Document dQdG93DYb5K9GqL1JeYZBKeXe

IWft-AvnAUttT^. NOTES ON THE NEWS continued potatoes in one operation. Work it also in progress on a double-row harvester. That tractor wheels are indeed harmful to soil has emerged from a unique field study at the institute. Using a gamma-ray probe and detcetor, researchers there have been aide to observe for the first time tlie actual local profiles of toil density across tractor ruts, plough furrows and the like. They have related these to the fsilure of plants tueh as raspberry canes to grow where the toil has become compacted. Clods are alto typically the result of the passage of heavy machinery across the soil for various purposes such as hoeing. At (hr National Institute of Agricultural Engineering, Howden, Midlothian, tome interesting new attitudes are developing, however, (''or one thing herbicide* neve eliminated the need for close manual prorcrturcs which means that it it no longer necessary to grow all crops in tingle rows. There would be distinct advantages in growing potatoes, for instance, in beds as wide as three or four rows. It would be more economical of land, earthing-up could be done quicker, and the soil would suffer less from the compressions) damage done by agricultural machinery. There is a drawback, however. Tradi tional tractor design does not permit (he use of wide strips; and no one elsewhere seems to have given much thought to ways in which tractors could be improved. At NIAK engineers have had a bard look at wliot farmers are going to need m the future and have designed an impretsiva "self-propelled,multi-purpose toolframe,\ so (hat cutting down the extent to which tractors and Sealed vehicles run over die soil will undoubtedly improve production. This is by no means the only application of modem methqdt of science to farm mechanisation a! NIAE. Novel work under way aim* at automated singling of sugar, beets. Again it is herbicides like paraquat that have made euch advances possible. Manual thinning by hoe is tedious and expensive. The plen is to use a machine equipped with photoelectric detectors sensitive to the speotra) absorption line* of the grean chlorophyll pigment in leaves. Signals from this device, indicating the . density of foliage, will control a paraquat spray which will squirt the excess plants, leaving only those required at specified interval* for optimum growth. Engineering data during field trials on new equipment is about to lie collected by radio telemetry, and modern dataprocessing methods are under develop ment at NIAE. which could well come to dominate our rural landscape* in a few years' time. Essentially it consists ofa large box frame, REPORT OF A NEW supported at chest-height on conventional tractor wheels--a large pair at the front and small pair at the rear corners. At the front ofthe frame in the centre it a power ful, 70-horsepower tractor engine coupled to the driving wheels by independent oildriven hydrodynamic motors. The driver aits high up tin the rear member of the box frame in a eeat that can be hydraulically shifted from aide to aide, or turned right round to faee the reverse direction. He has two levers at Id* left hand: both forward gives a range of CHEMICAL HAZARD A Swedish research worker has expressed concern over the increased amounts of polychlorinated biphenyl (PCB) entering the air, presumably from industrial smoke and rubbish-dump smoke, and being absorbed by water and taken up by fish and later humans. PCB which is related to and as poisonous s* DOT was detected by Mr Soren Jensen of the institute for Analytical Chemistry, University or Stockholm, in some 200 pike taken from forward speeds; both backward, reverse different parts of Sweden, fish ind fish- speeds. By moving them independently spawn throughout the country, an eagle ilio wheels will revolve at dHTerant rates and assist turning. The rear wheels are telescopically mounted and can be raised whieh was found dead in the Stockholm Archipelago, and in his own, his wife's and his baby daughter'! hair. As the baby or lowered hydraulically. They are aelf- is only five months old her father con levelling over uneven ground. Agricultural cludes that the cot her dose of PCB with implements are mounted--without the her mother's milk. need for soil-damaging wheels--in the It is not known at present how much centre of the box frame. Implements, of this substance is dangerous or even likewise, can be designed for hydraulic fata). Ifit is comparable with DDT thrn the operation and the frame is equipped with limit would be 0.5 mg per cubic metre of two large oil tanks at each front eomer air--and, for comparison, the dead eagle and several hydraulic take-off valves. had at least 10 times as high a concentra The whole contrivance is simplicity itself tion in its body. For purposes of elimina to control. tion Mr Jensen has obtained feathers from A planting unit hat now been construc eagles preserved at the Swedish Nations) ted Inal will plant and ridge four rows of Museum of Natural History sinee I860 Mew Surwr.tr. '*><?< /f. j and lias detected PCIt first in sit eaglr litmi 1944. In Sweden, PCH is known t< hr us. il in electrical insulations, hydraulic oil*, high-tempcraiure and liigh-prc-Mmlubricating oils, paints, lacquer.. nxt varnishes, and as pigment* mi various plastics. It docs not seem to he used as nn insecticide. It is not destroyed by incinera tion and msv enter the hndy di.rcih through the skin, by breathing, or byway of food (especially fish). It is partirulnrlv harmful to the liver, and alto the skin: this has been demonstrated hy rtprri- ments on mice. PCB is much harder in break down than DDT and there is ever, reason to suppose that ii is much mure I Jdifficult to gel ii out of ihr system. Tl Jsubstance has also been detected in the air over London and Hamburg and also M seals caught ofT Scotland. Ii can therefore be presumed to ba widespread ihruug/ui.M the world. V LOAVES AND FISHES The famine which now threaten* part* of India has tended to focus the attention id the developed countries on th-ii sub continent'* chronic inability to feed iflecming people, but warning note com, last week from another less puhlicir.nl area. Dr B. R. Ben tin-. Indian Dimtnr General of the UN Foot) ami Agricuhw* Organisation was addressing a regional conference at Puma del Este, Uruguay He lambasted the governments of Latin America for their unwillingness to fun what could be "a very tcrious situation indeed". It would take, he MKl,auinercnMin food production of four per rnit a ynn to stem "social and political unrest which still prevails'*, or even to prevent it from worsening. Dr Serna warning conies mint ton sown Malnutrition if not actual hunger is wide spread in Latin America, whereper-rpii,i food production has dropped In four pi t cent in the past six years. At thc-anir tim< the population it exported to double ii-ci (to 422 million) by 1985. Dr Si-n talir*.-. the four-per-eent rise to be tcrluiirnli' feasible, if an all-out effort is made no Apart from (he struggle to inrmw food supplies to keep pare with pnpulm ioni however, effort* are also tain;: made ><| overcome traditional prejudices agnin-i varioue foods which may ta plrntbn' though neglected. In the waters of Lake Vi. torm, < instance,--tlicy cover an ar, about d>. tine of Ireland--there are vi ...... Itilapia, a firm white fish, wc^lim^ il>-'>! 6 ot and very tatty.' European firm-. h.n already asked tta TaiiMuuan piv,n...... about the possibilities of tending fin/' filled to Europe but the local pruplc <' by no meant at keen to eat mis sort fare. HONS 031518