Thermophilic composting is a promising soil and waste management approach involving diverse micro and macro-organisms, including eukaryotes. Due to sub-optimal amounts of nutrients in manure, supplemental feedstock materials such as Lantana camara, and Tithonia diversifolia twigs are used in composting. These materials have, however, been reported to have antimicrobial activity in in-vitro experiments. Furthermore, the phytochemical analysis has shown differences in their complexities, thus possibly requiring various periods to break down. Therefore, it is necessary to understand these materials’ influence on the biological and physical-chemical stability of compost. Most compost microbiome studies have been bacterial-centric, leaving out eukaryotes despite their critical role in the environment. Here, the influence of different green feedstock on the fungal and non-fungal eukaryotic community structure in a thermophilic compost environment was examined. Total community fungal and non-fungal eukaryotic DNA was recovered from triplicate compost samples of four experimental regimes. Sequencing for fungal ITS and non-fungal eukaryotes; 18S rDNA was done under the Illumina Miseq platform, and bioinformatics analysis was done using Divisive Amplicon Denoising Algorithm version 2 workflow in R version 4.1. Samples of mixed compost and composting day 84 recorded significantly (P<0.05) higher overall fungal populations, while Lantana-based compost and composting day 84 revealed the highest fungal community diversity. Non-fungal eukaryotic richness was significantly (P< 0.05) more abundant in Tithonia-based compost and composting day 21. The most diverse non-fungal eukaryotic biome was in the Tithonia-based compost and composting day 84. Sordariomycetes and Holozoa were the most contributors to the fungal and non-fungal community interactions in the compost environment, respectively. The findings of this study unravel the inherent influence of diverse composting materials and days on the eukaryotic community structure and compost’s biological and chemical stability.

Composting is a sustainable waste management technique that transforms organic matter into a valuable, soil amendment through processes such as thermophilic decomposition. However, thermophilic composting leads to a loss of important nutrients such as nitrogen by up to 50% in some cases. This is due to low-quality feedstock and loss of labile nutrients caused by high pile temperatures in the early phase of the process. Ultimately, the low quality of compost can potentially reduce soil fertility and crop productivity. We sought to enhance compost quality by biochar addition during heaping and supplemental Tithonia diversifolia application during post-thermophilic stages. We did a field setup of four composting treatments; Conventional practice; (Cattle manure + dry maize stalks + Lantana camara); L, Biochar compost (Cattle manure + dry maize stalks + Lantana camara + Biochar); B, Biochar compost + Tithonia diversifolia; post-thermophilic phase Tithonia diversifolia supplementation to L (LT) and B (BT). Sampling for physicochemical parameters analysis was done every 21 days over 84 days on each heap. We used assorted functions in the R statistical package (version 4.3.1) to plot the principal component analysis, correlation matrix, and analysis of variance among compost treatments. Total nitrogen exhibited significant positive correlations with all other variables. We also observed significantly higher nutrient levels in biochar-based composts than those without biochar amendment. Supplemental addition of Tithonia diversifolia in the post-thermophilic stage significantly increased nitrogen levels (1.59% in BT and 1.32% in LT compared to 1.34% and 1.24% in B and L, respectively). However, this addition led to a rise in pile temperature, prolonging the composting duration. We observed the highest nitrogen and organic carbon levels in BT (1.59% and 24.9%, respectively) at the end of the composting process. Our study recommends applying nutrient-boosting materials such as Tithonia diversifolia, in the post-thermophilic stage to minimize nutrient losses during composting.

Compost fauna act by releasing various enzymes that break down organic matter into a stable, agriculturally useful products. Mesofauna are the least studied compared to micro- and macrofauna, with the existing studies relying on classical methods such as morphological identification, essentially leaving out cryptic taxa. We sought to evaluate the ecological response of the mesofauna community to different composting materials and durations. Total mesofauna community 18S rRNA was purified in triplicate from lantana-based, tithonia-based, grass-based, and mixed (lantana + tithonia + grass)-based compost heaps after 21, 42, 63, and 84 days of composting and sequenced using the Illumina Miseq platform. Before performing statistical data analysis, we used the Divisive Amplicon Denoising Algorithm version 2 workflow for bioinformatic analyses. The composting duration, but not the composting materials, significantly influenced the total population and composition of the mesofauna communities. The composting materials and duration significantly affected the dispersion and uniqueness of the compost mesofauna communities. Canonical correspondence analysis of the compost’s physical–chemical and biological states showed a significant influence of the materials on the mesofauna community colonization capacity. The mesofauna communities had a significant response to the composting duration. This, therefore, presents them as valuable tools for understanding the temporal evolution of compost.

Pest pressure is a major constraint on crop production in Sub-Saharan Africa, where smallholder farmers rely heavily on synthetic pesticides with potential environmental and health risks. Ecological pest management practices (EPMs) have been proposed as sustainable alternatives, although field-based evidence is limited. This study evaluated pest and natural-enemy responses to EPMs in a cabbage–garden pea rotation system over six years (2020–2025) in Central Kenya. Four treatments were assessed: homemade botanical extracts (Botanicals), coriander intercropping (Intercrop), botanical extracts combined with coriander intercropping (Botanicals + Intercrop), and a control. In cabbage, ecological treatments often recorded lower aphid and diamondback moth abundance and damage than the Control, although these patterns were not consistently significant. Aphid cumulative abundance ranged from an Area Under Disease Progress Curve (AUDPC) of 128.0 under the Control to 47.5 under Botanicals + Intercrop, while DBM abundance ranged from 68.5 to 20.0. In garden pea, aphid damage ranged from an AUDPC of 39.3 under Intercrop to 25.1 under Botanicals + Intercrop, while cutworm damage ranged from 56.3 under Botanicals to 14.8 under Intercrop. Significant treatment effects were detected for selected pest responses. Shannon diversity differed significantly among the treatments in both crop phases. As such, responses were pest- and season-specific rather than uniformly suppressive. These findings identify companion cropping and botanical applications as promising components of EPM within the treatments evaluated. Comparison with conventional pesticide-based or farmer-practice management is however required before recommendations for substitution or wider adoption can be made.

Phosphorus sorption in highly weathered tropical soils reduces fertiliser efficiency, limiting the phosphorus availability for crop uptake and increasing production costs for farmers. This study quantitatively characterised phosphorus sorption behaviour, standard phosphorus requirements, and associated fertiliser requirements across four major soil types (viz. humic Andosols, humic Nitisols, rhodic Nitisols, and orthic Acrisols) in the Central Highlands of Kenya, and evaluated the role of compost in mitigating phosphorus sorption and associated fertiliser costs. Phosphorus sorption isotherms were determined under laboratory conditions using six phosphorus concentrations (0, 6.46 × 10⁻⁴, 1.29 × 10⁻³, 1.94 × 10⁻³, 2.58 × 10⁻³, and 3.23 × 10⁻³ mol dm⁻³ P) and fitted to the Langmuir isotherm model. Linear regression analysis was used to relate sorption parameters to soil properties. Humic Nitisols and humic Andosols exhibited significantly higher phosphorus sorption (76–81%) and sorption maxima (up to 1000 mg kg^− 1) compared to rhodic Nitisols and orthic Acrisols (~ 46% and ~ 392 mg kg^− 1). The standard phosphorus requirements ranged from 65 to 249 mg kg^− 1, demonstrating substantial variability in fertiliser requirements and highlighting the limitations of blanket fertiliser application. Regression analysis identified gibbsite, kaolinite, calcium, and iron as significant predictors of sorption maxima. A field study on humic Andosols and orthic Acrisols further evaluated the role of compost in mitigating phosphorus sorption and reducing fertiliser-related costs. Phosphorus sorption under field conditions ranged from 57 to 79%, with fertiliser cost losses of US$47.83–54.52 ha^− 1 that reduced to US$31.00–41.84 ha^− 1 when triple superphosphate was combined with compost. The findings provide a soil-specific fertiliser management and demonstrate the role of organic amendments in improving phosphorus use efficiency and reducing costs in smallholder farming systems.