Microbial metabolism in the guts of termites and in waterlogged soils are two major sources of excess methane that is contributing to the global greenhouse effect.
Indicate whether the statement is true or false
Question 2Some irrigation systems have stimulated the formation of saline and saline-sodic soils. Which of the following contributes to this process?
A) inadequate drainage systems to remove soluble salts
B) low pH of the irrigation water
C) high Ca and Mg contents in the irrigation water
D) high contents of sulfates and chlorides in the irrigation water
E) the low sodium adsorption ratio in the irrigation water
Question 3Saline-sodic soils are characterized by all but which one of the following?
A) sodium adsorption ratio greater than 13
B) soil pH less than 8.5
C) exchangeable sodium percentage greater than 15
D) EC 4 dS/m or higher
E) CaCO3 layer near the soil surface
Question 4A homeowner in New Mexico attempted to grow azaleas in a well drained soil (pH 7.5 ) but the plants were stunted and the leaves were yellow. What is the most likely cause of this constraint?
A) Na toxicity
B) Mn toxicity
C) Ca toxicity
D) P deficiency
E) Fe deficiency
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