FIELD DRAINING.

Hauraki Plains Gazette, Volume XXXVIII, Issue 5169, 24 August 1927, Page 3

FIELD DRAINING.

| METHODS USED ON PLAINS.

SUCCESS OF DITCHES. The present winter, probably more than any .other period, has: proved to farmers of the Hauraki Plains that it is more important to have a system " of field drains than it is to have many arterial drains. So far this winter

the main drains on the Hauraki Plains have not been full for more than very fcjjiort periods ; yet most of the farms to-day are wetter than they have been for many years past. Everywhere may be seen pools of stagnant water right alongside drain-banks, for never before has there been so little natural drainage of the soil. It has- therefore become apparent to most farmers that arterial drains are insufficient to keep their farms dry, and that an efficient system of field drains fs necessary for such winters as is now being experienced. The weather conditions have beeh exceptional, for it is ma.ny years since there was such a small amount of rain, such a large number of wet day*, and such a prolonged lack of sunshine and drying wind. Normally, evaporation removes more water than drains. During a heavy downpour most of the water passes quickly to the- outlet drains, but in light rain it soaks; into the soil almost as quickly as it falls. A great part of the rain which has fallen on the Plains this winter is still lying in or on the land waiting to be evaporated. Except where there is a good sole of grass, the surface is soft mud varying in depth according to the level of the hard layer of impermeable clay. It is the peculiar nature of the surface of this clay that constitutes the problem of draining most of the farms on the Plains. In some isolated places; qbout Kaihere and Patetonga, where the hill streams have brought down sand and incorporated it with the clay, there is good : natural drainage, and on the few sand ridges on the Plains there is no need for surface Farmers have found wihen digging fence-post holes that a little below the surface of the clay the ground was dry and cracked, and tha.t if water was run into the hole it quickly soaked away-. It is apparent, then, that the nature of the clay should be taken into consideration when deciding the type of field drain to adopt. Experience has shown that it is almost as impossible to generalise in regard to field draining for Hauraki Plains land as it is to generalise in regard to manuring or cropping. Conditions vary so much, and in such very short distances, that the method found satisfactory by one man may prove useless on the next farm. In regard to underground drains, it is safe to summarise l from numerous inquiries and observations and state that in most cases they 'have proved more of a failure than a success, though the efficiency of those that are successful and the urgent, need for some sort of field drainage have led to their general adoption. The mole drain, made with a special type of plough, has some strong advogAes-, but it appears that this system has not yet been sufficiently tried out to fully demonstrate its worth. In many-cases it also has proved a failure. An interesting theory ha.s been advanced concerning the initial success and subsequent failure of these drains. When newly made, the surface water can get easy access to the channel by the cut made with the blade ■which carries the ball, but in a short time this cut becomes blocked up and the drain can then only draw very slowly through the clay. Mole drains when made in country with an uneven surface vqry in depth correspondingly and silt up in the hollows. The solution, therefore, appears to be in shallow surface) drains. Very good results have beetn obtained by those farmers! who have adopted this method, and at the present time more surface drains are being made- than all types of underground drains. The settlers of the Horahia-Opou district are using a ditcher made by a wellknown firm of agricultural implement makers, and are making ditches, about half a chain apart on all their paddocks. Three furrows are ploughed and the ditcher used to spread the spoil as far out as possible on each side. An extra cut is made when the ditch rises over a mound, and to ensure as many outlets as possible all the ditches a.re connected by cross ditches. To the use of this implement alone some of the settlers of this notoriously wet area ascribe the fact that for the first time they- have beep, able to winter their cattle on their farms. It would appear that if the ditcher were used in the early spring, so that the spoil could be evenly spread over the intervening area to become covered with grass before the following winter a great deal of the rain would quickly flow away. Farmers may demur at making their paddocks resemble a sheet of corrugated iron, but when it means, efficient surface drainage and comparatively dry farms it is worth while. Many farmers are thinking so at present.