TY  - BOOK
AU  - Geetha P
AU  - Sureshkumar P(Guide)
TI  - Quantity - intensity relations of phosphorus with reference to its bioavailability in lateritic soils
U1  - 631.4 
PY  - 2008///
CY  - Vellanikkara
PB  - Department Of Soil Science And Agricultural Chemistry,College of Horticulture 
N2  - Five benchmark soils of lateritic origin were collected and used for the present study of Q-I relations, dynamics and transformations of P. Samples of these soils were collected from Kunnamangalam (Calicut), Angadippuram (Malappuram), Vellanikkara (Thrissur), Pattambi and Thirumittakkodu(Palakkad) . The soils were characterized with respect to pH, EC, CEC and exchangeable cations,  AEC,   available nutrient status ( Organic carbon, available P, K, Fe, Mn,  Cu and Zn) and P fixing capacity The inorganic P fractions viz. soluble P, Al bound P Fe bound P, sesquioxide occluded P, and Ca bound P as well as organic P was estimated. The equilibrium phosphate potential and buffer power of these soils were estimated from the Q/I curve.

	Among the five soils, Vellanikkara soil series recorded the lowest available P and soluble P fraction, the highest P fixing capacity and highest adsorption maximum as per Langmuir equation   Based on the above characteristics this soil was selected for pot culture experiments to grow cowpea as a test crop using three different amendments (Pongamia, Cleistanthus, and lime) three levels of labeled phosphatic fertilizer and two methods applications. Available P and fractions of phosphorus in the soil was estimated at three stages. P content as well as 32P counts in the plants were also estimated. A and L values were computed at 15 and 30 days after sowing.  

	It can be concluded from the present study that application of different amendments dictated the transformation of P in soil. The available P, soluble P and %Pdff could be improved significantly. A different trend in radioactive phosphorus activity in available P as well as in  A and L values indicated that the applied P though contributing to the available pool in amended soils, this might be routed through the inorganic fraction Ca-P and not directly coming to the soluble/labile pool.  
































UR  - http://krishikosh.egranth.ac.in/handle/1/5810028311
ER  -