Moursi,E.A. ; M.M.I. Nassr and Mona A.M-EL-Mansoury ( 2014). Effect of irrigation intervals and different plant densities on faba bean yield, some water relations and some soil properties under drip irrigation system in north middle nile delta region.J.Soil Sci. and Agric. Eng., Mansoura Univ., Vol. 5 (12): 1691 -1716 , 2014
Abstract: Two field experiments were conducted at Sakha Agricultural Research Station, Kafr El-Sheikh Governorate. The site is located at 310 07ˉ N Latitude and 300 57ˉ E longitude with an elevation of about 6 meters above mean sea level. This location represents the conditions of the North Middle Nile Delta region during the two successive winter growing seasons 2012/2013 and 2013/2014 to investigate the effect of irrigation intervals and plant densities on faba bean yield, some yield attributes and some water relations under drip irrigation system. Faba bean (Vicia faba L.) seeds, variety Sakha 2, were planted on 10th and 15th November and harvested on 28th April and 2nd May in the first and second growing seasons, respectively. A split plot design with four replicates was used. The main plots were randomly assigned by (irrigation intervals, I) which were I1 (irrigation every 6 days), I2 (irrigation every 9 days), I3 (irrigation every12 days), I4 (irrigation every15 days), I5 (irrigation every18days). The sub- main treatments were also randomly assigned by (plant densities, D) which were, D1 (planting one plant on one lateral from each side adjusted with opening the emitter), D2 (planting two plants on one lateral from one side adjusted with the emitter), D3 (planting four plants on one lateral on the two sides of the emitter), two plants from each side and D4 (planting four plants on one lateral on the two sides of the emitter, two plants from each side). In addition, two plants were planted in the middle of the two adjacent emitters with one plant in each side. The obtained results can be summarized as follows:-
Data clearly illustrated that, the values of seasonal water applied, water stored in the effective root zone and water consumptive use were affected by irrigation intervals, where the highest overall mean values for the abovementioned three studied parameters were recorded under irrigation interval (I1) and the values are 1475.52, 1205.20 and 1059.44 m3/fed. On the other hand, the lowest values for the same abovementioned studied parameters were recorded under irrigation interval, I5 and the values are 990.64, 905.16 and 850.44 m3/fed. for seasonal water applied, water stored in the effective root zone and water consumptive use, respectively. Generally, the values of the three abovementioned studied parameters can be descended in order (I1) > (I2) > (I3) > (I4) > (I5). Concerning water application efficiency (WAE%) the mean values were slightly affected by irrigation intervals. The highest mean values were recorded under irrigation interval (I4) and the values are 94.92 and 94.47 %. The lowest mean values were recorded under irrigation interval (I1) and the values are 81.57 and 81.79% in the first and second growing seasons, respectively.
Regarding, water productivity (WP) and productivity of irrigation water (PIW), the highest overall mean values were recorded under irrigation interval (I5) and the values are 1.38 and 1.19 kg/ m3. Meanwhile, the lowest overall mean values were recorded under irrigation interval (I1) and the values are 1.29 and 0.92 kg/ m3 for (WP) and (PIW), respectively. Concerning water consumptive use efficiency (Ecu), the highest overall mean value was recorded under irrigation interval (I4) and the value is 86.18%, but the lowest one was recorded under irrigation interval (I1) 71.80%. Concerning the amount and percentage of water saving can be descended in order I5 > I4 > I3 > I2 > I1 in the two growing seasons.
Concerning the effect of irrigation intervals on faba bean seed yield, the highest mean values were achieved under irrigation interval, I1 and the values are 1357.19 and 1364.05 kg/fed., but the lowest mean values were recorded under irrigation interval I5 and the values are 1175.64 and 1170.16 kg/fed. in the first and second growing seasons, respectively. Generally, the mean values of faba bean seed yield can be descended in order I1> I2 > I3> I4> I5. Regarding, the effect of plant densities on faba bean seed yield, the highest mean values were recorded under D1 in the two growing seasons. The same trend was observed for straw yield, where the highest mean values were recorded under irrigation interval (I1) and the mean values are 2.79 and 2.80 ton/fed. On the other hand, the lowest mean values were recorded under irrigation interval (I5) and the mean values are 1.61 and 1.58 ton/fed. in the first and second growing seasons, respectively. Concerning the effect of plant densities on straw yield, the highest mean values were recorded under D1 in the two growing seasons. Data also declared that some yield components such as plant height, number of branches / plant, number of pods /plant and weight of 100 seeds were affected by irrigation intervals where the highest mean values were recorded under irrigation interval I1. Generally, the mean values of the abovementioned studied parameters can be descended in order I1 > I2 > I3 > I4 > I5. Regarding, the effect of plant densities, the highest mean values were recorded under D1 comparing with other plant densities D2, D3, and D4 in the two growing seasons. Concerning, the effect of irrigation intervals and plant densities on soil pH, soil salinity, soluble cations, anions, calculated SAR and ESP. The mean values of soil pH were increased under surface irrigation method comparing with using drip irrigation system. While the lowest mean value was recorded under irrigation interval (I1). Data also showed that, the highest mean value was recorded under plant density D4 under all irrigation intervals. Regarding, the soil salinity, the highest mean value was recorded under I5 and the value is 1.409 ds/ m, but the lowest mean value was recorded under I1 and the value is 1.075 ds/ m. The highest mean value for soil salinity was recorded under D4 for all irrigation intervals. Regarding, soluble cations, anions, calculated SAR and ESP, the highest mean value was recorded under irrigation interval (I1) but the lowest value was recorded under (I5). The effect of plant densities on the abovementioned studied parameters (Ca++, Mg++, Na+, K+, HCO-, CO3--, Cl-, SO4--, SAR and ESP) was not clear, however, some parameters increased under D1 but the others increased under D4.
Keywords: (drip irrigation, irrigation intervals, plant densities, faba bean yield, water relations, some soil characteristics. )
