Tomato root growth and phosphorus uptake as affected by phosphorus placement

Abstract

Phosphorus placement is an important factor to be considered in crop fertilization. Few studies have investigated the effects of varying the P-fertilized soil volume on tomato (Lycopersicon esculentum) growth, P uptake and root morphology. To investigate these effects three experiments were undertaken, in pots. In the first, six P levels were applied throughout the soil. In the second, 60 mg/kg of P of soil was applied in a central column in 12.5%; 25%; 50% and 100% of the volume of the pot. ln the third, a constant amount of P, 60 mg/kg of P soil, was applied in decreasing volumes of soil. The highest dry matter production and P uptake were obtained when all the soil was fertilized although P uptake efficiency was higher when only portion of the soil was fertilized. In that situation, the highest dry matter production and P uptake were obtained when 25% of the soil was fertilized. Root dry weight and root length were stimulated in P-fertilized soil. Also in the P-fertilized soil the roots were thinner and the root surface larger.