Shabnur Chowdhury
Department of Soil, Water and Environment, University of Dhaka, Dhaka-1000, Bangladesh
MK Rahman
Department of Soil, Water and Environment, University of Dhaka, Dhaka-1000, Bangladesh
Growth and yield, Lettuce, Organic manures, Nutrient content
Department of Soil, Water and Environment, University of Dhaka
Crop-Soil-Water Management
Organic fertilizer, Lettuce
Soil sample collection and characterization: Soil sample (0-15 cm depth) was collected from Dhamrai, Savar. The sample was air-dried, ground, and sieved through a 2 mm sieve.The soil had a pH of 7.45 (1 : 2.5 w/v H2O), organic carbon 0.265%(7), available nitrogen 2.56% Kjeldahl extraction(8) Marr and Cresser 1983), available phosphorus 0.42% blue color method using ascorbic acid(9), exchangeable potassium 0.87%(10), available sulfur 0.28% Turbidimetric method(11), and 4.68%, silt 69.45% and clay 26.01%, textural class- silt loam(12). Pot experiment: Pot experiment (8 kg soil/pot) was carried out in the net house of the Department of Soil, Water and Environment, the University of Dhaka from 10th January 2019 to 10th February 2019. Eight kilograms of air-dried soil were taken in a 10 kg capacity pot providing a drainage hole at the bottom. Ten treatments with three replications were as: T1: Control (- OM), T2: ACI, T3: Approshika, T4: Payel, T5: Green Life, T6: Sebok, T7: Vermicompost (Payel), T8: Kazi, T9: Alo and T10: Trichoderma. Pots were arranged in a completely randomized design (CRD). Organic manures were applied at the rate of 10 ton/ha. The seedlings of lettuce (Lactuca sativa L.) were collected from “Horticulture Center”, Asadgate, Mohammadpur, Dhaka. Five days old seedlings of lettuce were transplanted in each pot. The pots were watered up to field capacity. Inter culture practices like weeding etc. were done when needed. The height of plants, the number of leaves, leaf area, and longest leaf were measured at 6 days intervals. The plants were allowed to grow up to 30 days after transplanting. Harvesting and analysis: Plants were harvested as leaf, stem, and root, washed with tap water and distilled water and wrapped with soft tissue paper. Immediately after harvest, fresh weight of leaf, stem, and root were taken, air-dried at room temperature and oven-dried at 650C in the laboratory for 48 hours. The dry weight of the samples was measured, and ground with a mechanical grinder and stored in paper bags for chemical analysis. The concentrations of lead and cadmium in the leaf, stem, and root were determined using an atomic absorption spectrophotometer (VARIAN AA240). For nitrogen, 0.2g of yield (leaf) sample was digested in a Kjeldahl digestion flask(8), for potassium, sulfur, and phosphorus 0.1g of yield (leaf) was digested with nitric-perchloric acid. Phosphorus of the digest was determined by vanadomolybdophosphoric yellow color method at 430nm using a spectrophotometer ( DR 5000). The potassium of the digest was determined by using JENWAY flame photometer ( PFP 7). The sulfur of the digest was determined by using the turbidimetric method(11). LSD test of the results was performed using Minitab, version 17.
Dhaka Univ. J. Biol. Sci. 30(2): 159-168, 2021 (July)
Journal