The effect of silicate fertilizer on the root development of rice and its tolerance to salinity stress

Abstract

The problem of salinity stress in agricultural land is increasing rapidly, mainly due to climate change. Salinity in the soil has a detrimental effect on the root growth of rice and reduces the ability of the plant to absorb water and other nutrients from the soil resulting in stunted growth. The application of silicate fertilizers is an effort to reduce the negative effects of salinity stress. Absorption of beneficial element silicon (Si) by rice plants can reduce salinity stress. The objective of this research is to analyze the effect of calcium silicate on rice root growth and its tolerance to salinity stress. This research was conducted with the addition of silicate fertilizer consisting of three levels of CaSiO3 (0 mM, 2 mM, 4 mM) in red rice (Oryza sativa L. ‘Sembada Merah’) under salinity stress treatment at the level of 0 dS m-1(control), 3 dS m-1 (low), 7 dS m-1 (moderate) and 10 dS m-1 (high). The treatment with a salinity level of 10 dS m-1 reduced root length, fresh and dry weight of the root. The addition of calcium silicate in salinity stress conditions was able to improve the root anatomical characteristics of rice ‘Sembada Merah’ by increasing the epidermis thickness, cortex thickness, stele diameter and root diameter. Silicate fertilizer is indicated to play a role in increasing suberin and lignin to form apoplast defenses in order to prevent the entry of Na+ ions into the stele.