Zdravka Petkova and Kostadinka Nedyalkova
Agricultural Academy, “N. Poushkarov” Institute of Soil Science, Agrotechnologies and Plant Protection, 1080 Sofia, Bulgaria
Petkova, Z. & Nedyalkova, K. (2020). Multiannual growing of remontant strawberries (opportunities for biological production). Bulg. J. Agric. Sci., 26 (3), 513–519
The study purpose was to determine the influence and to evaluate the addition of different fertilizer sources on the growth and yield of strawberry in the conditions of vegetation experiment during 3 year period. Simultaneously, the impact of the fertilizer sources on the major groups of soil microorganisms was monitored and the relations with the plant yield were examined.
Compost-only treatment provided the highest yields over the three years of the experiment. A consistent increase in the yield of strawberries after the first and second year was found for all variants. It was maximum in the 3-rd year in the treatment with the compost. Consequently, the introduction of compost into the soil contributed to a longer term effect on soil fertility compared to the application of only mineral fertilizers and manure. Compost addition to soil or compost-only substrate could be recommended for biological production and high fruit yields of remontant strawberries.
Microorganisms responded sensitively to changes in the soil environment as a result of imported fertilizers. In the different variants, alterations in the microbial amount relative to the control were specific. The mineral NPK-fertilization and compost-only treatments caused a short time negative impact on the amount of most microbial groups at the beginning of the experiment, which was overcome at maturity stage. The long time effect of compost-only treatment was characterized by the highest amount of almost all microbial groups in all the three years. Positive correlations between the amount of microbial groups and strawberry yields were found.