Níveis de compactação do solo e produção do feijão-caupi

Abstract

Cowpea presents great social, economic and nutritional importance for the North and Northeast regions of Brazil, where it is a food staple for low income populations due to the favorable regional conditions for the crop and to its mineral composition. The objective of this work was to evaluate the behavior of two cultivars of cowpea submitted to two levels of soil density at two different depths. Two experiments were carried out between June and October 2018, in a greenhouse located at the Federal Rural Semi-Arid University, in Mossoró, RN, Brazil. The first experiment was with the cultivar BRS Tumucumaque, and the second with BRS Potengi. Treatments were applied in soil columns made with 15 cm diameter PVC rings. Each column was divided into three 10 cm high rings, and one ring 5 cm high which was compacted at the specified density level. The experimental design was completely randomized in a factorial scheme. The factors were levels of soil density in the compacted layer (1.65 or 1.85 g cm-3) and depths of the compacted layer (10-15 or 20-25 cm). After harvesting the dry grains, roots of each layer were collected for analysis of root development under compaction. The statistical analysis consisted of analysis of variance to verify the effect of the factors and their interaction by means of F Test, which was also used for assessing the differences of means between soil density levels and between the depths of compacted layer. The cultivar BRS Potengi presented behavior for the analyzed variables superior to the cultivar BRS Tumucumaque, when submitted to soil compaction. The variables presented higher average values when the compacted layer was located at 20-25 cm. Variables presented better behavior at the lower soil density (1.65 kg cm-3) when the compacted layer was at 10-15 cm, and at the higher soil density (1.85 kg cm-3) when the compacted layer was at 20-25 cm. The root development of BRS Potengi was better than that of BRS Tumucumaque in all soil layers.