M. A. Islam
Biotechnology Division, Bangladesh Institute of Nuclear Agriculture, Mymensingh- 2202
M. A. Khan
Department of Soil Science, Sher-e-Bangla Agricultural University, Dhaka-1207
M. A. Rouf
Adaptive Research and Extension Division, Bangladesh Institute of Nuclear Agriculture, Mymensingh- 2202
Fertilizer, Manure, Soil column, T. aman rice, Leaching, Rice
A net house of Sher-e-Bangla Agricultural University, Dhaka
Crop-Soil-Water Management
Rice, Fertilizer, Manures
An experiment was carried out in a net house of Sher-e-Bangla Agricultural University during the T. Aman season (July to November) to evaluate the nutrient dynamics in undisturbed paddy soil columns with rice culture. The climate of the experimental area is characterized by high temperature, high humidity and medium rainfall with occasional gusty winds during the season. Two soils were collected in poly vinyl choride (PVC) pipes from the SAU farm, Dhaka and Farmers field, Sonargaon, Narayanganj during July, 2011. Twenty four (2 soils x 4 fertilizer application x 3 replication) undisturbed soil cores (25 cm diameter and 40 cm length) were collected in PVC pipes. Initial soil samples were collected from each site and analyzed for physio-chemical properties. The PVC pipes were pushed into the soil by creating pressure inside pipe wall and by adding water in the soil. The soil cores were carried to the net house and were placed in the plastic container. Filter paper (Whatman No. 1), glass wool and a 4-cm layer of acid-washed silica sand (1–2 mm diameter) were placed at the bottom of the plastic container that served as the base for the PVC soil core. Two holes in the plastic base were connected by means of polypropylene tubes and a T tube to a air-tight conical flask to collect leachate. Two soils (Soil-1: SAU Soil, Soil-2: Sonargaon Soil) and four fertilizer treatments (F0: Control F1: (N120P20K45S20) (FRG 2012), F2: 50% NPKS + 5 t/ha cowdung , F3:50% NPKS + 2.1 t/ha poultry manure) were used for rice cultivation in the PVC cores. The treatment wise required amounts of manures and N, P, K and S fertilizers per core were applied by acre furrow slice based calculation. Full amounts of manure, TSP, MoP and gypsum were applied at final land preparation before transplanting. Urea was applied in 3 equal splits: one third was applied as basal dose before transplanting, one third at active tillering stage (30 DAT) and the remaining one third was applied at 5 days before panicle initiation stage (55 DAT). Chemical compositions of the soils and manures used have been presented in BR11 was used as the test crop in this experiment. The experimental design was Complete Randomized Design (CRD) with two factors and three replicates for each treatment. The distance maintained between core to core and row to row were 40 cm and 1m respectively. Thirty days old T.Aman seedlings of BR11 were transplanted on the 1st week of July. Two seedlings were used in each hill and one hill/ soil core. Traditional irrigation (23 cm continuous flooding) was applied during the growing period of T.Aman rice crop. Intercultural operations and plant protection measures were done to ensure normal growth of the crop. Leachates were collected at 25, 35, 45, 55, 65 and 75 DAT of T. Aman rice and analyzed for N, P, K and S by using standard analytical methods. The crop was harvested at full maturity when 80–90% of the grains were turned into straw color. The crop was cut at ground level. After harvest, the rice yield parameters and yield were recorded. Soil samples were analyzed for both physical and chemical characteristics viz. texture, pH, total N and available P, K, and S contents. The leachate samples were analyzed for N, P, K and S concentrations. Mechanical analysis of soil were done by hydrometer method (Bouyoucos, 1926) and the textural class was determined by plotting the values of % sand, % silt and % clay in the Marshall’s triangular co-ordinate following the USDA system. Soil pH was determined by glass electrode pH meter (Jackson, 1962). The organic carbon was determined by wet-oxidation method (Walkley and Black, 1935). Total N of soil was determined by the Micro Kjeldahl method. One g of oven dry ground soil sample was taken into a micro Kjeldahl flask to which 1.1 g catalyst mixture (K2SO4: CuSO4. 5H2O: Se in the ratio of 100: 10: 1), and 7 ml H2SO4 were added. The flasks were swirled and heated 160°C and added 2 ml H2O2 and then heating at 360°C was continued until the digest was clear and colorless. After cooling, the content was taken into 50 ml volumetric flask and the volume was made up to the mark with distilled water. A reagent blank was prepared in a similar manner. These digests were used for N determination (Page et al., 1982). Ten ml digest was transferred into the distillation flask, 10 ml of H3BO3 indicator solution was taken into a 250 ml conical flask which is marked to indicate a volume of 50 ml and placed the flask under the condenser outlet of the distillation apparatus so that the delivery end dipped in the boric acid. By operating switch of the distillation apparatus the distillate was collected and titrated with 0.01N sulphuric acid. Available P was determined from the soil with 0.5 M NaHCO3 solution, pH 8.5 (Olsen et al., 1954). Exchangeable K was determined by 1N NH4OAc (pH 7) extraction method and by using flame photometer and calibrated with a standard curve. Available S was extracted by CaCl2 (0.15%) solution and determined as described by Page et al. (1982). The leachates were analyzed for available N, P, K and S by using similar methods. The data obtained for different parameters were statistically analyzed to find the significant difference of different treatments on yield and yield contributing characters of BR11. The mean values of all the characters were calculated and analysis of variance was performed by the ‘F’ (variance ratio) test. The significance of the difference among the treatment means was estimated by the Duncan’s Multiple Range Test (DMRT) at 5% level of probability (Gomez and Gomez, 1984).
J Bangladesh Agril Univ 15(2): 199–205, 2017
Journal