M. A. Quddus
Senior Scientific Officer
Horticulture Research Centre, Bangladesh Agricultural Research Institute (BARI), Gazipur
J. U Mian
Professor
Department of Soil Science, BAU, Mymensingh, Bangladesh
M. A. Hashem
Professor
Department of Soil Science, BAU, Mymensingh, Bangladesh
H. M. Naser
Principal Scientific Officer
Soil Science Division, BARI, Gazipur
M. A. Hossain
Principal Scientific Officer
PRSS, BARI, Gazipur
System productivity, Nutrient uptake, Nutrient balance, Wheat- mungbean-T. aman rice.
At Pulses Research Sub-Station, BARI, Gazipur
Farming System
Performance
Experiment with wheat-mungbean-T. aman rice cropping system was conducted for consecutive two years (2008-09 and 2009-10) at Pulses Research Sub-Station, BARI, Gazipur (24° 0′ 13″ N latitude and 90° 25′ 0″ E longitude) which lies at an elevation of 8.4 m above the sea level. The crop field was medium high land with clay loam soil and it belongs to Chhiata series (Soil taxonomy: Udic Rhodustalf) under the agroecological zone Madhupur Tract (AEZ-28). The experiment consisted of four treatments-absolute nutrient controls (T1); farmer’s practice (T2); AEZ basis fertilizer application (T3) and soil test basis fertlizer application (T4). The experiment was laid out in a randomized complete block design (RCBD) with three replications. The unit plot size was 4 m × 3 m for all crops having a spacing of 30 cm × 10 cm for wheat, 30 cm × 10 cm for mungbean and 20 cm × 15 cm for T. aman rice. Full amount of fertilizers except urea in wheat and rice was applied to crop during final land preparation. Urea was applied in two equal splits for wheat and three equal splits for T. aman rice. The sources of N, P, K, S, Zn and B were urea, triple superphosphate, muriate of potash, gypsum, zinc sulphate and boric acid, respectively. Wheat (var. BARI Gom-24) seeds were sown on 15 November 2008 and 11 November 2009. Mungbean (BARI Mung-6) seeds were sown on 26 March 2009 and 20 March 2010. T.aman rice (var. BRRI dhan33) seedlings (30 days old) were transplanted on 15 July 2009 and 18 July 2010. Intercultural operations were done as and when required. The crops were harvested at maturity. Data on yields (kg ha-1) for all test crops were recorded from whole plot. Analysis of variance (ANOVA) for the yields and different nutrient content was done following the principle of F-statistics and the mean values were separated by DMRT (Gomez and Gomez, 1984) at 5% level of probability using MSTAT- C software.
Soil samples at 0-15 cm were collected before establishing the experiment and after completion of two cycles of the cropping system from each treatment plot. Plant samples (straw and grain) against each treatment plot were oven-dried at 70° C for 48 h and finely ground. The initial and final soil samples were analyzed for soil pH and organic matter by Nelson and Sommers (1982) method; total N by Microkjeldahl method (Bremner and Mulvaney, 1982); exchangeable K by 1N NH4OAc method (Jackson, 1973); available P by Olsen and Sommers (1982) method; available S by turbidity method using BaCl2 (Fox et al., 1964); available Zn by DTPA method (Lindsay and Norvell, 1978); available B by azomethine-H method (Page et al., 1982). Ground plant samples were digested with di-acid mixture (HNO3-HClO4) (5: 1) as described by Piper (1966) for the determination- concentration of N (Micro-Kjeldahl method), P (spectrophotometer method), K (atomic absorption spectrophotometer method), S (turbidity method using BaCl2 by spectrophotometer), Zn (atomic absorption spectrophotometer method) and B (spectrophotometer following azomethine-H method). Rain and irrigation water samples were analysed for concentration of P, K, S, Zn and B same as plant samples method. Crop nutrient uptake was calculated from the nutrient (N, P, K, S, Zn and B) concentration and the straw and grain yields (Quayyum et al., 2002). Apparent nutrient balance for the wheat-mungbean-T. aman rice cropping system (average of two years) was computed as the difference between nutrient input and output (Paul Fixen et al., 2014). The inputs were supplied from (i) fertilizer (ii) rainfall and (iii) irrigation water and the outputs were estimated from crop uptake in a cycle. Added cost and added benefit were calculated. Besides, the gross return was calculated on the basis of different treatments which were directly related to the price of product. Cost of cultivation was involved with wage rate (land preparation, weeding, seed sowing and fertilizers application), pesticides, irrigation and fertilizers cost. Land used cost or rental value of land was not considered here. Marginal benefit cost ratio (MBCR) is the ratio of marginal or added benefit and cost. To compare different treatments combination with one control treatment the following equation was applied (Rahman et al., 2011).
MBCR (over control) = {Gross return(T i)- Gross return (T o)} / {VC (T i)- VC (T o)} = Added benefit (over control)/Added cost (over control)
Where, Ti = T2, ......... T4 treatments; T0 = Control treatment; VC= Variable cost; and Gross return = Yield × price
Bangladesh J. Agril. Res. 42(3): 509-520, September 2017 ISSN 0258-7122 (Print), 2408-8293 (Online)
Journal