SIGNIFICANCE OF APPLIED SOME SOIL AMENDMENTS AND PHOSPHATE DISSOLVING BACTERIA FOR ENHANCING THE AVAILABILITY OF PHOSPHATE IN A CALCARIOUS SOIL

Document Type : Research articles.

Authors

Soils, Water and Environ. Res. Inst., Agric. Res. Center, Giza, Egypt.

Abstract

A field experiment was carried out on a Private Farm at Salah El-Din,
El-Bostan (30° 43 ֿ 25° 14 ֿ N and 30° 17 ֿ 23° 94 ֿ E, elevation 14 m),
Nobaria, El-Behiera Governorate, Egypt during the two successive growing
seasons of 2008/2009 and 2009/2010. The main target of this study was at
evaluating the best combination of rock phosphate with sulphur, organic
manure (organic compost) and inoculation with phosphate dissolving bacteria
to enhance the availability of phosphate from rock phosphate and their effects
on yield and its components of broad bean plants (V
icia faba,L. Luzdo Otono
cv.).
The obtained results indicated that plant growth, seed and straw yields
as well as nitrogen, phosphorus and potassium contents in various organs of
broad bean plants were highly significantly increased due to the applied
combined treatments comparing with the solely ones. It was also found that
either sulphur application or inoculation with phosphate dissolving bacteria
plus rock phosphate had a significant effect on broad bean yield and its
quality, with a superior effect for sulphur application which was more
effective than the biofertilizer (PDB). The interaction between rock
phosphate combined with PDB or sulphur had significant effect on seed
yield/fed, weight of 100 seeds and protein yield/fed. The highest values were
recorded when broad bean plants were fertilized with rock phosphate
combined with PDB plus sulphur and organic manure.
Application of rock phosphate and different soil amendments
individually or together increased N, P and K contents in straw and seeds
yields of broad bean plants. The highest contents of the studied nutrients
were found when the plants were fertilized by rock phosphate and different
soil amendments together. Results also showed the important role of organic
matter, sulphur and PDB for releasing phosphorus from rock phosphate. So,
it could be concluded that, the combination of different applied soil
amendments with simultaneous application of rock phosphate, as a natural Psource, found to be possibility for saving significant quantities from the
industrialized inorganic phosphate fertilizers.


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