Calibration of a seed Drill

Calibration of seed drill
    The procedure of testing the seed drill for correct seed rate is called calibration of seed drill. It is necessary to calibrate the seed drill before putting it in actual use to find the desired seed rate. It is done to get the pre determined seed rate of the machine. The following steps are followed for calibration of seed drill.
    Procedure :
    i. Determine the nominal width (W) of seed drill .
    W = M x S,
    Where, M = Number of furrow openers
    S = Spacing between the openers, m
    ii. Find the length of the strip (L) having nominal width (W) necessary to cover 1/25 ha (1 /25 x 10000 m2).
    L = 400/W, meter
    iii. Determine the number of revolutions (N) of the ground wheel of the seed drill required to cover the length of the strip (L).
    L = P x D x N = 400/W
    N = 400/P x D x W revolutions per minute
    iv. Jack the seed drill so that the ground wheels turn freely. Make a mark on the drive wheel and a corresponding mark at a convenient place on the body of the drill to help in counting the revolutions of the ground wheel..
    v. Fill the selected seed in the seed hopper. Place a container under each boot for collecting the seeds dropped from the hopper.
    vi. Set the seed rate control adjustment for maximum position and mark this position on the control for reference.
    vii. Engage the clutch and rotate the ground wheel for N = 400/P x D x N, revolutions per minute.
    viii. Weigh the quantity of seed collected in the container and record the observation.
    ix. Calculate the seed rate in kg/ha.
    x. If the calculated seed rate is higher or lower than the desired rate of selected crop, repeat the process by adjusting the seed rate control adjustment till the desired seed rate is obtained.

    Problem 1:
    Calculate the cost of seeding one hectare of land with bullock drawn seed drill of 5 x 22 cm size. The speed of bullocks is 3 km/hr. Hire charge of bullocks Rs.200/- per pair, hire charges of seed drill Rs.50/- per day and wage of operator Rs.150/- per day of 8 hours.
    Solution:
    Width of seed drill = 5x22 = 110 cm = 1.1 m
    Area covered/hr = width x speed = 1.1 x 3x1000 m = 0.33 ha
    Time taken/ha = 1/0.33 = 3.03 hrs.
    Hiring cost of per hour = 200+50+150/8 = Rs 50.
    Cost of seeding per hectare = 3.03 x 50= Rs. 151.50
Last modified: Tuesday, 26 June 2012, 1:29 PM