Effect of biological preparations on spring wheat yield

Soil of the experiment site was Calcari-Endohypogleyic Luvisol. The aim of the investigation was to assess the impact of biological preparations on spring wheat crop density, productivity elements and yield. The experiment soil was neutral (pHKCl 6.6), with high amount of phosphorus (265.0 mg kg-1 of P2O5), medium amount of potassium (116.1 mg kg-1 of K2O), and medium content of humus (2.31 %). Treatments of the experiment: Factor A – biological preparations: 1) without spraying, 2) sprayed with Bactogen 1.5 l ha-1 + Aurin 1.5 l ha-1, 3) sprayed with BactoMix5 2.0 l ha-1 (in the spring), 4) sprayed with Stimulin 3.0 l ha-1, 5) sprayed with BactoMix5 2.0 l ha-1 (in the autumn). Factor B – nitrogen rates: 1) fertilized with N105, 2) fertilized with N165. The lowest density (391.0 seedlings m-2) of spring wheat was found in plots where nitrogen rate of N105 spraying with Stimulin was applied. Spring wheat density in these plots was 25.0 seedlings m-2 less than that in the plots without spraying with biological preparations. Spraying with Stimulin significantly (P≤0.05) decreased density of spring wheat seedlings compared with no application of biopreparations when higher nitrogen rate (N165) was applied. The use of biological preparations and fertilization with different nitrogen fertilizer rates (N105 and N165) resulted in a slight change in the weight of 1000 grains of spring wheat, but no significant differences were established. Application of biopreparations (except BactoMix5 sprayed in spring) significantly (P≤0.05) increased grain yield of spring wheat when fertilization rate was N105. When fertilization rate N165 was used significantly (P≤0.05) higher yield of spring wheat grain was harvested in plots sprayed with biological preparation Stimulin and BactoMix5 in the autumn as compared with yield of unsprayed plotsAgronomijos fakultetasVytauto Didžiojo universiteta