Evaluating the efficacy of bacterial phosphorus fertilizers in the apple orchard on chernozem soil

Phosphorus is one of the most important elements of plant nutrition.
The highest demand for phosphorus is at the beginning of the growing season.
During this period, the activity of the root system is not as high as it will be later in the year.
Therefore, soil phosphorus availability at the beginning of the vegetation season is nearly as important.
The use of bacterial fertilizers can decrease the load on the environment by reducing artificial agrochemicals.
The concentration of total phosphorus in chernozem soils is usually very high, so its transformation to a form available to plants could be a significant source.
The influence of different bacterial fertilizers on the phosphorus status of apple trees (‘Zhigulevskoye’ on B396 rootstock) was studied in the experimental orchard of the I. V. Michurin Federal Scientific Centre (52.885340°N, 40.466197°E, Tambov region, Michurinsk, Russia) in 2017-2019. Bacterial fertilizers were applied annually with irrigation water through a drip irrigation system in early spring at the three rates: B-8966 Paenibacillus mucilaginosus, 0.12×10⁹ CFU g^‑1 – 4 L ha^‑1; LZ-20 Bacillus mucilaginosus, 1.0×10⁹ CFU mL^‑1 – 0.4 L ha^‑1; Bacillus megaterium var. phosphaticum, 9.0×10⁹ CFU g^‑1, 1 g ha^‑1 diluted in 4 L water.
The artificial fertilizer fertigation rate was N₂₅P₂₀K₃₀. In treatments with an application of bacterial cultures, mineral phosphorus was excluded from the fertigation program, or its amount was reduced in two times.
Soil and leaf samples were taken in late May to early June, after the petal fall.
We also recorded the flower density, fruit set, and yield.
The application of various bacterial fertilizers increased the concentration of available phosphorus in the soil.
The effects of application varied drastically, depending on weather conditions.
The optimum application was a combination of bacterial fertilizers and a decreased application rate of mineral phosphorus fertilizer.

IV International Symposium on Horticulture in Europe – SHE2021

A.I. Kuzin, M.Yu. Akimov, G.N. Pugachev, L.V. Stepantsova

bacterial fertilizer, phosphorus, nitrogen, potassium, calcium, apple tree, yield

https://doi.org/10.17660/ActaHortic.2021.1327.70