Spatial correlation between soil and leaf macronutrients in semiarid Brazilian mango (Mangifera indica L.) fields

Abstract

Understanding the relationship between the levels of nutrients in the soil and those found in the plant is of fundamental importance for site-specific fertility management in mango (Mangifera indica L.) crop fields. This study aimed to evaluate the spatial distribution of macronutrient contents both in the soil and in the leaf and their correlations in commercial mango orchards under semiarid region conditions and to delimit the management zones using soil and leaf data. The experiment was carried out in three commercial areas in San Francisco Valley, Brazil, cultivated with irrigated mango. Soil samples were collected in 0-0.2 and 0.2-0.4 m depths as well as leaf samples following sample grids. Ca, Mg, K, P, and N contents from soil and leaf samples were determined. Descriptive and geostatistics analyses were performed. Co-kriging was used for the delimitation of management zones. Positive spatial correlations were obtained between soil Ca2+ and leaf Ca contents (R2 = 0.80-0.93), soil K+ and leaf K contents (R2 = 0.35-0.61), and soil Mg2+ and leaf P contents (R2 = 0.51). Negative correlations were observed for soil Mg2+ and leaf Ca contents(R2 = 0.79-0.93) and soil Mg2+ and leaf K contents (R2 = 0.98). The soil 0-0.2 m depth had the greatest influence on mango Ca and K uptake. The negative correlation between soil Mg2+ and leaf Ca shows the competition existing in the plant uptake process. It was possible to delimit specific management zones using co-kriging for the three areas using soil and leaf data.