Urochloa ruziziensis Desiccation, Straw Quantity and Position on Nodulation and Production of Soybean ‘M-SOY 7908 RR’

Abstract

This study aimed to evaluate the effects of the quantity and soil position of Urochloa ruziziensis straw desiccated with glyphosate for different periods of time on ‘M-SOY 7908 RR’ soybean nodulation, growth and production characteristics. Three experiments were conducted under semi-controlled conditions. In the first, three quantities of U. ruziziensis straw (2.5, 5.0 and 10 ton ha-1) previously desiccated with glyphosate were incorporated into the soil (10 cm deep) or deposited on the soil surface, and in the second experiment, the treatments consisted of three U. ruziziensis desiccation periods, 0, 7 and 12 days before soybean sowing, and one treatment without U. ruziziensis. In the third treatment, desiccation was performed at 0, 5 and 10 days before soybean sowing, and the desiccated plant shoots were removed or left in place before soybean sowing. For each of the experiments, a completely randomized experimental design was adopted, and the masses of the shoot and root dry matter, the degree of nodulation and soybean production were evaluated. The deposition of U. ruziziensis straw on the soil surface promoted the nodulation and growth of ‘M-SOY 7908 RR’ soybean plant shoots, while its incorporation into the soil, even at 2.5 ton ha-1, caused deleterious effects. Desiccation of U. ruziziensis from 0 to 7 days before sowing was also detrimental to the nodulation and growth of M-SOY 7908 RR soybean, reducing its productivity.

Physiologic and morphologic characters of soybean and Urochloa sp. intercropped under reduced rates of glyphosate

“…As an example, the fasciculate root system of U. ruziziensis allows the plant to more easily explore soil volume when compared to plants with a pivoting root system such as soybean (Machado et al, 2017). In addition, studies conducted with U. ruziziensis have shown allelopathic inhibitory activity in soybean (Nepomuceno et al, 2019), mainly due the protodioscin that is compound that has a significant phytotoxic effect (Nepomuceno et al, 2017). Thus, the suppression of U. ruziziensis by the glyphosate underdose also contributed to the reduction of allelopathic capacity on soybean plants.…”

Adubação antecipada e formas de distribuição do fertilizante na semeadura do milho

“…O acúmulo de palhada sobre o solo, característico em SPD, aumenta problemas na implantação de culturas, como maior dificuldade para abertura adequada dos sulcos, aderência do solo nos componentes mecânicos, profundidade desuniforme de sementes e adubo, cobertura deficiente no sulco de semeadura, contato inadequado das sementes com o do solo e embuchamento por restos vegetais (López, et al, 2018;Nepomuceno, et al, 2019). A qualidade da semeadura depende da regulagem correta da semeadora-adubadora para um melhor corte da palha, abertura de sulcos homogêneos, deposição adequada de sementes e uma boa germinação .…”