mid term
Low matric potential of a soil sample represents low water content inside the sample,and it also represents strong adsorption and capillarity between soil particles and water. Is that right?
In the lecture notes it says massive clay and single grain of sand are structureless. Does this mean they will not form aggregates? In other words, massive clay only has micropores and sandy soil only has macropores. If this is correct, can I say that massive clay will have a higher field capacity than sandy soil because micropores hold water more strongly than macropores? You have mentioned that clay soil has a higher porosity than sandy soil, but I don't understand why this is the case.
Yes, that is correct - massive clay and single grain sand are both examples of structureless soils. And yes, massive clay only has micropores, and sand has only macropores.
Yes, macropores hold water more strongly than large (macro) pores. Consequently field capacity for clay would be higher than for sand.
Porosity (f) is defined as ratio of volume of all pores (Vf) relative to the total volume of soil (Vt). Hence, in a massive clay there will be a larger proportion of pore spaces (relative to total volume) than in the sandy soil.
For more explanation on this topic pls refer to your textbook