NPK nanofertilizer was prepared by loading nitrogen (N), phosphorous (P) and
potassium (K) into chitosan nanoparticles. The chitosan nanoparticles were prepared
via ionic gelation of tripolyphosphate and chitosan solution. The chitosan nanoparticles
were characterized by SEM, TEM, zeta potential and size distribution. The
results showed that size distribution was from 300 to 750 nm and zeta potential of
around 50 mV. The released kinetics of nitrogen, phosphorous and potassium in
nanofertilizer were also investigated for 240 h. The nanofertilizer was applied to
coffee seedlings in a greenhouse condition. The results showed that the nanofertilizer
enhanced uptake of nutrients, photosynthesis and growth of coffee plants.
Application of the nanofertilizer improved 17.04% nitrogen, 16.31% phosphorous
and 67.50% potassium content in the leaves of treated plots compared to the control;
total chlorophyll content increased up to 30.68% and 71.7% of photosynthesis
net rate. Application of nanofertilizer also enhanced leaf number, plant height and
leaf area of the coffee seedlings. Using the nanofertilizer may be a potential way to
enhance use efficiency of fertilizers for coffee.