Final answer:
Exact calculations of the matric potential cannot be completed without specific pressure measurements. Water direction can be inferred from the sign of the pressure readings, and the SI unit of hpg is indeed N/m², representing pressure.
Step-by-step explanation:
The question requires using the relationship between pressure, depth, and density to calculate the matric potential at different soil depths. However, since the specific pressure measurements from the tensiometers were not provided, an exact calculation cannot be performed. Generally, the matric potential is the potential energy of water in soil compared to pure water, due to the effects of adhesion and cohesion in the soil pores. If the pressure measurements acquired are positive, then water is likely to be moving upwards (capillary action towards the surface), while negative pressure indicates water movement downwards into the soil profile.
The verification that the SI unit of hydraulic head times density times gravity (hpg) is N/m² can be completed by checking the units involved: h (height in meters), p (density in kg/m³), and g (acceleration due to gravity in m/s²). Multiplying these units yields N/m², which is the unit for pressure in the International System of Units.