RESUMO Objetivou-se com este trabalho avaliar os parâmetros fitomorfológicos da cultura da soja em um sistema de integração lavoura-pecuária e inoculados com Azospirillum brasilense. O experimento foi conduzido em Santa Maria, em dois agrícolas (2012/2013 e 2013/2014), num delineamento experimental de blocos casualizados, com três repetições. No período de inverno a pastagem de aveia preta e azevém foi manejada com ovinos em diferentes sistemas de pastejo: (I) - pastejo convencional (PC), onde os animais permaneciam na pastagem por todo o período experimental sem um controle da altura da pastagem, (II,III e IV) - altura da pastagem na saída dos animais de 10, 20 e 30 cm e uma testemunha sem pastejo (SP), três doses de nitrogênio (0, 50 e 100 kg ha-1) e com ou sem inoculação (Azospirillum brasilense). A semeadura da soja foi realizada em semeadura direta em 16 de novembro de 2012 e 01 de dezembro de 2013, utilizando-se a cultivar BMX Potência RR. Em cada parcela, se utilizou sete fileiras de plantas com espaçamento de 0,45 m, sendo que em quatro fileiras as sementes foram inoculadas com a bactéria Azospirillum brasilense. Foram avaliadas variáveis fitomorfológicas e a produtividade de grãos. Em sistema de integração lavoura-pecuária a cultura da soja possui melhores produtividades quando estabelecida sobre pastagem de aveia preta e azevém manejadas com alturas de pastejo entre 20 e 30 cm. As áreas sob pastejo convencional no inverno proporcionam plantas de soja menores, com menores inserções de primeira e última vagem. A inoculação com Azospirillum brasilense não deve ser usada isoladamente na cultura da soja. | ABSTRACT The objective of this study was to evaluate the phytomorphological parameters of soybean in a crop-livestock system inoculated with Azospirillum brasilense. The experiment was conducted in Santa Maria, Brazil, for two agricultural years (2 Paper extracted from the doctoral thesis of the first author. 012/2013 and 2013/2014) in a randomized complete block design with three replications. In the winter, the black oat and ryegrass pasture was managed with sheep under different grazing systems: (I) - a conventional grazing (CG) system, where the animals remained in the pasture throughout the experimental period without any pasture height control; (II, III, and IV) - systems with post-grazing pasture heights of 10, 20, and 30 cm, respectively; and (NG) - one control without grazing. All treatments received two nitrogen doses (50 and 100 kg ha-1) and inoculation or no inoculation (A. brasilense). The soybean cultivar BMX Potência RR was sown using no-tillage on 16 November 2012 and 1 December 2013. In each plot, seven rows of plants with spacing of 0.45 m were used, and in four rows, the seeds were inoculated with the bacterium A. brasilense. The phytomorphological variables and grain productivity were evaluated. In a croplivestock system, soybean has better productivity when established on black oat and ryegrass pasture managed with post-grazing pasture heights of between 20 and 30 cm. Areas under conventional grazing in the winter led to smaller soybean plants with lower first and last pod heights. Inoculation with A. brasilense should not be used alone in soybean cultivation.

The objective of this study was to evaluate the phytomorphological parameters of soybean in a crop-livestock system inoculated with Azospirillum brasilense. The experiment was conducted in Santa Maria, Brazil, for two agricultural years (2 Paper extracted from the doctoral thesis of the first author. 012/2013 and 2013/2014) in a randomized complete block design with three replications. In the winter, the black oat and ryegrass pasture was managed with sheep under different grazing systems: (I) - a conventional grazing (CG) system, where the animals remained in the pasture throughout the experimental period without any pasture height control; (II, III, and IV) - systems with post-grazing pasture heights of 10, 20, and 30 cm, respectively; and (NG) - one control without grazing. All treatments received two nitrogen doses (50 and 100 kg ha-1) and inoculation or no inoculation (A. brasilense). The soybean cultivar BMX Potência RR was sown using no-tillage on 16 November 2012 and 1 December 2013. In each plot, seven rows of plants with spacing of 0.45 m were used, and in four rows, the seeds were inoculated with the bacterium A. brasilense. The phytomorphological variables and grain productivity were evaluated. In a croplivestock system, soybean has better productivity when established on black oat and ryegrass pasture managed with post-grazing pasture heights of between 20 and 30 cm. Areas under conventional grazing in the winter led to smaller soybean plants with lower first and last pod heights. Inoculation with A. brasilense should not be used alone in soybean cultivation.

RESUMO O trabalho teve como objetivo estudar variações nos parâmetros envolvidos no teste do pH do exsudato e alagamento para caracterização da qualidade fisiológica de sementes de soja. Inicialmente, foi determinado o teor de água e realizados os testes de germinação, primeira contagem, emergência e índice de velocidade de emergência. No teste do pH do exsudato foram estudadas variações no período de embebição e temperatura; e no teste de alagamento foram estudadas variações na quantidade de água e temperatura. O experimento foi realizado em delineamento inteiramente casualizado com quatro repetições, e as médias comparadas pelo teste de Scott-Knott a 5% de probabilidade. Foi estimado o coeficiente de correlação de Pearson entre os testes do pH do exsudato e alagamento com a emergência de plântulas. O teste do pH do exsudato pode ser utilizado na avaliação do potencial fisiológico de sementes de soja, sendo que este deve ser realizado na temperatura de 20 ºC por 30 minutos de embebição. O teste de alagamento é eficiente na avaliação do vigor de sementes de soja, podendo ser realizado nas combinações 25 ºC/50 mL ou 30 ºC/75 mL, durante 4 h. | ABSTRACT The present study aimed to assess the variations in the parameters of the exudate pH and flooding tests to evaluate the physiological quality of soybean seeds. We subjected the lots of soybean seeds to germination, emergence, exudate pH, and flooding tests. Further, water content of the seeds, first count of germination, and emergence speed index were also determined. The exudate pH test studied the variations in the soaking period and temperature, while the flooding test assessed the variations in the amount of water and temperature at different periods of immersion. The experiment design was completely randomized. The results were presented as means and were compared using the Scott-Knott test at 5% probability. The Pearson’s correlation coefficient between the exudate pH and emergence of seedlings, and also between the flooding test result and emergence of seedlings were calculated. The results of the study indicated that the exudate pH test can be used to evaluate the physiological quality of soybean seeds after 30 min of imbibition at 20 °C. Further, the flooding test was efficient in evaluating the vigor of soybean seeds after 4 h of immersion either in 50 mL of distilled water at 25 °C or in 75 mL of distilled water at 30 °C.

The present study aimed to assess the variations in the parameters of the exudate pH and flooding tests to evaluate the physiological quality of soybean seeds. We subjected the lots of soybean seeds to germination, emergence, exudate pH, and flooding tests. Further, water content of the seeds, first count of germination, and emergence speed index were also determined. The exudate pH test studied the variations in the soaking period and temperature, while the flooding test assessed the variations in the amount of water and temperature at different periods of immersion. The experiment design was completely randomized. The results were presented as means and were compared using the Scott-Knott test at 5% probability. The Pearson’s correlation coefficient between the exudate pH and emergence of seedlings, and also between the flooding test result and emergence of seedlings were calculated. The results of the study indicated that the exudate pH test can be used to evaluate the physiological quality of soybean seeds after 30 min of imbibition at 20 °C. Further, the flooding test was efficient in evaluating the vigor of soybean seeds after 4 h of immersion either in 50 mL of distilled water at 25 °C or in 75 mL of distilled water at 30 °C.

RESUMO O déficit hídrico é um fator limitante, pois desencadeiam diferentes adaptações fisiológicas e anatômicas que tem efeitos deletérios nas plantas o que pode afetar a seletividade dos herbicidas e ocasionar perdas às culturas agrícolas. O objetivo deste trabalho foi avaliar a ação do herbicida chlorimuron-ethyl, pulverizado em diferentes estádios de desenvolvimento da soja, cultivar convencional e transgênica, sob diferentes manejos de água no solo. A dose de 20 g i.a. ha-1 do herbicida chlorimuron-ethyl foi aplicada em dois estádios fenológico (V2-primeiro trifólio aberto e V4-terceiro trifólio aberto) de duas cultivares de soja: MG/BR 46 Conquista (convencional) e BRS Valiosa (RR), sob três condições hídricas no solo (-0,03; -0,07 e -0,5 MPa). Avaliou-se a fitointoxicação e altura de plantas aos 3, 7, 14 e 21 dias após a aplicação do herbicida. Ao final do estudo, determinou-se a massa seca da parte aérea, massa seca das raízes e nodulação do sistema radicular por meio do número e massa seca de nódulos. Constatou-se que, em condição de déficit hídrico as plantas de soja apresentaram uma menor fitotoxicidade visual quando submetida à pulverização do herbicida chlorimuron-ethyl. Além disso, o uso do herbicida chlorimuron-ethyl reduziu o crescimento e a biomassa das plantas de soja, afetando também a nodulação da cultura. A cultivar transgênica BRS Valiosa RR mostrou um melhor desempenho quando submetida a uma condição de escassez hídrica moderada (-0,07 MPa) para sustentar a fixação biológica de nitrogênio. | ABSTRACT Water deficit is a limiting factor for the soybean yield; it triggers different physiological and anatomical adaptations that have deleterious effects on the plants and can affect the selectivity of herbicides, causing production losses. In this context, the objective of this work was to evaluate the action of the chlorimuron-ethyl herbicide when applied at different stages of soybean plants, using conventional and transgenic cultivars, and different soil water potentials. A rate of 20 g ha-1 of the chlorimuron-ethyl herbicide was applied to two soybean cultivars (MG/BR46-Conquista - conventional, and BRS-Valiosa-RR - transgenic) at two phenological stages (V2 - first fully expanded trifoliate leaves, and V4 - third fully expanded trifoliate leaves), using three soil water potentials (-0.03 MPa, -0.07 MPa, and -0.5 MPa). Phytotoxicity, and plant height were evaluated at 3, 7, 14, and 21 days after the herbicide application. The shoot dry weight, root dry weight, and root system nodulation were evaluated. The soybean plants had lower phytotoxicity when subjected to application of chlorimuron-ethyl under water deficit conditions. The use of chlorimuron-ethyl reduced the growth and biomass of soybean plants and affected the plants' root system nodulation. The transgenic cultivar (BRS-Valiosa-RR) presented better performance when subjected to a moderate water deficit (-0.07 MPa), which contributes to biological nitrogen fixation.

Water deficit is a limiting factor for the soybean yield; it triggers different physiological and anatomical adaptations that have deleterious effects on the plants and can affect the selectivity of herbicides, causing production losses. In this context, the objective of this work was to evaluate the action of the chlorimuron-ethyl herbicide when applied at different stages of soybean plants, using conventional and transgenic cultivars, and different soil water potentials. A rate of 20 g ha-1 of the chlorimuron-ethyl herbicide was applied to two soybean cultivars (MG/BR46-Conquista - conventional, and BRS-Valiosa-RR - transgenic) at two phenological stages (V2 - first fully expanded trifoliate leaves, and V4 - third fully expanded trifoliate leaves), using three soil water potentials (-0.03 MPa, -0.07 MPa, and -0.5 MPa). Phytotoxicity, and plant height were evaluated at 3, 7, 14, and 21 days after the herbicide application. The shoot dry weight, root dry weight, and root system nodulation were evaluated. The soybean plants had lower phytotoxicity when subjected to application of chlorimuron-ethyl under water deficit conditions. The use of chlorimuron-ethyl reduced the growth and biomass of soybean plants and affected the plants' root system nodulation. The transgenic cultivar (BRS-Valiosa-RR) presented better performance when subjected to a moderate water deficit (-0.07 MPa), which contributes to biological nitrogen fixation.