EFFECT OF FURROW SPACING AND PHOSPHORUS FERTILIZATION TREATMENTS ON FABA BEAN YIELD, NUTRIENTS CONTENT AND SOME WATER RELATIONSHIPS

Two field trials were carried out at Sakha Agric. Res. St. farm during two successive winter seasons of 2007/2008 and 2008/2009, to assess the effect of planting methods and phosphorus fertilization treatments on faba bean yield, nutrient contents and some water relationships. Faba bean (Vicia faba L.) seeds var. Sakha 2 were planted on November in both seasons. Split plot design was used with four replicates. The main plots were assigned by two planting methods i.e. A: 120 cm furrow spacing with 4 planting rows per furrow and B:60 cm furrow spacing with 2 planting rows per furrow. The sub plots were assigned by four phosphorus treatments .e.1- application  of 30 kg P₂O₅ fed^-1 ( ha = 2.4 fed.) as superphosphate 15.5% P₂O₅ (P₂O₅ = 2.29 x P ) , 2- completing the soil available phosphorus up to 30 kg P₂O₅ fed^-1 by superphosphate, 3- application of 15 kg P₂O₅ fed^{-1 in addition to inoculating faba bean seeds with phosphate dissolving bacteria and 4-application of 15 kg P}₂O₅ + inoculation with phosphate dissolving bacteria + spraying with cyanobacteria extraction.
The obtained results were summarized as follows:

Planting methods high significantly affected seed yield in both seasons, the higher mean values of 1653.17 and 1766.75 kg fed^-1 were obtained with 60 cm furrow spacing in the first and second seasons, respectively.
Planting method of 60 cm furrow spacing had the higher mean values of biomass (6722.5 and 7161.4 kg fed^-1), higher 100 seed weight (99.04 and 101.56 g) and the higher N content mean values (56.0 and 61.4 kg fed^-1).
Planting method of 120 cm furrow spacing had the higher protein % mean value in the second season (22.34%), the higher seed P% mean values (0.55 and 0.56%) and the higher seed P content values of 6.87 and 7.39 kg fed^{-1 in the first and second seasons, respectively.}
Treatment of 15 kg P₂O₅ + inoculation with phosphate dissolving bacteria had the highest seed yield, biomass yield, seed N%, N content of the seeds, protein % and P%.
Treatment of 30 kg P₂O₅ fed^-1 had the highest 100 seeds weight values and the highest residual available P values in the soil after faba bean harvesting.
Planting method of 60 cm furrow spacing had the higher water applied mean values (1596 and 1586 m³ fed^-1) and the higher water consumptive use mean values of 1380 and 1359 m³ fed^-1, while, 120 cm furrow spacing had the lower water applied mean values (1314 and 1285 m³ fed^-1) and the lower water consumptive use mean values of 1113 and 1069 m³ fed^-1  in the first and second season, respectively.
The higher values of water productivity (WP) and productivity of irrigation water (PIW) were 1.24 and 1.30 kg m^-3 and 1.04 and 1.11 kg of seeds m^-3 were obtained from 60 cm furrow spacing in the 1^st and the 2^nd season, respectively.