Suchergebnisse

Intercropping of annual crops with tropical forages is an effective cultivation method to maximize grain production and pasture formation. The objective of this study was to evaluate the agronomic characteristics of sunflower and the productive and nutritional characteristics of Brachiaria brizantha cultivars grown with intercropping during two different sowing seasons in the interim harvest of the Center-West region of Brazil. The experiment was conducted in the municipality of Rio Verde, Goiás (GO), using a randomized block design with a 3x2+4 factorial scheme and three replicates per treatment. The following factors were tested: three Brachiaria brizantha cultivars (Marandu palisadegrass, Piata palisadegrass and Xaraes palisadegrass) grown with intercropping in the inter-row with the sunflower cultivar Charrua in two different sowing seasons (February and March); four additional treatments of sunflower; and the three tested Brachiaria brizantha cultivars grown in monoculture. Intercropping of sunflower with the Xaraes palisadegrass cultivar negatively affected the agronomic characteristics of sunflower, and intercropping with Marandu palisadegrass and Piata palisadegrass cultivars is recommended. Preference should be given to the Xaraes palisadegrass cultivar for forage production and to the Piata palisadegrass cultivar for the production of forage with higher nutritional value. Sowing in March led to the best sunflower agronomic characteristics, without affecting the productive and nutritional characteristics of the forages. Intercropping of sunflower with Brachiaria brizantha cultivars is therefore a promising cultivation method for the production of achenes and forage during the inter-harvest in the Center-West region of Brazil.

The degradation of pastures in Brazil is a problem of agronomic and environmental importance because it impairs the productive capacity of the soil and the hydrological cycle. In this context, the integration of agriculture and livestock emerges as a promising practice in recovering degraded soils through aggregation, increasing organic carbon in the soil and breaking compacted layers via the growth of grass roots. This study aimed to evaluate suitable indicators of physical quality in regard to mitigating structural changes of a Latosol cultivated with different species of the genus Brachiaria. We evaluated the grasses Brachiaria brizantha (Xaraés, Piatã, Marandu), Brachiaria decumbens and Brachiaria ruziziensis and adopted fallow and conventional tillage as controls. Soil samples were used to evaluate the parameters total organic carbon, soil aggregation via wet sieving and the least limiting water range (LLWR). Total organic carbon and aggregate stability were not suitable indicators for quantifying soil structural changes, remaining high in the evaluated conservation systems, with a difference observed only in the control with conventional tillage. The LLWR varied among all systems and layers evaluated. Xaraés palisadegrass, followed by the Piatã and Marandu cultivars, stood out in terms of biological soil loosening ability, being similar to the recovery caused by soil tillage. Furthermore, B. decumbens showed intermediate performance, while B. ruziziensis showed activity similar to that in the fallow treatment, indicating limited potential for soil physical recovery.

At critical levels, animal trampling can physically degrade soil, leading to the loss of sustainability of agricultural production. Therefore, it is becomes necessary to model and quantify the soil compaction potential. In this context, the objective was to evaluate the occurrence of soil compaction promoted by animal trampling in crop-livestock integration system (ICL). The study was conducted in a field at Centro Tecnológico da Comigo in the municipality of Rio Verde, Goias state, Brazil, during the agricultural off-season. The experimental area was composed of 1.97 ha, which was equally divided into eight paddocks. Soil was sampled before the grazing phase and after each of four grazing cycles. The compressive behavior of the soil was evaluated by determining the pre-consolidation and critical pressures. The results showed that only the first cycle of grazing showed additional compaction in 14.59% of samples. No critical compaction was observed in the evaluated area. Animal trampling under the studied conditions is not responsible for the dissemination of structural soil degradation in crop-livestock integration systems and may contribute to physical improvement resulting from biological soil loosening.

The partial substitution of maize by tropical legumes for the production of silage has aroused interest, for bringing benefits of increasing the crude protein content of corn-only silage, constituting an important alternative for the production of food in a more sustainable way. In this context, the objective of this study was to evaluate the effect of addition 30% tropical legumes on the fermentative characteristics and nutritive value of maize silage. The experimental design was entirely randomized with three replications. The treatments consisted of the following silages: Maize; Stylosanthes cv. Campo Grande, Stylosanthes cv. Bela: Pigeon pea (Cajanus cajan cv. BRS Mandarim), maize + 30% Campo Grande; maize + 30% Bela and maize + 30% Pigeon pea, totaling 21 experimental silos. The results show that exclusive legume silage without preservatives present fermentative losses that compromise the silage quality. Addition of 30% legumes to maize silage improves the nutritional quality of the silage without compromising its fermentation profile. Stylosanthes cv. Campo Grande and Bela are the most recommended locations for maize silage. Thus, a mixed silage of maize and legumes is an alternative to improve the crude protein content of exclusive maize exclusive silage, greater sustainability, and reduced fermentative losses of legume silages.

Tropical legumes are used to prepare mixed silages to enrich the crude protein (CP) content. In This context, objective of this study was to evaluate the dynamics of fermentation and quality of maize silage with different levels of Pigeon pea. The experimental design was entirely randomized, with four repetitions. The treatments comprised maize silages with six levels of added Pigeon pea (0, 20, 40, 60, 80, and 100%), calculated based on natural matter. The maize hybrid and Pigeon pea varieties used were B 2800 PWU and Cajanus cajan cv. BRS Mandarin, respectively. For the silage, the maize and Pigeon pea were harvested when they reached 335.7 g kg-1 dry matter (DM) and 281.3 g kg-1 DM, respectively. The results revealed that the added of up to 40% Pigeon pea in maize silages promote nutritive increment without compromising their fermentative profile of the silage. Exclusive Pigeon pea silage (100%) undergoes fermentative losses that compromise the silage quality. Therefore, mixed silages of maize with Pigeon pea, with appropriate levels of addition, are a viable alternative to increase the nutritive value of silages, mainly the CP content, contributing to reducing the cost of acquisition of protein salts.

Ensiling sorghum with tropical forages has been shown to be a promising alternative for ruminant feed production, as this approach improves the quality of the sorghum silage. In this context, the goal of this study was to evaluate the fermentation characteristics and nutritive value of sweet sorghum silage made with different levels of Paiaguas palisadegrass and Ipypora grass. The experiment was conducted in a completely randomized 2 x 6 factorial design with four replications. Two forages (Paiaguas palisadegrass and Ipypora grass) were added to sorghum at six levels (0, 20, 40, 60, 80 and 100%), for a total of 48 experimental silos. After 50 days of fermentation, the silos were opened, and the fermentation profile and chemical composition of the silage were analysed. The results showed that the addition of Paiaguas palisadegrass and Ipypora grass to the sorghum silage increased the pH, buffering capacity and NH3-NT of the silage and reduced its dry matter content but did not affect its fermentation characteristics, which remained within an appropriate range. The addition of increasing levels of Paiaguas palisadegrass and Ipypora grass to the sorghum silage increased the crude protein and in vitro dry matter digestibility (IVDMD) of the silage and decreased the fibre fraction (neutral detergent fibre, acid detergent fibre and lignin) and ether extract contents. Adding tropical forages to sorghum silage material at levels above 40% is recommended. Among forage crops, addition of Paiaguas palisadegrass to sorghum silage resulted in higher content of crude protein and IVDMD. Mixed silages can be an effective alternative to improve the quality of forage sorghum silage.

The use of silage has been an efficient alternative to feed supply during the shortage of roughage in dry periods, providing quality feed that is widely used in ruminant feeding. Thus, the objective of this study was to evaluate the fermentative characteristics and nutritive value of corn silage with Tamani guinea grass (Panicum maximum BRS cv. Tamani) through chemical composition, in vitro dry matter digestibility and protein fractionation. The experiment was conducted in a completely randomized design with four replications. The treatments consisted of five silages: corn; corn with 10% Tamani guinea grass; corn with 20% Tamani guinea grass; corn with 30% Tamani guinea grass; and corn with 40% Tamani guinea grass, totalling 20 experimental silos. The addition of tamani grass to silages was determined based on fresh matter. For ensiling, corn was harvested with 320 g kg-1 DM (dry matter) and Tamani guinea grass in a 30-day development cycle with 286 g kg-1 DM. After 50 days of silage, the silos were opened to analyse the fermentative characteristics, chemical composition and protein fractionation of the silage. The results showed that the addition of Tamani guinea grass in corn silage increased the pH and buffering capacity and reduced the dry matter and lactic acid concentration but did not compromise the fermentative characteristics of silages. The addition of 40% Tamani guinea grass in corn silage provided increased levels of crude protein, in vitro dry matter digestibility, protein A, B1 and C, and decreased the fractions B3 and C, which makes Tamani guinea grass an alternative to improve the quality of exclusive corn silage, resulting in better quality silage.