Effect of fertilization in drill-holes on soil gas exchange, apple root, and fruit characteristics

The experiment was carried out using 7-year-old apple trees (Malus domestica ‘Red Fuji’) by the fertilization in drill-holes in the fall.
The drill-holes were 15 cm in diameter and 60 cm in depth, 50 cm apart from each other, located between rows, 100 cm away from the trunk.
To initiate the fertilizer treatment, corn stover or apple tree branches mixed with fertilizers were inserted into the holes together in the first fall.
The volume flow and concentration of O₂ and CO₂ in the drill-holes, roots, yield, and fruit quality were investigated in the following fall.
The results showed that soil CO₂ and O₂ concentrations both significantly increased by the fertilization in drill-holes.
The increased degree was higher in drill-holes inserted with corn stover than those with apple tree branches and those backfilled with soil.
The volume flow rate of CO₂ and O₂ in the holes, as well as the root length, root density and activity, the single apple fresh weight, fruit total number, fruit firmness and soluble solids contents, were all increased by the fertilization in drill-holes, and the corn stover inserted holes had the most significant effects.
The increased degree of root density in the 40-60 cm soil layer was also the highest in corn stover inserted holes.
Taken together, fertilization in drill-holes significantly increased apple fruit quality and yield by improving soil gas exchange and root growth.
The treatment of corn stover inserted into drill-holes with fertilizers together had the best effects on apple roots and soil environment.

IV Asian Horticultural Congress – AHC2023

Tuo Ji, Weiwei Zhang, Hongqiang Yang

apple, soil, drilled holes, gas exchange, roots, fruits

https://doi.org/10.17660/ActaHortic.2024.1404.26