Exam 3 Soil Fertility Management | SOCR 350, Exams of Soil Mechanics and Foundations

Download Exam 3 Soil Fertility Management | SOCR 350 and more Exams Soil Mechanics and Foundations in PDF only on Docsity! Name: _________________________ SC 350 - Soil Fertility Management Exam #3 December 5, 2007 1. (6) Soils in Colorado usually have a high level of plant available K. Why? (Where does the K come from?) 2. (8) The biosolids regulations require application of biosolids at “agronomic rates”. a) What does “agronomic rate” mean? b) What plant nutrient controls the application rate of biosolids (not heavy metals)? 3. (12) We have discussed soil testing procedures for K and micronutrients. Different extractants are used. Considering the various soil pools where K and micronutrients occur, answer the following questions. a) Why do we use NH4 acetate as an extractant for potassium and not the DTPA extractant? b) Why do we use the DTPA extractant for zinc and not NH4 acetate? c) Why do we use hot water as an extractant of boron and not DTPA? 4. (6) The predominant K fertilizer in the market place is KCl, commonly called murate of potash. a) What is the primary (geologic) source of this fertilizer? b) KCl has a high “salt index”. What is a very important precaution that must be taken in using this fertilizer that could have a detrimental effect on plant growth? 5. (7) List the heavy metals and oxyanions that EPA has classified as of environmental concern (there are seven). 10. (12) The Colorado “confinal animal feeding operation” regulations set different application criteria for two types of operations as given below. Briefly describe the soil factors that must be considered when making manure application under each to be within the regulation guidelines in order to assure environmental safety. a) Commercial (typical) farmer. b) Dedicated land application site. 11. (12) You are developing a “nutrient management plan” for a client and have the following information. How many tons of dairy manure would you apply to meet the N requirement of the crop? GIVEN: Total N required to grow crop=225 lb N/A Residual soil NO3-N in rooting zone=50 lb N/A N in irrigation water=10 lb N/A ft. Crop ET=24 inches Soil organic matter=1.5% No legume as previous crop. Dairy manure contains a total of 12 lb N/T Assume 50% of N in manure will be available to the crop. (Show Calculations) 12. (5) Match the following nutrient deficiency symptom with the correct plant nutrient. (Write correct letter in space provided) P _____ N _____ K _____ Fe _____ Zn _____ a. Plants are light green in color and lower leaves yellow, chlorosis from tip to base of leaf along midrib. b. Interveinal chlorosis to leaf tip to base of leaf in monocots (like corn) and chlorosis between veins in dicots, veins remain green. Die back of branches in trees. c. Brown discoloration and scorching along outer margin of lower leaves, weak stalks, slow growth. d. Uniform chlorosis of entire plant, small and spindly plants, retarded growth. e. Pronounced interveinal chlorosis (sometimes band of chlorosis) and bronzing of leaves, shortened internodes and sometimes resetting of terminal leaves, dieback of twigs on trees. f. Purple pigments on lower leaf, reduced tillering, delayed maturity of grain crops, plants are dark green in color. g. None of the above.