growing media. Linear regression models of labile carbon with microbial biomass carbon (R2 = 0.8946) and with soil respiration (R2 = 0.9053) were significant and with a good fit. Interpretation: Fortification of thermochemical organic fertilizer with various organic sources of nitrogen imparted a high total soil organic carbon status. Synergic effect of the farmyard manure fortification was evident in labile carbon, microbial biomass carbon and soil respiration. Growing media fortified with farmyard manure was ideal for container cultivated okra whereas that with coir pith proved to be ideal for tomato, a solanaceous vegetable crop.

Comparative Evaluation of Sawdust with Different Casing Materials for the Production of Agaricus bisporus (Lange) Imbach under Natural Bamboo Hut Conditions

Studies were conducted to evaluate leached sawdust as a casing substrate for the cultivation of Agaricus bisporus either alone or in combination with other substrates at College of Horticulture and Forestry, Neri, Hamirpur, Himachal Pradesh, India during the year 2018–2020. Out of seven casing media evaluated alone, coconut coir pith performed best in terms of all production parameters like time for spawn run (20.3 days) and pinning (15.7 days), sporocarps’ number (55.33), yield (0.679 kg 5 kg-1 compost) and biological efficiency (33.95%). The efficiency of sawdust- leached improved with the addition of other casing substrates. In commercial trial, combination of sawdust - leached with coconut coir pith, spent compost and farmyard manure (1:1v/v) performed better as compared to control (FYM+local soil), but a combination of sawdust- leached+coconut coir pith (1:1v/v) proved to be the best in terms of sporocarps’ number (88.00) and yield (1.271 kg 10 kg-1 compost) despite of the delay in time for spawn run (26 days) and pinning (24.3 days). Casing media also affected the biological efficiency of compost which varied from 10.50% in local soil to 34.05% in sawdust- leached+farmyard manure (1:1v/v) in different experiments. Cap diameter was recorded to be maximum (41.37 mm) in 2 years old spent compost and minimum (34. 27 mm) in sawdust- leached while, stipe length ranged from 14.17 mm in vermicompost-leached to 22.90 mm in sawdust- leached+farmyard manure (1:1v/v). However, fruit bodies harvested from all the casing treatments including standard check were found to be silky smooth and firm to compact.

Investigation of Eco – Friendly Interlocking Masonry Units

This project reveals about the detailed investigation of eco-friendly interlocking masonry units. Interlocking between individual units is enabled by providing grooves, male and female joint on them. Hence less mortar is required for construction of masonry units while using these interlocking bricks. Various trails and tests will be conducted on these interlocking bricks by addition of various materials such as E-wastes, coir pith and saw dust in clay soil. Hence the cost of these masonry units will be reduced. All these various mixtures are mixed at different proportions and ideal mixture are to be found then the grooves are to be altered by male and female joints. Further in addition of clay and sand, wooden powder and coir pith are to be added so that while burning of these masonry units results in good colour and more strength (35% improved strength while comparing to an A-Class brick). Optimum ratio with minimal cost and max efficiency with sustainability to the environment is recommended to the market. In the past year there was a spread of pandemic COVID 19. Precautious measures are taken to avoid the spread of this pandemic. By considering this situation a chemical is to be added in this masonry unit which will be acting as an disinfectious agent which will avoid the entry of various common viruses and bacteria like rhino viruses, salmonella. This ability of the masonry unit will last more than 24 months and beyond. And this can also be replenished after specific period of time. These masonry units have less mortar consumption (70% less mortar consumption while comparing to an A-Class brick), more workability, disinfectious and accommodates waste materials. Hence it is considered to be eco-friendly and sustainable.

Characterization of substrates of growing media by Fourier transform infrared (FT-IR) spectroscopy for containerized crop production

Growing media used in soilless culture systems are those solid substrates, which alone or in mixtures can guarantee better plant growth conditions similar to agricultural soil in one or many aspects. This study was aimed to characterize lignocellulosic organic substances predominant in most available and effective organic substrates viz., coir pith and dhaincha (Sesbania aculeata) powder and compost maturity in vermicompost based on the presence of functional groups by Fourier transform infrared (FT-IR) spectroscopy. The dominant downward peaks noted at 3300-3500 cm-1 in coir pith and dhaincha indicate vibration of hydroxyl (OH­-) stretch in cellulose structure and presence of alcohols and phenols. Peaks at 2925-2850 cm-1 found prominently in coirpith would be indicative of vibration of C-H bonds showing aliphatic degradation of cellulose, hemicelluloses, lipids, fats, etc. Particularly in dhaincha, vibration at 1733.32 cm-1 would be due to C=O stretch associated with an unconjugated ketone, carbonyl and ester groups. In vermicompost, peak value around 1549.85 cm-1 indicates C=C aromatic structure formed during mineralization of protein, cellulose, and hemicelluloses showing compost maturity. In the present study, FT-IR analysis of organic lignocellulosic substrates confirmed the occurrence of lignin, hemicellulose and cellulose, which are the main characteristics of natural fibers with high water holding and cation exchange capacity. Presence of alcoholic and carboxylic groups indicated stages of compost maturity and stability. Therefore, these renewable and environmentally sustainable lignocellulosic organic materials could be recognized as ideal soilless substrates for preparing grow media for containerized crop production and also recycling organic wastes in an environmentally friendly manner.

Characterization of Hybrid Composites with Polyester Waste Fibers, Olive Root Fibers and Coir Pith Micro-Particles Using Mixture Design Analysis for Structural Applications

In the present work, hybrid composites were developed by using polyester waste fibers along with natural origin materials: olive root fibers and coir pitch filler. Such composite panels can be used as a potential alternative for fiber glass sunshade panels and room dividers in buildings. Hybrid composites were fabricated by mixing polyester waste fibers and olive root fibers in different ratios (0:100, 33:67, 67:33 and 100:0). Coir pith micro-particles with an average size of 312 d.nm were used as filler in the polyester matrix at three different levels (0%, 5%, and 10%) of the overall matrix weight. Mechanical properties, e.g., tensile strength, flexural strength and impact strength, thermal properties, e.g., coefficient of linear thermal expansion, thermo-gravimetric analysis (TGA) and environmental properties, e.g., water absorption, loss of density after exposure to weathering were characterized. For comparison purposes, a commercially available fiber glass sunshades sample was also investigated. Mixture design analysis was used to optimize the ratio of all components in the composite. Graphical comparison of experimental results using regression models showed a high degree of correlation. An optimized formulation of composite with an objective of maximization of tensile strength, flexural strength, impact strength and minimization of water absorption, density loss, as well as coefficient of linear thermal expansion, was determined at 70.83 wt%, 15.15 wt%, and 14.01 wt% of polyester waste fibers, olive root fibers and coir pith micro-fillers, respectively. Overall, it can be concluded that the developed hybrid composites from waste fibrous materials can be used as a promising alternative and a value-added application in buildings and construction purposes.