Land Improvement

New Zealand Journal of Agriculture, Volume 87, Issue 1, 15 July 1953, Page 51

Land Improvement

Seasonal Notes by the Extension Division

TF the standard of living at present enjoyed in New -*■ Zealand is to be maintained, exports and imports must increase at least proportionally in money terms with population; and progressive expansion of exports is dependent on an active programme of land improvement. A recent review of livestock numbers in various North Island districts indicates that scrub-land development and hill-country pasture improvement through discing or oversowing and topdressing have been important factors in expanding livestock numbers in recent years. There is still scope for a vast programme of land improvement, and now is a suitable time to plan next season’s work in this sphere. Finance for marginal land improvement is available through the Marginal Lands Board. The work shows quite satisfactory returns at present and should continue to do so in the immediate future.

GUMLAND

Development of gumland should begin with the preliminary crushing and burning of

scrub and fern. Heavy scrub is best crushed by a tracklaying tractor with scrub bar and heavy roller. A heavy roller fitted with steel flanges is very efficient for this work. A length of railway iron or a heavy swamp harrow with the spikes turned upward serves to flatten light scrub for obtaining a more efficient burn. Where the scrub is light and mixed with fern and rushes a satisfactory burn may be obtained without crushing, and gum holes and boggy areas can be more easily seen and avoided at the first discing. Seepage springs and boggy areas on the lower slopes should be drained with manuka fascine drains, but care must be taken, since the fact that the soil has been leached renders it liable to scouring and erosion if there is much fall. Burning the scrub in late summer aids germination of the manuka and gorse seedlings and allows subsequent discing to kill many of the seedlings.

CULTIVATION

Development of the heavy tracklaying tractor and giant discs has made it

possible to develop gumland satisfactorily with surface working instead of ploughing. Giant discing should follow in autumn when rains have softened the surface of the clay soil and germinated any gorse seeds. Double discing is necessary for complete cultivation of the hollows and hard ridges and to obtain the maximum amount of weathering of the disced soil. Winter fallowing weathers down the clay and ,rots the mat of roots of rushes and scrub and the soil is left loose and friable for the following summer cultivation.

—C. E. BALLINGER ** ■ *

PUMICE LAND

SCRUB clearing on pumice land should follow similar lines to those described for gumland. In large-scale land development the land is

usually ploughed and sown to permanent pasture in late spring or . early autumn, but for the farmer who develops only a small area each year it is usually advisable to sow first to a temporary pasture, composed largely of red clover, follow the temporary pasture with a crop of roots, and then sow to permanent grass after discing the surface of the fed-off root-crop area. The red clover of the temporary pasture enriches the land in nitrogen and vegetable matter and brings about a great improvement in the strike of the permanent pasture.

—C. R. TAYLOR

•X DISCING OF HILL COUNTRY

* * * A RECENT estimate suggests that there are about 3,000,000 acres of surface-sown hill country in the North

Island which might be disced. Even if this estimate is somewhat high, it still opens great possibilities for land improvement and increased carrying capacity for hill-country pastoralists. Experience has shown- that

discing and resowing and topdressing raise 1 ewe country to 2| ewe country, and in addition the better feeding of ewes through the taking of a winter forage crop before grassing has value in increasing wool weights. The first discing of surface-sown hill country in preparation for resowing to grass either direct or after a forage crop is usually done between March and June. This first discing moves only part of the soil, but in so doing allows partial fallowing without risk of erosion. If a forage crop is to be taken, subsequent working down should take place in August or September; and if the field is to be sown straight to grass, seed-bed preparation should be made between October and February.

—L. H. ALSOP

TOPDRESSING HILL COUNTRY

** • * EXPANSION of hill-country topdressing combined with oversowing has been an important factor in increasing

livestock numbers in the North Island. The extent to which hill-country topdressing has advanced during recent years is well illustrated by a selection of several representative counties and comparison of those where the practice is fairly new with those where it has been long established. Figures for the first group comparing topdressing in 1939-40 and 1951-52 are given below:—

Raglan County development is outstanding in that 100,000 more acres were topdressed in 1951-52 than were topdressed in 1939-40. In the established dairy farming districts where topdressing has long been practised there has not been any very great expansion in the area ton dressed, as can be seen from the following figures:

Undoubtedly the field for an expansion of topdressing lies in North Island hill-country pasture lands through the development of aerial topdressing. For this to be accomplished farmers will have to plan and construct landing-strip and fertiliser-storage facilities.

J. V. WHITE

County Percentage of 1939-40 of grassland topdressed 1951-52 Raglan . . 45 66 : Waitomo . . .. . . 26 52 Castlepoint .. 0.5 6

Percentage of grassland topdressed County Percentage 1939-40 of grassland topdressed 1951-52 Franklin .. .. 75 79 Waipa .. .. : .. 66 73 Waimate West .. . . 82 84