TOP-DRESSING TRIAL

Hauraki Plains Gazette, Volume XXXVII, Issue 5032, 27 September 1926, Page 1

TOP-DRESSING TRIAL

EXPERIMENT ON PRIMROSE HILL.

HIGH SCHOOL INITIATIVE.

During lari summer and autumn green lines could be seen on Primrose Hill, Paeroa, and ther excited a little comment. The explanation of these green lines, is that a top-dressing trial had been carried out in conjunction with the agricultural class at the District High School, by permission of the Paeroa Borough Council, to And out what difference top-dressing with artificial fertilisers would make in the composition of a worn-out pasture. The soil on Primrose Hill is a poor loam. With the exception of the sheep camp on the top of the hill the pasture had run out .to weeds and the poorer grasses. .Three sites, weie chosen, on which the pasture was approximately the same in composition. In all three the state of the pasture was particularly bad. The sites weie . A, north slope facing .the domain ; B, south-wes.t slope facing the school; C, flat near Mr Rickard’s house.

On each site five parallel areas were marked out, consisting of stiips 50yds long and 3yds wide. The examination of the pasture on each of the sites; showed the covering' to consist mainly of and cudweed, and stunted chewings fescue, paspalum, and rattail. Catsear was fairly common. Suckling clover was present at the rate of about one plant per square yard, and only occasional plants, of white clover, lotus major, and cocksfoot could be found. There was a large amount of bare ground on each strip, and moss was also fairly common. treatment. In each case strips 1,3, and 5 were treated and 2 and 4 left untreated. In May, 1925, the top third and bottom third of each strip, 1,3, and 5 were given a dressing of ground limestone at the rate of lOcwt per acre. In August, 1925, No. 1 strip in each case was broadcasted iwth- superphosphate, NW 3 with Ammonia top-dress-ing, and No. 5 with potash top-dress-ings at the rate of 3cwt per acre for each manure. RESULTS. Within a month from the application of the fertiliser a marked difference was noted in the growth of the manured strips as compared with the rest of the pasture. More remarkable than the increased growth was the difference in colour, the treated plots turning a healthy green in contrast with the brownish colour of .the rest of the hill. The difference in colour was so marked that the manured strips could be plainly picked out from a distance of a mile and a half. As opportunity offered, the sheep grazing on the hill were watched. It is usual for sheep to graze round the 'face of a hill, but on .two occasions at least, sheep were noticed to turn and feed directly up the hill when coming on a manured strip. This would seem to demonstrate either increased growth or palatibilty or both. Further, no grasses were allowed to/ go to seed on the manured stripb. Such tough seedheads as those of fescue, rattail, and paspalum were kept eaten down on the treated areas, although allowed to go to seed oh th'e rest of the hill.

An examination of the contents of the pasture on the strips in August, 1926, showed the greatest improvement to have been made in connection with the. clover content. More than two-thirds of the covering now consists; of suckling clover, while white closer and lotus major are more abundant than formerly. All bare spaces are occupied by clover. Moss has for the most part disappeared The greatest increase in the clover content appears, to have taken place on the strips, treated With pbtash topdressing. No difference could be noticed as between limed and unlimed plots. * CONCLUSIONS. All manured strips benefited by the ’treatment, potash top-dressing apparently giving the best results. In all strips there was an increase in (a) amount of herbage; (b) palatibility; (c) clover content.

Whether the treatment would be economical or not cannot be stated from observation alone. The strips will be examined from time to time to see if the growth of clover will result in permanent increased fertility on the manured area.

The cost of the manures, in August, 1925, was .as follows : superphosphate, £5 12s 6d per ton ; ammonia, top-dress-ing, £6 9s ; potash top-dressing, £5 19s. The mapure for the trials was supplied 'free of charge by Wright, Stephenson and Co., Auckland.