The following procedures can provide useful information to groundsmen.
Information on the physical nature of the bulli (clay percentage, swell/shrink characteristics etc.) will provide groundsmen with information on the suitability of any sample of bulli for use in constructing a pitch, or for use as topdressing. This information can also be used as a guide to the best rolling procedures to use but more work will need to be done on this aspect to allow groundsmen to use these procedures.
Required sample size: About 500 grams. Provincial offices will have current delivery instructions and costs, as well as a supply of sample boxes and Soil Testing Submission forms. Please use these when submitting bulli for tests.
(ii) Motty or Adams/Stewart Soil Binding test (ASSB)
This test provides data which have been shown to correlate well with rebound height when a ball is dropped vertically using a bounce meter (which in turn has been found to correlate well with the amount of bounce and the pace of a pitch). It is a test which does not need sophisticated equipment and can be undertaken in one's office.
Procedure:
(a) Transfer half a cupful of finely rubbed down soil (less than 2 mm) under test to a clean plate. To a second plate add a similar amount of a dry soil of which a large reserve is available. This second soil will serve as a standard for comparison with the test soil.
(b) Moisten the two samples with distilled water if available (otherwise with tap water) until they can be moulded by hand. Water must be added slowly to ensure that the soil does not become too sloppy to mould (just as one would mix a cake batter).
(c) Mould vigorously by hand over a period of 5 minutes to destroy all aggregates. Add more water if necessary.
(d) Roll the soil into a ball and place it on a clean plate. Cover the soil with a wet cloth (wrung out by hand) and leave standing for 2 hrs.
(e) Remould the soil by hand, making sure that it is plastic but not sloppy. It should have the consistency of putty and have little tendency to stick to the hands. It should also readily mould into a ball without forming cracks. Adjust moisture state if necessary by allowing it to dry further or by adding small amounts of water.
(f) Roll the soil into a worm approximately 12.5 mm (0.5 inch) in diameter on a plate and cut into cylinders 25 mm (1 inch) long.
(g) Carefully mould each cylinder into a ball and then roll between the palms of the hands.
(h) Place the two sets of balls onto clean plates and allow to air dry in a cupboard for 5 days.
(i) Place each dried ball in turn on a metal plate placed on a zeroed bathroom scale and break by slowly increasing foot pressure on a small flat metal plate placed on top of the ball. Note the reading on the scale when the ball breaks.
(j) Discount the lowest value in each set and obtain the mean value of the rest.
(k) Readings between 50 and 125 kg (110 to 275 lbs) have been shown to be optimum for British soils. We will need to do some work on our local soils, but would guess that our values could be much higher than this.
These tests are needed to establish the fertiliser requirements of a pitch. These tests should normally include tests for phosphate (P), potash (K), calcium (Ca), magnesium (Mg), acidity (pH), salinity and, if possible, sulphur (S).
Required sample size: About 500 grams. Provincial offices will have current delivery instructions and costs, as well as a supply of sample boxes and Soil Testing Submission forms. Please use these when submitting bulli for tests.
(iv) Chemical tests on irrigation water
If there is any suggestion that the water may be unsuitable for use (because, for example, of its high salt content), it should be tested before use.
Great care needs to be taken to ensure that a representative sample is submitted to the laboratory for testing. When sampling loose bulli, therefore, a number of grab samples should be taken from different batches and thoroughly mixed. A sub-sample can then be taken from this mixture for submission to the laboratory for testing. Where an existing pitch is to be tested, a number of cores (about 15) should be taken to a depth of 100 mm, thoroughly mixed, and if necessary sub-sampled.
(vi) Testing pitch performance
A number of different procedures have been developed to test the performance of a pitch. These include, for example, the 'Clegg impact soil tester' but we have found the very simple and easy-to- use 'vertical bounce meter' to be an extremely useful instrument to test pitch performance. This instrument is used to measure the vertical bounce of a ball when dropped from a standard height (3.5 metres in our model but 4.9 metres in the instrument most commonly used - we found the latter to be extremely cumbersome to use). The bounce recorded using this meter has been found to correlate well with both the bounce that would be extracted by a bowler, and the pace of the pitch. Also, by taking a number of readings down the length of the pitch, one is able to determine an index of the inconsistency of the pitch. This very simple instrument, therefore, provides an indication of the bounce, pace and consistency of a pitch. It cannot provide an indication of the turn that could be extracted from a pitch. This is dependent on the roughness of the surface of the pitch. The rougher it is, the more the ball would grip when it pitches, and so the more it will turn. Theoretically, however, it would be possible to produce an instrument to measure this.
Instructions on use of bounce meter.
(i) Readings must be taken only from the danger area. A seamless hockey ball which weighs the same as a cricket ball (156g) is used, thus eliminating the variation in bounce height depending on whether the cricket ball lands on the seam or otherwise.
(ii) Always start at the same position, and record which end this is e.g. North, Duck Pond, Pavilion etc.
(iii) When taking readings, two people are required, one to hold the staff and the other to observe and record the height of bounce.
(iv) The staff-bearer must keep the pole perfectly vertical. If not, the ball will often hit the staff-bearers hands or the pole on its way down, or it will bounce too far from the pole for an accurate reading to be taken. If any of these things happen, the reading needs to be repeated.
(v) The observer should crouch at a convenient distance from the staff where he is not too close, nor too far to read the scale (usually about 1.5 to 2 metres). Readings (to the nearest cm) must be taken consistently. We suggest that these readings should be taken from the top of the ball (to standardise over all grounds).
(vi) For each test, take at least 20 readings, 10 along each side and finishing where one started. Please note where in the data set the change in direction took place. A convenient procedure is for the staff-bearer to take a step sideways along the length of the pitch after each bounce, with the observer crouching on the opposite edge of the pitch and viewing across it. An alternative method is for the staff-bearer to walk up the centre of the pitch, dropping the ball from first his left and then his right down the length of the pitch.
(vii) Blank recording sheets and an example of processed results are included at the back of this text. If bounce height readings are faxed to John Klug at 0331-2605708, they will be processed and returned in the format shown.
Some useful information has been gathered using a "Clegg hammer", and it has proved to be an effective way of measuring the actual hardness of a pitch. Unfortunately this is an expensive piece of equipment and is therefore not readily available to clubs and schools.
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