Lethbridge Herald, The (Newspaper) - August 6, 1974, Lethbridge, Alberta
Tuesday, August 6, 1974 THE LiTHBRIDQE HERALD 13 Research Station report Good soil tilth By DR. L. E. LUTWICK Soil Scientist In cultivated soils, good soil structure or tilth is made it doesn't just happen. Forming good tilth in- volves not only cultivating the soil but also adding organic matter. Once the organic matter has been added to the soil, it must be decomposed and the products of decomposition combined with the soil mineral particles. By this process, the structure of the soil is improved. The main sources of organic matter are plant residues and animal manures. Within the soil, bacteria and other small organisms break up the organic materials Among the substances released from the organic matter and formed by the bacteria are complex sugars called polysacchandes. When the polysacchandes are dis- solved in water, they can link several clay particles together to form clusters or aggregates. Water is re- quired both while the polysaccharides are produced and while they are combining with the clay particles. Network In wet soils, the polysacchande-clay com- plexes form very large open networks, with water in the spaces. As they dry, the complexes contract and allow more contact between the clay particles and polysacchande molecules, thus forming more stable aggregates. The soil aggregates are the basis of good tilth. These soil aggregates are quite stable. However, the polysacchande part is biodegradable and, as a result, good tilth is not everlasting. Consequently, to main- tain a good soil structure, the supply of polysaccharides must be replenished by the con- tinued addition of plant residues or manure. It is ironic that manure, especially from feedlots, does not always appear to be worth the effort of spreading it to the land. Summer Stock SELLOUT SALE Complete sellout of all summer merchandise. Dresses, coats, shorties, slacks, skirts, leather coats. ELLEBRATION CONTINUES... Remember the great values you got back in the Roaring Twenties? Well, we're offering you the same value today, but look at the great cars you get for your money! 800 to choose from Sizes 10-20, to 26 Yz Fortrels, cottons, all washable, good assort- ment of sizes and fabrics. Short sleeves and sleeveless. Reg. to Now as Low as W to Now as Low as Some to clear at SPECIAL X FACTORY PURCHASED VEGAS CHEVROLETS NOVAS CHEVELLES CHEV TRUCKS 1 USED 1967 GMC TANDEM New Motor PLUS a good selection of USED CARS PRICED TO SELL! Highest Trade-in Allowance CMAC Financing Available ENTIRE STOCK SPRING COATS and Full Length All and Tapestry Fabrics Reg. to NOW AND UP ENTIRE STOCK SHORTIE COATS UP 2 Pee. and 3 Pee. PANT SUITS ALL SUMMER SHADES, SLEEVES and SLEEVELESS Reg. to NOW 20 UP MCDONALD'S CHEVROLET Corner 47 Ave. and 55 St. Phone 223-3556 Taber SLACKS 300 to choose from. All sizes, 10-20 38-42. Reg. to Now and 10 100 SKIRTS A SMALL ASSORTMENT AT SELLOUT PRICES 5 ONLY FULL LENGTH LEATHER COATS CABRETTAS Reg. to Now Sellout Modern Fashions 618-3rd Ave. S. Phone 327-3039 Open All Day Wednesday, Thursday and Friday Till 9 p.m.