Aspects of the phosphorus nutrition of white clover populations I. Inorganic phosphorus content of leaf tissue

Abstract

The effect of pretreatment with sufficient and deficient levels of phosphorus (P), applied for 16 days, on the subsequent P response of four populations of white clover (Trifolium repens L.) was studied in solution culture in a glasshouse. Inorganic‐P and total‐P levels of leaf tissue were measured at three harvest dates. Increasing the subsequent supply of P increased both inorganic‐p and total‐P levels of leaf tissue, especially if plants had previously been P‐stressed. The p content of leaves, and especially the ‘organic‐P’ content decreased with leaf age. Several white clover populations, collected from soils high in p and low in P, were grown at sufficient and deficient levels of p. populations collected from low‐P soils accumulated more inorganic‐P in their leaf tissue, especially when grown at high‐P, and were also able to reduce these inorganic‐p levels to lower concentrations when the P supply was deficient. This may be an important adaptive feature of white clover plants able to survive in low‐P soils.