Nano rock phosphate: a potential phosphatic fertilizer to crops

Nano rock phosphate (< 100 nm) was prepared by top down approach through a high energy ball mill. A series of solution culture experiments conducted with maize and soybean crops clearly established that P from rock phosphate nano particles can easily be taken up by the crops, and all the plant parameters like shoot and root weight, root length, root volume and enzymatic activity like nitrate reductase and phosphatase were also enhanced by rock phosphate nano particle application. A field experiment was also conducted with sorghum-wheat and finger millet-wheat wherein the crops were fertilized with nano rock phosphate at the rate of 50 kg P2O5/ha in water suspension (265 L/ha) stabilized with 150 mL of linear alkyl benzene sulphonate. The results of field experiment showed that mean yield of sorghum increased from 1350 to 2180 kg/ha and finger millet yield increased from 640 to 986 kg/ha due to nano rock phosphate application.