Potential of Biochar Application to Mitigate Salinity Stress in Eggplant

Abstract

Salinity stress is among the major abiotic stresses prevailing in arid and semiarid areas such as the southern high plains of the United States. In these areas, both declining quality of groundwater and cultivation practices have resulted in increased accumulation of salts in the root zone. The occurrence of excessive salts in the root zone is detrimental for plant growth and economic yield. Recently, biochar has received a great consideration as a soil amendment to mitigate the detrimental impacts of salinity stress. However, the effectiveness of biochar to mitigate the salinity stress depends on the feedstock type, pyrolysis temperature and time, soil type and properties, and plant species. Therefore, a pot experiment in a greenhouse was conducted to 1) examine the effects of salinity stress on physiology, shoot and root growth, and yield of eggplant (Solanum melongena L.), and 2) evaluate the potential of hardwood biochar and softwood biochar to mitigate the damaging effects of salinity stress on eggplant. The experiment was conducted in a split-plot design with three salinity levels of irrigation water [S0 (control, 0.04 dS·m−1), S1 (2 dS·m−1), and S2 (4 dS·m−1)] as main-plot factor and three biochar treatments [B0 (control, non-biochar), Bh (hardwood biochar), and Bs (softwood biochar)] as subplot factor with four replications. Results showed that stomatal conductance (gS) and photosynthesis rate decreased significantly, while leaf temperature and electrolyte leakage increased significantly with increase in irrigation water salinity levels. Root growth (root length density and root surface area density), shoot growth (plant height, stem diameter, and leaf area), and yield of eggplant declined with increase in levels of salinity stress. Biochar application helped to enhance gS and photosynthesis rate, and to decrease leaf temperature and electrolyte leakage in leaf tissues of plants. This resulted in better root growth, shoot growth, and fruit yield of eggplant in treatments amended with biochar than non-biochar (control) treatment. There was no significant difference in the effect of two types of biochars (hardwood and softwood biochar) on physiology, root growth, shoot growth, and yield of eggplant. Therefore, it can be concluded that softwood and hardwood biochars could be used to minimize the detrimental impacts of salinity stress in eggplant.

Field Crop Responses and Management Strategies to Mitigate Soil Salinity in Modern Agriculture: A Review

“…Because stomatal guard cells possess a range of mechano-sensitive ion channels, they could potentially transduce a change in the xylem pressure caused by salinity into altered stomatal apertures [48,49]. Furthermore, plants grown under salt stress suffer physiological and metabolic changes such as reduced enzyme activity, CO 2 assimilation, protein biosynthesis, leaves water relations, and photosystem II (PS II) [41,50].…”

The Negative Effects of High Rates of Biochar on Violas Can Be Counteracted with Fertilizer

“…Biochars are mainly classified as hardwood and softwood biochar based on their parent material used [23]. Generally, softwood biochar has lower pH than hardwood biochar [23,24], but it also depends upon the pyrolysis temperature and type of parent material used. Hardwood biochar is mainly used as amendment in greenhouse pot cultivation as it has many of the desired physical and chemical properties required.…”

Effect of Cotton Leafroll Dwarf Virus on Physiological Processes and Yield of Individual Cotton Plants

“…Therefore, it is possible that the decline in stomatal conductance that we observed in the symptomatic plants might be due to virus-induced increases in ABA synthesis. Additionally, reductions in g s are a well-known response to multiple wiltinducing stresses (biotic or abiotic), and stomatal closure due to decreases in leaf turgor limits access to CO 2 by rubisco (Kirkpatrick et al, 1995;Sampol et al, 2003;Farooq et al, 2009;Chastain et al, 2014;Snider et al, 2014;Parkash and Singh, 2020a;Parkash et al, 2021). Furthermore, if g s reaches sufficiently low levels, even processes that do not necessarily require CO 2 as a substrate (e.g., the thylakoid reactions) will become limited (Medrano et al, 2002).…”