put a handful of the soil in a jar about 3/4 full,fill with water,shake for a minute to disolve it all,put jar down and time 1 min,after min look at jar,there will be a definite sand line on bottom,take a permanet marker and make a line on jar were the sand and silt seperate,wait 1 hour and do the same for silt,make your line,wait 24 hrs and clay will be on top make your mark,then go to texture chart and figure out what type soil it is,looks like a gardensoil ,if so more than likely a sandy loam,but check the texture chart,then you will know what it will take to slow some of the runoff,check this vid out easy to do,he does it about the same as me,but a lot better explaining it
