Abstract:
Residual availability of P was investigated in three soils using rice plant for three consecutive years under greenhouse conditions. The `A` values of the three soils measured in different years were significantly higher than their respective preceding years and that of the first year (1964) compared to Olsen`s NaHCO3-P extracted from the original soils. Comparatively larger amounts of residual P were available in the Kala Shah Kaku loamy soil during all the years. A reverse tendency was observed in the Tando Mohammad Khan clay loam soil having the highest content of clay and carbonates. The fractions of P derived from the added P and per cent of superphosphate fertilizer utilized by the rice plants decreased as the availability of residual P in soils increased. Only slight fixation of P occurred in Tando Mohammad Khan soil in the first as well as the second year and in Dokri soil during the second year only otherwise large additional amounts of P released from all the soils over and above the P applied. This indicates a very negligible fixation of P in soils particularly the loamy ones grown to rice.
Page(s):
56-58
DOI:
DOI not available
Published:
Journal: Pakistan Journal of Scientific and Industrial Research, Volume: 16, Issue: 1--2, Year: 1973