Lesson 6. Field capacity, efficiency, economics of machinery use numerical / problems

Q.1.     Determine TFC for a machine that travels at 5.0 kmph and has an operating width of 20 m.

 

                                                    SXW

            TFC     =         -------

                                        10

 

                                    5X20

                        =         --------= 10 ha/hr

                                      10

            Say loss time is 0.75 hrs in a10 hr day what is the effective Field capacity?

                     

                                                           Output

            Field efficiency Ef       =         ------------ X 100

                                                           Input

                                                               10-0.75

                                                =         ------------ X 100

                                                               10hrs.

 

                                                =         92.5%

           

                                                         SXWXEf                          

     Effective field capacity C           =------------

                                                        10 X 100

                                   

                                                         5X20X0.925

                                            =         ----------------   

                                                              10

                                                           

                                              =         9.25 ha/hr

Q.2. A farmer purchased a 35 hp wheel type tractor at a total cost of Rs. 1,50,000/- and three bottom plough with 30 cm bottom width at Rs. 6000/-. The fuel consumption of tractor was 6 l/h at plough speed of 5 km/h.

a) Calculate area ploughed per hour

b) Determine cost of ploughing per ha

 

 eq_1

For tractor,

 Depreciation/h             

 If L=10 years, H = 1000 h

 D = Rs13.50

 Interest/h  I =eq_2

 Repair and maintenance cost @ 10% of initial cost = Rs. 15/hr.

 Housing, taxes & maintenance cost   = 3% of initial cost = Rs.4.5/hr.

 Fuel cost @ Rs. 5.50 per litre = Rs 35/hr.

 Lubricants @ 30% of fuel cost = Rs. 9.90/hr

Wages @ Rs.50 per day of 8 hrs= Rs. 6.25/hr

Cost of tractor operation/hr

 =13.50 + 9.90 + 15 + 4.5 + 33 + 9.90 + 6.25

 = Rs. 92.05/hr.

 For plough

                                        C-S           6000-600

Depreciation/hr  D    =      -----------=  ---------------

                                          LXH             2400

                        =         Rs. 2.25/hr

              H         =         300 hrs

            L          =         8 years

 

                            6000+600                   0.12

Interest            = --------------- X          -----------          = 1.32/hr

                                2                           300

                                                           

Repair and maintenance cost @ 10% of initial cost = Rs. 600/year = Rs. 2.00/hr

 Housing @ of 1% of initial cost = Rs.0.20/hr 

Cost of ploughing       = 2.25 + 1.32 + 2 + 2 +0.20

                                    =         Rs. 5.77/hr

Total cost of ploughing with a tractor= 92.05 +5.77 = Rs.97.82/hr

                                                      97.82

Total cost of ploughing/ha      = -------------= Rs. 217.34/ha  

                                                      0.45

 

Q.3:     A farmer has 4-bottom, 41 cm M.B. plough of Rs.3000, 5 bottom, 45 cm plough of Rs.4200/-

             With either plow operating speed = 6.5 km/h

                       Field efficiency = 82%

a)         If labour cost is Rs. 3.50/h what is minimum number of hectare  plowed per year that would justify the purchase of large plow ( i.e. break-even pt.)?           

b)         How many hrs per year would each plow be used at break-even area?

c)         How would increased labour cost affect the size of break-even area?

Q.2.     4 m grain drill pulled at 7 km/h with a wheel type tractor having 35 PTO kw. The cost of drill is 3000 & labour cost Rs. 3.50/h. Calculate the following:

a)         Total cost/ha for drilling 40 ha/yr.

b)         The cost/ha if annual use is 100 ha.

c)         The number of hrs required to plant 100 ha.

Last modified: Wednesday, 19 March 2014, 5:15 AM