Sulfur nutrition requirement for drip irrigated tomato, cabbage, and pepper

The reduction of atmosphere S due to pollution control and the increased use of fertilizer containing little or no S increases the potential need for S fertilization for Florida sandy soils. Polyethylene-mulched and drip irrigated tomato (Lycopersicon esculentum Mill), cabbage (Brassica oleracea L. var. capitata), and pepper ( Capsicum annuum L. var. grossum) were grown to determine their S requirement on an Arredondo fine sand. Sulfur source, rate, and methods of application were evaluated in greenhouse and field studies.;In greenhouse studies, using a high P and low organic matter Arredondo fine sand soil, tomato growth was not supported for 6 weeks without added S. The S deficiency symptom of chlorosis of the young leaves was pronounced when tomato leaf S concentration was less than 0.18% dry weight. The subsoil of 40 to 60 cm depth could not provide adequate available S to support maximum tomato growth.;In three of five field studies, tomato responded to S application. In two studies, marketable yield increased linearly from 39.6 tons·ha −1 with 0 S to 55.6 tons·ha−1 with 68 kg S·ha−1. In a third study, marketable yields increased linearly from 51.3 tons·ha−1 to 78.7 tons·ha−1 with an increased in S from 0 to 102 kg S·ha−1. Total marketable yields were similar with preplant (100% broadcast), drip (100% injected), and split (40% preplant + 60% drip) applied S. Total marketable yields were similar with S sources of ammonium sulfate and ammonium thiosulfate.;In each of four field studies, cabbage yields were influenced by S application. Maximum cabbage yield was obtained with application of S to 34 kg S·ha −1. An interaction between methods of application and S rate was significant on total yield. With 40% S applied preplant and 60% S drip applied, the maximum cabbage yield was higher than with 100% S applied preplant. In three filed studies, total marketable yield of pepper was not influenced by S rate and methods of application probably because the total yields were lower than average commercial yield of the pepper grown with polyethylene mulch.;Maximum yields of tomato and cabbage grown on an Arredondo fine sand with polyethylene mulch and drip irrigation were increased with S application to 34 kg S·ha−1. However, total marketable yield of pepper was not influenced by S application.