Cranberry industry., Cranberry Station (University of Massachusetts at Amherst), Nutrient management, Best Management Practices
Research in WI has shown that cranberries require additions of phosphorus fertilizer for sustained productivity. However, trying to determine the right amount of phosphorus to add and when to add it is very difficult - one of the few aspects of crop management where cranberries have something in common with other crops. What makes the situation extra hard in cranberries is that programs of soil and tissue testing often give conflicting information - it is not uncommon to see soil test values of phosphorus in or above the normal range (20-80 ppm Bray P) and tissue phosphorus contents either at the low end of the normal range (0.10%) or below this value.
Phosphorus availability in the soil is related to many things. In an established cranberry planting the moisture status of the soil (from the saturated conditions after winter flood water is drawn to the drier conditions of the summer) plays a role in phosphorus availability. Type of soil, whether a mineral, sandy soil, a classic sanded peat, or a straight peat planting also plays a role. Finally, the amount of iron in the soil is also important in how available phosphorus is in cranberry plantings.