Influence of cactus pear cultivation density on the physicochemical characteristics of the soil

Abstract

The objective was to evaluate the effect of the planting density of cactus pear cv. Mexican elephant ear under soil physical and chemical properties. Four planting densities were tested: 30,000, 45,000, 60,000 and 75,000 plants distributed in a randomised block design with four replications. After 360 days of cultivation, soil samples were taken in different profiles (0.0–0.10, 0.10–0.20, 0.20–0.30 and 0.30–0.40 m). The physical–chemical analysis included soil density, particle density, porosity, pH, electrical conductivity (EC), phosphorus (P), potassium (K+), sodium (Na+), calcium (Ca2+), magnesium (Mg2+), copper (Cu2+), iron (Fe2+), manganese (Mn2+), zinc (Zn2+), exchangeable acidity (H+Al), sums of bases (SB), cation exchange capacity and base saturation (V). The results were tested using analysis of variance, regression at 5% probability and principal component analysis (PCA). Physical properties along the soil profile and soil chemical properties in the 0–0.10 m profile were not altered (P > 0.05) by the density. There was a decreasing linear effect (P < 0.05) of density on the P content in the 0.10–0.20, 0.20–0.30 and 0.30–0.40 m profiles. Mg, Zn and V in the 0.10–0.20 m profile and Ca in the 0.30–0.40 m profile decreased linearly (P < 0.05) as a function of density. There was an increasing linear effect (P < 0.05) of planting density on Fe in the 0.20–0.30 m profile. The PCA showed that the factor loadings of the chemical properties of the soil in the different profiles were greater than 75% in the first two components. Except for the 0–0.10 m profile, with 55.77%. Minerals that contributed most to PC were Ca, K, P, Mg and Mn. In this sense, increasing the planting density of cactus pear without the use of fertiliser demands more from the soil, recommending lower densities between 30,000 and 45,000 plants ha−1.