THE CATLINS DISTRICT MOSSBANKS.

New Zealand Journal of Agriculture, Volume XIII, Issue 3, 20 September 1916, Page 198

THE CATLINS DISTRICT MOSSBANKS.

AN EXPERIMENT IN TREATMENT.

R. McGILLIVRAY,

Fields Inspector, Owaka.

In the Gatlins district, South Otago, there are large tracts of country more or less covered with what is known as “ mossbank.” These mossbanks are mounds or heaps of partly decayed vegetable matter lying on the surface of the soil and varying in. depth from 1 ft. to 10 ft. or more. The mounds appear to have been formed much in the same way as peat, and could only occur in a humid climate. The acidity of all mossbanks is very marked, but that in the region of the kamahi forest appears to have a greater degree of acidity than that found in the pine forest. Under all mossbanks is to be found a hard black pan at varying depths, and generally .of undulating formation. This pan is quite impervious to moisture. Blackberry, spurrey, and sorrel thrive on mossbanks, and rhubarb likewise responds to a dressing of this material. Patches of mossbank in a field give it an unsightly. appearance. In some cases a good crop of turnips or oats is to be seen with perhaps half a dozen bare mossbank patches, which detract very much from the appearance of the crop and are an annoyance to a careful farmer.

During last summer some experiments were conducted .on a typical piece .of mossbank near Owaka, on the property of Mr. Keith Ramsay, of Dunedin. The entire area was ploughed on the Bth and 9th September, 1915. Two swing ploughs were used, one turning the furrow, and a second following with mouldboard removed, so as to act as a subsoiler and pan-breaker. The pan was broken to a depth of 26 in., but in places it was - too deeply seated, to be reached. The field dried rapidly after this treatment.

Plots were set out on it and various treatments accorded. On the Ist February, 1916, the following observations' were made

Effect of Lime.—The effect of ground burnt lime was more or less marked on all plots on which it was applied, and the crop of oats and vetches was fairly proportionate in yield to the amount of lime applied. Thus, on the control (untreated) plot the crop was a total failure, the growth being only sorrel. The growth on the 1 ton lime, i| tons lime, and 2 tons lime (per acre) plots were respectively poor, light, and good. The effect of the heaviest dressing of lime was most marked on the ~ vetches ; a good growth of white and alsike clover also appeared in places on the heavily limed plots.

' Effect of Heavy Rolling. No apparent difference that could be attributed specially to extra-heavy rolling was produced on any of the plots.

Effect of Fertilizers.— Where wood -ashes (potash) were applied to plots which were also limed the result was very satisfactory, an excellent stand of oats and vetches being secured. Basic superphosphate, applied alone at the rate of 3 cwt. per acre, failed to produce any effect that could be recorded as significant.

These results ■ are suggestive, and in so far as they relate to the beneficial effects of burnt lime and potash are concordant with the results that have been noted elsewhere.