Structuring of a Haplortox by Cover Crops and Their Effects on the Yield of Soybean Grains

The intense agricultural machinery traffic over the plantation ground can lead the erosion and growth difficulty. The goal of this study was to evaluate the soya bean yield after the implantation of species named “recoverable”, of soil structure. The experiment was developed in plots of 20 m × 25 m, located in the Agronomic Institute of Parana (IAPAR), in Santa Tereza do Oeste, Paraná. The plots were cultivated by direct sowing of the following species, considered as treatments: sunn hemp (Crotalaria juncea), rattlebox (Crotalaria spectabilis), velvet bean (Mucuna aterrima), pearl millet (Pennisetum glaucum), pigeon pea (Cajanus cajan), dwarf pigeon pea (Cajanus cajan) beside them no-tillage and no-cover crop planting traditional system (control). Soil samples were collected from 0-10 cm, 10-20 cm, and 20-30 cm-layers with 4 repetitions on each treatment. Soil density and porous soil space were also determined. The plot yield of soybean grains was evaluated over an area of 4.5 m2 for each treatment and grain moisture corrected to 13%. The treatments’ mean yields were compared using the Tukey test at 5% probability. The dwarf pigeon pea and the rattlebox were the most efficient cover crops in the reduction of soil bulk density in 0-10 and 10-20 cm depths. The soybean grain yield did not differ between the evaluated treatments, possibly due to the good precipitation conditions during the soybean growing cycle.