An experiment was conducted at the research field in Farm Machinery and Postharvest Process Engineering (FMPE) Division, BARI during 2017-18. In this experiment, the residue retention level was constant (25cm). Strip tillage (ST) and Zero Tillage (ZT) were used as CA practice during rabi season. Strip till followed by manual transplanting (STMT) and unpuddled transplanting by trnsplanter (UPT) were used as CA practice during T. aman season comparing with conventional tillage (CT) methods. Thus, the following treatments was tested with 03 (three) replications
T1=CT T. Aman-CT Maize
T2=CT Machine transplanted T. Aman-CT Maize
T3=CT T. Aman-ST Maize
T4=CT T. Aman-ZT Maize
T5=STMT T. Aman-ST Maize
T6=STMT T. Aman-ZT Maize
T7=UPT T. Aman-ST Maize
T8=UPT T. Aman-ZT Maize
Variety of maize was BARI Hybrid maize-9. Date of Sowing was 17-12-2018. Plote size was 6 x5 m2. Date of harvesting was 11-05-2018. Standard fertilizer dose (255-55-140-40-6-2 kg/ha NPKSZnB), weed management practice and irrigation schedule were followed. Before selecting the yield estimation area, border effects were avoided. Across the rows, at least 1 meter border length (horizontally) and along the rows, 2 rows (parallel) from each side of the plot were avoided for yield determination. In all the tillage treatments, a plant population of 6 maize rows (excluding borders) and 5-meter length for each row (avoid border area mentioned as in step 1) were selected. This resulted in a harvestable area of 18 m2. All the ears from the harvest area were collected. The ear cover was removed. When the ears (with the grain) of the area were thoroughly dried, all of the remaining ears with attached grains from the harvested area were weighted. Then the maize was removed the grain with the help of a maize grain remover. All the maize grains were collected and weighed. A representative cob sub-sample of five representative cobs for moisture determination was collected and being weighed. Randomly 1 m2 area was selected from the main plot for crop biomass, plant height, ear length, ear girth, number of grains and 100 grain weight. Each of these areas should contain 10 plants. Energy conversion was done with standard energy equivalent
Operating cost was calculated to determine its economic performance and production cost. Fixed and variable costs were determined. Depreciation, interest on investment, tax, insurance and shelter costs are the components of fixed cost calculation using the following equations (Hunt, 1973).
- Annual depreciation, D=(P-S)/L (18)
Where, D= Depreciation, Tk/yr
P=Purchase price, Tk
S =Salvage value, Tk
L= Working life of the machine, yr
- Interest on investment, I=(P+S)/2*I (19)
Where, i= rate of interest
- Tax, insurance and shelter cost T=3% of P (20)
Total fixed cost per year, FC= (a+b+c)
In variable cost calculation, the cost of fuel, lubricant, and labour were considered. These cost increase with increase of machine use and vary to a large extent in direct proportion to days of use per year.
- Labour cost per hour, L= Tk/man/h (21)
- Fuel cost per hour, F= l/h × Tk/l (22)
- Lubrication oil cost per hour, O= 3% of fuel cost (23)
- Repair and maintenance cost per year=3.5% of purchase price (24)
Total variable cost= (d+e+f+g) (25)
A simple partial economic analysis was done based on total production. Price of the produce was collected from the local markets to compute total production cost, gross return, gross margin and benefit-cost ratio (BCR) with following formulas
Total product value= Yield (kg/ha) x Price (Tk/kg) (26)
Gross return (Tk/ha)= Total product value– Variable production cost(27)
Net return = Total Product value (Tk/ha) – Total production cost (Tk/ha)(28)
Benefit –cost ratio = (29)
Where
TPV= Total Production value (Tk/ha)
TPC= Total production cost (Tk/ha)