Amendment with sugarcane pith improves the hydrophysical characteristics of saline‐sodic soil

The application of organic materials is an environmental practice in soil restoration, but the use of sugarcane pith, a by‐product of the paper industry, as an amendment in soil reclamation has not been tested so far. The objective of this study was to quantify the effects of the application of sugarcane pith on various hydrophysical properties of saline‐sodic soil. A 4‐month incubation pot trial under stagnant water and leaching conditions was carried out. Application of 5, 10 and 20 t ha⁻¹ pith led to a decrease in bulk density by 19, 41 and 42%, respectively, and a corresponding increase in drainable porosity. Likewise, soil structure expressed in terms of aggregate stability was enhanced substantially from 0.5 to 0.9. Water‐saturated hydraulic conductivity (Kₛ) and available water content were also positively affected by the amendments with pith; these changes were attributed to its spongy nature and the increase in organic matter with its decomposition. The doubling of Kₛ to 1.4 cm hour⁻¹ with the application of 20 t ha⁻¹ pith was considered crucial because it resulted in larger rates of leaching of salt. The fast decomposition of pith released Ca²⁺, Mg²⁺ and K⁺ ions, which accelerated the leaching of Na⁺. We recommend that saline‐sodic soil of the type that we investigated in this study should be amended with sugarcane pith powder up to a rate of 10 t ha⁻¹. Future work should investigate the effects of pith amendments in field trials on a wide range of types of saline‐sodic soil. HIGHLIGHTS: Is fresh sugarcane pith effective as an amendment for saline‐sodic soil? Sugarcane pith could play a vital role in the management and reclamation of saline‐sodic soil. Application of 10–20 t ha⁻¹ sugarcane pith positively affected soil physicochemical properties. Sugarcane pith applied to saline‐sodic soil improves the hydrophysical characteristics.