Salt Tolerance and NaCl-removing Capacity of Fodder Beet, Oat, and Sorghum as Alternative Crops to Corn Irrigated with Saline-sodic Water in Calcareous Mediterranean Soil
摘要
A sustainable forage cropping system in saline conditions requires the insertion of salt-tolerant crops, particularly in the arid Mediterranean area. The salinity tolerance and salt-removing capacity of oat, fodder beet, and sorghum were evaluated as alternative crops to corn irrigated with saline-sodic water. The studied soil was calcareous. Five levels of water electrical conductivity (ECi) were tested: control (1), 4, 8, 12, and 16 dS m−1. The salinity rates were obtained by adding NaCl to the control water, and water requirement was supplied using a drip irrigation system. The results revealed that the salinity of water (ECi)> 4 dS m−1 resulted in a decline of corn biomass (−88%) compared to the control and the inhibition of sorghum emergence. The excessive ECi (16 dS m−1) reduced the biomass of oat and fodder beet by −50–34%, respectively, compared to the controls. The soil salinity at harvest reached 2.48 dS m−1 for fodder beet and 1.24 dS m−1 for oat at the ECi = 16 dS m−1. The NaCl-removing capacity of beet and oat reached 0.72 t ha−1 and 0.81 t ha−1 at ECi = 8 dS m−1, respectively. The ESP exceeded 14% for ECi ≥ 4 dS m−1 at harvest of all studied crops. Concerning the plant nutrient status, potassium (K) and boron (B) contents declined in oat with salinity. For beet, the salinity reduced calcium (Ca), magnesium (Mg), and B contents, whereas increases in K, Ca, Mg, and iron (Fe) were noticed in corn.