Variabilidad espacial de las propiedades físicas en suelo entisol con cultivo de banano y cacao, Machala - El Oro

Abstract

The physical properties of the soil have a high degree of variability both spatially and their variation over time. Spatial variability of the physical properties of the soil must be known to make proper use of this resource in the agricultural field. This research was conducted on an Entisol-order soil that is located on the taxonomic map of soils in the province of El Oro. These soils have a low development in their structure and are formed by having drainage problems. Two farms with different crops were located, bananas on the farm "La Libertad" with an area of 7.14 ha and cocoa on the farm "La Tola" with an area of 2.43 ha. The objective was to carry out a statistical and geostatistical analysis for the elaboration of maps of the study variables that are: %clay, %silt, %sand, apparent density, real density, porosity, field capacity and permanent point of wilt, based on two types of interpolation being the spherical and exponential by the krigreado method using the tightest in each variable. Soil sampling was done with the help of GPS and AUTOCAD software where it consisted of surveying to perform a grid in both areas. The banana area was made a grid or mesh of 90x90 m resulting in 7 points and in the cocoa area a mesh of 70x70 m was made obtaining 7 points. Identified these points were taken to the field by marking them with a beacon previously identified for sample extraction. The samples were extracted at depths of 0-25 and 25-50 cm, as well as the unchanged samples were taken with the cylinders for the determination of apparent density. Water infiltration was also evaluated into the soil by the infiltration rings method in which three repetitions were performed on both crops, taking strategic points on behalf of each area. As a result, sand particles predominate followed by silt and with a low percentage of clay with a coefficient of variation of 2.07 in sand, 13.22 in silt and 52.65 in clay between the two crops. Apparent density, actual density, porosity and field capacity were similar with a coefficient of variation of 1.23; 2,57; 6.03 and 4.76. The variable permanent withering point has a difference between crops being 6.14 % in banana cultivation and 4.56 % in cocoa cultivation obtaining a coefficient of 20.91. For the realization of the maps, the ARCGIS software was used, obtaining eight maps in each crop. The infiltration of water into the soil in the banana area its initial speed was 11 cm/h until reaching a constant speed of 3,076 cm/h, considered as the basic infiltration of the soil, this soil was wet. While the cocoa area presents dry soil with an initial infiltration rate of 21 cm/h, the test was performed on both soils in a cumulative time of 106 minutes.