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The quantification of forage availability in tropical grasses is generally done in a destructive and time-consuming manner, involving cutting, weighing, and waiting for drying. To expedite this process, non-destructive methods can be used, such as unmanned aerial vehicles (UAVs) equipped with high-definition cameras, mobile device images, and the use of the normalized difference vegetation index (NDVI). However, these methods have been underutilized in tropical pastures. A literature review was conducted to present the current state of remote tools’ use in predicting forage availability and quality in tropical pastures. Few publications address the use of non-destructive methods to estimate forage availability in major tropical grasses (Megathyrsus maximus; Urochloa spp.). Additionally, these studies do not consider the fertility requirements of each cultivar and the effect of management on the phenotypic plasticity of tillers. To obtain accurate estimates of forage availability and properly manage pastures, it is necessary to integrate remote methods with in situ collection of soil parameters. This way, it will be possible to train machine learning models to obtain precise and reliable estimates of forage availability for domestic ruminant production.

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.

Aquaculture produces more than 122 million tons of fish globally. Among the several economically important species are the Serrasalmidae, which are valued for their nutritional and sensory characteristics. To meet the growing demand, there is a need for automation and accuracy of processes, at a lower cost. Convolutional neural networks (CNNs) are a viable alternative for automation, reducing human intervention, work time, errors, and production costs. Therefore, the objective of this work is to evaluate the efficacy of convolutional neural networks (CNNs) in counting round fish fingerlings (Serrasalmidae) at different densities using 390 color photographs in an illuminated environment. The photographs were submitted to two convolutional neural networks for object detection: one model was adapted from a pre-trained CNN and the other was an online platform based on AutoML. The metrics used for performance evaluation were precision (P), recall (R), accuracy (A), and F1-Score. In conclusion, convolutional neural networks (CNNs) are effective tools for detecting and counting fish. The pre-trained CNN demonstrated outstanding performance in identifying fish fingerlings, achieving accuracy, precision, and recall rates of 99% or higher, regardless of fish density. On the other hand, the AutoML exhibited reduced accuracy and recall rates as the number of fish increased.

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.

Inter-cropping between annual crops with tropical forages through integration crop-livestock systems (ICL) is considered a sustainable option to increase crop diversity and soybean productivity. In this study, we evaluated (1) the biomass production, desiccation efficiency, nutrient accumulation, and biomass decomposition of soil crop residues produced by Panicum maximum plants intercropped with maize in two different sowing methods during the second harvest and (2) investigated how soil crop residues impact the productivity of soybean. The experiment was conducted in a complete block design with three replicates. We compared conventional soybean cultivation with soybean cultivated over soil crop residues produced by a previous integration between maize and two Panicum maximum cultivars: Tamani and Zuri guinea grass, within and between rows of maize plants. Our results showed that Tamani guinea grass showed the highest desiccation efficiency. Zuri and Tamani guinea grass cultivated within and between maize plants resulted in higher biomass production and nutrient cycling potential, resulting in an increase of 28.4% in soybean productivity, compared to soybean grown without soil crop residues. We concluded that ICL system is an efficient method to increase the sustainability of soybean cultivation.

Crop–livestock integration systems are efficient technologies for diversifying production and promoting agricultural sustainability. However, less is known about the triple intercropping of crops for silage production. The objective of this study was to evaluate the dry mass production, fermentation profile, and nutritive value of sorghum silage intercropped with Tamani guinea grass and Stylosanthes cv. Bela in integrated systems. We used an experimental design with randomized blocks with four replicates. The treatments consisted of silage of (1) sorghum in monocropped; (2) Tamani guinea grass in monocropped (Panicum maximum cv. BRS Tamani); (3) Stylosanthes cv. Bela in monocropped (Stylosanthes guianensis cv. BRS Bela); (4) sorghum intercropped with Tamani guinea grass; (5) sorghum intercropped with Stylosanthes cv. Bela; (6) Stylosanthes cv. Bela intercropped with Tamani guinea grass; and (7) sorghum intercropped with Tamani guinea grass and Stylosanthes cv. Bela, totaling 28 experimental silos. Our results demonstrated that intercropping sorghum with tropical forages can be utilized in integrated silage production systems. This practice led to an increase in silage mass production per unit area while also providing pasture forage after the crop harvest for silage production, ultimately enhancing land-use efficiency in a sustainable manner. Silage produced from sorghum intercropped with Tamani guinea grass and Stylosanthes cv. Bela exhibited improved fermentative characteristics, as well as higher ether extract and total digestible nutrient contents compared with silage from monocropped forages. Tropical forages contributed to an increase in the crude protein content of monocropped sorghum silage, which could potentially reduce costs associated with acquiring protein salts for ruminant feed supplementation. Consequently, we recommend the triple intercropping of sorghum, Tamani guinea grass, and Bela for silage production, as it offers advantages for the cultivation of annual and tropical forage crops.

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.

Soybean is one of the most widely grown crops in the world and technologies are increasingly needed to increase productivity without impacting environmental degradation. In this context, the aim was to evaluate the action of forage plants of the genus Brachiaria sp. in crop–livestock integration on physical soil, agronomic and environmental aspects of soybean cultivation. The experiment was conducted in a subdivided plot design with seven integrated systems corresponding to the previous cultivation of Paiaguas palisadegrass, Xaraes palisadegrass and Ruziziensis grass in monocropping and intercropped with maize, as well as maize in monocropping. In the subplots, two grass management systems were evaluated: free growth and a grazing simulation cut. The bulk density and least limiting water range were assessed using soil samples and, after the pastures were desiccated when the soybean crop was planted, straw decomposition and plantability. A soil physics diagnosis by the bulk density and least limiting water range showed that the Paiaguas palisadegrass and Xaraes palisadegrass improved the soil environment due to biological soil loosening. The remaining mulch biomass did not affect soybean sowing and the adoption of Brachiaria sp. grass in the off-season, in addition to contributing to the provision of environmental services, and did not compromise grain productivity in succession.

New feed assessment systems and methodologies for ruminants are being used with the aim of maximizing the use of nutrients by animals. The Cornell Net Carbohydrate and Protein System (CNCPS) considers the dynamics of ruminal fermentation and the potential loss of nitrogen in feed evaluation. We used this system to evaluate the protein and carbohydrate fractionation of silages made from maize and Urochloa species alone and in combination (70:30). The experiment was carried out under a completely randomized experimental design with 4 replications. Treatments comprised silages made from the following forages: maize (Zea mays); Congo grass (Urochloa ruziziensis); Xaraes palisadegrass (U. brizantha 'Xaraés'); Paiaguas palisadegrass (U. brizantha 'BRS Paiaguás'); 70% maize + 30% Congo grass; 70% maize + 30% Xaraes palisadegrass; and 70% maize + 30% Paiaguas palisadegrass. The results showed that despite the Urochloa exclusive silages having higher crude protein concentration than maize and mixed silages, they have a higher proportion of unavailable fractions with slow degradation rates, which can compromise animal performance. The maize silage and mixed silages had higher percentages of protein and carbohydrates with high degradation potential than Urochloa exclusive silages. Therefore, mixed silages represent one more alternative to provide forage with good nutritional value for ruminant feeding in times of feed shortage. Mixing grass and maize at ensiling would increase the volume of silage produced relative to ensiling maize alone without any significant reduction in quality of the silage produced. However, further studies are needed to determine the appropriate combinations of maize and grass at ensiling to produce silage with the desired nutritional value for the particular application and class of animals being fed. Feeding studies with animals would verify production levels achieved with the various silages.

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.

ABSTRACT The objective of this study was to evaluate dry matter production, fermentative parameters, and nutritional value of the silage of corn intercropped with Paiaguas palisadegrass in different forage systems and maturity stages, in the off-season. The experiment was carried out in a randomized block design, with four replications, in a 5×3 factorial arrangement consisting of five forage systems: corn monocropped; Paiaguas palisadegrass monocropped; corn intercropped with Paiaguas palisadegrass in the row, inter-row, and oversown; and three corn maturity stages (milky, soft dough, and hard dough with 80, 90, and 110 days after sowing, respectively). The results showed that the silage of corn intercropped with Paiaguas palisadegrass in the row and inter-row at the hard dough stage presented greater productivity per area and better fermentative and nutritional characteristics. They can, therefore, be recommended as suitable sowing systems for silage production. Silages produced from intercropping systems proved to be an alternative feed supply technique, allowing the intensification of production systems, maximizing nutrient production per area, in a sustainable manner.

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.

Corn and sorghum are standard silage crops because of their fermentative characteristics. While corn and sorghum silages have lower crude protein (CP) contents than other crops, intercropping with legumes can increase CP content. Furthermore, one way to increase CP content is the addition of legumes to silage. Consequently, the research objective was to evaluate the fermentative and bromatological characteristics of corn (Zea mays) and sorghum (Sorghum bicolor) silages added with forage peanuts (Arachis pintoi). The experimental design was completely randomized with four replicates. The treatments consisted of corn silage, sorghum silage, forage peanut silage, corn silage with 30% forage peanut, and sorghum silage with 30% forage peanut. The results showed that the corn and sorghum added with peanut helped to improve the silage fermentative and bromatological characteristics, proving to be an efficient technique for silage quality. The forage peanut silage had lower fermentative characteristics than the corn and sorghum silages. However, the forage peanut silage had a greater CP content, which increased the protein contents of the corn and sorghum silages when intercropped with forage peanuts.

With the arrival of new early genotypes and high nutritive value and productive potential, millet has been gaining prominence in recent years for the production of silage, and it promises lower costs of production. Thus, the consortium of millet with tropical forages can increase the production of silage, providing more food to be used in the offseason, where there is low availability of forage. The objective of this study was to evaluate the dry mass production, fermentative characteristics and chemical-bromatological of pearl millet silage and Paiaguas palisadegrass in monocropping and intercropping in different forage systems in the second cropping season. The experimental design consisted of randomized blocks with four replicates. The treatments consisted of silage of the following forage systems: monocropped pearl millet, monocropped Paiaguas palisadegrass, pearl millet intercropped in rows with Paiaguas palisadegrass, pearl millet intercropped inter-row with Paiaguas palisadegrass, and pearl millet oversown and intercropped with Paiaguas palisadegrass (totaling 20 experimental plots). The consortium of pearl millet with Paiaguas palisadegrass contributed to raise the dry matter contents of the silages, except in the system using the overgrowth. Pearl millet silages monocropped and intercropped with Paiaguas palisadegrass presented reductions in pH and ammoniacal nitrogen values as well as favor lactic fermentation. Pearl millet monocropped and intercropped silage exhibited better fermentative and bromatological characteristics than silage obtained from monocropped Paiaguas palisadegrass. Therefore, creating silage from intercropped forages provides an interesting supplemental roughage option that can be used during the offseason for animal feeding.

Soil compaction associated with pastures degradation can decrease animal productivity, forage longevity and compromise environmental sustainability. To confront this serious issue, the loosening potential of forages should be recognized. We evaluated the least limiting water range as indicator of biological loosening potential in relation to cultivation of grasses the genus Brachiaria in crop-livestock integration. We also evaluated the water availability to soybean crop that succeeded these grasses. Our studies were performed in two stages. In the first stage, we divided 32 plots into four randomized blocks in which we cultivated corn combined with following treatments: 1 - Brachiaria brizantha cultivar Marandu; 2 - Xaraes; 3 - Piata; 4 - MG4; 5 - B. decumbens; 6 - B. ruziziensis; 7 - Invasive plants; and 8 - uncovered soil. We evaluated soil, to quantify the biological soil loosening, and also forages. In the second stage, we cultivated soybean and added: 9 - conventional tillage as a control treatment, increasing number of plots to 36. Our results suggest that it is possible to cultivate Brachiaria brizantha or Brachiaria decumbens as management strategy to aid edaphic recovery. Xaraes and Piata grasses provide greater soil loosening while increasing water availability to successive soybean crop.

Agricultural production systems that include the production of mulch for no-tillage farming and structural improvement of the soil can be considered key measures for agricultural activity in the Cerrado region without causing environmental degradation. In this respect, our work aimed to evaluate the chemical and physical-hydric properties of a dystrophic Red Latosol (Oxisol) in the municipality of Rio Verde, Goias, Brazil, under different soil management systems in the between-crop season of soybean cultivation five years after first planting. The following conditions were evaluated: Brachiaria brizantha cv. Marandu as a cover crop during the between-crop season; Second crop of maize intercropped with Brachiaria ruziziensis; Second crop of grain alone in a no-tillage system; Fallow soil after the soybean harvest; and Forest (natural vegetation) located in an adjacent area. Soil samples up to a depth of 40 cm were taken and used in the assessment of chemical properties and soil structure diagnostics. The results demonstrated that the conversion of native vegetation areas into agricultural fields altered the chemical and physical-hydric properties of the soil at all the depths evaluated, especially up to 10 cm, due to the activity of root systems in the soil structure. Cultivation of B. brizantha as a cover crop during the summer between-crop season increased soil water availability, which is important for agricultural activities in the region under study.

Recently it has emerged a technique for silage production of intercropping systems of annual crop with forage through crop-livestock integration, aiming to reduce the deficit forage in the offseason. The study was conducted to evaluate the fermentation characteristics and nutritional value of silage of sorghum and Urochloa brizantha cultivars monocropped or intercropped in different planting systems. The experiment was a randomized block design, with three replications, in a 3x2+4 factorial arrangement, with three cultivars of Urochloa brizantha (Marandu; Xaraes and Piata) intercropped with grain sorghum in two planting systems (row and between rows) and four monocrops (Sorghum, Marandu palisadegrass, Xaraes palisadegrass and Piata palisadegrass). The planting system of intercropping systems did not interfere with fermentation characteristics and chemical composition of silages. The same was found for Urochloa cultivars. Silages from intercropping sorghum with Urochloa brizantha cultivars had lower pH values, buffering capacity, acetic and butyric acids and higher values of lactic acid, besides showed superior quality, as for the parameters dry matter, ether extract and total digestible nutrient than silages from grasses produced in monocropping system. Therefore, silages of intercropping systems ensure fermentation and nutritional quality, providing interesting supplementary bulky options to be used in the offseason for feeding animals.

This study aimed to determine the protein and carbohydrate fractionation of Piata palisadegrass silage of brans from biodiesel industry. The experiment was developed in the Federal Institute of Goiás State, Campus Rio Verde, with a completely randomized experimental design, four replications, in a 4 x 4 factorial scheme, with four oleaginous brans (cotton, sunflower, soybean and canola) and four levels of inclusion (0, 5, 10 and 15%). The results showed that brans from biodiesel industry are good sources of additives for ensiling thePiata palisadegrass, by considerably improving fractions of proteins and carbohydrates. However, the soybean meal proved to be more efficient by having higher fractions of proteins and carbohydrates A+B1 and lower fractions C, compared with other additives. It is recommended the addition of 15% of brans for providing better nutritional value of silage.

This study determined the fractionation of protein and carbohydrate of Piata palisadegrass ensiled with energetic meals. The experiment was developed at the Federal Institute of Goiás State, Rio Verde Campus, using a completely randomized design with four replications, in a 4 x 5 factorial arrangement, being four energetic meals (millet, corn, sorghum and wheat) and five levels of addition (0, 8, 16, 24 and 32%). The meals were obtained by grinding the grains, where the levels of addition were calculated based on natural material. The results indicated that the energetic meals represented good sources of additives for ensiling Piata palisadegrass, for considerably improving protein and carbohydrate fractions. However, among the meals used, the sorghum was less efficient by presenting a lower protein fraction (A) and higher fraction C, compared with other additives. The meals of wheat and sorghum showed higher contents of carbohydrate fractions (A+B1 and C). It is recommended the level of addition of 24% of meals, for providing better nutritional value to silage.

In the south-central region of Brazil, there is a trend toward reducing the sugarcane inter-harvest period and increasing traffic of heavy harvesting machinery on soil with high water content, which may intensify the compaction process. In this study, we assessed the structural changes of a distroferric Red Latosol (Oxisol) by monitoring soil water content as a function of the Least Limiting Water Range (LLWR) and quantified its effects on the crop yield and industrial quality of the first ratoon crop of sugarcane cultivars with different maturation cycles. Three cultivars (RB 83-5054, RB 84-5210 and RB 86-7515) were subjected to four levels of soil compaction brought about by a differing number of passes of a farm tractor (T0 = soil not trafficked, T2 = 2 passes, T10 = 10 passes, and T20 = 20 passes of the tractor in the same place) in a 3 × 4 factorial arrangement with three replications. The deleterious effects on the soil structure from the farm machinery traffic were limited to the surface layer (0-10 cm) of the inter-row area of the ratoon crop. The LLWR dropped to nearly zero after 20 tractor passes between the cane rows. We detected differences among the cultivars studied; cultivar RB 86-7515 stood out for its industrial processing quality, regardless of the level of soil compaction. Monitoring of soil moisture in the crop showed exposure to water stress conditions, although soil compaction did not affect the production variables of the sugarcane cultivars. We thus conclude that the absence of traffic on the plant row maintained suitable soil conditions for plant development and may have offset the harmful effects of soil compaction shown by the high values for bulk density between the rows of the sugarcane cultivars.

The goal of this study was to evaluate the fermentative and bromatological characteristics of Piata palisadegrass (Brachiaria brizantha cv. Piata) ensiled with levels of meals from biodiesel industry. The experiment was performed at the Federal Institute of Goias State, Campus Rio Verde. The experiment was a completely randomized design with four replications, in 4 x 4 factorial arrangement, being four meals (cotton, sunflower, soybean, and canola) and four levels of inclusion (0, 5, 10 and 15%). The results showed the oleaginous meals from biodiesel industry are indicated as additives for ensiling Piata palisadegrass, by improving the qualitative, nutritional and fermentative characteristics of the Piata palisadegrass silage. It is recommended the addition of 15% of the meals, since this level provides the best quality of silage. The soybean meal is the most effective to improve the silage quality, in comparison with the other additives.

This study was developed to evaluate silage quality of Piata palisadegrass with palm kernel cake (Elaeis guineensis Jacq.). The experiment was carried out at the Federal Institute of Goiás State, Campus Rio Verde, in a completely randomized design with four treatments and five repetitions. The treatments consisted of Piata palisadegrass ensiled with palm kernel in the levels of 0, 5, 10 and 15% on a natural basis of the Piata palisadegrass. The material was minced, mixed, packed into experimental silos and opened after 60 days of fermentation. The palm kernel cake is an agro-industrial by-product that can enrich the silage, increasing its nutritional value.The addition of palm kernel cake improved the fermentative and bromatological parameters of the silage, increasing the dry matter, crude protein, ether extract, and total digestible nutrients, with a reduction in the fiber fraction, values of pH, ammonia nitrogen, and titratable acidity. The use of palm kernel cake in Piata palisadegrass silage increase the fractions A, B1, B2 and in vitro dry matter digestibility, and decrease the fractions B3 and C. For achieving the best quality silage it is recommended the addition of 15% palm kernel cake.

Aiming to evaluate the sorghum intercropping on the line in two seeding dephts of brachiaria species, a trial was conducted on the field in february 2009 in Rio Verde, GO. The experimental design used was randomized blocks in factorial scheme 2x3+1+3, with four replications, being made up two brachiaria sowing depths (2 and 10 cm), three brachiaria species (Brachiaria decumbens, B. brizantha cv. Marandu and B. ruziziensis) intercropped with the sorghum DKB 599, plus four additional treatments of sorghum and brachiaria monocultures. At 52 days after to harvest the sorghum grains, it was made up the cutting on brachiaria at 30 cm from the soil to explore the regrowth of plants in off-season cultivation, and further evaluation of forage yield at 36 days after the cutting. The intercropping in the line with B. brizantha, at 2 or 10 cm sowing depth, and with B. decumbens, sown at 2cm, appeared as the most promising for sorghum grain production. The brachiaria and sorghum intercropping in the line increased the total dry matter and crude protein yields. The regrowth of brachiaria plants in the intercropping showed to be a technique viable for forage production and soil cover in dry season at Brazil cerrado.

This study was developed with the purpose of evaluating the protein fractionation and in vitro di- gestibility of the dry matter (IVDMD) of millet genotypes for grazing, managed at different heights and sub- jected to several cuts. The experiment had a randomized complete block design, with repeated measures over time, four replications in a 3x3 factorial arrangement, with three cultivars of millet (ADR 500, LAB 1542 and LAB 1838) and three average cutting heights (60; 80 and 100 cm). Evaluations were undertaken through cuts in the same plots during four months. Results showed that millet genotypes were similar as for the values of pro- tein fractionation and IVDMD. The forage quality is affected by the management of cutting height, thereby it is not recommended to manage millet genotypes at 100 cm height for providing lower fraction A, B1, B2 and digestibility and higher fraction B3 and C of the forage.

This study evaluated the effect of nitrogen sources and doses on dry matter yield and bromatological composition of xaraés grass throughout the year. The experiment was carried out at the Agronomy Faculty of Rio Verde University from October 2008 to January 2010. The experiment consisted of a randomized complete block design in a 2 x 4 factorial arrangement with measures repeated in time, and four replications. We tested two nitrogen sources (ammonium sulfate and urea) and four nitrogen levels (0, 200, 400 and 600 kg ha-1). The evaluations were conducted on the same plots throughout the year and during all four seasons (autumn, winter, spring, and summer). The results demonstrated that the maximum grass production of dry matter and crude protein of xaraés grass for the sources of urea and ammonium sulfate were estimated at doses of 500 and 472 kg ha-1 and 407 and 396 kg N ha-1, respectively. And for TDN level the maximum dose was 404.74 kg ha-1 N, for the source of ammonium sulfate. This result indicates that, regardless of the source, the application of increasing doses of up to 400 kg ha-1 of nitrogen in xaraés grass is sufficient to maintain a high dry matter production, associated with the nutritional value of the forage. The source ammonium sulfate demonstrated higher efficacy for xaraés grass dry matter production in the seasons evaluated, however additional studies are needed to evaluate the economical feasibility of its use.

A reconstituição da fertilidade do solo é um dos caminhos para se recuperar a capacidade produtiva da pastagem em degradação. A adubação nitrogenada é fundamental para o aumento da produção de forragem, principalmente, quando se trata da recuperação de pastagens. Diante disso, o objetivo do trabalho foi avaliar as características estruturais e o acúmulo de massa seca (MS) de lâminas foliares e colmos mais bainhas do capim-marandu de pastagem em estágio moderado de degradação, sob doses e fontes de nitrogênio (N), por três anos. O experimento foi conduzido de julho de 2003 a março de 2006, na Fazenda Modelo da Universidade Estadual de Goiás (UEG), em uma área de 882 m², com parcelas de 20 m² e área útil de 6 m². O delineamento experimental utilizado foi o de blocos ao acaso, com três repetições. Os tratamentos nas parcelas foram caracterizados pelo fatorial 2 x 4, sendo duas fontes de N (sulfato de amônio e uréia) e quatro doses de N (0; 100; 200 e 300 kg ha-1 ano-1). Na subparcela, os tratamentos foram representados pelos anos (2004; 2005 e 2006), referentes ao tempo de recuperação da pastagem. A adubação nitrogenada foi parcelada em três aplicações, após cada corte de avaliação da forrageira. Os resultados obtidos mostraram que a adubação nitrogenada influenciou as características estruturais e o acúmulo de massa seca do capim-marandu, e, consequentemente, a sua recuperação. A dose de 300 kg ha-1 ano-1 de sulfato de amônio proporcionou maiores valores de altura de plantas, densidade de perfilhos e massa seca das lâminas foliares.To replenish soil fertility is one of the ways of recovering the productive capacity of degraded pasture. Nitrogen fertilisation is fundamental to increasing forage production, especially when it comes to the recovery of pasture. With this in mind, the objective of this work was to evaluate the structural characteristics and dry matter (DM) accumulation of the leaf blades and sheathed stems of marandu-grass pasture at a moderate stage of degradation, for different dosages and sources of nitrogen, during a three-year period. The experiment was carried out from July, 2003 to March, 2006 at the Model Farm of the Goiás State University (UEG), over an area of 882 m² with plots of 20 m² and usable area of 6 m². The experimental design was of randomized blocks with three replications. The treatments in the plots were characterized by a 2 x 4 factorial, being two nitrogen sources (ammonium sulphate and urea) and four nitrogen dosages (0; 100; 200 and 300 kg ha-1 yr-1). For each sub-plot, treatments were represented by the years (2004, 2005 and 2006), as relating to the time of the recovery of the pasture. Nitrogen fertilization was divided into three applications, following each harvesting of the grass for forage evaluation. The results showed that nitrogen fertilisation influenced the structural characteristics and dry matter accumulation of marandu grass, and hence its recovery. The dosage of 300 kg ha-1 yr-1 of ammonium sulphate resulted in greater values for plant height, tiller density and leaf-blade dry matter.

The seasonality of forage production represents a limiting factor in the production of ruminants. The use of silages has been a solution for periods of low forage production, providing high quality food. This study was conducted to evaluate the fermentative characteristics and the chemical composition of silage of Urochloa brizantha cultivars with different levels of Campo Grande Stylosanthes. It was used a complete randomized block design with three replications in a 2 x 4 factorial design, being two cultivars of Urochloa brizantha (BRS Piata palisadegrass and BRS Paiaguas palisadegrass) and four levels of Campo Grande Stylosanthes (0, 10, 20 and 30%). Silages of Urochloa brizantha with Campo Grande Stylosanthes exhibit satisfactory quality, on the basis of the characteristics evaluated, with no significant difference between cultivars. The mixed silage of Campo Grande Stylosanthes with grasses at 30% has proven to be an interesting option, thus promoting adequate fermentation and maintaining the nutritional quality of silage.

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 Brachiaria 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.

O presente estudo foi desenvolvido sob condições de campo, visando avaliar a eficiência no uso e no aproveitamento do nitrogênio pelo capim-marandu por meio de diversos índices. O experimento foi conduzido na Fazenda Modelo da Universidade Estadual de Goiás (UEG) num Latossolo Vermelho distrófico, no período de julho de 2003 a março de 2006. O delineamento experimental utilizado foi de blocos ao acaso, com três repetições. Os tratamentos nas parcelas foram caracterizados por um fatorial 2 x 4, sendo duas fontes de N (sulfato de amônio e uréia) e quatro doses de N (0, 100, 200 e 300 kg/ha). Na subparcela, os tratamentos foram representados pelos anos (2004, 2005 e 2006), referentes ao tempo de recuperação da pastagem. A adubação nitrogenada foi parcelada em três aplicações após cada corte de avaliação da forrageira. Foram realizados três cortes da forrageira por ano, avaliando-se a massa seca e os teores de N nos tecidos. Com esses resultados, avaliaram-se os índices de Eficiência de Utilização do N (EUN), Recuperação do N Aplicado (RNA), Eficiência Agronômica do N Aplicado (EA) e Eficiência Fisiológica (EF) ou Eficiência Biológica. Os resultados mostraram que a EUN aumentou, enquanto que a RNA, EA e a EF diminuíram com o aumento das doses de N aplicadas. Em todos os casos, os índices foram influenciados pelos anos de recuperação da forrageira estudados, mas não pelas fontes de N.This study was accomplished under field conditions, to evaluate the use and efficiency of nitrogen uptake, through various indexes, in pasture of Brachiaria brizantha. The experiment was conduced at the Model Farm of the Goiás State University in a distrophic Dark Red Latosol, from 2003 July to 2006 March. The experimental design was randon blocks, with three replicates. The treatments were placed in parcels characterized by a 2x4 factorial, with two sources of N (ammonium sulfate and urea) and four doses of N (0, 100, 200 and 300 kg/ha/year). In sub - parcel, the treatments were represented per years (2004, 2005 and 2006) refering to time of pasture recovery. The use of nitrogen was divided in three times, after each cut evaluation of the forage pasture. Three cuts were made per year, evaluating dry mass and N accumulation in the tissue. Nitrogen Utilization Efficiency, Recovery from the N Applied, Agronomic Efficiency from the N Applied, Physiological or Biological Efficiency indexes were evaluated. The results showed that EUN increased, while RNA, EA and EF reduced with the increase in the N doses applied. In all cases, the indexes were influenced by the years of recovery the herbage, and not by the sources of N.

Adequate amounts and balanced proportions of nutrient supplyis fundamental for the forage productive process. For the fertilization handling, forage plant nutrient requiriment must be known and, consequently, the plant capacity to extract soil nutrients. Therefore, the research had as objective to evaluate the nutrient extraction by Brachiaria brizantha phytomass under nitrogen doses. A randomized complete block experimental design with three replications in a plot repeated in time was used. In the plots, a factorial 3 x 4 arrangement was used, being three cultivars of Brachiaria brizantha (MG-4,Marandu and Xaraés) and four nitrogen doses (0, 50, 100 and 150mg.dm-3). Three cuts of evaluation were allocated in time, referring to the time of cuts. The source of nitrogen used was urea. The sharpest treatment effects on phytomass production of Brachiaria brizantha cultivars and nutrient extraction were influenced by the highest nitrogen doses. Xaraés-grass showed greater productivity in relation to the other cultivars, being considered more responsive to the nitrogen fertilization. The maximum macronutrient extraction by Brachiaria brizantha followed the decreasing order for the macronutrients: K > N > P > Mg.> S and micronutrients: Mn > Faith > Zn > Cu, being necessary to restore soil nutrients, with the increase of nitrogen.

O nitrogênio (N) é considerado um dos nutrientes responsável pelo crescimento vegetativo das plantas, mantendo as pastagens produtivas e com bom valor nutritivo. Diante disso, objetivou-se avaliar o efeito da adubação nitrogenada na produção de massa seca, valor nutritivo e nutrição nitrogenada de cultivares de Brachiaria brizantha (A. Rich) Stapf. O delineamento utilizado foi blocos ao acaso em esquema fatorial 3 x 4 (três cultivares de Brachiaria brizantha: Marandu, Xaraés e MG-4; e quatro doses de N: 0, 50, 100 e 150 mg.dm-3, tendo como fonte a uréia), com três repetições. Avaliaram-se três cortes nas forrageiras, com intervalos de 30 dias. A adubação nitrogenada proporciona aumentos lineares nas produções de massa seca, teores de PB, nitrato, amônio e clorofila (unidade SPAD); e redução nos teores de FDN e FDA nos cultivares de Brachiaria brizantha. O cultivar Xaraés apresenta maior produção de massa seca, teor de PB, clorofila (unidade SPAD) e menores teores de FDN e FDA que os cultivares Marandu e MG-4.Nitrogen (N) is considered one of the major nutrients responsible for vegetative pasture growth, by influencing forage productivity and nutritive value. With this in mind, dry mass production and quality of Brachiaria brizantha (A. Rich) Stapf cultivars were studied and evaluated in order to discover nitrogen (N) fertilization effect on pasture grown under Brazilian savanna conditions. The experimental design used was randomized block in a 3 x 4 factorial scheme (three Brachiaria brizantha cultivars: Marandu, Xaraés, and MG-4 and applying four doses of N: 0, 50, 100, and 150 mg.dm-3, using urea as N source with three replications. Three forage cuttings were done in 30 day intervals. Nitrogen fertilization resulted in a linear increase of dry mass production, crude protein content, nitrate, ammonium, and chlorophyll (SPAD unit) content and a decrease of neutral detergent fiber (NDF) and acid detergent fiber (ADF) content in Brachiaria brizantha cultivars. Xaraés cultivar presented greater dry mass production, crude protein content, chlorophyll (SPAD unit) content, and lower NDF and ADF content than Marandu and MG-4 cultivars.

Nitrogen is an one principal among others, essential and responsible nutrient for forage productivity and pasture quality increasing. Besides that, this paper objective was to evaluate nitrogen doses and source effects on nutrient concentration in marandu palisadegrass. The experiment was carried out from July of 2003 to March of 2006 at the Modelo Farm of University Goiás State in an 882 m2 area. The pasture was established for more than ten years and it was presenting low herbage production being considered in moderate degradation phase. The treatment combination was made in a split-plot design with three replicates. Main plot, arrangements in a randomized complete block design was employed, were turned by a 2 x 4 factorial, being two sources of N (ammonium sulfate and urea) and four doses of N (0, 100, 200 and 300 kg ha-1 yr-1). On each year, during the three years, three cuts evaluating are done at the forage plant. The rates of Nitrogen didn’t come to the maximum point to the concentrates of N, K, Mg, S, Cu and Fe. Increasing N rates promoted reduction in phosphorus absorption in plant tissue. Higher N:S relation were observed in plants which received urea as nitrogen source. The application of nitrogen, affected the nutritional status of signal grass and the recovery of this. The application of nitrogen, affected the nutritional status of signal grass and it recovering. KEY WORDS: Ammonium sulfate, Brachiaria brizantha, nutrient absorption, urea. O nitrogênio é um dos principais nutrientes responsáveis pelo aumento da produtividade e melhoria da qualidade da forragem. Diante disso, objetivou-se avaliar o efeito de doses e fontes de nitrogênio na concentração de nutrientes do capim-marandu. O experimento foi desenvolvido de julho de 2003 a março de 2006, na Fazenda Modelo da Universidade Estadual de Goiás. O delineamento experimental utilizado foi em blocos casualizados com parcelas subdivididas no tempo, com três repetições. Utilizou-se o esquema fatorial 2 x 4, sendo duas fontes de nitrogênio (sulfato de amônio e ureia) e quatro doses de nitrogênio (0, 100, 200 e 300 kg ha-1 ano-1). Em cada um dos anos, procedeu-se a três cortes de avaliação da planta forrageira. As doses de nitrogênio não atingiram o ponto de máximo para as concentrações de N, K, Mg, S, Cu e Fe. O incremento na adubação nitrogenada reduz a absorção de P. O nitrogênio na fonte de ureia promove maior relação N:S. A aplicação de nitrogênio influencia o estado nutricional do capim-marandu e sua recuperação.PALAVRAS-CHAVES: Absorção de nutrientes, Brachiaria brizantha, sulfato de amônio, ureia.

The soil compaction promoted for animal trampling and traffic of machines, is one of great impediments to attainment of raised pasture productivities. However, the soil-pasture relationship studies have not taken in consideration the biological soil descompaction, as well as its effect in productivity. This study objective was to evaluate dry mass production of Tifton 85 grass in function of different soil compaction degrees and potential of structural quality recovery of an Red-Yellow Argisol, promoted by forage plant. The experiment was carried out in green house, in delineation entirely randomized, with the tifton 85 grass crop in the following degrees of compacting: 64%, 84%, 90%, 93% and 100%, gotten for the assay of Normal Proctor. The attributes had been evaluated the soil physical- hydric, least limiting water range and forage dry mass production. Tifton 85 grass recovered the structure of Red-Yellow Argisol. The soil descompaction promoted adequate soil biophysics conditions to forage development. The dry mass production increased with the cutting succession independent of initial degree of soil compaction.KEY WORDS: Biological soil descompaction, Cynodon sp., least limiting water range, recovery of pastures. A compactação do solo, promovida pelo pisoteio animal e pelo tráfego de máquinas, é um dos grandes entraves à obtenção de elevadas produtividades das pastagens. Entretanto, os estudos de relação solo–pastagem não têm levado em consideração a descompactação biológica do solo, nem seus efeitos na produtividade. O objetivo deste estudo foi avaliar a produção de massa seca do capim-tifton 85 em função de diferentes graus de compactação do solo e o potencial de recuperação da qualidade estrutural de um argissolo vermelho-amarelo, promovida pela planta forrageira. Desenvolveu-se o experimento em casa de vegetação, mediante delineamento inteiramente casualizado, com o cultivo do capim-tifton 85 nos seguintes graus de compactação: 64%, 84%, 90%, 93% e 100%, obtidos pelo ensaio de Proctor Normal. Avaliaram-se os atributos físico-hídricos do solo, o intervalo hídrico ótimo e a produção de massa seca da forrageira. O capim-tifton 85 recuperou a estrutura do argissolo vermelho-amarelo. A descompactação do solo promoveu condições biofísicas do solo adequadas ao desenvolvimento da forrageira. A produção de massa seca aumentou com a sucessão dos cortes, independentemente do grau de compactação inicial do solo.PALAVRAS-CHAVES: Cynodon sp., descompactação biológica do solo, intervalo hídrico ótimo, recuperação de pastagem.

A adubação nitrogenada influencia positivamente no aspecto nutricional das gramíneas forrageiras, a ponto de resultar na recuperação adequada de pastagem. Objetivou-se com este estudo, avaliar a nutrição do capim-marandu, submetido a doses e fontes de N, pela determinação indireta de clorofila e pela concentração de N total, bem como a relação entre eles e os teores de N inorgânico (N-NH4+ e N-NO3-) nas folhas das plantas por um período de três anos. O experimento foi realizado de julho de 2003 a março de 2006, na Fazenda Modelo da UEG, numa área de 882 m², com pastagem estabelecida há mais de dez anos, com baixa produção de forragem. O delineamento experimental utilizado foi em blocos casualizados, com parcelas subdivididas no tempo, com três repetições. Foi utilizado o esquema fatorial 2 x 4, sendo duas fontes de N (sulfato de amônio e uréia) e quatro doses de N (0, 100, 200 e 300 kg ha-1 ano-1). Em cada um dos anos, foram realizados três cortes para avaliação da planta forrageira. Os teores de clorofila aumentaram com as doses de N e anos de avaliação da pastagem. A maior concentração de N foi encontrada na maior dose de N aplicada na forma de sulfato de amônio. Verificou-se uma relação direta entre os teores de clorofila e as concentrações de N nas folhas recém-expandidas de capim-marandu. O N inorgânico (N-NH4+ e N-NO3-) representou pequena fração do N total das folhas de capim-marandu.Nitrogen fertilization positively influences nutritional aspects in grass and can result in largely recovered pastures. The research objective was to study the nutrition of marandu grass treated with nitrogen doses and sources, by methods of indirect determination of chlorophyll (SPAD) and total nitrogen concentration and the relation between them and inorganic nitrogen contents (N-NH4+ and N-NO3-) in plant leaves. The experiment was carried out from July of 2003 to March of 2006 on a model farm of the Universidade Estadual de Goiás, in an area of 882 m². The pasture had been used for more than ten years and the herbage yield was low and considered moderately degraded. A split-plot with three replications was used. The experiment had a complete randomized block, 2 x 4 factorial design, with two nitrogen sources (ammonium sulfate and urea) and four nitrogen doses (0, 100, 200, and 300 kg ha-1 yr-1 ). In each year, marandu grass was cut and evaluated three times. Chlorophyll contents increased owing to the nitrogen doses and over the years. Nitrogen concentration was highest after the application of highest nitrogen doses in form of ammonium sulfate. The chlorophyll content and leaf nitrogen concentration in newly expanded leaves of marandu grass were directly related. Mineral nitrogen concentration (N-NH4+ and N-NO3-) represented little total nitrogen fraction of forage lives. Chlorophyll meter can be used for evaluation of nutritional state of marandu grass to know nitrogen absorption. The inorganic nitrogen concentration (N-NH4+ and N-NO3-) represented a small fraction of total nitrogen in the forage leaves.

A deficiência de N é uma das principais causas de degradação de pastagens cultivadas, principalmente do gênero Brachiaria. A reconstituição da fertilidade do solo é um dos caminhos para recuperar a capacidade produtiva de pastagem em degradação. Dentre os nutrientes, destaca-se o N, que é o grande responsável pela recuperação dessas áreas. Diante disso, objetivou-se avaliar o efeito da aplicação de doses e fontes de N em pastagem de capim-marandu em estádio moderado de degradação, por um período de três anos, sobre atributos químicos do solo, como pH, teores de Al trocável, matéria orgânica do solo, N total e N inorgânico (N-NO3-, N-NH4+). O experimento foi realizado de julho de 2003 a março de 2006, na Fazenda Modelo da UEG, numa área de 882 m². A pastagem já se encontrava estabelecida há mais de 10 anos, com baixa produção de forragem. O delineamento experimental utilizado foi em blocos casualizados com parcelas subdivididas no tempo, com três repetições. Foi utilizado o esquema fatorial 2 x 4, sendo duas fontes de N (sulfato de amônio e uréia) e quatro doses de N elemento (0, 100, 200 e 300 kg ha-1 ano-1 ). Após três anos de aplicação contínua com as maiores doses de N, o pH do solo diminuiu de 5,6 para 4,6 e o teor de Al3+ aumentou de 0,05 para 0,41 cmol c dm-3; o sulfato de amônio causou maior acidificação do solo em relação à uréia. A aplicação de doses elevadas de N aumentou os teores de Al3+, MO, N total, N-NO3- e N-NH4+ no solo, e os teores de N-NH4+ foram mais elevados que os de N-NO3-.Nitrogen deficiency is one of the important causes of degradation of cultivated pasture, mainly in the case of Brachiaria pastures. Soil recovery is a way to restore the productive capacity of pastures in degradation. Among nutrients, nitrogen is considered essential and largely responsible for pasture area recovery. The research objective was to evaluate the effects of application of nitrogen doses and sources on marandu grass pasture over a period of three years, based on soil chemical characteristics such as pH, exchangeable aluminum, soil organic matter, total nitrogen and inorganic nitrogen (N-NO3-, N-NH4+). The experiment was carried out from July 2003 to March 2006 on a model farm of the Universidade Estadual de Goiás, in an area of 882 m². Pasture had been grown for more than ten years and was considered in moderate degradation phase, in view of the low herbage yields. A split-plot combination with three replications was used. The experiment had a complete randomized block, 2 x 4 factorial design, with two N sources (ammonium sulfate and urea) and four N doses (0, 100, 200, and 300 kg ha-1 yr-1 ). After three years of continuous nitrogen application at highest doses to marandu grass, the soil pH decreased from 5.6 to 4.6 and Al3+ content increase from 0.05 to 0.41 cmol c dm-3. The ammonium sulfate source increased soil acidity more than urea. Application of high nitrogen rates increased Al and organic matter contents, soil total nitrogen, N-NO3- and N-NH4+. The N-NH4+ contents were higher than N-NO3- in all nitrogen doses and years evaluated.

O experimento foi conduzido em casa de vegetação, na Embrapa Arroz e Feijão, com objetivo de avaliar o efeito de doses de N e K na produção de massa seca e extração de macronutrientes pela fitomassa do capim xaraés. O delineamento utilizado foi bloco ao acaso, com esquema fatorial 4 x 4, sendo quatro doses de Nitrogênio: 0; 25, 50 e 100mg dm-3, e quatro doses de Potássio: 0; 25, 50 e 100mg dm-3, com três repetições. Foram realizados três cortes de avaliação da forrageira. Todos os macronutrientes sofreram variações significativas em função das doses de Nitrogênio e Potássio aplicadas. O efeito mais pronunciado sobre a extração dos macronutrientes foi proporcionado pelas doses de Potássio. A ordem decrescente de extração para o capim-xaraés, considerando extração máxima de cada nutriente, foi: N = K > Ca > Mg > P > S. Contudo, sugerem-se estudos dessas variáveis, em condições de campo, de modo a se obter mais informações sobre esse cultivar para que as estratégias de manejo da cultura sejam mais eficientes.The experiment was carried out in a greenhouse at Embrapa Arroz e Feijão station, with the objective of evaluating the extraction of macronutrients by the phytomass of Brachiaria brizantha cv. 'Xaraés'. The experimental design was randomized blocks in a factorial scheme 4 x 4 (four rates of nitrogen aplication: 0; 25, 50 e 100mg dm-3, and four rates of potassium aplication: 0; 25, 50 e 100mg dm-3), with three repetitions. Three cuttings were performed with 30-day intervals, where the forage plant was cut at a height of 5cm from soil. All the nutrients underwent significant variations as related with the doses of N e K applied. In general, the most marked effect on the extraction of macronutrients was provided by the K rates. The decreasing order of macronutrient extration for capim-Xaraés, considering maximum extration of each nutrient, was: N = K > Ca > P > S. However, one suggests studies of these nutrients, in field conditions, in order to get more information on this forage plant so that the handling strategies one becomes more efficient.

The experiment was carried out in glasshouse, at Rice and Beans Embrapa aiming to evaluate the effect of nitrogen and potassium fertilization, on nutrients concentration in grass Xaraés. The experimental design was randomized blocks in a 4 x 4 factorial scheme combination (four doses of N: 0; 25, 50 and 100 mg dm-3 and four doses of K: 0; 25, 50 and 100 mg dm-3) with three replicates. The nitrogen source utilized, was urea and the K source was potassium chloride. Three cuttings were performed with 30 days intervals. Each dose of nitrogen and potassium fertilization was split into three applications. The forage plant was cut at a height of 5 cm from the ground. The results showed significant interactions between doses of nitrogen and potassium that increases the leaf nitrogen and potassium concentrations. Nitrogen fertilization increased the potassium, copper and iron concentration. Considering that the plant used in this study is a new cultivar, it suggests studies of these nutrients, in a field condition, in order to get more information on this forage plant so that the handling strategies one becomes more efficient. KEY WORDS: Brachiaria brizantha cv. xaraés, macronutrients, micronutrients, potassium chloride and urea Desenvolveu-se o experimento em casa de vegetação na Embrapa Arroz e Feijão, com o objetivo de se avaliar o efeito da adubação nitrogenada e potássica na concentração de nutrientes do capim-xaraés. O delineamento utilizado foi o de blocos ao acaso em esquema fatorial 4 x 4 (quatro doses de nitrogênio: 0; 25, 50 e 100 mg dm-3 e quatro doses de potássio: 0; 25, 50 e 100 mg dm-3) com três repetições. Empregou-se, como fonte de nitrogênio, a uréia e de potássio, o cloreto de potássio. Efetuaram-se três cortes, com intervalos de trinta dias. Cada dose da adubação nitrogenada e potássica foi parcelada em três aplicações. Cortou-se a forrageira a uma altura de 5 cm do solo. A interação entre doses de nitrogênio e potássio promoveu aumentos significativos nas concentrações foliares de nitrogênio e fósforo. A adubação nitrogenada aumentou a concentração de potássio, cobre e ferro, enquanto a adubação potássica aumentou a concentração de potássio, mesmo com altos teores de potássio no solo. Contudo, por se tratar de um cultivar novo, sugerem-se estudos dessas variáveis, em condições de campo, de modo a se obter mais informações na absorção de nutrientes para esse cultivar, para que as estratégias de manejo sejam mais eficientes. PALAVRAS-CHAVES: Brachiaria brizantha cv. xaraés, cloreto de potássio, macronutrientes, micronutrientes e uréia.

O experimento foi conduzido em casa de vegetação, na Embrapa Arroz e Feijão, com o objetivo de avaliar o intervalo de corte na produção de massa seca, altura de planta e composição químico-bromatológica da Brachiaria brizantha cv. MG-5. O delineamento utilizado foi o inteiramente casualizado. Os tratamentos constituíram de quatro intervalos de corte (15, 20, 30 e 60 dias), com cinco repetições, totalizando 20 parcelas. Foram aplicados 100 mg dm-3 de nitrogênio, utilizando como fonte o sulfato de amônio, em todas as parcelas. A adubação nitrogenada foi parcelada, de acordo com os cortes de avaliações. Foram realizados quatro cortes para o intervalo de 15 dias, três cortes para o de 20 dias, dois cortes para o de 30 dias e um corte para o de 60 dias. A forrageira foi cortada a uma altura de 5 cm do solo. O aumento no intervalo de corte na Brachiaria brizantha cv. M-5 determina acréscimos na produção de massa seca e teores de FDN e FDA. Contudo, o inverso pode ser observado no teor de PB e concentrações de P, Cu e Fe.The experiment was carried out in a green house, at Embrapa Arroz e Feijão. It aimed to evaluate the offect of cutting period on dry mass production and bromatologic- chemical composition of Brachiaria brizantha cv. MG-5. The experimental design was completely randomized, with five replications. The treatments were constituted by four cutting intervals (15, 20, 30 and 60 days). After cuttings at a distant from soil, of ammonium sulfate (100 mg dm-3) was applied to all treatments. Four cuttings were carried out at 15 - day intervals, three at 20 day-intervals, two at 30 - day intervals and one at a 60 day-interval. Increases in cutting intervals caused dry mass production, neutral detergent fiber and acid detergent fiber rase. However, the opposite was observed for bromatologic composition and phosphorus, copper and iron concentrations.

O experimento foi conduzido em casa-de-vegetação, com objetivo de avaliar o efeito de doses de P e K na altura, produção de massa seca e nutrição da crotalária em ARGISSOLO VERMELHO-AMARELO-Eutrófico, sob vegetação do cerrado.O delineamento utilizado foi blocos ao acaso em esquema fatorial 4 x 4, com 3 repetições. Os tratamentos constituíram de quatro doses de P (0, 25, 50 e 75 kg ha-1 de P2O5) e quatro de K (0, 25, 50 e 75 kg ha-1 de K2O). Aos 60 dias após a germinação, antes do período de floração, foi realizado o corte da leguminosa. Foram realizadas análises químicas da parte área para determinação das concentrações de macro e micronutrientes. A aplicação de 75 kg ha-1 de P2O5 e K2O, promoveu melhores resultados na altura de planta e produção de massa seca da crotalária. As maiores concentrações de P e Ca foram observadas com as doses de 75 kg ha-1 de P2O5 e a maior concentração de K foi obtida com a aplicação de 75 kg ha-1 de K2O.The experiment was carried under greenhouse conditions with the objective of evaluating P and K effects on plant height, dry matter production and nutrition of crotalaria in an eutrophic Red - Yellow Argisol (alfisol), under cerrado vegetation. The experimental design was a randomized blocks in a 4 x 4 factorial scheme, with three replications. The treatments involved four phosphorus levels (0, 25, 50, and 75 kg/ha of P2O5) and four potassium levels (0, 25, 50, and 75 kg/ha of K2O). At sixty days, after sowing and before flowering period, plants were harvested. Shoot's macro and micronutrient concentrations were determined by chemical analysis. Application of 75 kg ha-1 P2O5 and K2O promoted the best reults in plant height and dry matter production of crotalaria. Highest P and Ca concentrations were observed by applying 75 kg ha-1 of P2O5 and the highest K concentration was verified when 75 kg ha-1 of K2O were applied.

O experimento foi realizado na Embrapa Arroz e Feijão, com o objetivo de avaliar a produção de matéria seca e composição bromatológica da Brachiaria brizantha cv. Marandu. O trabalho foi desenvolvido em um Latossolo Vermelho Escuro de média fertilidade. Esta área era ocupada por lavouras anuais, corrigida esporadicamente e adubada anualmente. Inicialmente, esta ficou em repouso por um período de um ano, onde desenvolveu a Brachiaria brizantha. A área total ocupada era de 16 hectares, sendo dividida em cinco piquetes de 3,2 ha. O pasto foi roçado para uniformização da pastagem. Foram colocados 34 animais, onde se utilizou o sistema rotacionado com 32 dias de descanso e oito dias de ocupação. A forrageira era amostrada semanalmente antes da entrada dos animais nos piquetes, para o acompanhamento da produção de matéria seca e composição bromatológica. As baixas temperaturas e a falta de umidade do solo foram os fatores que mais influenciaram na produtividade e qualidade da Brachiaria brizantha cv. Marandu. PALAVRAS-CHAVE: Coleta de amostra, manejo de pastagem, pastejo rotacionado, qualidade da pastagem.

O objetivo deste trabalho foi avaliar a produção de matéria seca e concentração residual de nutrientes na parte foliar e no solo. O plantio foi realizado em vasos de plástico com capacidade de 10 kg, e os tratamentos constituíram-se de seis dosagens de gesso agrícola: 0; 250; 500; 1.000; 2.000 e 4.000 kg/ha. O delineamento utilizado foi o inteiramente ao acaso, com quatro repetições, e quinze dias após a emergência das plântulas foi realizado um desbaste, com seleção de dez plantas por vaso. Aos sessenta dias após a germinação, efetuou-se o corte da forrageira, para realização das análises químicas foliares e determinação dos nutrientes. Procedeu-se também a uma amostragem do solo, em todos os tratamentos, para verificação das concentrações de nutrientes existentes nele. Houve aumento de altura de plantas, matéria seca e massa verde até a dose de 2,75 t/ha de gesso. Os teores de Ca e P foliar apresentaram-se baixos, e Mg e Mn altos coeficientes de correlação, em relação a diferentes doses de gesso. Para Ca, N, K, Fe, Cu e Zn houve tendência de redução do seu teor residual com o aumento das doses de gesso aplicadas ao solo. Doses crescentes de gesso promoveram acúmulo de Ca e P na superfície do solo; Mn, Fe e Zn sofreram pequeno aumento do seu teor residual no solo com o aumento das doses de gesso; o K apresentou pequena redução do seu teor residual no solo com a aplicação de gesso. O aumento das doses de gesso promoveu a absorção apenas do Mn. PALAVRAS-CHAVE: Absorção de nutrientes, Panicum maximum, produção de matéria seca.

O experimento foi realizado na Fazenda Modelo do Departamento de Produção Animal da Escola de Veterinária, com o objetivo de foi avaliar a composição bromatológica e química do capim-Tanzânia em função de doses de nitrogênio (N), potássio (K) e enxofre (S). Foram aplicados em cobertura 150, 300 e 450 kg/ha da formulação N:K, com 20,40 e 60 kg/ha de S. O delineamento experimental utilizado foi blocos ao acaso em esquema fatorial 3 x 3 com três repetições. O período de avaliação da forrageira foi de um ano. Foram realizados três cortes no período das águas e dois cortes no período da seca. As coletas das amostras foram realizadas com auxílio de um quadrado de ferro de1m2, e a forragem foi cortada a uma altura de 30 cm acima do solo. O material, após ser identificado e pesado, foi enviado ao laboratório, onde foram realizadas as análises bromatológicas para determinação de PB, MS, FDN e FDA e análise química para determinação do S, P, K, Ca, Mg, Zn,Cu, Mn e Fe . Os teores PB e FDN não foram influenciados pelas doses aplicadas de N:K e S nos períodos avaliados. A percentagem de MS variou com as doses de N:K aplicadas no período da seca e a FDA na época das águas. O P e o Mge Cu foram influenciados pelas doses de N:K no período das águas e apenas o S na época da seca. O K foi influenciado pelas doses de S nas águas e na seca, e o K e Fe foram influenciados pela interação N:K x S. PALAVRAS-CHAVE: Absorção, composição bromatológica, macronutrientes, micronutrientes.

O experimento foi realizado com o objetivo de avaliar o efeito de doses crescentes de calcário dolomítico no desenvolvimento de plantas, teores de proteína bruta e absorção de fósforo, zinco, cálcio e magnésio do Stylosanthes guianensis cv. Mineirão. Foram considerados cinco tratamentos: 0, 1, 2, 3 e 4 t/ha de calcário dolomítico. Os vasos foram arranjados em blocos ao acaso com quatro repetições. Dez dias após a geminação, foi realizado um desbaste que permitiu a permanência de 10 plantas por vaso. Foram realizados dois cortes numa altura de 10 cm do solo. A altura da planta e a produção de matéria seca foram influenciadas pela aplicação de calcário. Baixas doses de calcário são suficientes para se elevar o teor de proteína. A eficiência do calcário na absorção de fósforo é muito pequena. Doses muito elevadas de calcário são exigidas para se conseguir a absorção máxima de fósforo. A aplicação de calcário afeta negativamente a absorção de zinco pela planta mãe mas positivamente pelos brotos e perfilhos. Doses relativamente baixas são necessárias para a absorção máxima de cálcio e magnésio no primeiro corte, mas doses maiores são requeridas para a absorção desses nutrientes pelas plantas produzidas após o corte. PALAVRAS-CHAVE: Absorção de Ca, Mg, P e Zn, correção do solo, produção de matéria seca, proteína bruta, solo de cerrado.

O experimento foi realizado em um Latossolo Vermelho Escuro, na Fazenda Modelo da Universidade Federal de Goiás, com o objetivo de avaliar o efeito de doses da formulação N: K com o uso do S na produção de massa seca do capim-Tanzânia. Também foram avaliadas a eficiência de conversão em massa seca e a recuperação relativa do N e do S. A formulação N:K foi aplicada em cobertura, nas doses de 150, 300 e 450 kg/ha, com adição de enxofre de 20, 40 e 60 kg/ha. O delineamento experimental foi de blocos completos ao acaso, em esquema fatorial 3 x 3, com três repetições. O período de avaliação da forrageira foi seis meses e as amostras foram coletadas à altura de 30 cm acima do solo. Melhores ECN e ECS são observadas quando se aplica menores doses de N:K e S, mesmo não havendo diferenças significativas nas concentrações destes nutrientes no tecido da planta sob a ação de doses crescentes dos mesmos. Ao contrário, as maiores RRN e RRS foram observadas quando se aplicou 450 kg/ha da formulação N:K na presença de 60 kg/ha de S.The experiment was carried out in a Dark Red Latosol at Fazenda Modelo, Federal University of Goiás, in order to evaluate the effect of N:K rates with the use of S in the production of dry mass of Tanzania grass. Also, the efficiency of N and S conversion and recovery in dry mass were evaluated. Rates of 150, 300 and 450 kg/ha of N:K aditioning 20, 40 and 60 kg/ha of S were applied as broadcast covering. The experimental design was a randomized complete blocks in a 3x3 factorial with three replications. The forage evaluation period was six months and the samples were collected at 30 cm-plant height. The highest productions of dry mass of Tanzania grass were obtained with applications of greater N:K and S rates. The highest efficiencies of nitrogen and sulfur conversions were verified with applications of the lowest N:K and S rates, with no significant differences in concentration of these nutrients in the plant tissues as their rate of application increased. Higher S contensts in leaf tissue and relative recovery of N and S were observed by applying 450 kg/ha N:K and 60 kg/ha of S.

The determination of protein fraction and rumen fermentation characteristics of pearl millet genotypes is important, since generate information about food nutritional value and also guide the breeding programs of genotypes to be used in diets of ruminants. The objective of this research was to determine the digestion rates of protein fractions, dry matter degradability and in vitro dry matter digestibility of silages from pearl millet genotypes produced at different cutting ages. The experiment was carried out on the Agronomy campus of theRioVerdeUniversityand on the Rio Verde campus of Goiano Federal Institute. The experimental design was randomized blocks with four replications in a 5 x 3 factorial arrangement, with five genotypes of millet: ARD 500, ADR 7010, LAB 0730, LAB 0731 and LAB 0732 and three cutting ages: 57, 65 and 73 days after sowing (DAS). The silage produced from pearl millet, regardless of genotype can be considered of good quality. The evaluated genotypes are considered early, so that the age that provided the best silage quality was 57 DAS. This age provided higher fractions A, lower fraction C and high degradability and digestibility.

The nutritional value of Xaraes and Piata palisadegrass silages wilted or with additives was evaluated in a completely randomized design (2x4 factorial arrangement), being two cultivars of Brachiaria brizantha (Xaraes and Piata palisadegrass) and four ensiling methods as treatments: T1- control, in natura forage (INF); T2 – INF wilted for 4 hours under the sun; T3- INF + bacterial additive (BactoSilo® Lallemand) 2 g ton-1 of in natura forage; T4 – INF + 15% of pearl millet meal. For ensiling, the grasses were harvested in the growth stage of 40 days, at 20 cm from the ground level. The addition of the inoculant and millet meal improved the fermentative and chemical parameters of both cultivars silages, by increasing soluble carbohydrates (SC), CP and TDN contents and reducing ammonia-nitrogen and pH. Because of its composition, 15% of millet meal inclusion affected SC, NDF, ADF and increased the IVDDM of silages. Bacterial inoculant or millet meal inclusion enhanced the nutritional value of Brachiaria brizantha silages and, could have a positive performance response on ruminants fed with these silages. Wilting was also effective in improving the fermentative stability of grass silages and may be a cheaper alternative to additives.

Desenvolveu-se esse estudo com o objetivo de avaliar a produção e a composição bromatológica de genótipos de milheto, manejados em diferentes alturas e submetidos a vários cortes. O delineamento experimental utilizado foi o de blocos completos ao acaso, com medidas repetidas no tempo, com quatro repetições, em esquema fatorial 3 x 3, sendo três cultivares de milheto (ADR 500, LAB 1542 e LAB 1838) e três alturas média de cortes (60; 80 e 100 cm). As avaliações foram realizadas durante quatro meses, consistindo de avaliações por cortes nas mesmas parcelas. Os resultados demonstraram que os genótipos de milheto representam uma boa alternativa para pastejo. Os genótipos (ADR 500; LAB 1542 e LAB 1838), apresentaram produção de massa seca e composição bromatológica semelhantes entre os materiais. A qualidade da forragem é afetada pelo manejo da altura de corte, sendo assim recomenda-se que os genótipos de milheto sejam manejados nas alturas de 80 cm, para associar melhor produção e qualidade da forragem.

A study was carried out to evaluate the protein fraction and in vitro dry matter digestibility of marandu, xaraes grasses and campo grande in monocropping and intercropping systems under different planting methods, for a period of two years. The experimental design was a complete randomized block with four replications. The treatments consisted of the following crop systems: campo grande in monocropping; xaraés grass in monocropping; marandu grass in monocropping; xaraés intercropped with campo grande in rows; xaraés intercropped with campo grande, broadcast; marandu grass intercropped with campo grande in rows; and marandu intercropped with campo grand, broadcast. The evaluations were conducted for two years, consisting of seasonal evaluations (autumn, winter, spring and summer) in the same plots, with repeated measurements over time. The results showed that xaraes and marandu grasses were similar between crop systems, indicating that both can be intercropped with campo grande. The intercropping of campo grande with Brachiaria brizantha cultivars improved the protein fraction and digestibility. The row method of planting provided better protein fractions and in vitro dry matter digestibility.