Rotavator FMTTI Testing: The Minimum Performance Criteria a Machine Must Meet

Most manufacturers approach a rotavator test knowing roughly what will be measured, and not at all what counts as good enough. Those are different questions, and only the second one decides whether the report says Yes.

Rotavators are the highest-volume implement category in Indian farm mechanisation, so this is the machine where the gap between "we tested it" and "it met the criteria" costs the most. Here are the actual pass marks.

The evaluative field-performance criteria

An Initial Commercial Test report sets out each characteristic, the requirement from the applicable Indian Standard, the value observed, and a plain Yes or No on whether the requirement was met.

For field performance, every one of those characteristics is classed evaluative — meaning it counts toward whether the machine meets the minimum performance criteria. Here is how a real machine measured up, from a September 2021 Initial Commercial Test report for a tractor-mounted, PTO-operated rotavator in the 1.5-metre working-width class.

Characteristic	Requirement	Observed	Met?
Suitability for wet-land operation	Should be suitable	Suitable	Yes
Depth of cut, dry land	Minimum 10 cm	10.22 – 10.80 cm	Yes
Depth of puddle, wet land	Minimum 12 cm	20.51 – 21.50 cm	Yes
Field efficiency	Minimum 75%	76.57 – 84.18%	Yes
Puddling index	Minimum 65%	74.0 – 78.0%	Yes

Read the margins rather than the verdicts. Puddle depth cleared its requirement by roughly 70 percent, and puddling index by a comfortable stretch. Depth of cut cleared 10 cm by two millimetres at the worst run. Field efficiency cleared 75 percent by 1.57 points at its lowest.

That is the practical lesson buried in a passing report: two of the four numeric criteria passed with almost no headroom. A slightly harder soil, a slightly different moisture band, or a marginally worn blade set on the day, and the same machine could have produced a different answer on the same test.

What the conditions actually were

Criteria mean nothing without the context they were measured in. The same report records the field test as 26.0 hours of dry-land operation and 11.0 hours of wet-land operation, in medium soil, with the tractor's no-load PTO speed set to 585 rpm.

Soil moisture ran 6.0 to 9.5 percent in dry land, with bulk density 1.73 to 1.94 g/cc. Wet-land work was done with 10.52 to 10.83 cm of standing water.

Those are the conditions behind the numbers in the table. If your own field trials run in lighter soil or wetter ground, your internal figures are not comparable to what an institute will record.

The rate-of-work figures that come with it

Alongside the pass/fail criteria, the report captures what the machine actually achieved — the numbers a dealer or a scheme buyer will read:

• Area covered: 0.304 to 0.348 ha/h
• Time per hectare: 2.87 to 3.29 hours
• Forward speed: 2.74 to 2.90 kmph dry land, 2.31 to 2.47 kmph wet land
• Working width in operation: 142 to 149 cm
• Fuel consumption: 4.10 to 4.60 l/h dry land, 12.34 to 14.81 l/ha
• Wheel slippage: −2.54 to −0.79 percent

The negative slippage is not an error. A PTO-driven rotavator pushes the tractor forward as the rotor engages the soil, so the drive wheels turn slightly slower than ground speed rather than faster. It is normal for the category, and it is one of the details that separates a real report from a marketing sheet.

Working width is not the model number

Worth flagging because it catches buyers and, occasionally, tender committees. The machine in this report carried a model designation implying 1600, a declared working width of 1480 mm, and a measured width in operation of 142 to 149 cm.

None of those three numbers are the same, and only the last one describes what the machine does in a field. A model number is a product name. If a specification or a tender turns on working width, take it from the declared specification or the measured figure in a test report, not from the badge.

What this means before you apply

Four things follow from the criteria being what they are:

1. Know your soil. The criteria are fixed; the conditions are not. Test internally across the hardest soil you expect the machine to face, not the most convenient plot.
2. Watch depth of cut most closely. Of the four numeric criteria it is the one with the least natural headroom, and it depends directly on rotor diameter, blade condition and how the machine is set.
3. Field efficiency is a systems number. It reflects turning, adjustment stops and interruptions as much as the rotor itself. It is improved by ease of operation, not only by cutting performance.
4. Confirm which code edition applies. Criteria are drawn from the Indian Standard in force at the time of test, and rotavators have had more than one relevant code in play. Your institute will confirm which applies to your application.

Establishing which criteria your machine will be judged against, and what your own trial data says about the margin you have, is the work test process guidance covers before an application goes in. AgPro doesn't run the tests — FMTTI's engineers do that, at the institute — but arriving with a machine that clears the criteria with room to spare is a decision made months earlier.

For what the rest of the report contains, see what's inside a rotavator FMTTI test report, and for the criteria that a machine can fail without failing the test, see evaluative vs non-evaluative parameters.