Fig. 3. Effect of extraction ratio on inorganic water-extractable phosphorus measured colorimetrically without digestion (WEP_I) and total water-extractable phosphorus measured colorimetrically with digestion (WEP_T) in two poultry manures from (a and b) Pennsylvania or (c and d) Texas, both with sawdust–woodchip bedding and as analyzed fresh, air-dried, or oven-dried. Data are averages of single and sequential batch extractions.