Soil salinity and yield of mango fertigated with potassium sources

Salinidade do solo e produtividade de mangueira fertigada com fontes de potássio

ABSTRACT

Irrigated fruit crops have an important role in the economic and social aspects in the region of the Sub-middle São Francisco River Valley. Thus, the aim of this study was to evaluate soil salinity and the productive aspects of the mango crop, cv. Tommy Atkins, fertigated with doses of potassium chloride (KCl) and potassium sulfate (K₂SO₄) during two crop cycles (from January to March 2014 and from January to March 2015). The experiment was carried out in a strip-split-plot design and five potassium doses (50, 75, 100, 125 and 150% of the recommended dose) as plots and two potassium sources (KCl and K₂SO₄) as subplots, with four replicates. Soil electrical conductivity (EC), exchangeable sodium (Na⁺) and potassium (K⁺) contents and pH were evaluated. In addition, the number of commercial fruits and yield were determined. The fertilization with KCl resulted in higher soil EC compared with K₂SO₄ fertigation. Soil Na⁺ and K⁺ contents increased with increasing doses of fertilizers. K₂SO₄ was more efficient for the production per plant and yield than KCl. Thus, under the conditions of this study, the K₂SO₄ dose of 174.24 g plant^-1 (24.89 kg ha^-1 or 96.8% of recommendation, spacing of 10 x 7 m) was recommended for a yield of 23.1 t ha^-1 of mango fruits, cv. Tommy Atkins.

Key words:
electrical conductivity; plant nutrition; Mangifera indica L.; semi-arid region