الفهرس 
IntroductionOnly 14 pages are availabe for public view
 |  | from | 215 |  |  |
| | | from | 215 | | |
Abstract
Three field experiments were conducted at Ismailia Agriculture Research Station, Egypt, during two growing seasons 2012/2013.
The first experiment was conducted on peanut crop in order to study the effect of inoculation of seeds of peanut with phosphate dissolving bacteria (PDB) B.megaterium var. phosphaticum , rock phosphate (RP) and super phosphate (SP) at rates 0, 15.5 and 31 kg P ha-1 yield, yield components, soil available N, P and K, pH, ECe and bulk density at anthesis and ripeness stage were determined. Also bacteria counts were determined. Asucceding crop of faba beans was grown on same plots following the peanut crop in order to assess the residual effect of treatments conducted to peanut crop. The second experiment was conducted in order to study the effect of RP and SP at rates 0, 15.5 and 31 kg P ha-1 with and without sulfur (S) application at rates 0, 476 and 952 kg ha-1 on peanut plants. The third experiment was conducted in order to study the effect of RP and SP at rates 0 and 23.23 kg P ha-1 combined with compost (C) at rates 0, 9.52 and 19.04 Mg ha-1 and sulfur at three above-mentioned
1.First experiment:
a. Effect of SP , RP and PDB on peanut plant growth
1. Growth characters
Inoculation of peanut seeds with PDB increased plant height and plant dry weight, SP application at two rates increased plant height, dry weight plant, number of pods/plant and weight of pods/plant. Application of rock phosphate alone had not significant effect on all growth characters. Combined effect of SP or RP with PDB increased all growth characters.
2. Yield and yield components
Phosphate dissolving bacteria inoculation increased number of pods/plant, weight of pods/plant, weight of seeds/plant, seed yield and straw yield. Application of SP at two rates significantly increased peanut yield and its components. The highest effect were obtained due to addition of 30.98 kg P ha-1. Solely RP application had not significant effect on yield and yield components. SP or RP combined with PDB increased yield and yied components over non treated soil. The increase of seed yield of plants fertilized with 15.49 kg P ha-1, and 30.98 kg P ha-1 as SP combined with PDB were 29.1 and 48.8% respectively, while the application of 15.49 kg P ha-1, and 30.98 kg P ha-1 as rock phosphate combined with phosphate dissolving bacteria were 25.35 and 29.11% respectively.
3. Nutrient contents
At antesis stage inoculation with PDB increased P contents of shoot by 17.39% over non treated soil, whereas N and K contents not affected by inoculation. At ripeness stage inoculation increased N and P contents of both seed and straw, whereas K content was not affected. SP application increased P contents up to 30.98 kg P ha-1 at anthesis stage, whereas N and K concentration were not significantly affected. Application of SP increased P contents of seed and straw at two rates of P-fertilizer.
Application of RP alone had not significant effect on N, P and K contents of seed and straw, but SP or RP combined with PDB at anthesis stage significantly increased on N and P contents, whereas K was not significant. Nitrogen and phosphorus contents of seed and straw significantly affected by combined with PDB and SP or RP.
4. Oil and protein seed contents
Seed oil contents not significantly affectet by all treatments. With respect of seed protein contents it can concluded that addition of SP or RP combined PDB, the highest seed protein contents was obtained with application of SP combined with PDB.
5. Soil available N, P and K
Soil available nitrogen and potassium were not affected significantly relative to non treated soil at anthesis and ripeness stage by all treatments, while available phosphorus increased. Available P at anthesis and ripeness stage significantly increased due to PDB inoculation. Also SP application significantly increased on available P at two stages of growth. RP, alon not affected significantly on available P at two stages of growth. combined with PDB and SP or RP affected significantly on available P at two stages of growth. Its obvious mentioned that soil available P at anthesis stage was higher than available P at ripeness stage. This may be due to the condition of studied soil and plant uptake.
6. Soil EC, pH and bulk density
Application of SP or RP solely or combined with PDB were not significant effect on soil EC, pH and bulk density.
7. Soil microorganisms
Generally, counts of phosphate dissolving bacteria increased as the time of growth periods increased reaching their maximum values at 60 days after peanut sowing in super phosphate treated soil, but their maximum values at 90 days, after peanut sowing in rock phosphate treated soil, and the counts of the phosphate dissolving bacteria at rock phosphate rate 30.98 kg P ha-1 with PDB generally to be higher than 15.49 kg P ha-1,with PDB while at super phosphate rate 30.98 kg P ha-1 with PDB generally to be lower than 15.49 kg P ha-1.
b. Effect of residual SP , RP and PDB on faba bean plant
1. Growth characters
In general the results indicated that the residual application of 30.98 Kg P ha-1 as SP solely or with PDB significantly increased on plant height and dry weight plant of faba bean but application of 15.49 kg P ha-1 not significant, whereas residual effect of RP solely at two rates and 15.49 kg P ha-1 combined with PDB not significant effect. Effect of residual 30.98 kg P ha-1 as SP or RP combined with PDB significantly increased on plant height and dry weight plant of faba bean.
2. Yield and yield components
Data indicated that residual effect of 30.98 kg P ha-1 as SP significantly increased on faba bean yield and yield components i.e. seed yield, straw yield, seed weight/plant and number of pods plant. Residual effect of SP or RP at rate 30.98 kg P ha-1 combined with PDB significantly increased on yield and yield components. Residual effect of solely addition of SP or RP at rate 15.49 kg P ha-1 and combined with phosphate dissolving bacteria had not significant effect on faba bean yield and yield componenet.