Rainfed lentil (lens culinaris Medik.) responses to manganese foliar spray when grown in a high-calcareous soil

Abstract

This study was designed to evaluate the response of rainfed lentil to manganese (Mn) foliar application in high-calcareous soil located in the arid Mediterranean area. Field experiments on two clay calcareous soils containing different free carbonates and exchangeable Mn contents were carried out. The soil“1” has Mn content (DTPA extraction) of 7.5 mg kg−1 and it contains 8.9% of free carbonates. The soil“2” contains 3.3 mg kg−1 of Mn and it has a free carbonates level of 15.9%. Five foliar spray concentrations of Mn in lentil (0 as control; 0.5%; 1%; 3%; and 8%) were tested. Mn was applied in the sulfate form at flower bud and flowering. The soil“1” and soil”2” were evaluated during the 2016–17 and 2017–18 seasons, respectively. Results showed that foliar Mn feeding did not enhance grain yield and its components. Mn foliar spray over than 1% resulted in leaf damage during the rainfall season 2017–18 (429 mm) compared to 2016–17 (289 mm). At 8% of Mn, the phytotoxicity reduced grain yield by 34.5% compared to control. For both calcareous soils, shoot Mn content at the end of flowering was over 30 mg kg−1 for control and exceeded 1800 mg kg−1 at 8% of Mn. No antagonism or synergy between Mn and the other nutrients (N, P, K, Ca, Mg, Cu, and Zn) was recorded.

Keywords

• Lentil
• Manganese
• Free carbonates
• Foliar spray
• Phytotoxicity