Production and nutritional characteristics of sunflowers and paiaguas palisadegrass under different forage systems in the off season

Abstract

ABSTRACT:The high efficiency of sunflowers in extracting water from the soil under water stress conditions is a factor that promotes sunflower cultivation in the offseason. Therefore, sunflowers have been intercropped with grasses of the Urochloa genus in crop-livestock integration systems. However, little is known of sowing methods for intercropping; thus, the present study aimed to assess sunflower agronomic traits and the production and nutritional characteristics of Paiaguas palisadegrass under different forage systems in the offseason in the midwest region of Brazil. The experiment was conducted at the Federal Institute of Goiás (Instituto Federal Goiano), Rio Verde Campus in a randomized block experimental design with four replicates. The treatments consisted of the following forage systems: sunflower monocropped; Paiaguas palisadegrass monocropped; sunflower rows intercropped with Paiaguas palisadegrass; sunflower inter-row intercropped with Paiaguas palisadegrass; and sunflower oversown and intercropped with Paiaguas palisadegrass. The results show that the sunflower rows intercropped with Paiaguas palisadegrass negatively affect the agronomic traits of sunflower; thus, inter-row sowing and oversowing are recommended. Sowing Paiaguas palisadegrass with oversown sunflower for forage production is hampered by intercropping and shows low forage production. In turn, the intercropped sowing method had no effect on the nutritional characteristics of the produced forage. Intercropping sunflowers with Paiaguas palisadegrass in the offseason has the potential to provide a promising cropping method for the production of achenes and after harvest enables the availability of forage with good nutritional value for use in the offseason in the midwest region of Brazil.

Agronomic performance of sunflower intercropped with Urochloa ruziziensis

“…Coefficients of variance (CV) for agronomic characteristics of the sunflower were classified low or average, following classification suggested by Pimentel-Gomes (2009). They were similar to those reported by Souza et al (2015) and Santos et al (2016), who evaluated the agronomic characteristics of the sunflower intercropping species of the genus Urochloa.…”

Soybean yield in integrated crop–livestock system in comparison to soybean–maize succession system

“…Nitrogen and potassium are the two nutrients most absorbed by forage plants (Costa et al, 2016(Costa et al, , 2017, and in the present study, they were found in greater abundance in the Paiaguas palisadegrass and Tamani guinea grass biomasses. The phosphorus, potassium and sulphur accumulation was satisfactory in the biomass of the Paiaguas palisadegrass and Tamani guinea grass cropping systems for the uptake required by soybean as a successor crop, showing that these forages can release amounts close to the crop needs.…”

“…Grazing animals in an integrated crop-livestock system can modify nutrient and plant residue cycling rates, changing the biochemical form of nutrients, their spatial distribution within the pasture, and their time of release or availability (Assmann et al, 2017) via their return in manure and urine. In this sense, animals act as nutrient recycling agents (Carvalho et al, 2010), which may result in a lesser need for fertilizer for the next crop and maintenance of production sustainability over time (Costa et al, 2016).…”

“…Even in the final soybean cycle, Paiaguas palisadegrass had an average production of 1498 kg/ha, 39% higher than that of Tamani guinea grass (1076 kg/ha) and 61% higher than that of maize (930 kg/ha), and it remained longer on the soil surface and ensured cover for a prolonged time. This result is relevant and very important in the Cerrado region of Central Brazil, where the high temperatures throughout the year accelerate the decomposition of the material, which hinders the permanence of the biomass on the soil surface (Costa et al, 2016;Zagato et al, 2018). In addition, this region often has short-term droughts, hindering crop development.…”

“…In this way, the persistence of biomass in the soil is a determining factor that itself depends on climatic conditions and plant species (Zagato et al, 2018). High temperature and humidity accelerate the biomass decomposition process on the soil surface (Costa et al, 2016).…”