Nitrogen and potassium in the cultivation of Piatã grass in Brazilian Cerrado soil

ABSTRACT This study aimed to evaluate the production and mineral nutrition of Piatã grass as a function of nitrogen and potassium fertilization in Oxisol collected in the Cerrado. The experiment was carried out in a greenhouse, the experimental design was completely randomized, in a 5 x 5 factorial scheme, corresponding to five nitrogen doses (0, 100, 200, 300 and 400 mg dm-3 of N) and five potassium doses (0, 90, 180, 270 and 360 mg dm-3 of K2O), with four replicates. Three cuts of the shoots were performed every 30 days. Chlorophyll index, dry mass of shoots and roots, and nitrogen and potassium contents in the leaves were evaluated. The dry mass of shoots showed interaction between nitrogen and potassium in the three cuts; in the second and third cuts, it had maximum production at the nitrogen and potassium doses of 254 and 158 mg dm-3, in the second, and 250 and 306 mg dm-3 in the third, respectively. The nitrogen and potassium contents are influenced as a function of nitrogen and potassium fertilization isolated by factor. The nitrogen and potassium ratio in the Piatã grass crop was around 1:1

Sorghum Densification with Changes in Plant Spacing Arrangement: Productivity and Qualitative Characteristics of Silage Material

The aim of this study was to evaluate the agronomic performance of sorghum grown in different combinations of row spacing and plant density, as well as possible interferences on silage quality. No other study dedicated to identifying the interference of plant spatial arrangement on the cultivation of silage material has been developed in the productive context of the Amazon Biome, making it necessary to understand the behavior of the studied factors. The treatments were arranged in a split-plot scheme: the plots corresponded to three row spacings (0.45 m, 0.60 m, and 0.75 m) and subplots at four densities (105,000, 120,000, 135,000, and 150,000 plants ha−1). The agronomic and productivity characteristics of sorghum and the fermentative and bromatological characteristics of forage and silage were evaluated. The sorghum plants showed an increase in plant height and green and dry mass yield when using higher densities (p p > 0.05) for morphological plant components. In silage, wider spacing promoted higher dry matter content. Regarding crude protein in the silage, higher percentages were obtained at closer spacing and higher plant density. The sorghum growing in dense conditions is indicated, given the positive performance in productivity and bromatological composition

Probiótico e/ou prebiótico sobre as características da leitegada e da matriz lactante Probiotic and/or prebiotic on litter characteristics and sow breastfeeding

Conduziu-se este trabalho, com o objetivo de verificar o efeito do uso de probiótico e/ou prebiótico na alimentação de matrizes suínas. Foi utilizado um delineamento inteiramente casualizado com 4 tratamentos e 6 repetições (T1= controle; T2= prebiótico; T3= probiótico; e T4= prebiótico + probiótico), sendo cada fêmea considerada uma parcela. A adição de probiótico e/ou prebiótico diminuiu o número de leitões mumificados. A adição de prebiótico na ração das matrizes adicionado ou não de probiótico, elevou a concentração de proteína no leite no 21º dia de lactação. No 14º dia de lactação, as concentrações de Clostridium perfringens foram menores nas fezes de matrizes que se alimentaram de probiótico. No 21º dia de lactação, as concentrações de Bifidobacterium nas fezes das matrizes foram estatisticamente menores no tratamento com prebiótico (T2). As concentrações de Enterobacteriaceae foram maiores nas fezes de matrizes que receberam a adição de probiótico (T3).<br>The objective of the present study was to in determine the effect of probiotic and/or prebiotic added to feed for sows. An entirely randomized design with 24 sows, 4 treatments and 6 replicates (T1 = control; T2 = prebiotic; T3 = probiotic; and T4 = prebiotic + probiotic) was used. The addition of probiotic and/or prebiotic decreased the number of mummified piglets. The addition of prebiotic to sow´s feed, with or without probiotic, increased the concentration of milk protein on the 21st day of lactation. On the14th day of lactation, the of Clostridium perfringens was smaller in the faeces of sows fed with probiotic (T3 and T4). On the 21st day of lactation, the concentration of Bifidobacterium in the faeces was statistically lower in sow food with prebiotic (T2). Concentrations of Enterobacteriaceae were higher in the faeces of sows that received probiotic (T3)

Glyphosate e nitrgênio no controle de Brachiaria decumbens Stapf em capineiras estabelecidas Glyphosate and nitrogen in the control of Brachiaria decumbens Stapf in established elephant grass stocking piles

O objetivo do experimento foi avaliar a eficiência de utilização do herbicida glyphosate associado com adubação nitrogenada no controle de Brachiaria decumbens Stapf em capineiras estabelecidas. O delineamento experimental foi em blocos casualizados, com dezessete tratamentos e três repetições. Os tratamentos foram arranjados em esquema fatorial 4 x 4 + 1, sendo quatro doses de glyphosate (0, 720, 1440 e 2160 g/ha/aplicação), quatro doses de nitrogênio (0, 75, 150 e 225 kg/ha/ano) e um tratamento adicional (testemunha com capina). As aplicações do nitrogênio e glyphosate, nas respectivas doses, foram realizadas imediatamente após o corte do capim-elefante. A associação entre o herbicida glyphosate (2160 g/ha/aplicação) e nitrogênio (225 kg/ha/ano) foi eficiente no controle de capim-braquiária em capineiras estabelecidas. A aplicação do herbicida glyphosate (2160 g/ha/aplicação) reduziu o tamanho do banco de sementes de capim-braquiária no solo em 64%.<br>The objective of this experiment was to evaluate the efficiency of the use of the herbicide glyphosate associated with nitrogen fertilization in the control of Brachiaria decumbens Stapf in elephant grass stocking piles. The experimental design used was a randomized blocks with 17 treatments and three replications. The treatments were arranged in 4x4+1 factorial scheme, namely four doses of glyphosate (0, 720, 1440 e 2160 g/ha/application), four doses of nitrogen (0, 75, 150 e 225 kg/ha/ano) and one additional treatment (control with a hoeing). The application of the nitrogen and glyphosate, in the respective doses were performed immediately after the cutting of elephant grass. The association between glyphosate (2160 g/ha/application) and nitrogen (225 kg/ha/ano) was efficient in the control brachiaria grass in established elephant grass stocking piles. The application of the glyphosate (2160 g/ha/application) reduced the size of the bank of brachiaria grass seeds in the soil in 64%