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Light intensity available in growing environments may influence the susceptibility of plants to glyphosate and decomposition of their residues. This study aimed to assess the productivity, control, and decomposition of forage straw submitted to glyphosate doses and exposed to full sun and 50% shade. Two experiments were carried out, one for Piatã grass (Urochloa brizantha cv. Piatã) and other for Tanzania grass (Megathyrsus maximus cv. Tanzania). The experimental design was a randomized block design with strip-plot and four replications. Two growing environments (at full sun and under 50% shade) were installed in strips in the growing area, combined with six doses of glyphosate (0, 360, 720, 1,080, 1,440, and 1,800 g a.e. ha-1) used for forage desiccation. Shade did not change Tanzania grass productivity (p<0.05), but it reduced Piatã grass productivity (p>0.05), suggesting its low tolerance to light restriction. Tanzania grass is more tolerant to glyphosate when compared to Piatã grass, especially at full sun conditions. In general, the evaluated forages present a high susceptibility to glyphosate as incident radiation is reduced, which allows using lower doses to desiccate them in shaded environments. Straw decomposition of Piatã and Tanzania grasses was slower under shading. In this environment with light restriction, straw is more durable and has a better quality for the no-tillage system.

Os sistemas integrados de produção agropecuária podem promover melhoria da qualidade física, química e biológica do solo. A obtenção de efeitos sinérgicos entre os diferentes componentes de produção permite a sustentabilidade dos sistemas agropastoril, silvipastoril, agroflorestal e agrossilvipastoril. Aumentos na estocagem de carbono podem ser obtidos com a adoção de sistemas integrados de produção, além de maiores retornos econômicos. A diversificação da produção possibilita a redução de riscos frente às oscilações de preços de mercado. Contudo, estudos envolvendo a estocagem de carbono e, principalmente, a viabilidade econômica de sistemas integrados em região semiárida são limitados. Neste contexto, objetivou-se apresentar resultados de estocagem de carbono e retorno econômico obtidos com a adoção de sistemas integrados de produção no semiárido, visando apresentar resultados que possam subsidiar a implementação de projetos futuros, permitindo a obtenção de ganhos nos estoques de carbono e maior viabilidade econômica em condições de baixa disponibilidade hídrica.

Production systems that promote the accumulation of soil organic matter (SOM) must be implemented to maintain the sustainability of agriculture, livestock, and forestry. Since increases in MOS content contribute to improving the chemical, physical, and biological quality of the soil, as well as helping to reduce carbon emissions to mitigate climate change. Therefore, the objective of this study was to evaluate soil organic carbon (SOC) and nitrogen (N) stocks after the implementation of agrosilvopastoral (ASP) systems in a Cerrado-Caatinga transition zone in Brazil. Native vegetation of Cerrado-Caatinga (NV), regenerating stratum of Cerrado-Caatinga (RS), two arrangements of ASP systems cultivating Cenchrus ciliaris L. intercropped with Eucalyptus camaldulensis Dehnh. × Eucalyptus tereticornis Sm. hybrid (ASP1 and ASP2), and intercropped with Eucalyptus urophylla S.T. Blake × Eucalyptus grandis W. Mill ex Maiden hybrid (ASP3 and ASP4) were evaluated. Soil C and N stocks and the C content in the humic fractions of SOM were evaluated at 0–10, 10–20, and 20–30 cm soil depths. The introduction of ASP2, ASP3, and ASP4 systems in an area previously occupied by low productivity pasture increased and restored SOC stocks to levels found in NV, at a depth of 0–30 cm. N stocks were higher in ASP systems, regardless of the arrangement studied. As a result, the ASP systems provided accumulations that ranged from 1.0 to 4.31 Mg SOC ha−1 yr−1 and from 0.33 to 0.36 Mg N ha−1 yr−1. The carbon contents in humic fractions remained higher in NV. The hierarchical grouping and principal component analysis showed that the implementation of the ASP systems was efficient in increasing soil C and N stocks over time. In conclusion, the present study identified that integrated production systems can support land use intensification strategies based on sustainable and low-carbon agriculture in a transition area between the Cerrado and Caatinga biomes in Brazil.

Choosing the species suitable for cultivation in intercropped systems is a critical limiting factor for grain and forage production. This study aimed to evaluate the growth, nodulation, production, and physiology of cowpea (Vigna unguiculata) and guandu bean (Cajanus cajan) intercropped with buffel grass (Cenchrus ciliaris) and Eucalyptus urograndis (Eucalyptus grandis × Eucalyptus urophylla) in an integrated production system. Two experiments were conducted simultaneously, arranged in a 2 × 4 factorial scheme. The first factor consisted of the use of two integrated production systems. The second factor consisted of four distances (2, 4, 6, and 8 m) from the eucalyptus planting rows. In the first experiment, crop-forest systems (CFIS: eucalyptus trees and cowpea) and crop-livestock-forest systems (CLFIS: eucalyptus trees, cowpea, and buffel grass) were evaluated. In the second, livestock-forest systems LFIS1 (eucalyptus trees and guandu bean) and LFIS2 (eucalyptus trees, guandu bean, and buffel grass) were evaluated. In cowpea, nodulation was not influenced by production systems and distances, whereas in guandu bean, there was a reduction in the nodules' number and dry mass with the distance from the trees. Higher growth, biomass production, and photosynthetic activity of cowpea and guandu bean were observed with the increasing distance from the eucalyptus planting rows. However, cowpea increased the 100-seed weight at 2 and 4 m distances from the eucalyptus rows, improving the grains' quality close to the trees. The simultaneous cultivation with buffel grass did not affect the leguminous plant yield, promoting greater diversification and increasing the total biomass production of the intercropping.

The objective of this study was to evaluate the chemical attributes and quality of an Oxisol after one year of conversion of degraded pasture into integrated production system. The evaluated treatments were degraded pasture (PAST-Control); Eucalyptus, clone Urograndis 144 (Eucalyptus grandis x E. urophylla hybrid) intercropped with cor and marandu grass (Brachiaria brizantha) (integration crop-livestock-forest system - ICLFS-M); with maize and perennial horse gram (Macrotyloma axillare) (ICLFS-HG); and with maize, java and marandu grass (ICLFS-M+J); Monoculture of marandu grass (MAR) and perennial horse gram (HG); and marandu grass intercropped with Java/ perennial horse gram (H+M). Soil samples were collected in July/2015 and January/2016 in 0-5, 5-10, 10-20 and 20-30 cm soil depth layers. The soil attributes such as pH, organic matter, phosphorus, sum of bases, effective and potential cation exchange capacity and base saturation were evaluated. The implantation of ICLFS system contributed to increase of soil organic matter, sum of bases, effective and potential cation exchange capacity and soil base saturation. The soil biological activity was increased in the rainy season, and the soil microbial carbon increased in ICLFS-HG+M, ICLFS- HG, ICLFS-M and HG+M when compared to monocultures and PAST. Integrated production systems provide improved in soil quality even with a short time implementation.

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