Alleviation of Drought Stress in Turfgrass by the Combined Application of Nano-compost and Microbes from Compost

Abstract

Drought stress is a key environmental factor limiting the growth and productivity of plants. Turfgrasses are often affected by drought in north China due to water shortage. In the present study, the impact of nanosized compost either alone or in combination with drought tolerant isolates from compost on turfgrass response to drought was investigated. Municipal solid waste (MSW) compost was processed into nanosized particles and added in turfgrass soil. Microorganisms in the MSW compost were screened for drought stress tolerance using increasing concentrations of polyethylene glycol (PEG 6000). Festuca arundinacea Schreb. plants were inoculated with this mixture and exposed to drought stress by reducing the amount of water added at vegetative growth stage. The drought-tolerant isolates from compost were identified as Bacillus cereus, Lysinibacillus sp. and Rhodotorula glutinis. Our results revealed that nanocompost and microbial inoculation minimized the drought stress-imposed effects significantly increasing shoot biomass, root biomass, and chlorophyll content. Similarly, nanocompost-treated and inoculated seedlings showed higher levels of antioxidant enzymes and lower MDA content compared to nontreated control under drought stress. The combination of nano-sized compost and microbial inoculation were more efficient than nanocompost alone in terms of influencing growth and physiological status of the seedlings under drought stress. Our data suggest that nanocompost combined with drought-tolerant isolates may enhance drought tolerance in turfgrass by promoting plant growth and increasing the capacity to eliminate toxic reactive oxygen species (ROS).