Does the Application of Different Compost and Vermicompost Teas Affect Maize Germination and Initial Growth Under Water Deficit and Irrigated Conditions?

This study evaluated aerated teas produced from compost and vermicompost (using cattle manure, elephant grass, and castor bean cake) applied to maize. Two growth chamber experiments assessed initial development under irrigation and water deficit to identify the most effective tea and concentration. Subsequently, a greenhouse pot experiment evaluated the best treatment under different application modes (soil, foliar, or soil + foliar). Results showed that Mixed Vermicompost Tea (MVT) at a 1:10 dilution outperformed other extracts, promoting greater biomass under both water conditions. In the greenhouse, the combined application (soil + foliar) was the most effective. Notably, MVT acted as a root architecture modulator. Under irrigated conditions, it increased both fine and thick roots. However, under water deficit, it prioritized the proliferation of fine roots (< 2 mm) over thick ones, facilitating a dehydration avoidance strategy through improved soil exploration. Additionally, MVT reduced non-photochemical quenching (NPQ) upon rehydration, indicating faster photoprotective recovery. These findings suggest that MVT serves as a viable bioinput, enhancing maize resilience primarily through morphological plasticity rather than direct nutritional supply.