Effects of biochar amendments on rice growth and metabolic response to salinity stress in salt-affected soils

Abstract

Exploring cheaper and sustainable strategies for managing salt-affected soils remains crucial in irrigated areas. Many researchers recommended using gypsum as material for reclamation salt-affected soils, which are costly and unavailable for most farmers. In this study, we used biochar derived from the common materials found in the irrigated areas that are locally available and less utilized as a substitute for gypsum for sustainable reclamation of salt-affected soils. Salt-affected soils (saline, saline-sodic and sodic) and unaffected were collected from the Watari Irrigation project, Kano State Nigeria using farmers' perceptions about the salinity situations of the irrigation scheme and existing legacy map data. The biochar used for this study were made using the Typha grass, rice straw, and rice bran samples collected from the same area. Thirty-six (36) containers (plastic pots) with a diameter of 27.5cm and height of 45cm each were filled with eight-kilogram dried soils, including non-saline, saline, and saline-sodic. We measured plant height, and normalized difference vegetation index (NDVI) at interval of 14 days. Number of tillers per plant were also measured during tillering stage at interval of 14 days. Stover dry weight, grain dry weight, electrolytic leakage and proline contents were measured after the end of the experiment. The results revealed a high significant effect (p<0.01) of biochar amendments in remediating different forms of salt affected soils. Saline sodic soil was effectively managed when using Typha biochar with a mean value very close to non-saline soil. Rice straw and rice bran reduces the salinity levels particularly in sodic soil. Therefore, biochar from different source could be used in addressing salt-specific problems rather than using a uniform treatment.