课程名称︰土壤学
课程性质︰选修
课程教师︰李达源
开课学院：生农
开课系所︰农化系
考试日期（年月日）︰103/11/14
考试时限（分钟）：10:20~12:10 (共110分钟)
试题 :
1.Please describe the function of soil in the ecosystem.(5%)
2.What are major minerals in sand and silt fractions of soils?What are major minerals in clay fraction of soils?(5%)
3.Please give one example of 1:1, 2:1, 2:1:1 layer silicates respectively and explain the difference in structure and properties among those layer silicates.(10%)
4.Please illustrate the important function of soil microorganisms and the beneficial effects of Rhizobia and mycorrhizae on supplying nutrients to plant.(10%)
5.What are the important function od soil organic matter?What are important functional groups of soil humus?How do those functional groups effect the properties of soil humus?(10%)
6.How do you describe soil color?If the color of a soil is red, what soil characteristics do you expect?If the color of a soil is black, what soil characteristics do you expect?(5%)
7.What is soil structure?Why is aggregated soil structure suitable for crop growth?Why is soil crusting not suitable for crop growth?How do you promote the formation of aggregated soil structure?(10%)
8.Please calculate the porosity of a soil which has bulk density of 1.5 g/cm3 and particle density of 2.65 g/cm3.Also explain the difference between porosity and pore size distribution of soils.(10%)
9.Please explain the difference between "soil water content" and "soil water potential".In addition, give one apparatus (or method) for measuring "soil water content" and "soil water potential" respectively.(10%)
10.Please draw the typical soil moisture characteristic curves for a sandy and a clay soil respectively and indicate the "field capacity" and "wilting point" on the curve and illustrate the importance of these two point on soil water management.(10%)
11.Please define the following terms:(15%)
(a)soil texture
(b)isomorphous substitution
(c)cation exchange capacity
(d)soil saturated hydraulic conductivity
(e)infiltration