Agronomic, morphogenic and structural characteristics of Marandu grass in silvopastoral systems composed of babassu palm and grass monoculture.

This study evaluated the agronomic, morphogenic and structural characteristics of palisadegrass (Urochloa brizantha) in silvopastoral systems (SSP?s) composed of babassu palms (Attalea speciosa) and grass monoculture in the Pre-Amazon region of the state of Maranhão, Brazil. The study followed a completely randomized design, with the arrangement in split plots with six replicates for the evaluation of agronomic characteristics and 30 repetitions for the morphogenic and structural characteristics. The plots were divided into pasture environments with different palm densities (monoculture, 80, 131, 160 palms.ha-¹), and the subplots were divided into the different seasons (rainy and dry).

Plant density and mineral nitrogen fertilization influencing yield, yield components and concentration of oil and protein in soybean grains.

There are few studies on the interaction between soybean plant density and nitrogen fertilization. This research aimed to assess the effect of mineral nitrogen associated to different plant densities on yield, yield components and oil and protein concentrations of soybean grains. Two experiments were conducted in the 2013/2014 and 2014/2015 growing seasons, with randomized complete block design, in a split plots scheme, with six replications. Four sowing densities (150, 300, 440 and 560 thousand viable seeds; ha-1) were allocated in the plots, and two nitrogen levels (0 and 45 kg N; ha-1, applied at V2, using ammonium sulfate) were allocated in the subplots. There was no interaction between soybean plant density and the application of mineral nitrogen on yield, yield components and oil and protein concentrations in soybean grains. Higher plant population reduced the number of pods per plant and the contribution of branch sinks to the grain yield, but the effects on yield differed among the growing seasons. The mineral nitrogen fertilization did not increase yield and protein and oil concentrations in the grains, thus it was unnecessary.

N20 fluxes evaluation in pasture management system under different densities of babassu palms.

2016

Effect of different methods of soil preparation on soil moisture loss, weed growth and soil resistance to penetration.

The effect of different methods of soil preparation on soil moisture loss, weed growth and soil resistance to penetration has been quantified for the Latosols of Bebedouro experiment station of CPATSA-EMBRAPA, Petrolina,PE, Brazil. The methods studied are manual preparation, preparation by animal drawn wheeled tool carrier and tractorized implements. The drying characteristics of three fields with different soil physical properties were studied prior to conducting the experiment. The different methods of soil preparation caused the soil moisture loss differently. The plot prepared by animal drawn tool carrier retained more moisture for longer time even at deeper layers. The soil resistance to penetration on the surface increased with time with little variation at deeper layers.