## 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 For tractor,

Depreciation/h

If L=10 years, H = 1000 h

D = Rs13.50

Interest/h  I = 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.