The influence of norms, forms and input rules of nitrogen fertilizers upon NO3 consistency in orange and lemon crops

Abstract

The paper overviews what is the influence of norms and forms of nitrogen-based fertilizers on the nitrate accumulation in the fruits of Washington Navel orange and Meyer lemon. Researches took place in Anaseuli on red and yellow soils of the expe-rimental plots of subtropical crops and tea industry institutes of Georgian Agricurtural University. In order to determine the impact of nitrogen fertilizer norms on nitrate accumulation in Washington Navel orange, amonium sulfate and amonium nitrate have been used with the dozes-75, 150, 300, 450 g/per tree on the background of P,K,Ca,Mg in accordance with agricultural laws. As for the nitrate accumulation from the nitrogen fertilizer forms, we used amonium sulfate, amonium nitrate, ammonium sulfate, ammonium nitrate, carbamide, montanus nitrate and sodium nitrate on the background of P,K,Ca,Mg. In order to accumulate nitrates in Meyer lemon fruits in condition of yel- low soil, single and twofold norms of carbamide and montanus nitrate of nitrogen fertilizers (150 and 300 g/per tree), various rules of input and organic fertilizers such as N:P:K have been applied in different ratios. It has been investigated that there is slight impact of nitrogen fertilizers on nitrate deposition in orange fruits and formed fruits are ecologically clean. The same relation has been identified in lemon fruits while using nitrogen ferti-lizers. Taking into account all above mentioned things we can figure out that the most efficient and pertinent nitrogen fertilizer norm to orange and lemon in case of having the red and yellow soil 150 g/per tree, for orange it is P2O5 300 K2O 200 and for lemon- P2O5 150 K2O 100. As for nitrate accumulation in Meyer lemon prserving all nitrogen fertilizer application rules, growing tendecy of NO3 is obvious, but it does not exceed permissable limit (50 mg/kg).