Utilization of Nano Rock Phosphate by Maize （Zea mays L.） Crop in a Vertisol of Central India

An attempt was made in the present investigation to utilize the vast deposit of rock phosphate （RP） of India by preparing nano RP using modem tool of nano-science and nano-technology for field application to maize crop （Zea mays L.）. To evaluate the efficacy of different nano RP, a field experiment was conducted during kharif season （June to September） of 2012 at India Institute of Soil Science （IISS）, Bhopal, taking maize as a test crop. The experiment consisted of five treatments （control, NK （100%）, NPK （100%）, NK （I00%） ＋ 60 kg P205） as nano RP through Udaipur nano RP （34% P205） and Udaipur nano RP （31% P205） were tested in randomized block design with four replications. The results showed that the shelling percentage, 1,000 grain weight, grain and stover yield, etc., were significantly higher in the maize plant treated with Udaipur nano RP （34% P205） as compared to the control, which was being at par with single super phosphate （SSP） treated plants. The total P content and its uptake were higher （0.65% and 40.29 kg/ha） in SSP treated plant, which was closely followed by Udaipur nano RP 34% （0.63% and 38.29 kg/ha） over the control （0.60% and 27.82 kg/ha）. The SSP treated plants had significantly highest apparent P recovery （47.98%） which was comparable to Udaipur nano RP （34% P205）, where as the Udaipur nano RP （31% P205） had the lowest. The additional N and K uptake by the plant was also observed with application of P sources, which were ranged from 16.5 kg/ha to 37.2 kg/ha and 27.9 kg/ha to 64.7 kg/ha under different P treatments. These results showed that crop utilization of P from nano RP was at par with that of P from SSP while yield response to P from nano RP was marginally lower than to P from SSP but serve as a cheaper source.