Compost mixed fruits and vegetable waste biochar with ACC deaminase rhizobacteria can minimize lead stress in mint plants

Muhammad Zafar-Ul-Hye,Muhammad Tahzeeb-Ul-Hassan,Ghulam Sabir Hussain,Shah Fahad,Subhan Danish,Rahul Datta,Abdul Wahid,Martin Brtnicky,Martin Leonardo Battaglia,Muhammad Jamil Khan

doi:10.1038/s41598-021-86082-9

Abstract

High lead (Pb) concentration in soils is becoming a severe threat to human health. It also deteriorates plants, growth, yield and quality of food. Although the use of plant growth-promoting rhizobacteria (PGPR), biochar and compost can be effective environment-friendly amendments for decreasing Pb stress in crop plants, the impacts of their simultaneous co-application has not been well documented. Thus current study was carried, was conducted to investigate the role of rhizobacteria and compost mixed biochar (CB) under Pb stress on selected soil properties and agronomic parameters in mint (Mentha piperita L.) plants. To this end, six treatments were studied: Alcaligenes faecalis, Bacillus amyloliquefaciens, CB, PGPR1 + CB, PGPR2 + CB and control. Results showed that the application A. faecalis + CB significantly decreased soil pH and EC over control. However, OM, nitrogen, phosphorus and potassium concentration were significantly improved in the soil where A. faecalis + CB was applied over control. The A. faecalis + CB treatment significantly improved mint plant root dry weight (58%), leaves dry weight (32%), chlorophyll (37%), and N (46%), P (39%) and K (63%) leave concentration, while also decreasing the leaves Pb uptake by 13.5% when compared to the unamended control. In conclusion, A. faecalis + CB has a greater potential to improve overall soil quality, fertility and mint plant productivity under high Pb soil concentration compared to the sole application of CB and A. faecalis.

Highlights

High lead (Pb) concentration in soils is becoming a severe threat to human health
Results showed that PGPR1 + compost mixed biochar (CB), CB, and PGPR2 + CB significantly decreased soil pH over control (Fig. 1A)
No significant increase was noted over soil pH of control, where sole inoculation of PGPR1 and PGPR2 was done

Summary

Introduction

High lead (Pb) concentration in soils is becoming a severe threat to human health. It deteriorates plants, growth, yield and quality of food. The use of plant growth-promoting rhizobacteria (PGPR), biochar and compost can be effective environment-friendly amendments for decreasing Pb stress in crop plants, the impacts of their simultaneous co-application has not been well documented. Current study was carried, was conducted to investigate the role of rhizobacteria and compost mixed biochar (CB) under Pb stress on selected soil properties and agronomic parameters in mint (Mentha piperita L.) plants To this end, six treatments were studied: Alcaligenes faecalis, Bacillus amyloliquefaciens, CB, PGPR1 + CB, PGPR2 + CB and control. Use of organic a mendments[31,32] i.e., compost in agriculture increases rhizobacterial proliferation, water and nutrients holding capacity and soil aggregation It decreases soil pH when applied in soil[33]. These PGPR enhanced systemic resistance (disease-resistance mechanisms) and Scientific Reports | (2021) 11:6606 |

Results

Discussion

Conclusion