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.

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.

The coffee industry generates significant amounts organic residues that, if mismanaged, can lead to environmental degradation. Valorization techniques such as composting, Bokashi fermentation, and pyrolysis (biochar production) offer sustainable avenues to enhance soil fertility and health while promoting a circular economy. This study aimed to evaluate the effects of various coffee residue-derived conditioners on soil properties and coffee productivity. Field trials were conducted over two agricultural seasons (2021/2022 and 2022/2023) in Minas Gerais state, Brazil. Treatments included coffee husk, compost, Bokashi, biochar (from coffee husk and wood), a compost-biochar blend (COMBI), organomineral fertilizer, and conventional fertilizer. The experiment followed a randomized block design with four replications. Soil properties, biological indicators, and coffee yield were assessed. Principal component analysis was used to identify key variables influencing treatment efficacy. COMBI notably increased calcium and magnesium levels by 50% and 46%, respectively, and enhanced base saturation by 24% in the first season. In the second season, biochar application led to a 20% increase in cation exchange capacity. COMBI also improved microbial biomass carbon and urease activity by 8% and 21%, respectively, compared to conventional fertilization. Despite improvements in soil properties and biological indicators, no significant effects on coffee yield were observed. These findings underscore the potential of coffee residue valorization in sustainable soil management. Although short-term impacts on productivity were not detected, soil improvements highlight the promise of these conditioners for enhancing soil quality and promoting circular agricultural systems. Graphical Abstract