-THERURAL WORLD

Otago Daily Times, Issue 24828, 30 January 1942, Page 2

-THERURAL WORLD

By Rustlcus

VALUE OF LEGUMES

MAINTAINING SOIL FERTILITY

Leguminous crops of agricultural importance are the lucerne, lupins, clovers, beans and peas. For several reasons they are of the highest importance and possess characteristics which distinguish them from all other crops (says a Canadian exchange). Their value as hay, pasture feed and feed crops is well recognised. But not so well known is their value in maintaining soil fertility. These plants possess the unique power of making use of the free nitrogen in the air and thus adding to the soil supplies of this plant food. By the practice of including some leguminous crop as part of a rotation, it is easily possible to reduce appreciably the amount of costly plant-food nitrogen that one needs to purchase. However, it is essential that the soil be provided with the proper nodule-forming organisms of nitrogen-fixing legume bacteria. These bacteria exist in several strains; lucerne and sweet clover require one strain, red clover and white clover another. They are common in soils where legume crops have been grown successfully. On soils where a particular legume crop has not been grown, it is usually advisable to inoculate the seed with the specific bacteria. The soil conditions that favour the activity of nitrogen-fixing bacteria are abundance of calcium carbonate, soluble carbohydrates, air and moisture. In soils poorly drained, strongly acid and low in organic matter, the bacteria tend to be weakened and killed. It is also a striking fact that the bacteria store nitorgen in the nodules to the best advantage when they are provided with a minimum supply of available nitrogen-contain-ing compounds. In a soil that contains an abundance of nitrogen compounds, or in one in which nitrates have been generously applied, the formation of root nodules is prevented in part or entirely. The bacteria in these circumstances usa the available nitrogen compounds in preference to using free nitrogen. As a matter of practical application, a commercial fertiliser applied to a legume crop should contain potash and phosphate but no nitrate, in order that the nitrogen-gathering powers of the legume bacteria be put to full use.

The nitrogenous compounds which the legume bacteria produce from the use of the atmospheric nitrogen may be used in several ways. First, the legume using them in promoting growth; second, it has been shown that a portion diffuses into the soil and may be immediately utilised by a companion plant species such as grass; third, when the legume crop dies or is ploughed into the soirthe nodules decompose, their nitrogen being thus available for the following crop.

WORLD CHAMPIONS FOUR GENERATION GROUP For many years a New Zealand Friesian four direct female generation group has held the world's butterfat production record for three times daily milking. New Zealand group: Rosevale Queen Daphne, 805.541 b fat; Rosevale Queen Sylvia Triumph, 1055.251 b fat; Rosevale Queen Daphne Triumph, 856.721 b fat; Rosevale Queen Daphne Sylvia, 878.431 b fat; average. 898.981 b fat. The " Holstein-Friesian World" reports that a Canadian four generation group has now beaten the above record. . . „ , ~ Canadian group: Oakhurst Colantha Abbekerk, 10611 b; Montvic Colantha Abbekerk, 6691 b fat; Montvic R.A. Colantha Abbekerk, 12631 b fat; Montvic Chieftain Abbekerk, 7581 b fat; average, 937.81 b fat.