Organic manure, Chemical fertilizers, Recommended dose, Cabbage yield, Terrace Soil, Gross margin
1) To find out the relative requirement of cowdung, poultry manure, oil cake and chemical fertilizer for maximizing the yield of cabbage and
2) To evaluate the contribution of organic manures (cowdung, poultry manures and oil cake) in reducing the chemical fertilizer from the present recommendation.
A field experiment with cabbage was carried out in the experimental field of Bangladesh Agricultural Research Institute, Joydebpur, Gazipur during rabi season of 2000-2001 and 2001-2002. The soil belongs to the Chhiata series of the Grey Terrace Soils (Aeric Albaquept). Results on some physical and chemical properties of initial soil samples collected from 0-20 cm depth from the experimental field are presented in Table-1.
Table 1. Texture and fertility status if initial soil sample at central farm, BARI, Gazipur
Texture p-H OM Ca Mg K Total N% P S B Cu Fe Mn Zn
Meq 100-1 g µg g-1
Silty clay 6.2 1.5 12 4.1 0.17 0.08 15 17 0.24 5.67 120 13 2.7
Critical level 2.0 0.8 0.2 - 14 14 0.2 1 10 5 2
The soil was silty clay in texture having pH 6.2 and low in organic matter, total-N, available P, B and exchangeable K. The experiment was set up in randomized complete block design with 3 replications. There were 27 plots having an area of 3.0 m × 2.4 m each. Healthy cabbage (Atlas-70) seedlings of equal size (25 days old) were transplanted in rabi season with a spacing of 60 cm from row to row and 60 cm from plant to plant. There were nine treatments viz. T1 : 250-35-80-40-2-1 kg ha-1 (RD) of N-P-K-S-B-Mo, T2: 70% of RD, T3: 70% RD + 5 t CD ha-1, T4: 70% RD + 10 t CD ha-1, T5: 70% of RD + 5 t PM ha-1, T6: 70% RD + 10 t PM ha-1, T7: 70% RD + 2.5 t OC ha-1, T8: 70% RD + 5 t OC ha-1 and T9: absolute control. Urea, TSP, MP, gypsum, boric acid and sodium molybdate were used as source of N, P, K, S, B and Mo, respectively. All P, K, S, B, Mo, cowdung, poultry manure, oil cake and 1/3 N were applied at the time of final land preparation and the remaining 2/3 N was applied in two equal installments at 21 and 42 days after planting. Cowdung, poultry manure and oil cake used in the study were also analyzed and data are presented in Table 2.
Table 2. Nutrient status of the oil cake, poultry manure and cowdung used in the experimental field
Organic manure N P K Ca Mg S Mn Zn
% µg g-1
Oil Cake 4.9 0.8 1.48 4.4 1.6 2.4 0.42 1.2
Poultry manure 1.8 1.6 1.64 8.5 6.2 1.6 0.92 1.5
Cowdung 0.8 0.5 0.9 0.6 0.31 0.3 0.89 1.0
Oil cake was very rich in nutrient content followed by poultry manure while cowdung contained much lower amount of plant nutrients. All intercultural operations such as weeding, irrigation etc. were done as and when necessary to raise healthy crop. Harvesting was done when the head attained proper size and at the right stage of maturity. As all the heads did not develop uniformly, the harvesting lasted for 17 days. Ten plants from each plot were tagged at random to take records on number of unfold leaves, head circumference and yield. The yield and yield attributes data were analyzed statistically and the mean differences were tested by Duncan’s Multiple Range Test (Steel and Torrie, 1960). Particle size distribution was done by hydrometer method, the textural class was ascertained using Marshals’s traiangular co-ordinates and soil pH was measured with a combined glass calomel electrode (Jackson, 1958). Exchangeable K and available P, S, Cu, Fe, Mn, Zn and B were analyzed following standard laboratory procedures (Hunter, 1984).
A package of 70% recommended dose of chemical fertilizer (N175 P25 K56 S28 B1.4 Mo0.7 kg ha-1) along with 5 t ha-1 poultry manure may be recommended for the cultivation of cabbage in Grey Terrace Soil of Joydebpur for yield sustainability and economic profitability. However, rich farmers may use either 10 t PM or 2.5 t OC ha-1 instead of 5 t PM ha-1 along with 70% RD for highest gross margin. Use of 10 t PM or 2.5 OC is sufficient enough to reduce 30% chemical fertilizers from the present conventional recommendation.