code: private static String calcMoisture33KpaFst(String slsnd, String slcly, String omPct) {
  
          String ret = sum(product("-0.251", slsnd), product("0.195", slcly), product("1.1", omPct),
                  product("0.006", slsnd, omPct), product("-0.027", slcly, omPct), product("0.00452", slsnd, slcly), "29.9");
          LOG.debug("Calculate result for 33 kPa moisture, first solution, %v is {}", ret);
          return ret;
      }
docs: Equation 2 for calculating 33 kPa moisture, first solution, %v
  
  @param slsnd Sand weight percentage by layer ([0,100]%)
  @param slcly Clay weight percentage by layer ([0,100]%)
  @param omPct Organic matter weight percentage by layer ([0,100]%), (=
  SLOC * 1.72)