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Agroforestry systems are multifunctional land-use systems that promote soil life. Despite their large potential spatio-temporal complexity, the majority of studies that investigated soil organisms in temperate cropland agroforestry systems focused on rather non-complex systems. Here, we investigated the topsoil and subsoil microbiome of two complex and innovative alley cropping systems: an agrosilvopastoral system combining poplar trees, crops, and livestock and a syntropic agroforestry system combining 35 tree and shrub species with forage crops. Increasing soil depth resulted in a decline of bacterial and fungal richness and a community shift towards oligotrophic taxa in both agroforestry systems, which we attribute to resource-deprived conditions in subsoil. At each soil depth, the microbiome of the tree rows was compositionally distinct from the crop rows. We detected a shift towards beneficial microorganisms as well as a decline in putative phytopathogens under the trees as compared to the crop rows. Finally, based on our results on community dissimilarity, we found that compared to an open cropland without trees, spatial heterogeneity introduced by the tree rows in the agrosilvopastoral system translated into a compositionally less homogeneous soil microbiome, highlighting the potential of agroforestry to counteract the homogenization of the soil microbiome through agriculture. [ABSTRACT FROM AUTHOR]

The objective of this study was to evaluate the damage caused to trees by beef cattle in integrated crop-livestock-forestry (ICLF) systems with different tree arrangements. The treatments evaluated were the ICLF-1L system, with single lines of eucalyptus (187 trees ha−1), and the ICLF-3L system, with three lines of eucalyptus (446 trees ha−1). The experimental design consisted of randomized blocks with four replications. The eucalyptus clone I-224 and Nellore cattle breed were used for this study. The damage caused by cattle to eucalyptus was classified as follows: Tb, trunk breakage; Ti, trunk injury reaching the wood by removing the cambium tissue; Bb, breakage branches greater than 2 cm in diameter; Bi, bark injury without reaching the cambium; Bt, breakage of thin branches and browsing on leaves; and Di, lesions greater than 5 cm in diameter. The damage score was calculated for each tree by the sum of grade the damage that cattle caused to the tree: Tb = 10.0; Ti = 4.0; Bb = 2.0; Bi = 1.5; Bt = 1.0; and Di = 1.0. The diameter at breast height (DBH), height and wood volume of the trees were also evaluated. The frequencies of Ti, Bb and Di were greater in the ICLF-1L system than in the ICLF-3L system (P < 0.05); in contrast, the frequencies of Bt and Bi were greater in the ICLF-3L system. The damage score was greater in the ICLF-1L system (6.61; P < 0.05) than in the ICLF-3L system (4.60). The height was greater in the ICLF-3L system (P < 0.05), and the DBH and individual wood volume did not differ between the systems (P > 0.05). Cattle cause damage to eucalyptus trees regardless of tree arrangement (ICLF-1L and ICLF-3L), but the damages were greater in the ICLF-1L system. Although the damages were more severe in ICLF-1L, tree growth and wood production were the same in both systems. Additional studies should be conducted to assess the impacts of livestock damage in wood quality. [ABSTRACT FROM AUTHOR]

Integrated agricultural production systems can increase soil organic carbon stocks over time and contribute to the mitigation of climate change. The present study aimed to evaluate soil carbon stocks, accumulation rates (TOC), total nitrogen (TN), and the quality of soil organic matter (SOM) after the transition of a low-productivity pasture into agrosilvopastoral systems in the Cerrado biome. We evaluated an 11-year-old experiment, and the treatments studied were: Eucalyptus + buffel grass; Eucalyptus + cowpea; Eucalyptus + pigeon pea; eucalyptus + buffel grass + cowpea; Eucalyptus + buffel grass + pigeon pea; Eucalyptus in monoculture (with a 20 × 3 m tree arrangement and no cultivation between rows but with a history of forage and grain crop production); and a low-productivity pasture as additional treatment and reference to the soil condition previously the land-use change. In this study, TOC and TN stocks and accumulation, labile (LC) and non-labile carbon (NLC), and SOM humic fractions were evaluated at 0-10, 10-20, 20-40, and 0-40 cm depth layers. Integrated farming systems have increased TOC and TN, NLC, carbon contents and stocks in SOM chemical fractions in all depths and TOC and TN accumulation of 5.22 Mg ha-1 year-1 and 0.23 Mg ha-1 year-1, respectively, at the 0-40 cm depth layer. The integration of Eucalyptus with legumes or buffel grass increased the LC content in the surface layer of the soil. The transition from low-productivity pasture into integrated farming systems can promote the recovery of SOM and soil quality. Hence, our results suggest that agrosilvopastoral systems can be used as sustainable farming systems in the Cerrado biome. [ABSTRACT FROM AUTHOR]