Journal of Applied and Natural Science 6 (2): 362-365 (2014)
Differential response of phosphorus utilization efficiency in rice by tracer
technique using phosphorus-32 under phosphorus stress environment.
V. Sanjivkumar* and P. Malarvizhi
Department of Soil Science and Agricultural Chemistry, Tamil Nadu Agricultural University, Coimbatore - 641003
(Tamil Nadu), INDIA
*Corresponding author. E-mail: email@example.com
Abstract : In most soils, soil and fertilizer Phosphorus (P) are
easily bound by either soil organic matter or chemicals and thus are unavailable
to plants unless hydrolyzed to release inorganic phosphate. Therefore, the
development of P-efficient rice varieties that can grow and yield better with
low P supply is a key to improve crop production. P efficient plants play a
major role in increasing crop yields due to shortage of inorganic P fertilizer
resources, limited land and water resources and increasing environmental
concerns. Based on the P uptake efficiency, four rice genotypes viz.,TNRH
180, CB08504, CB06732 and ADT 47 were selected from the field experiment and
used in pot culture experiment with three levels of P using radio isotope
technique to quantify the P acquisition efficiency (PAE) and P use efficiency
(PUE) and also to determine the native P supplying power of the soils using 32P in low P soils.
Growth and yield parameters, grain and straw yield and major nutrients uptake of rice genotypes were increased
with enhanced level of phosphorus application. Among the four genotypes, TNRH 180 recorded the highest grain
yield and uptake. Increasing the P application rate from 25 to 50 kg P2O5 ha-1 increased the %Pdff in grain and
straw for all the genotypes. The mean per cent phosphorus utilization (PPU) ranged between 18.74 and 23.72. The
PPU of the genotypes followed the order TNRH 180 (23.72 %) > CB08504 (23.36 %) > CB06732 (20.54%) > ADT
47 (18.74%). The PPU values were higher at lower level of P application (25 kg P2O5 ha-1) for the genotypes TNRH
180, CB08504 and CB06732. From this study showed that rice genotypes have the ability to utilize the both available
and unavailable form of phosphorus by secreting some organic acids in the root portion to solubilize. Hence
rice genotypes indicated above have the ability to increase phosphorus utilization efficiency.
Keywords :Pdff, Pdfs, Phosphorus-32 (32P), P utilization, Rice, Yield.