Lethbridge Herald (Newspaper) - August 6, 1974, Lethbridge, Alberta
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 involves 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 polysaccharides. When the polysaccharides are dissolved in water, they can link several clay particles together to form clusters or aggregates. Water is required both while the polysaccharides are produced and while they are combining with the clay particles. Network In wet soils, the polysaccharide-clay complexes 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 polysaccharide molecules, thus forming more stable aggregates. The soil aggregates are the basis of good tilth. These soil aggregates are quite stable. However, the polysaccharide part is biodegradable' and, as a result, good tilth is not everlasting. Consequently, to maintain a good soil structure, the supply of polysaccharides must be replenished by the continued 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. Tuesday, August 8, 1974 - THE LETHBRIDGE HERALD - 13 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! SPECIAL FACTORY PURCHASE VEGAS CHEVROLETS NOVAS CHEVELLES CHEV TRUCKS PLUS a good selection of USED CARS PRICED TO SELL! Highest Trade-In Allowance CMAC Financing Available MCDONALD'S CHEVROLET Corner 47 Ave. and 55 St. Phone 223-3556 - Taber Summer Stock SELLOUT SALE Complete sellout of all summer merchandise. Dresses, coats, shorties, slacks, skirts, leather coats. DRESSES 800 to choose from Sizes 10-20, ^4V^ to 26V2 Fortrels, cottons, all washable, good assortment of sizes and fabrics. Short sleeves and sleeveless. Rag. to $25.00. Now as Low as ................. I V Rag. to $45.00. $10 Now as Low as ................. I W Some to $i; $Q clBarat .................. U" %f ENTIRE STOCK SPRING COATS 3/4-^8 and Full Length All Weather-Fortrels and Tapestry Fabrics Reg. $35.00 to $90.00 NOW n5J45 AND UP ENTIRE STOCK SHORTIE COATS 3/4-% as above n5 UP 2 Poe. and 3 Pee. PANT SUITS ALL SUMMER SHADES, SLEEVES and SLEEVELESS .....................'20 Reg. to $55.00 NOW ....... UP SLACKS SKIRTS 300 to choose from. All sizes, A SMALL ASSORTMENT 10-20 38-42. Reg. to $20.00. AT SELLOUT Now7"andlO�� PRICES 5 ONLY FULL LENGTH LEATHER COATS CABRETTAS Reg. to $175.00. Now Sellout.................... Modern Fashions 618-3rdAve.S. Phone 327-3039 Open All Day Wednesday, Thursday and Friday Till 9 p.m.