Incorporated Biochar-Based Soil Amendment and Exogenous Glycine Betaine Foliar Application Ameliorate Rice (Oryza sativa L.) Tolerance and Resilience to Osmotic Stress.

Emad M Hafez,Salah M Gowayed,Raghda M Sakran,Alaa El-Dein Omara,Abdelmoniem Awadalla,Asmaa M S Rady,Bassam F Alowaiesh,Yasser Nehela

doi:10.3390/plants10091930

Abstract

Osmotic stress is a major physiologic dysfunction that alters the water movement across the cell membrane. Soil salinity and water stress are major causal factors of osmotic stress that severely affect agricultural productivity and sustainability. Herein, we suggested and evaluated the impact of integrated biochar-based soil amendment and exogenous glycine betaine application on the growth, physiology, productivity, grain quality, and osmotic stress tolerance of rice (Oryza sativa L., cv. Sakha 105) grown in salt-affected soil under three irrigation intervals (6, 9, or 12 days), as well as soil properties and nutrient uptake under field conditions during the 2019 and 2020 seasons. Our findings showed that dual application of biochar and glycine betaine (biochar + glycine betaine) reduced the soil pH, electrical conductivity, and exchangeable sodium percentage. However, it enhanced the K+ uptake which increased in the leaves of treated-rice plants. Additionally, biochar and glycine betaine supplementation enhanced the photosynthetic pigments (chlorophyll a, b, and carotenoids) and physiological attributes (net photosynthetic rate, stomatal conductance, relative water content, and electrolyte leakage) of osmotic-stressed rice plants. Biochar + glycine betaine altered the activity of antioxidant-related enzymes (catalase, ascorbate peroxide, and peroxidase). Moreover, it improved the yield components, biological yield, and harvest index, as well as the nutrient value of rice grains of osmotic-stressed rice plants. Collectively, these findings underline the potential application of biochar and glycine betaine as a sustainable eco-friendly strategy to improve plant resilience, not only rice, but other plant species in general and other cereal crops in particular, to abiotic stress, particularly those growing in salt-affected soil.

Highlights

Rice (Oryza sativa L.) is the main imperative food crop that feeds most people all over the world [1]
The same pH profile was noticed during the 2020 season (Figure 1B; PIR×TR = 0.0352)
Quantitative trait loci (QTLs) have been reported to play a key role in drought, flood, and salt tolerance in mega rice varieties [13]. Soil amendment such as biochar and foliar spraying like glycine betaine has found its way into maintaining agricultural sustainable development, which has a great potential for enhancing the performance of crop yield and mitigating the environmental stress [28,29]

Summary

Introduction

Rice (Oryza sativa L.) is the main imperative food crop that feeds most people all over the world [1]. In Egypt, rice is grown on over 0.5 million hectares, with a productivity estimated at 6.1 million tons according to the FAO report 2020 [2]. Climate change poses a major threat to agricultural production, in developing countries, resulting in abiotic stresses such as soil salinity and water stress on plant growth and production especially in the arid and semi-arid ecosystems [4]. It is imperative to minimize the environmental stresses to increase rice yield with improved soil quality [5]. The world population is growing promptly annually, which requires the need to increase the agricultural production in field crops such as rice, on which most of the world’s population depends, especially in Egypt by 2050 [6]

Methods

Results

Discussion

Conclusion