Ssistema de integração soja-sorgo-brachiaria sob diferentes formas de semeadura

Abstract

The recovery of degraded pastures is an opportunity to avoid the expansion of new agricultural areas. In this context, soybean and sorghum crops, due to their hardiness in newly opened or degraded areas, can be an excellent option for soil recovery. Brachiaria plays a crucial role in integrated intercropping systems, such as the Crop-Livestock-Forest Integration (CLFI) system, due to its multiple agronomic and environmental benefits. In addition to providing high-quality forage for animal feed, brachiaria significantly contributes to the sustainability and productivity of agricultural properties. Therefore, integrating brachiaria can be incorporated into crop production systems. Thus, the research hypothesis is that different brachiaria sowing methods affect the intercropping with soybean and sorghum. The objective of the research is to evaluate the soil chemical attributes in soybean-sorghum intercropped with forage, resulting from the use of integrated systems. The experiment was conducted after the soybean harvest, which was sown on October 13, 2023, and was arranged in a randomized block design with four replications. The treatments consisted of four sowing methods for the forage: (1) broadcasting the forage at the final phenological stage of sorghum; (2) sowing in the fertilizer box simultaneously with sorghum; (3) simultaneous broadcast sowing between the sorghum rows; and (4) control no forage, with four replications, totaling 16 plots of 9 m² (3 x 3 m). It was concluded that the soil pH in water was highest in the treatment where the forage was sown in the fertilizer box simultaneously with sorghum, while the pH in CaCl₂ was highest in the control treatment. For potassium, calcium, and magnesium levels, the best results were obtained with simultaneous broadcast sowing between the sorghum rows. For base sum and potential CEC, the same sowing method—simultaneous broadcasting between sorghum rows—yielded the best results. Regarding base saturation, the control treatment had the highest percentage. In the evaluation of organic matter content, the best result was also found in the simultaneous broadcast sowing between sorghum rows. For organic carbon content, the best results were obtained with broadcast sowing at the final phenological stage of sorghum and simultaneous broadcasting between the sorghum rows.