Estimation of nitrogen use efficiency by mango seedlings under nano and convention calcium fertilization using the enriched stable isotope (N-15)

This study aimed to investigate the effect of nano-Ca fertilizer on nitrogen uptake, use efficiency and determine best calcium form dose for mango. A pot experiment was conducted using two year old mango seedlings (cv. Zebda). The pots were filled with sandy soil (8 kg per pot) one seedling transplanted into each pot. Four treatments including nano-Ca, convention Ca, application foliar have been formulated. Calcium applied as CaO both nanoforms. enriched (15NH4)2SO4 at a rate (5g pot). Plants harvested end fall, spring, summer growth cycles dried 70 oC. plant is used making fine powder total nitrogen, calcium, %15N atom excess. Results revealed that in all cycles, 15N translocation higher under treatment than Ca 100% rate. highest translocation, observed 50% (250 mg. L-1) cycles. In Fall cycle, values 81.8%, while it recorded 64.9% 25% 51.2% concentration, shoot roots, also nano-calcium (for fall cycle = 3.0 2.8 root) 2.7% 2.2 biomass compared or spring Allocation reported mg.L-1) resulted N-15 efficiency. Nano proves be more efficient conventional calcium.