SOIL EXPERIMENTS

Sun (Auckland), Volume II, Issue 602, 2 March 1929, Page 27

SOIL EXPERIMENTS

GUARDING AGAINST EROSION Land in Missouri, continuously in corn, lost by erosion at tbe rate of IS tons of surface soil to tire acre eacli year; that which was in cultivation, but without any crop, lost 41 tons of soil to the acre each year, while that in blue-grass sod lost less than onethird of a ton a year by washing. This would be equivalent to hauling IS wagonloads of surface soil oh each acre of the corn land every year, or 41 loads an acre off of the land which was cultivated but not cropped, and very few farms would be able to supply enough barnyard manure to restore this lost fertility.

Experiments have proved that, while sod is the best protection against washing of the soil, a rotation of corn, wheat and clover came next, as the clover ploughed under for the corn protected the soil. Stated in another way: If the ei'osion continued as indicated by the experiments it would require only 28 years in which to completely wash away the top seven inches of soil on the land which was cultivated but not cropped. It would take 56 years to remove the soil from the land in crop, but it would take 3,547 years to remove that which was in sod.

The land cultivated but not cropped absorbed only 68.74 per cent, gf the rainfall; that in corn absorbed 72.62 per cent., while that in sod absorbed 85.45 per cent, of all rains. A “stand” of clover was found to be practically equal to the blue-grass sod in preventing surface washing. The use of sweet clover as a hay crop for pasture or for seed production is fairly well established, but for reclaiming idle acres its use has only begun. Sweet clover seems to offer to the Americans a ready and inexpensive method of redeeming idle acres into productivity, of making them pay their share of the taxes, and of enlarging the productive area of the farm where such acres exist, and all this in addition to the cropping uses for hay, for seed and for pasture to which it has heretofore been put. As a pasture crop sweet clover has many merits, as it comes into growth earlier in the season than any other crop and is quite resistant to dry weather, growing all through the summer. It is greedily eaten by all classes of live stock once they become accustomed to it, and there seems to be very much less danger from bloating than from either alfalfa or red clover. If a permanent pasture is desired it must be allowed to reseed.

Sweet clover is the one plant of agricultural value that will grow where there Is little or no humus in the soil, but it must have lime. It will grow In pure sand, in clay or on alkali land, but will not grow In an acid soil. It will grow on the hard, dry roadside, in a railroad cut or In the "edge of a marsh, provided there is lime. Crops differ in their requirements. Alsike clover will grow in an j acid soil, but alfalfa, red clover or I sw£et clover will not. WHEAT IN SOUTH AFRICA ! GREATER USE OF FERTILISERS The South African wheat farmers as a whole have paid so little attention to the need for efficient scientific fertilisation that it is doubtful now whether South Africa can raise sufficient wheat to feed its population, says the “Fertiliser Journal.” The yield per acre has fallen steadily year after year. The Department of Agriculture and the chemists of several private organisations are carrying out a series of experiments to drive home to farmers the urgent need for the use of fertilisers. Super, in conjunction with bird guano, as now used on many farms has proved insufficient. Better results are being obtained from a balanced fertiliser containing potash, phosphates and nitrogen. South Africa’s yield .per acre is probably the smallest in the world. Taking th% average yield of wheat in pounds per acre as T,856 for Great Britain and Ireland, figures for South Africa are only 526. Those for Germany are 1,558 and for the United States 755. The fertilisers needed to double South Africa's production per acre, in the way recent experiments have proved possible, are available. Increasing amounts are being imported, while the output of local factories has been quadrupled since 1922. One has had to seek markets in Rhodesia and Nyassaland. Only 70 per cent, of South Africa’s annual consumption of 120,000,000 bushels of wheat is produced locally.

The problem is complicated by the fact that wheat growing is restricted to a few parts of the Cape Province, farmers elsewhere concentrating on crops they regard as more profitable. Agricultural experts, however, are agreed that with proper chemical fertilisation South Africa could satisfy all its cereal needs. The Government is helping by supplying bird guano below market price. TRACTORS IN U.S.A. There are now over 675,000 tractors on U.S. farms, according to the best estimates of members of the American Society of Agricultural Engineers, who has been making estimates based on 1925 census figures, factory production and sales, annual wear-out, trade-ins, etc. One of the national farm papers figures over 625,000 tractors at the beginning of 1927. Estimates of 189,000 manufactured in 1927, with 50,000 exported and 40,000 going into U.S. industry, while another 62,500 went to replace old models worn out and junked, leave 39,000 to add to the 625,000 already at work on the farm a year ago. Probably these figures of replacements are high, as the population of the old models of ten years ago is small compared with the hundreds of thousands added the past five years. Hence, 675,000 is probably conserva-