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Phosphorus (P) is the second important key plant nutrient after nitrogen. An adequate supply of P is therefore required for proper functioning and various metabolisms of plants. Majority of P in soils is fixed and hence, plant available P is scarcely available despite the abundance of both inorganic and organic P forms in soils.A group of soil microorganisms capable of transforming insoluble P into soluble and plant accessible forms across different genera, collectively called phosphate-solubilizing bacteria (PSB), have been found as best ecofriendly option for providing inexpensive P to plants. These organisms in addition to supplying soluble P to plants also facilitate the growth of plants by several other mechanisms, for instance, improving the uptake of nutrients and stimulating the production of some phytohormones. Two field experiments were conducted at EL-Gemmiza, Agric. Res. Station, (30º ‫׳74‬ ‫״5.22‬ N, 31° ‫׳70‬ ‫״43‬ E, elev. 10 m), Agric. Res. Centre., El-Gharbia Governorate, Egypt, during the two successive summer seasons of 2017 and 2018, to study the effect of different application sources and rates of phosphorus on the growth, productivity, yield characters and quality of soybean (Glycine max L.), c.v. Giza 111. The treatments consisted of four sources of phosphorus [single super phosphate (SSP), rock phosphate (RP), single super phosphate (SSP) + phosphate solubilizing bacteria (PSB) and rock phosphate (RP) + phosphate solubilizing bacteria (PSB)] at three levels of added P.i.e (0, 15 and 22.5 kg P 2 O 5 fed -1 ).Results revealed that seed and straw yield and uptake of N, P and K increased significantly with both sources of P over control. Application of single superphosphate proved superior increases compared to rock phosphate in respect of yield and uptake of nutrients. There was a significant increase in yield and uptake of nutrients with increase in P application rate from 15 kg P 2 O 5 fed -1 to 22.5 kg P 2 O 5 fed -1 applied either as SSP or RP. Protein content in soybean seed increased significantly with both the sources of P. The application of SSP +PSB (T 9 ) recorded higher yield (grain and straw) and uptake of nutrients than phosphorus alone. The maximum seed (1572 kg/fed) and straw (4473.33 kg/fed) yields were recorded with 22.5 kg P 2 O 5 fed -1 as SSP+PSB. Significant differences among the treatments were noticed with respect to number of pods per plant, seed yield per plant, test weight and seed yield. Application of 22.5 kg P 2 O 5 fed -1 with PSB (T 9 ) produced maximum number of pods/plant (150.67), seed yield (74.23 g/plant) and hundred seed weight (18.77 g/plant) as SSP and the lowest was in the control. Regarding evaluation of phosphorus use efficiency had more pronounced effects on combined application of SSP+PSB followed by RP+ PSB. Quality parameters viz., oil content, oil yield and crude protein content differ markedly among different treatments with the application of levels of phosphorus and bio-fertilizer.

A field experiment was conducted at El-Gemmeiza Agric. Res. Station, Gharbeya Governorate, Egypt during the two successive winter seasons of 2017/2018 and 2018/2019, to study the effect of sulphur ( 0, 40 and 80 kg/fad.) and three foliar spray treatments (mixture of FeSO4 20%+MnSO43H2O 23%+ZnSO47H2O 23% +B as boric acid 17%) at 1%, blue green algae extract at 1 liter /fad. and yeast extract at 100 ml/liter water on growth , yield and root quality of sugar beet (cv Oskar poly) grown in a clay soil conditions. These treatments were arranged in a split plot in a complete block design with three replications. Sulphuer levels were randomly distributed in the main plots, while foliar spray treatments were randomly arranged in the sub plots. The interaction between sulphur at 80 kg/fad. and spraying with blue green algae extract at 1 liter / fad. gave the highest values of sugar beet shoots, roots and its components. While, the interaction between sulphur at 80 kg/fad. and spraying with the mixture of Fe+Zn+Mn+B at 1 % recorded maximum values of Fe, Zn, Mn and B in leaf tissues and roots. The increases in yield of sugar were about 32.8 and 56.3 % for the interaction between 80 kg S/fad. and spraying with blue green algae, 24.9 and 42.7 % for the interaction between 80 kg S/fad. and spraying with mixture of Fe+Zn+Mn+B over the interaction between 0 S and spraying with yeast extract in the 1 st and 2 nd seasons, respectively.

Two field experiments (tomato and squash) in rotation were conducted at Sakha Agricultural Research Station Farm, Kafr El-Sheikh Governorate, Egypt during the summer and the autumn seasons of 2008 and 2009 to evaluate the effects of some multinutrient fertilizers for long term cultivation under two irrigation systems on crop yield and soil quality. The experiments were carried out under wire proof green house conditions. Tomato (Lycopersicon esculentum L) seedlings under the local name of Alessa was planted . Two irrigation systems and nine fertilizer treatments were examined . Split plot design was used with four replicates. The main plots were assigned by two irrigation systems (surface furrow irrigation, and drip irrigation). The sub plots were randomly assigned by nine fertilizer treatments of :-1-control (without fertilization), 2-recommended dose of N and P (200 kg N and 13.08 kg P fed -1 ), 3recommended dose of P and K (13.08 kg P and 41.5 kg K fed .-1 ), 4-recommended dose of N and K, 5-multinutrients 20 -20 -20 +1% Mg + micro nutrients, 6multinutrient 20 -20 -20 + 1% Mg, 7-multinutrient 20 -20 -20 NPK as compound fertilizer (200 kg fed .-1 ), 8-commercial multinutrient 20 -20 -20 NPK as mixed fertilizer and 9-recommended dose of N. P and K (as urea, superphosphat and potassium sulphate). Squash was transplanted on the same design without fertilization depending on the previous fertilizer residuals. The obtained results can be summarized as :-surface irrigation gave higher tomato fruit yield of 32178.3 kg fed -1 , the highest dry fruit weight of 2413.37 kg fed -1 , higher P %, P content of the fruits (0.257% and6.2 kg fed -1 ) respectively, higher values of K % in the shoot and fruits ( 0.9 and 2.7%) , NUE, PUE, KUE and the highest squash fruit yield of 10202.67 kg fed -1 . Drip irrigation produced the highest N % in the shoot and fruits of 0.602 and 0.912 % respectively. Surface irrigation generally decreased available N, K in the soil after squash while available P was increased compared to the values before planting. The highest tomato fruit yield of 31105.2 kg fed -1 , N% in tomato shoot of 0.677%, NUE155.5, PUE 814.0 and KUE 622.1 were obtained with T5.

Two field experiments were conducted during the two successive seasons of 2013 and 2014 at El-Gemmeiza Research Station (30º ‫׳74‬ ‫״5.22‬ N, 31° ‫׳70‬ ‫״43‬ E, elev. 10 m), Agriculture Research Center, El-Gharbia Governorate, Egypt to study the effect of integrated fertilization of N-mineral and organic fertilizer combined with bio fertilizer (including the genera Azotobacter and Azospirillium) on sunflower (c.v. Sakha 53) seed yield and quality. The experiment was laid out in a randomized complete block design with three replicates. The experimental treatments comprised partial substitution of the recommended mineral N (MNRec.) rate (30kgN/fed.) with organic N fertilizer (ONF) as compost combined with bio fertilizer. Results revealed that application of T 4 (50%MNRec. +25% ONF +Bio) significantly improved yield, as well as yield attributes and protein and oil yields as compared to 100%ONF(T 8 ) or 100%MN(T 1 ) only .The integrated MN with ONF(25-50%ONF)always gave higher values than those obtained with full N rate as mineral or organic only. However, maximum seed oil percentage was recorded, when crop was fertilized by T 6 (100%ONF+Bio) followed by T 5 (25%MNRec. +75% ONF) while maximum seed oil yield was recorded by T 2 (50% MN Rec. +50% ONF) followed by T 4 (50%MN Rec. +25% ONF +Bio). According to the results of this experiment, unsaturated fatty acids, mainly linoleic and oleic acids raised in response to the integrated fertilization system while the saturated fatty acid (palmitic and stearic acid) were reduced. High percentages of oleic acids (50.17%) and linoleic acid (45.29%) were observed in T 4 and T 9 . So, bio-organic fertilizer could be considered as a suitable substitute (25-50%) for mineral nitrogen fertilizer in agricultural systems.