PG Thesis
Permanent URI for this collectionhttp://localhost:4000/handle/123456789/2
Browse
Item Enriched vermiwash from microbially accelerated vermicomposting process for crop nutrition(Department of Soil Scince and Agricultural Chemistry, College of Agriculture, Vellayani, 2024-11-05) Aarush Lal; Sailajakumari, M SA study entitled “Enriched vermiwash from microbially accelerated vermicomposting process for crop nutrition” was conducted in the Department of Soil Science and Agricultural Chemistry, College of Agriculture, Vellayani, from January 2024 to August 2024. The objective of the study was to produce and characterize enriched vermiwash synthesized via microbially accelerated vermicomposting process and study its effect on the growth and productivity of okra variety ‘Anjitha’ as test crop. The study was carried out in three parts; viz. preliminary characterization of substrates used for vermicomposting, vermicomposting and vermiwash collection and study of effect of vermiwash on okra crop. Feedstocks selected for vermicomposting included: Gliricidia sepium leaves, banana pseudostem, rice husk and rice straw. Treatment combinations consisted of T1 – Gliricidia sepium leaves, T2 – Banana pseudostem, T3 – Rice straw, T4 – Rice husk, T5 – Rice straw + banana pseudostem 8:1 (w/w), T6 – Rice husk + banana pseudostem 8:1 (w/w), T7 – Rice straw + rice husk + banana pseudostem 4:4:1 (w/w) and T8 - Rice straw + rice husk + banana pseudostem + Gliricidia sepium leaves 4:4:0.5:0.5 (w/w). Vermiwash collection units were fabricated and setup as per guidelines of vermiwash production method-II of KAU PoP 15th edition. Earthworm species, Eudrilus eugeniae and fungal decomposer consortium, Pusa decomposer were the prime decomposing agents. Substrate characterization revealed Gliricidia sepium leaves to be the best in terms of N (1.94 %), Ca (0.98 %), Mg (0.44 %), S (0.11 %) and Cu (20.11 mg kg-1) concentration. Rice straw exhibited highest P (0.77 %), Fe (1125.76 mg kg-1), Mn (464.22 mg kg-1) content, while banana pseudostem expressed peak K (1.06 %), B (39.88 mg kg-1) and Zn (116.60 mg kg-1) values. The collected vermicompost was subjected to nutrient profiling and microbial assessment. Nutrient mineralization via earthworm foraging resulted in augmented nutrient content of the final vermicompost. Vermicompost derived from banana pseudostem registered lowest C:N ratio (9.80) which attained maturity within 45 days. 125 In terms of essential macronutrients, T2 (Banana pseudostem) reported highest K (1.20 %), Ca (1.13 %), S (0.54 %), Mn (418.40 mg kg-1), Zn (247.50 mg kg-1) and Cu (55.12 mg kg-1) content. While T5 (Rice straw + banana pseudostem) expressed peak N (2.41 %) and EC (2.61 ds/m) values. Highest Mg was recorded in T1 (Gliricidia sepium leaves) at 0.95 %. T3 (Rice straw) exhibited summit Fe (8669.50 mg kg-1) and B (37.00 mg kg 1 ) content. Microbial analysis revealed highest bacterial population in T2 (Banana pseudostem) at 7 × 107 cfu g-1 and peak fungal load in T7 (Rice straw + rice husk + banana pseudostem) at 8.5 × 105 cfu g-1. Vermiwash was extracted from vermicompost after 24 hours of incubation within the vermireactors and characterized. T5 (Rice straw + banana pseudostem) emerged as the best treatment in terms of N (0.33 %), K (0.11 %), S (161.47 mg kg-1), Cu (2.04 mg kg-1) and Si (2.17 %) content, while T3 (Rice straw) expressed peak EC (7.33 ds/m) and Mn (4.05 mg kg-1) values. T2 (Banana pseudostem) exhibited highest Fe (36.61 mg kg-1) and Zn (5.95 mg kg-1) concentration. Microbial assessment revealed that highest bacterial population was in T7 (Rice straw + rice husk + banana pseudostem) at 5.5 × 107 cfu g-1. Decomposition of lignocellulose dominant biomass such as rice straw improved with the augmented action of Eudrilus eugeniae and microbial consortium (Pusa decomposer), thus allowing silicon fortification within vermiwash in relatively shorter timeframe. The innate nutrient composition of the substrates expressed major influence on the nutrient content of the final vermiwash with T5, consisting of: Rice straw + Banana pseudostem in 8:1 ratio (w/w) exhibiting peak outputs for majority of parameters. Hence vermiwash from T5 was selected as the best treatment for foliar nutrition. Effect of foliar nutrition of enriched vermiwash on okra was studied with various treatments, including T1 : PoP of KAU, T2 : Organic PoP of KAU, T3 : T1 + Foliar Spray 5%, T4 : T2 + Foliar Spray 5%, T5 : T1 + Foliar Spray 10% and T6 : T2 + Foliar Spray 10%. Foliar nutrition was done with vermiwash extracted from vermicomposting of rice straw and banana pseudostem. Significant difference among treatments was recorded in terms of plant growth parameters with the tallest plant height at 80 DAS and 120 DAS and the highest number of leaves per plant throughout the cropping period achieved by plants following conventional KAU PoP protocol with 10 % vermiwash foliar spray. 126 Plants subjected to organic KAU PoP with 10 % vermiwash foliar spray reported shortest duration to first flowering at 48 days. Yield parameters also differed significantly under the influence of vermiwash with the highest yield per plant and peak number of fruits per plant recorded by organic KAU PoP with 10 % foliar spray at 296.52 g and 21.33, respectively, which was on par with conventional KAU PoP with 10 % foliar spray. Foliar application of vermiwash at 10% concentration supplemented essential plant growth nutrients, significantly improved the growth and yield parameters of okra. Given the yield parameter outcomes, a foliar application of 10 % vermiwash derived from vermicompost prepared from rice straw and banana pseudostem (8:1 w/w), integrated with either the conventional or organic POP of KAU for okra may be recommended.