PRIZE ESSAYS.

Hokitika Guardian, 22 October 1924, Page 4

PRIZE ESSAYS.

I UN USE OF LI.ME. I Recently there lias been an essay competition on the uses of lime, conducted by the West Coast Farmers’ Co-operative Company (which is inviting school children on Saturday, Nov. Uth. to make an excursion to Boss on the occasion of the opening of the new bridge over Donnelly’s Creek, to the Company's works, over which the visitors are to he specially shown by the officials and members of the Company). As it is only too true farming in a .scientific sense remains on the West Coast in its infancy, still, it is ' desirable that all educative influences should have full scope, and for that • reason the winning essays in this com- . petition are deserving of both publication and careful perusal. They arc as follows: FIRST PRIZE ESSAY (B.v J. Graham). Limes, as manures, are usually call-

ed natural manures, to distinguish them from all other manures which are classed as either general or special manures. General manures contain all ingredients for the healthy growth of plants (farm-yard ami green crop manures as examples). Special manures (artificial or fertilizers) contain one or more of the ingredients that plants require for food. Lime has heen used as a manure from the earliest times, and it is made by crushing and burning limestone. Lime has the cfleet of breaking down heavy soils and rendering them less sticky, thus allowing water and air to penetrate and fertilise the soil. On light, sandy soils it makes the particles more compact by cementing them, and it assists, them to retain their warmth and moisture. It sets free potash, decomposes vegetable matter, produces ammonia by setting it free. Any soil containing less than one per cent, ot carbonate of lime would benefit by the percentage of carbonate of lime. The object oF liming is to increase the percentage of carbonate of lime in the soil, so that the effect of a dressing depends on the thorough mixture of the min-

ute particles ol the lime through c\ci\ part of the treated soil. Lumps of carbonate are useless until they have liven broken down into fine powder. Slaked lime quickly takes up carbon dioxide gas from the air and is converted hack into carbonate »> lime exactly the same as it was before d was burnt, the change taking place very quickly. Chalk and limestone niv nothin'' iuoiv than carbonate of lime in a pure form. It takes 11 tons of chalk and limestone to produce one ton of burnt lime, and when the lime Ims gone hack again to carbonate of lime'll will weigh 1:1 lons. Lime is one of the four most valuable forms of plant- food in the soil, and it is used in very large quantities hv most. of plants. A moderate crop of turnips will absorb as much as 7 libs of lime per acre, while a crop of clover will use as much as Sfilhs per acre. It is only when the soil is deficient in lime that the application of it benefits the soil. Lime has a tendency to sink deep into the soil, and as it is of greater benefit to plants near the surface. lime is a stimulant and does not ; ;idd to the fertility of the soil. hut. enables the land to yield up the fertility of the soil, so on that account must he used in conjunction with manures. Carbonate of lime used as a top dressing for grass is very beneficial, and is best done in the autumn, winter, or early spring. Tn helping nil the growth of lucerne, lime is indispensable. Beans, parrots and parsnips benefit greatly by the free use of burnt lime. The li.me obtained from the kilns at Ross is considered by experts to lie the best in New Zealand, j SECOND PRIZE ESSAY j (By J. Adamson). ' Lime is a natural manure which has been used since early times. Carbonate of lime contains oyster shells, chalk and limestone. It is a compound of calcium oxide and carbonic acid. In the process of burning the carbonic acid is driven ufl as a gas. and the burnt product consists of calcium oxide (lime) of greater

or less purity in the original stone. II the lime lias been properly burnt, it forms a very hard, stony substance, nearly while, which slakes nr combines with water with great avidity, crumbling to a line, white powder and sending out such a heat that it turns part of the water into steam. In slaking, it combines with the water: slsked blue being a li’.dlalr ol lime. It ian

1 lie used for all Ihe purposes specified ill t hr-sub-clll in-os la-low: (I) To lighti ell and open tip stiff, clay soils. (”) r To ameliorate loose, sandy soils, on I which il has a binding action. Cl) To sweeten sour soils. (I) To supply lime to certain crops which require it 1 in larger proportions than ale usually I present in the soil. ((!) To provide - the necessary base for the growth of > soil organisms, notably the nitrifying [ organisms on whose presence the fertility of the soil depends. Another i way in which tho addition of lime is stated to increase the soil’s fertility, is its power of liberating potash and phosphoric acid from their insoluble ' combination and rendering them avail- , able as plant food. Limed land is drier and Manner and more readily cultii vatod. Land that has been limed is , ready for the plough sooner than ifn- . limed land. The addition of one ton of lime per acre represents one part of lime to nearly ‘JO,Oft;) parts of sand. Lime changes many poisonous com- : pounds M'liieh are present in the soil, 1 and renders them harmless to the plant life. A fertile soil must contain a rich, fresh humus; hut if carbonate of lime and magnesia tire deficient. the humus becomes spur and tho soil unfertile. The fungus known tts potato scab has not a chance of developing mlicii carlionne of lime is in the soil. Chih-root is lessened by the use of lime. When the soil is sour, lime should he used freely. Turnips thrive Moll under tlie influence of lime. Turnips -absorb about 7 libs of lime per acre. White clover absorbs 801 Hs per acre. There is tin old rhyme I that says: “Tho use of lime without manure, will make Iwilli farm ami I farmer poor.”