Soil nematode community response to integrated pest management using native shrub residues

Overview

This research investigates how Integrated Pest Management (IPM) strategies using native shrub residues, specifically Guiera senegalensis and Piliostigma reticulatum, influence soil nematode communities in pearl millet (Pennisetum glaucum) cultivation. The work focuses on characterizing changes in plant-parasitic nematode populations and beneficial nematode trophic groups in response to shrub-based soil amendments. Prior studies showed that millet grown in association with P. reticulatum had reduced overall nematode abundance, while opportunistic bacterial feeders such as Cephalobidae increased under shrub treatments, suggesting a shift toward more beneficial soil food web dynamics.

The goal is to generate empirical evidence supporting shrub-residue-based IPM as a sustainable alternative or complement to conventional chemical pesticide use, with potential benefits for soil health and crop productivity in semi-arid cropping systems.

Technical specifications

Experimental design:

• Randomized block design with three treatments and three replications per treatment
• Treatments include: (1) conventional chemical pesticide application, (2) no pesticide control, and (3) IPM nematode management using nematocidal plant materials such as neem leaves and neem oil
• Pearl millet seeds sown in mid-May, with seedlings transplanted in mid-June 2021
• Seedling spacing of approximately 30 cm, consistent with regional farmer practices

Monitoring procedures:

• Monthly soil sampling throughout the growing season until experiment completion
• Extraction and enumeration of nematode populations from soil samples
• Assessment of plant-parasitic nematode populations and shifts in beneficial nematode trophic groups

Key research targets:

• Plant-feeding (parasitic) nematode abundance and community composition
• Beneficial nematode communities, including opportunistic bacterial feeders (Cephalobidae)
• Comparative response across chemical, control, and IPM treatments

Technology readiness level

This work is at an early experimental stage, consisting of a single-season field trial with replicated plots. Validation is ongoing through monthly nematode population monitoring, and findings will build on prior observational evidence of shrub-mediated shifts in nematode communities. Further multi-season and multi-location trials would be needed to confirm consistency of effects and to translate results into actionable management recommendations for farmers.