Phyto-availability of phosphorus to Lactuca sativa in response to soil applied TiO2 nanoparticles

Phytoavailability of phosphorus (p) in soil remains a major issue for crop production particularly in developing world. the objective of present work was to study the effects of engineered tio 2 nanoparticles (nano-tio2) on phytoavailability of p and growth response of lactuca sativa (lettuce). suspensions of 0,25,50,75 and 100 mg kg -1 of nano-tio2 having size less than 65 nm were applied to a sandy loam soil. the concentration of phytoavailable p in soil increased up to 56% after 72 h incubation at room temperature (25°c) in petri dishes when 100 mg nano -tio2 kg -1 soil was applied. similar trends were also observed for phytoavailable p in the soil after culturing l. sativa plants onto it for 14 days. shoot and root lengths were increased up to 49% and 62% respectively at 100 mg kg -1 of soil applied nano-tio2,as compared to the control treatment. shoot and root p concentrations were increased up to 36 and 175% respectively at 100 mg kg -1 of nano-tio2,as compared to the control. p uptake per plant was five-folds with reference to the control. l. sativa significantly acidified its rhizosphere. this innovative study provides an important base line to further investigate the detailed mechanis ms involved in improved p uptake and plant growth in response to application of engineered nanoparticles in the field. © 2015,university of agriculture. all right reserved.