Wheat straw biochar application improves the morphological, physiological, and yield attributes of maize and the physicochemical properties of soil under deficit irrigation and salinity stress

Abstract

Soil salinity and water scarcity adversely affect maize productivity. The use of biochar could enhance soil quality and increase the salt and/or drought threshold tolerance and yield of maize. Therefore, a pot experiment was conducted with three biochar addition rates of 0% (BA₀), 5% (BA₅), and 10% (BA₁₀) concerning salinity stresses of 2.0 (WS₂) and 5.0 dS m⁻¹ (WS₅) under deficit irrigation comprising three levels at 60% (DI₆₀), 75% (DI₇₅), and 100% (DI₁₀₀) of the reference evapotranspiration. Compared with the BA₀ rate, the BA₁₀ rate improved soil properties and the growth, nutrient uptake, and yield of maize. The DI₁₀₀ × SW₂ × BA₁₀ combination improved plant growth, providing the highest yield (257.7 g/plant) and water productivity (WP) (2.92 kg/m³) values. However, the combination DI₆₀ × SW₅ × BA₀ decreased plant growth, offering the lowest yield (121.9 g/plant) and WP (1.96 kg/m³) values. While the former combination increased water and nutrient contents in the soil, the latter combination reduced their values. Considering the salt tolerance index, the yield was more tolerant to salinity stress under the BA₁₀ rate as a 3.60% decrease in yield was detected when soil salinity exceeded the threshold value (5.56 dS/m). The drought threshold was declined from 390 L under BA₀ to 280 L under BA₁₀ rate. The study suggests that biochar could mitigate the adverse effects of deficit irrigation and salinity stress on maize growth and productivity. Thus, biochar could be used in salt-affected soils or when irrigation water is of low quality to sustain maize production.

Keywords:

• biochar
• deficit irrigation
• nutrient uptake
• salt stress
• stress tolerance
• Zea may L

Acknowledgments

The authors thank the National Key R&D Program of China (2018YFD0900805) on behalf of providing financial support in all experimental work.

Conflict of interest

No potential conflict of interest was reported by the authors.

Additional information

Funding

The authors thank the National Key R&D Program of China (2018YFD0900805) on behalf of providing financial support in all experimental work.