Analysis of the Water Leakage Rate from the Cells of Nursery Containers

Abstract

In container production, the key issue is proper irrigation and fertilization. Typically, the water required for plant growth is supplied through an irrigation ramp system, which can also perform fertilization. The frequency of irrigation and the amount of water supplied by the ramp depends on several factors, such as the species of plants grown, the container used, the substrate, and atmospheric factors accompanying production. For effective irrigation, the substrate in the container cell must retain the supplied water long enough for plant absorption. However, any excess water should drain from the container. To optimize irrigation, it is important to determine the parameter of the water outflow speed from the container cell, which is difficult to determine. This work proposes a new solution for a station that can measure the water outflow speed from various container cells (patent application P.443675 2022). In tests, the water outflow speed was assessed for two Styrofoam container types (V150—650/312/150 mm, 74 cells, and 0.145 dm3 cell volume; and V300—650/312/180 mm, 53 cells, and 0.275 dm3 cell volume). Both were filled with a peat and perlite substrate (95/5%) using the Urbinati Ypsilon line (V150 substrate moisture 75.7 ± 1.1%, and V300 75.9 ± 2.1%, efficiency of the line 400 containers∙h−1, vibration intensity of the vibrating table—maximum acceleration 12 G). The results indicated that the water outflow speed varied between container types. The V300 container had a higher outflow speed (0.0344 cm·s−1) compared to the V150 (0.0252 cm·s−1). This discrepancy may be due to differences in dry bulk density, with a correlation of r = −0.523. The V300 had a lower actual and dry bulk density (0.418 g·cm−3; 0.079 g·cm−3) compared to V150 (0.322 g·cm−3; 0.103 g·cm−3). This highlights the need for individual selection of parameters on the backfilling line for different container types when filling. Using identical parameters for diverse containers can lead to varying substrate volume densities, impacting water outflow rates.

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).…”

“…These gutters discharge the liquid into a marked collecting tank III (17) to measure the amount of liquid that drained but did not reach the containers. Steel cables (18) are mounted in the upper part on the extreme, higher vertical elements of the frame, on which aprons made of protective foil (19) were mounted so that the working liquid during rain would not splash outside the measuring station and accumulate in longitudinal gutters (16). Based on the amount of water accumulating in the outflow collecting tanks I, II, III (5, 9, and 17) and in the liquid-measuring cylinders (11), a water flow balance could be determined at the drainage station.…”

“…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]. Imported sphagnum-rich peat is mainly used in container production in Poland.…”

“…Figure 2. The scheme of a newly developed station for collecting liquid leachate from container cells with a ramp for irrigation and fertilization-Patent 242506 (specified in Section 6): frame (1), containers (2), sprinkler arm (3), drainage gutters I (4), collecting tank I (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).…”