Influence of Long Term Fertilization With NPK on Wheat Production and Chemical Characteristics of Typical Chernozem From Valu Lui Traian

To determine the evolution soil fertility as a result of NPK fertilization, are presented experimental results from a long-term experience after 44 years of fertilization. The experimental field is located on the chernozem - soil type, the plant of culture was wheat. Nitrogen and phosphorus doses that were applied had 2 graduations. We tracked the influence of fertilizers on the production and content of nitrogen, phosphorus, potassium, humus, pH and heavy metals: Cu, Cd, Pb and Zn from the soil after harvesting. The highest yield (4288 kg / ha) was obtained in fertilized variants with N100K150, variants where the production level increased by 216% compared to the unfertilized soil (1987 kg / ha); Fertilization with 100 kg / ha of phosphorus alone or with 50-150 kg / ha of potassium and fertilization with N100P100 along with doses of 50-150 kg / ha of potassium have led to very significant increases in the level of the mobile phosphorus in soil (from 34 mg / kg in unfertilized soil to 178 mg / kg in variant fertilized with N100P100 kg / ha), the potassium content of the soil increased very significantly with the increase of the applied potassium dose.