DRAINAGE OF SOIL

Taranaki Daily News, 8 June 1932, Page 16

DRAINAGE OF SOIL

AN IMPORTANT WORK. ESSENTIAL TO GOOD FARMING. > . —’ —7 . Farmers' in New Zealand have an advanced knowledge ,of most 'phases of agriculture and generally put it into practise .to the full limits •of their financial ability. As far. as pasture management is concerned they have fewpeers in the world and as stock breeders they stand in a high class. One thing, however, they could take up much more, energetically,, one thing to which, they must pay serious attention if they are to get the best out of the land—and that is soil drainage. ■ One iof the characteristics of farming in. New Zealand is that returns are secured so comparatively easily, in contrast with the efforts v/hich farmers in other lands have to make, that many details which -would ensure increased production, on a profitable scale are inclined to be neglected. Soil drainage is one of these. Mud-drain,ed land, even under such mild climatic -conditions as those existing in New Zealand .can. never give results on a maximum scale.. It is wetter in winter than it ’should be, and it becomes cold earliei-' ih the’ autumn and remains so later in the spring than it would if adequate drainage were, provided. At all seasons of the year it wastes the benefits of the sup’s warmth and restricts the action of the soil bacteria which make' such am important contribution to fertility. The consequence is that vegetation, and therefore the . stock grazing it, is not healthy. ’

Farmers spend large sums of money annually on the purchase of fertilisers for top-dressing the land, and in recent times have been giving more attention to the use of nitrogenous manures to secure earlier grass in the spring and later grass in the autumn. Encouraging as the results of this policy might have been, there is not the slightest doubt that they would have been even more satisfactory had it been combined with a scheme of drainage. When soil is waterlogged, ’or when it is saturated for months on end as it frequently is in our winters, the warmth of the sun, which should normally play its part in the promotion of bacterial action, is wasted in the process of evaporating excessive moisture,, while that very process itself has an effect in rendering the soil colder still. .Then, too, in wet soils injurious bacteria and fungoid parasites thrive, seriously affecting the health of plants, while the process of nitrification, by which' valuable plant foods are liberated, is delayed and perhaps stopped altogether. Stock is subject to great discomfort and is more susceptible to disease when compelled to graze and lie on damp, soggy ground, and moreover, the physical condition of the soil suffers greatly as a result of poaching. New Zealand’s comparatively wet climate is one’of its chief advantages from the. viewpoint of production. It can be safely said that it would become an even greater advantage if the practice of drainage were a more common one. For it is certain in various localities and on particular soils the most energetic efforts of the farmer in the way of top-dressing are largely nullified because of inadequate drainage provision. Soils of- a light, deep, porous nature, having a fine subsoil, do not, of course, call for artificial drainage, except in places which are low-lying in. comparison with the rest' of the land; or where water accumulates near the surface of the soil, but on : any farm .with. a. retentive subsoil and in every place where conditions allow water to'stand for any length of time drainage is absolutely essential to the profitable working- of the land. The farmer .has the. choice of various systems of artificial drainage. The cheapest method is probably that effected -by the ’ mole' plough, and if the subsoil is sufficiently retentive the method will give efficient and reasonably prolonged service. Tile drainage is the most permanent form, and has been practised in most civilised countries for, a great number of years. It is, perhaps, ' the most suitable for the large areas of • clay-loam soils which are such a feature of the Auckland provinnee. In the case of low-lying swamp lands where the outfall is insufficient, it is possible that pumping may have to be 'resorted to, a practice which is quite common in other countries and one which is brought more within the field of practicability in New Zealand by the introduction of hydro-electric power. The urgency of the question of soil drainage can be judged only by the need for greater and. more efficient production. The farmer must remember that no land used for production purposes can give its maximum profit unless provision exists for preventing water from stagnating on it or in it. Field drainage, therefore, should be regarded as being nothing but a. sound and profit-