Effect of super absorbent water application in soil and humic acid foliar application on some agroecological characteristics of bean (Phaseolus vulgaris L.) in Mashhad (Iran)

In recent years، concern over the health of food products، particularly of legumes which are a leading source of protein throughout the world، has increased significantly. To study the effect of different levels of super absorbent water application in soil and humic acid foliar application on some agroecological characteristics of bean، (Phaseolus vulgaris L.)، a split strip plot arrangement based on RCBD with three replications was conducted in the 2010-11 growing season at the Research Field of Agriculture Faculty of Ferdowsi University of Mashhad. The main plot factor was application of super absorbent water polymer in 3 levels (0، 40 and 80 kg ha-1) and the sub-plot factor was foliar application of humic acid in 2 levels (0 and 3 kg ha-1). Two irrigation intervals (7 and 14 days) were assigned to the strip plots. The results showed that the interaction of super absorbent application and humic acid foliar application on seed yield was significant، as the highest and the lowest seed yield resulted from 80 kg ha1- super absorbent، with and without humic acid application (3475. 9 and 1710. 6 kg ha-1، respectively). Dry matter accumulation was significantly affected by interaction of super absorbent application and irrigation interval، as the seven-day irrigation interval in all super absorbent levels was superior compared to the 14 days of irrigation interval، as dry matter accumulation at 0، 40 and 80 kg ha-1 of super absorbent application were increased by 15، 9 and 11 percent، respectively. The interaction of humic acid and irrigation interval revealed that humic acid application at 7 and 14 days of irrigation intervals increased LAI 11 and 14 percent، respectively. The triple interaction effect of experimental factors showed that CGR increased as a result of application with no application of humic acid plus seven and 14 days of irrigation intervals when the super absorbent application was increased. In general، these results suggest that it could be possible to reduce chemical fertilizer use as a result of using of ecological inputs، meanwhile reducing environmental hazards and conserving of long term sustainability.