Tillage Implements Questions and Answers

Answer: C

Compared with the spring tyne cultivator, the rotary cultivator needs lower draft and higher total power.

In the concurrent (forward-rotating, down-cut) mode the rotor blades cut the soil while turning in the same direction as the wheels, so they push the machine forward. Much of the energy then comes through the PTO rather than as a pull at the drawbar, and the draft can be small or even negative.

Total power is nevertheless higher, because the rotor cuts and pulverises the soil much more finely than a tyne that only loosens and stirs it, and that extra soil breakage costs energy. So 'higher and higher' and 'higher and lower' get the draft wrong, and 'lower and lower' misses the extra PTO power.

Answer: A

The shank is mainly subjected to bending.

A rigid tyne is a cantilever clamped to the tool frame. The soil resistance acts on the sweep at its lower end, well below the clamp, so the horizontal draft force produces a large bending moment that grows towards the clamp. This is why tyne shanks are designed on bending stress and are deep in the direction of travel.

Direct shear from the same force is small beside that moment. Torsion arises only if the soil force is off the shank's centre line, which a symmetrical sweep largely avoids, so neither torsion alone nor bending and torsion together is the main loading.

Answer: A

The total energy falls when the bite length is increased.

Bite length is the forward distance the tiller advances between successive cuts by blades on the same flange. A longer bite means each blade cuts a larger slice of soil, so fewer cuts, and less pulverisation, are needed per unit volume tilled. Much of a rotary tiller's energy goes into cutting and breaking up soil, so the specific energy drops as bite length rises (at the cost of a coarser tilth).

A shorter bite cuts the soil finer and needs more energy. A higher cone index means harder, stronger soil, which needs more energy. Reducing forward speed at the same rotor speed shortens the bite, which also raises energy per unit volume.

Answer: A

The total width of cut is 1.19 m.

Each disc cuts a chord of the disc circle at the working depth, and the disc angle (between the disc face and the direction of travel) turns that chord across the line of travel:

\[ \begin{aligned} \text{chord} &= 2\sqrt{d(D - d)} = 2\sqrt{0.15 \times 0.45} = 0.520 \\ w &= 0.520 \times \sin 40^{\circ} = 0.334\ \text{m} \end{aligned} \]

Five discs cut 5 w, less the four overlaps between neighbours:

\[ W = 5(0.334) - 4(0.12) = 1.670 - 0.48 = 1.19\ \text{m} \]

Ignoring the overlaps leaves 1.67 m, which is not offered; using the full chord without the sine factor gives 2.60 - 0.48 = 2.12, close to 2.11. The key's method projects the chord with sin 40 degrees and subtracts the overlaps once between each pair of discs.

Answer: A

The attachment is the jointer.

A jointer is a small plough bottom, a miniature mouldboard, fixed to the beam ahead of the main bottom. It skims a narrow, shallow strip off the top of the furrow slice and turns surface trash, weeds and roots towards the main furrow, so that the mouldboard then buries them completely. That is exactly the description in the question.

A coulter is a disc or knife that cuts vertically through the soil and trash ahead of the share, but it does not turn a furrow. A subsoiler is a heavy tine that breaks hardpan well below normal ploughing depth. A weed hook is a curved rod or chain that drags tall weeds into the furrow; it is not a plough bottom.

Answer: A

Direct sowing in the harvested field is zero tillage.

In zero tillage (no-till), the next crop is sown straight into the stubble of the harvested crop with no primary or secondary tillage, usually with a zero-till seed drill that cuts a narrow slit and places seed in it. It is widely used in the rice-wheat system of north India to sow wheat soon after the rice harvest, saving time, fuel and soil moisture.

Minimum tillage reduces the number of operations but still works the soil. Conservation tillage is the broad group of practices leaving at least 30% residue cover, of which zero tillage is one. Mulch tillage works the soil while leaving residue on the surface.

Answer: C

A coulter is used with the MB plough (mouldboard plough).

A coulter is a sharp vertical knife or rolling disc mounted ahead of the plough bottom. It cuts the furrow slice vertically from the unploughed land and slices through trash and roots, which gives a clean furrow wall and less draft. Rolling coulters and knife coulters are attachments of the mouldboard plough.

A disc harrow cuts with its own discs and needs no coulter. A seed drill uses furrow openers, and a subsoiler uses a narrow shank and point to break hardpan.

Answer: C

The implement is the Indigenous plough.

Primary tillage is the first deep opening of the soil. In India the indigenous wooden plough (desi hal), drawn by bullocks, is used on far more farms than any other primary tillage implement, because it is cheap, light, easy to make and repair locally, and suits small holdings.

The disc harrow and cultivator are secondary tillage implements used to break clods and prepare the seedbed. A puddler is used only for wetland rice preparation.

Answer: A

The key names the Gauge wheel.

On an animal-drawn mouldboard plough the depth of furrow is set by the gauge wheel, an adjustable wheel carried on the beam. Raising or lowering it changes how far the share can sink, so it limits the depth of ploughing and also helps in transport. That is the part the question describes as controlling the depth of the soil worked.

The share is the cutting edge that penetrates and cuts the furrow slice, and the landside is the flat plate that takes the side thrust and keeps the plough steady against the furrow wall. Neither sets the depth. The handle is the part the ploughman holds to guide the plough and to lift it out at the end of a furrow, so it is the part that has handles. The stem joins two descriptions in one clause, and the keyed reading follows the depth-control function, which belongs to the gauge wheel; the handle controls steering rather than the setting of depth.

Answer: A

The implement is the Cultivator.

A cultivator (tiller) with tynes or shovels stirs and breaks the soil to a moderate depth. It is used after ploughing to break clods and prepare the seedbed, and for interculture and weeding. Its working depth and action place it between the plough, which opens the soil deeply, and the harrow, which only works the surface.

The disc harrow is a harrow itself, the mouldboard is a plough, and the rotavator is a separate rotary implement.