Inorganic Phosphorus Forms in Alluvial and Calcareous Soils as Affected by Different Phosphorus Application Levels and Incubation Periods.

Abstract

There is a debate concerning the optimum time of phosphorus application under Egyptian soil conditions. For this purpose, a laboratory incubation experiment was carried out at Soils Department, Faculty of Agriculture, Mansoura University to determine the inorganic phosphorus forms (Olsen-P, Ca-P, Oc-P, Al-P and Fe-P) in calcareous and non-calcareous (alluvial ) soil types after different times of incubation. Phosphorus was applied at rates of 10, 20 and 30 mg / kg soil. Inorganic phosphorus forms was determined in both soils at the beginning of the experiment (at zero time of phosphorus application), and after one, two, three, four and five weeks from application. Results indicated that inorganic phosphorus forms increased with increasing phosphorus application rate. Available phosphorus form recorded the highest value after the immediate phosphorus application. Available phosphorus concentration decreased gradually over the time to reach the lowest value after the fifth week of application. On the other hand, the other precipitated phosphorus forms were increased over the time of application. Available P form was converted to unavailable P forms in the order Ca-P> Oc-P>Al-P>Fe-P. Results also showed that the fixation power of the calcareous soil was higher than the non-calcareous soil. Based on the obtained results of our experiment, it is recommended to add phosphorus fertilizers at the critical stage of phosphorus needed by plants.

Comparative Study between Traditional and Nano Calcium Phosphate Fertilizers on Growth and Production of Snap Bean (Phaseolus vulgaris L.) Plants

“…Plants absorb 15-20% of phosphate in fertilizer added to the soil, while 80-90% rapidly converts to low-available forms [4]. The soil of Egypt suffers from phosphorus deficiency [5] and applied phosphorus is retained in the soil due to many factors (i.e., clay minerals and high soil pH) [6]. Due to multiple problems associated with traditional phosphate fertilizers, nanofertilizers could be a suitable alternative.…”

Implications of Applying Nano-Hydroxyapatite and Nano-Iron Oxide on Faba Bean (Vicia faba L.) Productivity

“…This plant has unique potentials in biological N-fixation (symbiotically with Rhizobium), itcould reach up to 300 kg N ha -1 (Singh et al, 2013) therefore it contributes to soil fertility effectively (Gasim and Link, 2007) and considered an effective choice for cropping system (Jensen et al, 2010).Framers growing beans do not need to use large amounts of nitrogen fertilizers compared with other crops (Chaieb et al, 2011). Egyptian soils suffer from deficiency of phosphorus (El-Agrodi et al, 2011) and applied phosphorus is tightly retained in soil due to many factors such as clay minerals (Devau et al, 2010) and high pH. Most of P retention in alkaline soils occur in calcareous soils, calcium ions retain P by precipitating P on the surface of calcium carbonate also it produce low soluble salt of calcium phosphate (Osemwotai et al, 2005;Shen et al, 2011); therefore the available fraction or plants is very low.…”