Zeolite Use Effi ciency Variation under Water Defi cit Stress in Grass Pea and Lentil

Abstract

To evaluate the effect of different application rates of zeolites under drought stress conditions on the protein and biomass production, and zeolite use efficiency in grass pea (Lathyrus sativus L.) and lentil (Lens culinaris L.), two-way ANOVA based on randomized complete block design was conducted at Research Farm of Urmia University in 2012. Two levels of irrigation (irrigation at field capacity (FC) and 50 % FC) and four levels of zeolites (0, 10, 20 and 30 tons/ha) were applied. Results of ANOVA showed the significant effect of zeolite application on protein yield, protein harvest index, and zeolite use efficiency for protein and biomass production and significant effect of irrigation regime on protein yield, protein harvest index and zeolite use efficiency for grass pea protein production. There were significant effects of zeolite application on the biomass, protein yield, and protein harvest index, and significant effects of irrigation regime on protein yield and protein harvest index of lentil. However significant interaction effect between zeolite and irrigation on zeolite use efficiency for protein and biomass production in lentil was obtained. The results indicated that water deficit stress significantly decreased these traits, whereas the application of zeolite compensated the negative effect of the drought stress. Zeolite use efficiency for grass pea and lentil biomass and protein production decreased in high rates of mineral application (30 tons/ha). The highest protein yield (307.12 kg/ha) and protein harvest index (14.2 %) of grass pea, and protein yield (222.59 kg/ha), biological yield (2587.6 kg/ha), and protein harvest index (8.6 %) of lentil were obtained when 30 tons/ha of zeolite were applied. These findings strongly suggested that the irrigation intervals of grass pea and lentil could be extended by application of zeolite.