TRANSFORMATION OF PHOSPHORUS IN A VERTISOL IN SUNFLOWER-JOWAR CROPPING SEQUENCE
Loading...
Date
2001-08-09
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
UNIVERSITY OF AGRICULTURAL SCIENCES GKVK BANGALORE
Abstract
An investigation was carried out to know the effect of Diammonium
Phosphate (DAP), Single Super Phosphate (SSP), Mussoori Rock
Phosphate (MRP) with pyrite, P solubilizers and their combination with
FYM on P availability, P transformation and crop yield under sunflowerjowar
cropping sequence in a vertisol of Agricultural Research Station,
Annigeri during 1996-97. An incubation study with 18 treatment
combination comprising of P-sources and P-solubilizers was also
conducted to assess the extent of release of P with time.
Incubation study revealed that recovery of P from DAP applied at
the rate of 50 kg P2O5 ha ' at 30, 60 and 90 days was 31.74, 19.34 and
18.08 per cent, respectively, whereas recovery of P from MRP with same
rate of application at corresponding period was low and it was 2.54, 4.26
and 4.50 per cent, respectively. Incorporation of FYM increased available
P at all the periods of incubation.
Phosphorus transformation study revealed that the dominance of
different P forms among the mineral P fraction is in the following order:
saloid-P<Fe-P<Al-P<Occl-P<RS-P<Ca-P. The content of saloid-P, Al-P and
Fe-P, RS-P, Occl-P was higher in the soils receiving water soluble P
sources, while MRP treated plot was dominated by Ca-P and organic-P.
The content of saloid-P, Al-P and organic-P were significantly higher and
Ca-P, RS-P and Occl-P were significantly lower with FYM treated plot
irrespective of P-sources.
DAP treatment recorded highest seed yield of sunflower (14.38
q/ha) and grain yield of jowar (14.15 q/ha) which worked out to 23.43
and 16.07 per cent, respectively over MRP treatment. In FYM treatment,
grain yields of sunflower and jowar were 14.29 and 14.18 of per ha,
respectively and it was 22.55 and 20.47 per cent increase over no FYM
treatment. Diammonium phosphate is the best P fertilizer in vertisol and
however it can be substituted either with MRP + pyrite + PSB or in
combination with MRP which can replace DAP partially in a vertisol.
Description
Keywords
null