Salt removal capacity and nutrient status of a forage cropping system based on triticale and alfalfa when grown on a salinized calcareous soil

Abstract

Managing soil salinization requires identifying a sustainable cropping system to improve soil quality by removing salts, particularly in the south Mediterranean area. The present study aimed to evaluate the efficiency of the forage crop succession containing triticale and alfalfa in removing salt from salinized calcareous soil. The experiment was conducted in field during two successive seasons. Five electrical conductivity levels of salinized soil (ECs) were tested: 0.3 (control), 0.8, 1.4, 1.8, and 2 dS m-1 (1:5extraction). The triticale was grown from November 2019 to April 2020. The alfalfa occupied the same soil from June 2020 to October 2021 (11cuts). The electrical conductivity of the irrigation water was ECi=1.1 dS m-1. The results revealed that the soil salinity and the exchangeable sodium percentage (ESP) decreased during the cropping seasons. The high ECs=2 dS m-1 and its ESP=85.2% became similar to control levels (ECs=0.25 dS m-1, ESP=5%) after the succession of triticale and fourth cuts of alfalfa. The NaCl uptake at the end of the cropping succession was 1433 kg ha-1 at an initial ECs=2 dS m-1. Concerning the nutrient status of the plants, nitrogen, phosphorus, and potassium contents were invariable with ECs levels. For alfalfa, a reduction in calcium and magnesium contents was noticed with soil salinity in the first season (2020). The results suggest that the insertion of triticale and alfalfa in the forage cropping system is an efficient solution for removing salt from salinized soils to ensure sustainable agricultural production.