A Single Application of Phosphorus at Planting Improves Long-term Asparagus Root Growth and Yield

Abstract

ABSTRACTMature Asparagus (Asparagus officinalis L) plantings are only marginally responsive to added phosphorus (P). There is little information addressing P needs of new asparagus plantings. In 1999, a trial was established in a P-deficient soil to assess effects of increasing P levels at planting on asparagus growth and productivity. Prior to planting, 0 to 450 kg·ha−1 of P was blended in the planting furrow. Fleshy root growth and carbohydrate content were measured periodically and fern growth was evaluated during the summer and autumn of each year. Spears were harvested beginning in 2001. Increasing soil P levels had a variable effect on asparagus spear yield during limited harvests of 2001 and 2002. By full harvest in 2003–2005, spear yield increased linearly with increasing P. Yield increase was associated with a linear increase in root biomass but not root carbohydrate content. A single early application of P can improve asparagus productivity.