Silicon improves maize photosynthesis in saline-alkaline soils

Area of Science:

• Agricultural Science
• Plant Physiology
• Soil Science

Background:

• Saline-alkaline soils pose significant challenges to crop production, impacting plant physiological processes.
• Maize (Zea mays L.) is a vital crop susceptible to soil salinity and alkalinity, affecting its photosynthetic capacity.
• Silicon (Si) is increasingly recognized for its role in enhancing plant stress tolerance.

Purpose of the Study:

• To investigate the impact of varying silicon (Si) application rates on the photosynthetic characteristics of maize grown in saline-alkaline soil.
• To determine the optimal Si dosage for improving maize photosynthetic efficiency under stress conditions.
• To assess the relationship between Si application and key photosynthetic parameters like photosynthetic rate, stomatal conductance, transpiration rate, and intercellular CO2 concentration.

Main Methods:

• Field experiment conducted with five Si application levels (0, 45, 90, 150, and 225 kg·ha⁻¹).
• Measurements of photosynthetic rate (P n), stomatal conductance (g s), transpiration rate (E), and intercellular CO2 concentration (C i) were performed.
• Analysis of the effects of Si on maize photosynthetic characteristics at different growth stages.

Main Results:

• Silicon application significantly enhanced photosynthetic rate (P n), stomatal conductance (g s), and intercellular CO2 concentration (C i) in maize.
• Transpiration rate (E) was significantly decreased with appropriate Si application doses.
• The optimal Si application rate for improving maize photosynthetic efficiency under saline-alkaline stress was identified as 150 kg·ha⁻¹.

Conclusions:

• Silicon application, particularly at optimal doses, effectively mitigates the negative impacts of saline-alkaline stress on maize photosynthesis.
• Enhanced photosynthetic efficiency due to Si application contributes to improved maize growth and yield potential in challenging soil environments.
• The findings highlight the importance of Si fertilization for sustainable maize cultivation on saline-alkaline lands.