Silvopastoral systems (SPS) have been widely implemented in the Colombian Amazon region to improve pastures involving a greater diversity of species, soil tillage, fertilization, and higher stocking rate, which can induce changes in soil properties and functions. This study aimed to evaluate soil chemical properties and carbon sequestration changes due to the transition from traditional pastures to silvopastoral systems. The study was conducted in the Colombian Amazon region, specifically in La Montañita and El Doncello Counties, in Caquetá, the second most important hotspot of deforestation in the entire Amazon basin. In each study site, we established a chronosequence consisting of three areas following the typical land‐use change at the region: (i) native vegetation, (ii) traditional pasture, and (iii) silvopastoral system. We found that agricultural practices involving liming and tillage, performed under the silvopastoral management, contributed to reducing soil active acidity and exchangeable acidity with soil pH increasing from 3.8 to 4.3 and H++Al3+ decreasing from 5.8 to 2.3 cmolc kg−1. These alterations favored increases in Ca2+ and Mg2+ contents mainly, increasing the base saturation from 17% in traditional pastures to 55% under silvopastoral systems. The synergic effect of the mix of grasses and trees under silvopastoral management improved soil micronutrient contents and modified soil C stocks in 20–30 cm layer. A rate of soil C accretion of 0.26 Mg ha−1 yr−1 for the 0–30 cm detected in silvopastoral systems suggests that its implementation could be a promising tool for C sequestration in tropical regions, capable of restoring soil functioning of degraded areas.

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Silvopastoral systems (SPS), an integrated farming system in which tropical grasses are combined with trees and shrubs, have been implemented in the last years in the Amazon region in order to mitigate the impacts generated by the traditional cattle ranching system. However, despite the multiple SPS’s benefits to soil and ecosystem, there is a paucity of comprehensive studies revealing the potential soil health (SH) restoration through SPS. Here, by developing an overall SH index using local native vegetation (Amazon rainforest) as a reference, we aimed to assess SH changes induced by the land transition from the traditional livestock production system to the SPS in the Colombian Amazon region. A chronosequence conformed by three areas: (i) native vegetation, (ii) traditional pasture and (iii) silvopastoral system was established in two study sites located in the Colombian Amazon, specifically in Caquetá State, the second hotspot of deforestation in the Amazon Basin. The results indicated high soil compaction and loss of macrofauna diversity and richness due to pasture management, causing a loss of 9% of soil capacity to function. In contrast, by integrating 31 soil indicators, our SH assessment revealed that SPS was an effective strategy for the recovery of SH, impacting positively multiple soil functions related to nutrient dynamics, water retention and supply, and biological activity.

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Inoculation with phosphate-solubilizing bacteria (PSB) and the application of phosphorus (P) sources can improve soil P availability, enhancing the sustainability and efficiency of agricultural systems. The implementation of this technology in perennial grasses, such as Kikuyu grass, for cattle feed in soils with high P retention, such as Andisols, has been little explored. The objective of this study was to evaluate the productive response of Kikuyu grass and soil P dynamics to BSF inoculation with different P sources. The experiment was conducted on a Kikuyu pasture, which was evaluated for 18 months (September 2020 to March 2022). Three P fertilizers with different solubility levels were applied: diammonium phosphate (DAP) (high-solubility), rock phosphate (RP), and compost (OM) (low-solubility). Moreover, the inoculation of a PSB consortium (Azospirillum brasilense D7, Rhizobium leguminosarum T88 and Herbaspirillum sp. AP21) was tested. Inoculation with PSB and fertilization with rock phosphate (RP) increased soil labile P and acid phosphomonoesterase activity. Increased grass yield and quality were related with higher soil inorganic P (Pi) availability. This study validated, under field conditions, the benefits of PSB inoculation for soil P availability and Kikuyu grass productivity.