Effect of different plant nutrient compositionon the development and some plant nutrient content of lettuce plant grown in hydroponic culture

The study was carried out in a hydroponic system under greenhouse conditions in order to investigate the effects of nitrogen (N), phosphorus (P) and potassium (K) nutrient combination applications on the growth and on some nutrient element amounts of lettuce (Lactuca sativa L. var crispa) plants. For this purpose, Maritima lettuce variety was grown in 18 different nutrient solution combinations containing nitrogen (6, 8, 10 mM), phosphorus (1, 2 mM) and potassium (4, 6, 8 mM) doses. During the 42-day trial period, the effects of the applications were observed by changing the solutions in the food tanks in 3-4 day intervals. According to the analysis results, it was observed that the applied N, P, K solution combinations had a statistically significant effect on the growth of the lettuce plant (p <0.01).The applied N, P, K doses had a positive effect on plant growth, dry matter amount and the nutrient elements uptake (p <0.01). However, while the effect of the highest solution dose (10, 2, 8 mM) containing 10 mM N, 2 mM P and 8 mM K applied to lettuce plants was negative, it was observed that N, P, K, Mg and Na accumulation occurred in the leaves of the lettuce plant.It was determined that high Fe accumulation in the roots caused a decrease in Zn and Mn uptake.While the vegetative growth of the lettuce plant increased with increasing phosphorus doses, a similar increase in nutrient intake could not be observed with the effect of the dilution factor that occurs with the increase in volume in the plant.According to the results obtained from our experiment, it was seen that the effect of N, P, K doses to be applied on plant growth, nutrient uptake, yield and market quality was significant.It was determined that the ideal N, P, K dose for the cultivation of lettuce plant in hydroponic system is 6 mM N, 2 mM P and 6 mM K doses. It has been observed that the application of high concentrations of nutrients does not provide an extra advantage in the growth of the plant.Therefore, it has been concluded that instead of excessive fertilization, less fertilizer usage, and their balanced nutrient constituents will be more beneficial for both the environment and human health, as well as economic and profitable production.