Integrated Crop Livestock Forest Research Articles

Carbon and Methane as Indicators of Environmental Efficiency of a Silvopastoral System in Eastern Amazon, Brazil

Livestock systems have been identified as major emitters of greenhouse gases due to the use of extensive areas with degraded pastures. The objective of this study was to analyze carbon (CO2) and methane (CH4) fluxes in the atmosphere as indicators of environmental sustainability in silvopastoral systems. CO2 and CH4 fluxes from soil to the atmosphere were monitored in a degraded pasture (predominant species: Panicum maximum cv. Mombaça) grown in full sun and compared with areas with tree species (Bertholletia excelsa, Dipteryx odorata, and Khaya grandifoliola) and productive pasture (Panicum maximum cv. Mombaça) grown in full sun. The study area was in Mojuí dos Campos, western Pará state, Eastern Amazon, Brazil. The evaluations were conducted in a Technological Reference Unit with a silvopastoral system, where animals used the shade of trees during high-temperature periods. The fluxes were measured using an ultraportable greenhouse gas analyzer coupled with static polyvinyl chloride ring chambers installed at the soil–air interface. In conclusion, areas with integrated systems (B. excelsa + pasture and K. grandifoliola + pasture) were better mitigators of CO2 emissions; the highest emissions occurred in the degraded pasture area during the rainiest months. The CH4 fluxes were more intense in the areas with degraded pasture and K. grandifoliola + pasture. Converting degraded pasture areas into integrated crop–livestock–forest systems reduced greenhouse gas emissions in the Amazon over 10 years of implementation. The implementation of integrated crop–livestock–forest systems in long-deforested areas with degraded pastures and a low production capacity showed high potential for changes focused on developing sustainable agriculture in the Amazon.

Physical characteristics of soybean cultivated under the conditions of integrated agrosystems

Integrated crop-livestock-forest (ICLF) systems involve intercropping of various crops to achieve beneficial and synergistic outcomes, enhancing both economic viability and environmental sustainability. Considering the complexity of integrated agrosystems and the economic importance of soybean production in Brazil, we aimed to investigate the effects of two ICLF systems on the physical characteristics and quality of soybeans produced. The treatments comprised plots (two ha) with either single-row (ICLFS) or triple-row (ICLFT), tree configurations intercropped with soybean (maize and forage grass), and control plots (one ha), whose crops were cultivated under full sunlight (CFS). Soybeans were harvested from plants located at 3, 6, 10 and 15 m from tree bands in the north and south faces of the ICLF systems and at random positions in the CFS plots. The moisture content, electrical conductivity of the exudate solution, hue angle and chroma index of grains harvested from ICLFS and ICLFT were similar to those of CFS-grown soybeans. However, the mass of 1000 grains and the bulk density values of ICLF-grown soybeans were significantly higher (P ≤ 0.05) than those of grains harvested from CFS plots. We conclude that the quality of soybean seeds was not negatively affected by the conditions prevailing in the ICLF systems. Moreover, it appears that the forest component contributed positively to the ecosystem by providing a favorable microclimate for the development of soybean grains.

Fuzzy Logic and Artificial Neural Network Perceptron Multi-Layer and Radial Basis in Estimating Marandu Grass Yield in Integrated Systems

ABSTRACT The integrated crop-livestock-forest (ICLF) system integrates different components of animal husbandry. The implementation of this system aims at sustainability, seeking to exploit the area as much as possible, in addition to reducing the impact on the physical, chemical, and biological properties of the soil. With technological advances and numerous variables, fuzzy logic, and artificial neural networks (ANNs) have been used for data classification and estimation. This study aims to estimate the Marandu grass yield in integrated systems using the input, volume of rainfall, and experimental period. A performance of approximately 0.077 was observed for the mean square error (MSE), and the radial basis in estimation (RBR) network had an error of 0.255%, which is much lower than that of the multi-layer perceptron (MLP) network and methodology based on fuzzy logic, with errors of 2.713 and 10.840%, respectively, between the obtained and expected output. This indicates that the quality of the grass was better with one or three eucalyptus lines in the ICLF system and demonstrates the application efficiency of the model with a tool for forecasting the Marandu grass yield in the studied soil and climate conditions.

Can Intensified Pasture Systems Reduce Enteric Methane Emissions from Beef Cattle in the Atlantic Forest Biome?

The objective of this study was to evaluate the effect of different pasture systems on beef steers’ performance, dry matter intake, enteric methane emission, carcass production, forage quality, and animal production per hectare (ha). The trial was conducted at Embrapa Southeast Livestock, São Carlos/SP, Brazil. Sixty Cachim beef steers (5/8 Charolais × 3/8 Zebu) with initial liveweights of 255 ± 7 kg were evaluated for two years under five different grazing production systems (EXT = Extensive; INT = Intensive; iCL = Integrated crop livestock; iCLF = Integrated crop livestock forest; iLF = Integrated livestock forest). The final liveweight was greater (p < 0.05) for the animals under the INT and iCL systems (484 ± 51 and 466 ± 79 kg, respectively) compared to animals in the iCLF, iLF and EXT systems (416 ± 57, 414 ± 50 and 429 ± 48 kg). The dry matter intake was significantly greater under the EXT system than it was under the iCL system (9.8 ± 2.1 and 7.5 ± 2.9 kg day−1). Regarding the emission intensity in relation to the liveweight gain per unit area (g CH4 kg LWG−1 ha−1 year−1), it differed significantly among the systems (EXT = 1.6; INT = 0.6; iCL = 0.8; ICLF = 1.1; ILF = 0.7). Similarly, the methane emission intensity differed in relation to the carcass production (kg CH4 kg−1 carcass; EXT = 0.496; INT = 0.250; iCL = 0.297; iCLF = 0.345; iLF = 0.286). Beef cattle that are raised in intensive and/or integrated pasture systems have a greater availability of forage mass and nutrients than those that are raised extensively. Pasture systems that undergo soil pH correction and fertilization, rotational grazing and/or integrated with maize cropping produce animals with greater average daily gain and final liveweights, thereby lessening the enteric methane emissions per kg of weight gain. In these systems, the efficiency in terms of the gain per land area is also greater, however, the systems that are integrated with a forest component (iLF and iCLF) are equal to that of the EXT system. The same pattern is observed in the intensity of the methane emission as for the efficiency of the animal gain per unit of land area.

Soil physical quality in the topsoil of integrated and non-integrated grazing systems in a Brazilian Ferralsol

Integrated grazing systems are important to tackle pasture degradation and promote agricultural sustainability, contributing to sustainable development goals and to soil quality. This study aimed to assess physical indicators of soil quality in the topsoil of integrated and non-integrated grazing systems. The studied systems included continuous grazing (CONT), rotational grazing (ROT), integrated crop-livestock (ICL), integrated livestock-forest (ILF), integrated crop-livestock-forest (ICLF) and an adjacent area with native vegetation (NV). The agricultural systems were established by 2011 and the soil was sampled in 2019. Assessments included saturated soil hydraulic conductivity (Ksat), soil bulk density (BD), total porosity (TP), macroporosity (MA), microporosity (MI), soil resistance to penetration (RP), mean weight diameter of soil aggregates (MWD) and total organic carbon (TOC). Apart from MWD, the soil quality indicators were sensitive in differentiating the studied systems. NV accounted for the highest means for Ksat, TP, and MA, and the lowest means for BD, MI, RP and MWD. Ksat in ICLF and ILF was higher than the other grazing systems. The lowest means for TP and MA, and the highest TOC was found in ICLF. BD, TP, MA and RP, which were strongly correlated with each other, suggest a degree of soil compaction in all grazing systems, caused mainly by cattle trampling. BD, MI, RP and MWD did not differentiate between grazing systems, indicating a similar soil quality between integrated and non-integrated grazing systems, which might be related to time since the experiment establishment. Further research is required for integrated and non-integrated grazing systems, including assessments of long-term experiments and testing novel indicators of soil quality.

Understanding the flux of nitrous oxide from the eucalypt soil in monoculture and Integrated Crop–Livestock–Forest systems

The Brazilian agricultural sector is largely responsible for nitrous oxide (N2O) soil emissions, mainly due to beef cattle and the use of synthetic nitrogen fertilizers. Therefore, Brazil is looking for measures, such as integrated crop–livestock– forest (ICLF), to increase productivity and reduce greenhouse gas emissions in this sector. The forest component within this system plays a positive role in the context of climate change, soil conservation, carbon dioxide (CO2) sequestration, and biodiversity protection. The aim of this study was to evaluate the effect of management and rainfall on N2O emissions in eucalypt monoculture soils and eucalypt soils in ICLF systems. Manual static chambers were used to collect gas samples, from November 2013 to October 2014, in four treatments, i.e., one eucalypt monoculture (F) and three modalities of ICLF (livestock–forest [LF], livestock–crop–forest [LCF], and integrated crop–livestock–forest [ICLF]). A gas chromatograph with an electron capture detector was used to measure the N2O concentrations. The results showed that rainfall considerably affected N2O fluxes across all the treatments, indicating that rainfall is the main factor in increasing emissions. During the wet season, the N2O levels ranged from 0.158 to 0.482 kg N-N2O ha-1 across all treatments. During the dry season, all treatments behaved like sinks of N2O. Moreover, N2O flux did not differ between the soils in the eucalypt monoculture and ICLF systems. This indicates that the forestry component in the ICLF systems did not affect N2O soil fluxes.

Potential impact of plans and policies based on the principles of conservation agriculture on the control of soil erosion in Brazil

AbstractLand use and coverage surveys show that 30.5% of Brazil's territory was dedicated to the production of food, fibers, biofuels, and raw materials. This paper fills a gap and provides information to society and decision‐makers about the effectiveness of the adoption of conservation agriculture (CA) principles with zero tillage (ZT/CA) and integrated crop–livestock–forest (iCLF‐CA) systems as the central policies to mitigate soil erosion, the main agent of land degradation and productivity loss. The increase in CA area by 2030 was estimated using Holt's damped technique for ZT/CA and simple linear models for iCLF‐CA. The annual potential for soil erosion with intensive conventional tillage and monocropping, considering land use and cover in 2017, is 3.0 billion tons. The economic impact, based only on replacement of nutrient losses, is estimated to be 15.7 billion US$ yr−1. To control soil erosion by water, to intensify agricultural production, and mitigate the greenhouse gas emissions are the goals of the PRONASOLOS, a national program for detailed soil survey and interpretation. The annual economic impact of the adoption of CA principles by controlling soil erosion was estimated at 1.5 billion US$ for ZT/CA in 2017 and 0.5 billion US$ for iCLF‐CA in 2015. The future increase of the CA area was forecast at 34.4 and 25.4 Mha for ZT/CA and iCLF‐CA, respectively. The positive impacts of the adoption of CA principles in Brazil are the result of the determination of farmers, among many actors, and of the effectiveness of government plans and policies.

Soil quality assessments in integrated crop–livestock–forest systems: A review

AbstractIntegrated crop–livestock–forest is a promising strategy to improve soil quality. It comprises four different integrated farming systems: crop–livestock, crop–forest, forest–livestock and crop–livestock–forest. This work systematically reviewed studies about integrated crop–livestock–forest systems and soil quality. A total of 92 papers were retrieved from the Web of Science—Clarivate Analytics platform, and the following information was analysed: publication year, institution, region of the studied site, type of integrated system, soil type, tillage system, maximum soil depth and the soil quality indicators assessed. Most studies were published in the second half of the 2010s. Brazil is a prominent focus of research about soil quality and integrated crop–livestock–forest systems, with significant contribution from its central and southern regions. The Embrapa was the main publishing institution, present in over one‐third of the studies. Crop–livestock was the most common integrated system, Ferralsols was the most common soil group, and most of the studied soils were clayey. No tillage was the main tillage system. Most studies focused on the topsoil, assessing physical and/or chemical soil quality indicators. More emphasis on biological indicators of soil quality is required, as well as assessments integrating biological, physical and chemical indicators of soil quality. Future works should compare different integrated systems, including assessments deeper in the soil profile, especially in systems with the forest component, and also in sandy and silty soils. Soil quality indicators that have been rarely used should be further tested. Novel indicators should be added to better understand the promotion of soil quality by integrated crop–livestock–forest systems.

Agrosilvopastoral Systems and Well-Managed Pastures Increase Soil Carbon Stocks in the Brazilian Cerrado

Agrosilvopastoral systems have been promoted as sustainable models that combine crops, livestock grazing, and forestry in the same area. We hypothesize that agrosilvopastoral systems can improve soil C and N stocks over time. Therefore, in this study, we aimed to evaluate the changes in soil C and N stocks after conversion of low-productivity pasture into well-managed pasture and agrosilvopastoral land in the Brazilian Cerrado. Soil samples were collected in 2016 and 2018 at 0–5, 5–10, 10–20, and 20–30 cm depths from the following areas: integrated crop-livestock-forest (ICLF), marandu grass (Brachiaria brizantha) monoculture (MAR), low productivity pasture of signal grass (Brachiaria decumbens) monoculture (PAST), and native vegetation (NV; “Cerrado”). The C and N content and stocks, 13C natural abundance, and C contents in the physical and chemical fractions of soil organic matter (SOM) were measured. The ICLF and MAR systems promoted faster recovery of soil C and N stocks at all soil depths compared with PAST. The C content of the free light fraction of SOM under the ICLF and MAR systems increased, reaching values similar to NV up to 20 cm. The C content was higher in the humin fraction at all depths in all areas, and for this measurement, the ICLF system performed remarkably compared with PAST at a depth of 5−10 cm. Our findings support the hypothesis that conversion of low-productivity pasture into agrosilvopastoral and actively managed pasture systems leads to improvements in soil quality and C and N stocks in the Brazilian Cerrado.

Reducing competition in a crop–livestock–forest integrated system by thinning eucalyptus trees

AbstractThe goal of this study was to evaluate the effects of thinning eucalyptus trees on yield and nutritive value of corn for silage and palisadegrass in a crop–livestock–forest integrated system and to evaluate the total aboveground biomass yield in systems with and without trees. Plant variables, as well as the incidence of photosynthetically active radiation (PAR) and soil moisture, were evaluated between October 2016 and March 2018 in São Carlos, Brazil, in a crop–livestock–forest and a crop–livestock system. In the crop–livestock–forest system, eucalyptus trees (Eucalyptus urograndis clone GG100) were planted in April 2011, in single rows, with 15 × 2 m spacing. In 2016, the trees were thinned, and the spacing was changed to 15 × 4 m. The treatments comprised measurements at 0.00, 3.75, 7.50, and 11.25 m from the trees of the North row in the integrated crop–livestock–forest (iCLF) system and integrated crop–livestock (iCL) system. Palisadegrass (Urochloa brizantha) was sown after harvesting the corn. Corn yields were similar between treatments, with an average of 13.6 Mg ha−1. Corn for silage presented a higher percentage of grain in total biomass in the crop–livestock–forest positions (41.4 and 42.1%) than in the crop–livestock system (35.6%). No differences in forage accumulation were observed. Crude protein content in corn for silage and palisadegrass was higher in the crop–livestock–forest treatments than in the crop–livestock system. Such results indicate that thinning was favorable to production in the crop–livestock–forest system. Total aboveground biomass yield was higher in the iCLF system, indicating better land use for this type of integrated system.

Shading effect on physiological parameters and in vitro embryo production of tropical adapted Nellore heifers in integrated crop-livestock-forest systems

The aim of this study was to evaluate the impact of increased shadow supply in integrated crop-livestock-forest systems on in vitro embryonic development and physiological parameters related to stress response in Nellore heifers (Bos indicus). For the study, animals (n = 16) were randomly divided into two groups and kept in areas with different afforestation systems, the integrated crop-livestock-forest (ICLF) and the integrated crop-livestock (ICL) system. The microclimate of the ICLF system provided better comfort conditions than ICL. No differences of respiratory rate, rectal temperature, cortisol, T3, T4, oocyte quality, and cleavage rate between the systems were verified. A higher blastocyst rate was observed in the ICLF (p < 0.05). The results demonstrate that Nellore heifers managed in ICLF during summer in Midwest of Brazil showed higher production of in vitro embryos, without typical changes in its physiological parameters. The results observed in the present study indicate that zebu females are able to respond satisfactorily to the intense heat conditions; however, we believe that the long period to which these animals are exposed to these conditions interferes in the oocyte competence and embryo development.

Root and shoot interactions in a tropical integrated crop–livestock–forest system

Integrated crop–livestock–forest systems (ICLFS) have potential advantages compared to monoculture, but most studies quantifying plant biomass in integrated production systems, have quantified only the aboveground component rather than the total biomass. The objective of this study was to investigate the ecological interactions of Eucalyptus trees intercropped with palisade grass in a tropical region. The study was conducted in an 8-year-old ICLFS in which Eucalyptus trees were introduced into a palisade grass pasture [Urochloa brizantha (Hochst. Ex A. Rich.) R. Webster ‘Marandu’]. Samples were collected at four locations from the Eucalyptus trees: 0.0 (planting line), 2.0, 4.0, and 6.0 m (middle of the plots). A monoculture palisade grass pasture was included for comparison. The addition of Eucalyptus in the pasture reduced the forage yield, root length density, root density and root diameter of palisade grass close to the Eucalyptus trees. Eucalyptus roots were more abundant near the trees, and decreased with distance from the tree at soil depths up to 1.0 m. The total amount of roots decreased by 36 % with the addition of the forest component compared with the monoculture pasture, i.e., 11.6 Mg ha−1 in the ICLFS compared with 18.4 Mg ha−1 in the pasture. In the ICLFS, the proportion of palisade grass roots in the soil profile increased with distance from the tree line. However, the high degree of competition in root development in the ICLFS resulted in 20% lower root length and fine roots densities compared with monoculture pasture in the upper 0–0.20 m soil layer.

Economic Analysis of Corn Culture in Integrated Crop-Livestock-Forest System

Aims: Aim was to analyze the economic viability of an integrated crop-livestock-forest (ICLF) system area, in the municipality of Pindare-Mirim, State of Maranhao, Brazil, using the consortium of maize (Zea mays L.), forage species Urochloa brizantha cv. Marandu and Eucalyptus (Eucalyptus urograndis). Study Design: Case study. Place and Duration of Study: The work was developed in a Technological Reference Unit of ICLF of Embrapa Cocais, located in the municipality of Pindare-Mirim - Maranhao, Brazil, between January 2016 and July 2017 and The experimental area was 3 ha, divided into three subareas: Treatment I - single corn planting; Treatment II - Barreirao system; and Treatment III - Santa Fe system. Methods: In this work, the method of operational costs was used. The following economic performance measures were calculated: Gross income (GI), Gross margin (GM), Net margin (NM), Profit, Leveling point (LP) and Rates of return (RR). The economic indicators calculated were: Net Present Value (NPV), Internal Rate of Return (IRR) and Benefit-Cost Ratio (RBC). The data collected from the costs and revenues of each treatment were tabulated and treated with the help of Microsoft Office Excel. Results: All the treatments presented a profit, being the Barreirao System the one that had better results, presenting P of 163 bags of maize ha-1, GI of US$ 1974, profit of US$ 780, LP in 99 bags, of 60 kg, of corn ha-1 and RR of 65.33%. Treatments I and III presented, respectively, P of 135 and 143 bags of maize ha-1, GI of US$ 1635 and US$ 1732, profit of US$ 504 and US$ 543, LP in 94 and 99 bags of corn ha-1 and RR of 44.63% and 45.67%. Conclusion: The results obtained reinforce the importance of studying the economic feasibility of ICLF system to provide the investor with the conditions for better decision making.

Soil N2O fluxes in integrated production systems, continuous pasture and Cerrado

The objective of this study was to evaluate N2O fluxes from integrated crop-livestock (ICL) and integrated crop-livestock forest (ICLF) systems, continuous pasture and native Cerrado. The experiment was conducted at Embrapa Cerrados, Planaltina-DF, in a Red Oxisol, between February 2012 and April 2014, following the transition of crop to livestock, which began in March 2012, with the sowing of Brachiaria brizantha cv. Piata, intercropped with sorghum. The experimental design was a randomized block with three replications. The treatments were: cultivated area intercropped with rows of Eucalyptus, spaced 2 × 2 m between plants and 22 m between rows (ICLF); and an area cultivated without tree species (ICL), and also two adjacent reference areas: native Cerrado and continuous pasture. N2O productions were characterized by fluxes below 20 μg N m−2 h−1. The ICL system had the highest cumulative flux with 2.84 kg N ha−1, while the ICLF system obtained cumulative fluxes of 2.05 kg N ha−1. The native Cerrado showed a negative balance, with –0.05 kg N ha−1. The dry season was mostly characterized by low N2O fluxes ranging between 10 μg N m−2 h−1 and negative values, whereas higher N2O fluxes were observed after precipitation events, especially those following a long drought period. The water filled pore space was the factor that best explained N2O fluxes, but higher fluxes were observed after the application of nitrogen fertilizer. There was a positive correlation between microbial biomass carbon and N2O fluxes in the ICL and ICLF systems.

Spatial variability of soil fertility in an integrated crop livestock forest system

Knowledge on spatial variability of soil properties is useful for the rational use of inputs, as in the site specific application of lime and fertilizer. Crop-livestock-forest integrated systems (CLFIS) provide a strategy of sustainable agricultural production which integrates annual crops, trees and livestock activities on a same area and in the same season. Since the lime and fertilizer are key factors for the intensification of agricultural systems in acid-soil in the tropics, precision agriculture (PA) is the tool to improve the efficiency of use of these issues. The objective of this research was to map and evaluate the spatial variability of soil properties, liming and fertilizer need of a CLFIS. The field study was carried out in a 30 ha area at Embrapa Pecuária Sudeste in São Carlos, SP, Brazil. Soil samples were collected at 0–0.2 m depth, and each sample represented a paddock. The spatial variability of soil properties and site-specific liming and fertilizer needs were modeled using semi-variograms, the soil fertility information were modeled. Spatial variability soil properties and site specific liming and fertilizer need were modeled by kriging and inverse distance weighting (IDW) techniques. Another approach used was based on lime and fertilizer recommendation considering the paddocks as the minimum management unit. The results showed that geostatistics and GIS were useful tools for revealing soil spatial variability and supporting management strategies. Soil nutrients were used to classify the soil spatial distribution map and design site-specific lime and fertilizer application zones. Spatial analyses of crop needs and requirement can provide management tools for avoiding potential environmental problems, caused by unbalanced nutrient supplies.

English

The integrated crop-livestock-forest (ICLF) has been indicated as an important alternative of agricultural production, in economic and environmental terms. This study aimed to evaluate and compare the chemical properties of soil under the system on integrated crop-livestock-forest in the Santa Brigida Farm, Ipameri City, southeast of Goias State, Brazil. It was used a completely randomized design in a 4 × 2, with four replications. The analyzed factors consisted of four land uses (SS2 = Eucalyptus sp. 2 years age + Urochloa brizantha grass, SS6 = Eucalyptus sp. 6 years age + U. brizantha grass, ILF = corn + U. brizantha grass and RF = remaining forest - control) combined with two different depths of the soil (0-20 and 20-40 cm). Data from soil analyzes were used to generate the cluster analysis and principal component analysis (PCA) using the R program. In both depths was checked the grouping of sampled areas in three groups: One containing the ILF and SS2 areas samples of, which were the most similar to each other; a second group containing SS6 area samples; and a third group containing the remaining forest samples. A gradual variation in organic matter, Ca + Mg, H + Al, K and pH, CEC and V% can be observed in the samples of 0-20 cm layer, where in the remaining forest area was with the highest values of these variables, follow by the areas SS6, ILF and SS2 respectively. In the layer soil 20-40 cm depth, SS6 area stood out in relation to Ca + Mg, pH, CEC and V%. It can be concluded that the ICLF is a promising production system to be deployed, especially in areas with the purpose of recovering degraded pastures. Key words: Soil quality, agroforestry systems, sustainability, biodiversity.

ATRIBUTOS BIOLÓGICOS DO SOLO EM SISTEMA DE INTEGRAÇÃO LAVOURA-PECUÁRIAFLORESTA, NA REGIÃO AMAZÔNICA - DOI: 10.13083/1414-3984/reveng.v23n5p448-456

As propriedades biológicas do solo são importantes ferramentas a serem utilizadas no monitoramento das alterações ambientais no solo decorrentes do uso agrícola. Nesta perspectiva, o objetivo do trabalho foi avaliar os atributos biológicos do solo em área submetida ao sistema de integração Lavoura-Pecuária-Floresta. Essa pesquisa foi realizada em uma Unidade de Referência Tecnológica (URT) de integração Lavoura-Pecuária-Floresta (iLPF) implantada em 20 hectares na Fazenda Gamada, no município de Nova Canaã do Norte (MT). Caracterizados pelas espécies florestais implantadas, os tratamentos foram constituídos pela combinação das espécies: Pinho cuiabano (Schizolobium amazonicum), Pau-balsa (Ochroma pyramidale), Teca (Tectona grandis) e Eucalipto (Eucalyptus urograndis), sendo estas, implantadas em linha tripla, intercalada por faixas de 20 metros de largura, destinadas para implantação das atividades agrícola e pecuária. Foram analisadas também solos sob vegetação nativa e pastagem conduzida por meio de sistema convencional, localizadas em área adjacente à URT e que apresentam a mesma classe de solo (Latossolo Vermelho Amarelo distroférrico). O delineamento utilizado foi o inteiramente casualizado, em arranjo fatorial (6 x 2), sendo seis tratamentos e dois locais de avaliações (entre os renques florestais e na faixa de pastagem), com três repetições. As seguintes características foram analisadas: Respiração Basal do Solo, Carbono Orgânico, e teor de Matéria Orgânica. O tratamento Vegetação nativa apresentou o maior valor de respiração basal do solo, 2,54 mg de C-CO2 por kg de solo por hora. Entre os tratamentos sob os sistemas integração lavoura-pecuária-floresta o tratamento Pau-balsa entre os renques florestais foi o que apresentou as melhores médias para as características analisadas.

Distribuição horizontal e vertical de fósforo em sistemas de cultivos exclusivos de soja e de integração lavoura-pecuária-floresta

O objetivo deste trabalho foi avaliar a distribuição horizontal e vertical do fósforo no solo e a produtividade de soja em sistemas de cultivos exclusivos e de integração lavoura-pecuária-floresta (ILPF). Foram avaliados os tratamentos: floresta plantada de eucalipto; lavoura de soja e milho safrinha consorciado com Urochloa brizantha 'Marandu'; pastagem de U. brizantha; sistema de ILPF; e duas áreas controle, com floresta nativa e pousio. O solo foi coletado nas camadas de 0-5, 5-10, 10-20 e 20-30 cm, para determinação das características químicas. As avaliações foram realizadas no segundo ano agrícola após a implantação do experimento. No sistema de ILPF, solo e produtividade foram avaliados em quatro transectos equidistantes, no centro do renque e a 3, 6, 10 e 15 m do renque, nas faces norte e sul. Os teores de P disponível (Mehlich-1) foram maiores nas camadas superficiais do solo, nos sistemas com soja/milho safrinha e com ILPF. No ILPF, os teores de P disponível não diferiram entre as distâncias do renque das árvores, e a produtividade de soja não diferiu da observada no sistema com soja/milho safrinha. Portanto, com dois anos de implantação, o sistema ILPF ainda não é capaz de interferir marcadamente nas características químicas do solo e na produtividade da soja.

The value of improved pastures to Brazilian beef production

Brazil is an agricultural country, with 190 Mha of pastures sustaining 209 million cattle. Fewer than 10% of the cattle are fattened in feedlots, whereas cattle reared on pastures have a competitive advantage for export, eliminating the risks presented by the mad cow disease (bovine spongiform encephalopathy) and considerations related to animal welfare. Brazil has been the world’s largest exporter of beef since 2004 and has the largest commercial herd in the world. In 2011, 16.5% of its production was exported, and the livestock sector contributed 30.4% of the gross national product from agribusiness and 6.73% of the total GNP. Many forage breeding programs, mainly at Embrapa, have contributed to the development of improved pastures, and cultivars of Brachiaria brizantha, B. decumbens, B. humidicola and Panicum maximum are the main pastures used in the country. All have apomictic reproduction, which means there are few cultivars occupying very large, continuous areas, thus suggesting a risk to the productive system. Such is the case of B. brizantha cv. Marandu, which occupies around 50 Mha. The Brazilian tropical forage seed industry is also important, and Brazil is the main seed exporter, supplying all Latin American countries. Due to pasture degradation, around 8 Mha is renovated or recovered each year. Forages are also used and planted each year in integrated crop–livestock and integrated crop–livestock–forest systems. Nowadays, these systems occupy 4 Mha. Improved pastures are thus a major asset in Brazil not only for the beef production chain but also for the dairy industry.