Overabundant and unbalanced input of nutritional elements to soil has a negative effect to the yield and quality of lettuce. Accumulation of nitrates and harmful effects of the chloride ion are the reasons why there i...Overabundant and unbalanced input of nutritional elements to soil has a negative effect to the yield and quality of lettuce. Accumulation of nitrates and harmful effects of the chloride ion are the reasons why there is a need to establish an optimal quantity and relation of nutrients in lettuce nourishment. In the experiment which was carried out during years 2010 and 2011 on the farm of Secondary Agricultural Boarding School in Futog, nitrate content in a fresh mass of lettuce （mg NO3/kg） was obesrved, in dependence on applied compound fertilizers produced by different technologies at different quantities of nitrate and potassium fertilizers. The results of the research show that in a technological ripeness, the highest average lettuce yield has been obtained in the treatment where the highest dosage of nitrate fertilizers was used in spring, in a combination with complex fertilizers in autumn. The lowest average yield has been obtained on the control plot. The highest average nitrate concentration in a fresh lettuce mass has been recorded in using technology of applying mixed fertilizers and the smallest in using a technology of complex fertilizers. At the moment of harvest, the highest nitrogen content in a dry mass of a plant has been recorded when complex fertilizers of phosphorus and potassium were used by the technology of mixed fertilizers.展开更多
文摘Overabundant and unbalanced input of nutritional elements to soil has a negative effect to the yield and quality of lettuce. Accumulation of nitrates and harmful effects of the chloride ion are the reasons why there is a need to establish an optimal quantity and relation of nutrients in lettuce nourishment. In the experiment which was carried out during years 2010 and 2011 on the farm of Secondary Agricultural Boarding School in Futog, nitrate content in a fresh mass of lettuce （mg NO3/kg） was obesrved, in dependence on applied compound fertilizers produced by different technologies at different quantities of nitrate and potassium fertilizers. The results of the research show that in a technological ripeness, the highest average lettuce yield has been obtained in the treatment where the highest dosage of nitrate fertilizers was used in spring, in a combination with complex fertilizers in autumn. The lowest average yield has been obtained on the control plot. The highest average nitrate concentration in a fresh lettuce mass has been recorded in using technology of applying mixed fertilizers and the smallest in using a technology of complex fertilizers. At the moment of harvest, the highest nitrogen content in a dry mass of a plant has been recorded when complex fertilizers of phosphorus and potassium were used by the technology of mixed fertilizers.
