AGRICULTURAL NEWS.

Waipawa Mail, Volume XIV, Issue 2712, 23 January 1892, Page 3 (Supplement)

AGRICULTURAL NEWS.

THE SURFACE STIRRING OF THE SOIL —WHAT IS THE USE OF IT ?

It lets in the air, it keeps out tbe drought, and mediates between the two extremes of heat and cold. Baked, soaked, sour soils are virtually air-proof. The air hugs their tops in vain, and they present an impenetrable nou-porousnese to its advance into their texture or substauce. Earth without air is like a body without, breath ; it is, in fact, dead, inert, lifeless, useless to meet the wants and supply foe needs of living roots. The air with its oxygen is as needful to endow the earth with life-giving, life-eustaining powers as the fire beneath the boiler is to endow the steam-engine with motive power. The machinery, water, coal, are all there, but they are useless without foe expansive energy, and consequent motive power of fire. Bo it is with soils everywhere. They are full of manure—that is, plant food —but these can only be decomposed, consumed, aud transformed through the energy of oxygen. Let them into tbe soil of farm or garden through digging, ploughing, harrowing, surface scarificatioii, and the dead soil becomes alive, the hoarded-up foods and manures are let. loose for the use of tbe food and the growth of plants. The more oxygen, the more alive, and hence foe more available foe resources of soils for the wants of plants. Hence if at first the surface stirrer or scarifier does not succeed, he must stir, stir, scarify, or hoe yet again. Next to the importance of lettiug and keeping the air into the soil is that Of keeping tbe drought out. Busybody oxygen, almost omnipotent as it is, can do but little good in a drought-parched soil. Water, a« a solvent, is the handmaid of oxygen in most of its marvellous combinations aud transformations, affected through oxygen in its progress in changing crude earths and subtle fluids into foods; hence in tilths properly drained, the less moisture lost from their surface the better. And this for many reasons, probably chiefly this, that every drop of water raised thus through evaporation needs many molecules of heat to lift it, hence foe greater the evaporation the colder the tilth. Loose earth on the surface checks, almost stops, evaporation, consequently surface-stirring keeps the earth warm ae well » moist. Consequently it mediates in a double sense between the extremes of heat and cold; the loose, porous surface presents a double barrier against the depression of temperature through the energy of radiation, and also presents an all but impenetrable barrier to foe direct absorption of solar heat. A loose surface i® almost as potent a barrier to the direct conduction of heat from the sun as a layer of wool ot of long grass. And yet a hoe or a harrow nut over the surface is all that is needful to create this powerful and natural mediator between heat and cold, and great natural means of enforcing a mean or medium temperature.