I.F.S. EXM-2016

AGRICULTURAL ENGINEERING

PAPER-I

1.
What are the main causes of soil erosion in India? Explain the agronomic practices adopted fr controlling the soil erosion.

What are the contour and graded bunds? How do they differ in design and functional aspects.

Let P1, P2 P3 ···, Pn be the depths of rainfall recorded inn rain gauges enclosed by polygon having areas A1 A2 A3 ···, An within the watershed. Calculate the average depth of rainfall in the watershed of area A.

Calculate the cross-section of a contour bund used to store 24-hour excess rainfall of 10 cm. The annual rainfall is about 120 cm with a high intake rate and there is low coverage of crops over the land. The land slope is 4%. Use Cox's formula for VI of contour bund.


2.
With a neat sketch, explain the working of drop inlet spillway. Under what situation is it preferred?

What are the main objectives of watershed management programme? What survey is required to be conducted while planning for watershed development?

Design the dimensions of a weir used to discharge excess runoff through a contour bund for the conditions given below
Land slope 1.5%
Top width of the bund 45 cm
Height of the bund 60 cm
Height of crest above GL 30 cm
Side slope of the bund 2 1
VI m
Length of the bund 400 m
Intensity of rainfall for the return period and time of concentration 12 cm/hr
During the peak rainfall constant infiltration rate 2 · 5 cm/hr
No water is stored behind the bund before the peak rainfall occurs

Determine the volume of water stored behind the bund before it starts flowing.


3.
Describe in brief the runoff inducing practices fr increasing runoff for water harvesting.
Define rational formula fr estimating peak runoff rate. Why is it called rational? What are the limitations of rational formula?

Design a 150 m long inward sloping bench terrace for a sandy loam soil with an average slope of 15%. The entire width of the terrace acts as a channel which is provided with a uniform grade of 0·6%. The rainfall intensity for the return period and time of concentration is 20 cm/hr, runoff coefficient 0.3, riser side slope shoulder bund height 30 cm, bottom width 75 cm,
side slope 1 Manning's n 0.04, VI= 1.06 area of the terrace 0.09 ha.
4.
Classify remote sensing based on type of data acquisition. Explain in brief the application of remote sensing in agriculture ad forestry.

What is water-stage recorder? Discuss the current meter as a water flow measuring device.

Design a parabolic shaped grassed waterway to carry a flow of 3 cu m/s down a slope of 4%. An excellent stand of dub grass is to be maintained in the waterway. Take Manning's n 0.04.

5.
Define a weir. Draw the neat sketch of a rectangular weir placed in a channel and label it.

Write short notes on the following irrigation efficiencies
Water conveyance efficiency
Water application efficiency
Water storage efficiency
Water distribution efficiency

Define a centrifugal pump. Discuss the probable reasons when the centrifugal pump may fail to operate.
An engine-driven centrifugal pump is to be installed in an open well. The yield of the well is sufficient to deliver 16000 litres of water per hour. The static water level is 15 m and the pumping water level is 18 m from ground level. Total losses due to fiction in pipe and accessories may be assumed 15% of the total static head. If the pump efficiency is 55% and drive efficiency is
calculate the BHP of the engine required to drive the pump.

6.
Venturi meter
Parshall flume
Cipolletti weir
Tensiometer

Discuss the major components of a drip irrigation system with necessary drawing.
Tomato with 60 cm effective root zone depth is grown in a soil with field capacity and permanent wilting point of 22% and respectively. Irrigation is applied after 40% depletion of the available moisture. Apparent specific
gravity of soil 1.6. Calculate the depth of irrigation required. If a pump delivers 10 1/s discharge, how much time will it take for the irrigation of 2 ha? Assume no loss of water.

7.
Define agricultural drainage. What are the sources and ill effects of drainage?

Runoff water from a watershed enters into a drainage area for 8 hours at the rate of 3 m^3/s. The total rainfall during 24-hour period is 12 cm and the total infiltration during the period is 4 cm. If the total drainage area is 200 ha and the crop can tolerate a ponding of 10 cm, calculate the drainage coefficient of the land.

Mole drain
Interceptor drain
Bio-drainage
Channel lining

8.
What is polyhouse? Describe the working of fan and pad cooling system with a neat sketch.

Classify silos. Describe constructional features and use of pit silos.

A rectangular farm of 10 ha (500 m x 200 is to be fenced by barbed wires with concrete poles. Estimate the cost of fencing with six rows of barbed wires. Assume suitable values for spacing of posts and appropriate prices for posts and wires.