Effect of Soil Available Phosphorus Levels on Chickpea (Cicer arietinum L.) - Rhizobia Symbiotic Association

Background: Growing chickpea (Cicer arietinum) plants is affected by several environmental constraints as osmotic stress and nutrients deficiency particularly phosphorus (P). For other legume species, it was confirmed that P deficiency affects negatively their rhizobial symbiosis. The purpose of this study was to assess the effect of soil available P level on chickpea-rhizobia symbiosis under field conditions at Oualidia region of Morocco. Methods: Ten farmers' fields with different soil available P levels were considered to carry out this study based on samples of 10 plants per plot. Result: The results showed that the plants from soil 7, with the lowest pH and the highest available P level (23.52ppm), presented high shoot dry weight (38.3 g/plant). Meanwhile the soil 5 with the lowest available P content showed low plant growth. The shoot P content was positively linked to soil P level but nodule biomass showed an irregular variation with soil available P level. Furthermore, it was confirmed that adequate plant P nutrition results in high chickpea yield and it was the case for plants from soil 7 presenting a mean yield of 62 seeds per plant). Finally, strong correlation was noted between yield and phosphorus concentration in soil (r=0.94).