Tomato nutrient uptake as affected by limestone type

Abstract

Experiments were conducted at the Horticultural Research Farm at Rock Springs, PA and with a commercial grower at Clarks Summit, PA in 1986-8. 'Count II' tomato transplants (Lycopersicum esculentum Mill) were grown in rows 1.52 m apart with 30 cm inrow spacing. Seven limestone type treatments were applied at 11.3 t/ha with a check. Calcitic (trace of Mg) and dolomitic (12% Mg) types and 5 mixtures with 2, 4, 6, 8 and 10% Mg were combined with banded NPK fertilizers in 4 replications. Of special interest was the Ca/Mg balance. Leaf Ca was increased by the calcitic but not by the dolomitic type. Leaf Mg was increased substantially by dolomitic but tended to be decreased by calcitic. Limestone with 4% Mg was required to increase leaf Mg. Mg deficiency in commercial production has been caused by excessive calcitic application. Meaningful increases were obtained in leaf Ca and Mg, as were decreases in leaf Mn indicating increased soil pH, within 2-3 months after limestone application. Limestone types 1391 1392 SMITH AND DEMCHAK also affected fruit Ca and Mg. Leaf Mn, Zn and B were decreased by all types. Soil Ca and Mg levels were increased more than soil pH. Most changes in soil and plant nutrient levels took place during the first year after liming. Increases in leaf Mn caused by banding NPK fertilizer were counteracted by liming.