Physical and water properties in soybean (Glycine max) cultivation

Abstract

The department of San Pedro, Paraguay, presents moderate to severe levels of soil degradation mainly due to compaction. A good alternative is the incorporation of precision agriculture in the technological package, in order to improve the quality and yield of agricultural crops. The general objective of the research was to evaluate the physical and hydric properties of the soil on a no-tillage system using precision agriculture technology and its influence on yield. A plot of 82.74 hectares was used, which was divided into two-hectares grids for soil compaction sampling at various depths 0-10, 10-20, 20-30 and 30-35 cm, soil moisture and soybean yield, as well as organic matter, pH, phosphorus and potassium levels. The results were as follows: the levels of organic matter were very low, with a general average level of 1.8 %; the pH level of the plot studied was relatively low according to the needs of agricultural crops, so the general average pH level was 5.2, indicating that the soil is mostly acidic. The general average potassium and phosphorus levels were 0.14 cmol kg^-1 and 9.22 mg kg^-1 respectively. Soil compaction was not observed at a depth of 0 to 10 cm; however, at depths greater than 10 cm, there was variability in the resistance to mechanical penetration, with an average soil moisture content of 19.32 % at the time of sampling. It is concluded that the soybean crop yield was very low, which demonstrates the effect caused by compaction, low humidity and deficiency in the main nutrients.