# Investigation of Plant Growth Promotion Potential of Novel Compost‐Derived Bacilli and Anticipating Their In Vivo Effectiveness Through Mathematical Modelling

## TL;DR

This study explores compost-derived bacteria that promote plant growth and validates their effectiveness in field trials on maize and okra.

## Contribution

The paper introduces a novel scoring system combining in vitro and in vivo data to evaluate compost-derived Bacillus isolates for sustainable agriculture.

## Key findings

- Compost-derived Bacillus isolates showed significant plant growth promotion in field trials.
- Selected strains improved fruit yield in okra and grain filling in maize.
- The scoring system effectively predicted the isolates' performance in real-world conditions.

## Abstract

Concerns about the unintended consequences of using pesticides in agricultural settings have led to a shift in practise towards more environmentally friendly methods such as composting, manuring and using plant growth‐promoting bacteria. While compost is known for its ability to promote plant growth and serve as a soil amendment, little is known about the various types of bacteria that can be found in it and how effective they are in sustainable agriculture. This study was designed to assess the potency of a few common isolates from local compost by quantifying their capacity to fix nutrients, produce growth hormone, mitigate abiotic stress, produce lignocellulose‐degrading enzyme and produce soil‐amending enzyme, all while scaling them using an objective in silico method. In addition, the isolates were tested in the field against test crops selected from the monocot and dicot families, namely maize (
Zea mays
) and okra (
Abelmoschus esculentus
). When comparing the treated settings to the untreated control setups, an increase was seen in the quantity of fruits (okra) and percentage of grain filling (maize). By creating a score system, an attempt was made to compare the efficiency of five strains based on the in vitro and in vivo experiments.

Compost derived Bacillus isolates were screened for plant growth promoting traits, scored through modelling and validated in field trials on maize and okra. Selected strains enhanced growth significantly, enabling reduced chemical fertiliser use, ecofriendly bioinputs and improved soil health.