Download Practice Exam 1 - Soil Fertility Management - Fall 2007 | SOCR 350 and more Exams Soil Mechanics and Foundations in PDF only on Docsity! SOCR 350 - Soil Fertility Management Exam #1 October 5, 2007 Name _________________________ SHOW ALL CALCULATIONS FOR PROBLEMS. GIVEN: Molecular weights: Ca=40, Mg=24, H=1, K=39, Na=23, S=32, C=12, O=16 Lime Material Effectiveness (%) % LR = ECiw x 100 Particle size ______________ 5ECoe - ECiw <60 mesh 100 1-acre foot soil weighs 4,000,000 lb. 8-60 50 mmhos/cm x 640 = ppm salt >8 0 ppm x 2.7 = lb/A ft H2O Leaching Salt Removed ppm x 4 = lb/A ft Soil 6 inches water 50% 0.086g CaSO4 • 2H2O / 1 meg Na 12 inches water 80% 0.186 g S˚ / 1 g CaSO4 • 2H2O 24 inches water 90% CCE = eq. wt. CaCO3 SAR = Na meq/l eq.wt.substance Ca + Mg NI = CCE x EFF. 2 ppm = meq/l eq.wt. 1. (5) Colorado State University is a “Land Grant” University. What is the significance of CSU being a Land Grant University in relationship to research, teaching and extension? 2. (7) Is it important that the potential acidity be neutralized during liming? True False (Circle correct answer) Explain the reason for your answer. 3. (10) Below is a list of clay minerals found in soils. Rank them from the least weathered (1) to the most harshly weathered (5) minerals, rank in order of highest (1) to lowest CEC. Which are 2:1 or 1:1. (Write answer in blank) Weathered CEC 2:1 or 1:1 Smectites _____ _____ _____ Kaolonite _____ _____ _____ Micas _____ _____ _____ Vermiculite _____ _____ _____ Gibisite _____ _____ _____ 4. (8) What does the Lyotrophic series tell us? List the elements of the series in the proper order. 5. (7) All irrigation water contain salts. How do you keep the salt content of a soil at a desired level during irrigation. Hatch Act (1888): Deficient range (Plant nutrient): Electrical conductivity: Sodium adsorption ratio: Sodic soil: 11. (23) It is early July 2007 and you have just harvested barley that is relatively salt tolerant. Next spring, you want to turn the field into a sod farm. The grass you are going to plant has an E.C. tolerance of 2.0 mmhos/cm and a Na tolerance of 4% ESP before growth will be adversely affected. You are going to use recycled water as an irrigation source with an EC of 1.1 mmhos/cm. You have a good market and want to product healthy grass. You have access to both gypsum and elemental sulfur. The soil test is as follows: ESP = 9% CEC = 21 mq/100q EC = 6 mmhos/cm pH = 7.5 CaCO3 = 3% Gypsum = 0% NO3-N = 8ppm Organic matter = 1.4% K = 230ppm P = 18ppm Gypsum = $75/T S o = $310/T Grass ET = 24” Water table – None a. Explain in detail that steps you would use to reclaim this soil so you can grow a healthy and marketable crop of sod in 2008 in the most economical manner. b. How would you manage your irrigation water to insure the long-term productivity of this field?
