Effect of Changing Substrate Density and Water Application Method on Substrate Physical Properties and Container-Grown Seedling Growth

Abstract

The quality of container-grown seedlings is influenced by the air and water properties of the substrate. These properties are closely tied to the amount and frequency of water supplied through sprinkler systems in nurseries, as well as the density of the substrate in the container cells. Throughout the entire growing season, this study examined how various parameters of Scots pine, Norway spruce, European beech, and pedunculate oak seedlings cultivated in HIKO V120SS and V265 containers were affected by two factors. Firstly, the study analyzed the impact of increased substrate density when filling the containers. Secondly, it explored the precise dosing of water applied by the sprinkler system, which was determined based on substrate sensors and meteorological conditions surrounding the seedlings. The results revealed that increased substrate compaction led to a long-term reduction in air capacity and an increase in water capacity within pine, spruce, and beech containers. However, oak seedlings were not affected by the increased substrate density. Additionally, the higher density of the compacted substrate positively influenced the growth parameters of pine seedlings but did not affect the other species. As a result, the current substrate compaction level used in the nursery where the measurements were taken appears to be optimal for spruce, beech, and oak seedlings. Furthermore, precise control over the amount of water applied during irrigation allowed for a reduction in water consumption by about 8%. This control also resulted in improved seedling sturdiness quotient and a more developed root system in the case of pine seedlings. However, no significant differences were observed for the other species.

Leachate Tables as a Tool for Monitoring Changes in Physical and Chemical Parameters of the Peat Substrate in the Cells of Nursery Containers

“…For the experiment, a leachate table (Figure 2) was designed and constructed that would enable the collection of liquid filtrate and substrate samples from the cells of nursery containers during the long-term irrigation process and fertilization using an irrigation ramp (Figure 1). 5), drawers (6), guides (7), valves (8), collecting tanks II (9), drainage racks (10), measuring cylinders (11), rods with nuts (12), base (13), lower templates (14), upper templates (15), drainage gutters II (16), collecting tank II (17), steel cables (18), protective foil (19).…”

“…Irrigation and fertilization are carried out by means of a sprinkler arm moving above the table (3). Drainage gutters I( 4) are situated at the beginning and end of the frame, in the parts outside the working area that holds the containers, for draining water from under 5), drawers (6), guides (7), valves (8), collecting tanks II (9), drainage racks (10), measuring cylinders (11), rods with nuts (12), base (13), lower templates (14), upper templates (15), drainage gutters II (16), collecting tank II (17), steel cables (18), protective foil (19).…”

“…The drainage racks (10) consist of rods with nuts (12), base (13) on which the measuring cylinders (11) are placed. The placement of the cylinders was determined by the lower (14) and upper (15) templates, in which holes were made that corresponded to the spacing of the holes in the bottom of the nursery container (2). Thanks to the use of the lower (14) and upper (15) templates, the cylinders (11) could be stabilized in a vertical position.…”

“…According to Benito et al [11], the texture of the substrate best suited to growing seedlings has a granulometric fraction in the range of 0.25 to 2.5 mm, while the appropriate amount of oxygen and water accumulated in the substrate is ensured by high overall porosity in a range of 50 to 80% [12]. The most favorable parameters for peat-perlite substrates, according to the majority of the literature, include a general porosity of >70% and up to 93% of the volume, a total water capacity of up to 73% of the volume, and 20%-48% of the volume available for the plants, an air capacity of 20%-30% volume, and a wet weight of 864 kg m −3 [1,[13][14][15]. The main problem that occurs during seedling cultivation in containers is the control and maintenance of these recommended ranges for the physical parameters due to the methodological problems associated with their determination [7,8,16,17].…”

“…With a dry substrate, the salt concentration in the soil solution can increase to high levels, and as a result of drainage, key elements, such as nitrogen (N) and potassium (K), can be leached out of the container. If these are not successfully replenished during fertilization, there will be a deficit in the substrate [15].…”