Use of Impact Penetrometer to Determine Changes in Soil Compactness After Entracon Sioux EH30 Timber Harvesting

Wood harvesting with the use of wheeled harvesters is now common in Polish and Czech forests. While moving in the forest, the wheels of these machines affect the forest soil and the extent of this impact is interesting. The paper presents the results of measurements of the changes that occur in the soil on the operational trails after the timber harvesting using the Entracon Sioux EH30 thinning harvester. The measurements were taken on fragments of three operational trails, in and between the ruts and at a distance of 1.0 m off the trail. An impact penetrometer was used to measure the penetration resistance, soil samples were collected to determine the bulk density and moisture content, and soil deformations on the trail were measured with a profile meter. Unit pressures exerted by harvester wheels on the ground were determined. It was shown that in the places where the harvester wheels pass, even of a small weight (5.73 tons, 8 wheels) and with unit pressures of the wheels on the ground <50 kPa, changes in soil parameters occurred. A statistically significant increase in penetration resistance in relation to the control occurred at a depth of up to 35 cm, while at a depth of up to 5 cm the increase was more than 2-fold. There was also a slight decrease in soil moisture content (up to 7.9%) and an increase (up to 8.4%) in bulk density in the ruts, while rut depths were small and reached 4 cm. As it was shown, the impact penetrometer, simple in design, which was assumed to be used for measurements, and which is not used in this type of research in forestry, despite its limitations, can be used to determine the compactness of the soil and its changes resulting from machine work

Ground Pressure Changes Caused by MHT 8002HV Crawler Harvester Chassis

Ground contact pressures exerted by elements of the machine chassis on the ground in the forest are associated with the machine impact on the soil during its operation. In the case of a crawler system, determining the ground contact pressure appears simple, which is not entirely true. The aim of the study was to analyze the loads on the ground (forest soil) exerted by the MHT 8002HV crawler harvester chassis. The measurements were made in Forest School Enterprise in Kostelec nad Černými Lesy, Central Bohemia Region in the Czech Republic, on brown soil made of clay on stony formations, fresh mixed mountain forest (FMMF), with the use of a hydraulic scale when extending the harvester crane forward along and perpendicular to the longitudinal axis of the machine. The calculations were carried out with a simulated load of the crane on the tree in question, assuming that the impact on the ground of the crawler system is heterogeneous and that the point impact comes from the crawler support wheels. As it was shown, the average ground contact pressures under the crawler track of the analyzed harvester generally do not exceed 70 kPa. The crane extension with a simulated load, which would have caused the crawler track to act on the ground with an average pressure exceeding 70 kPa, was limited by machine stability. On the other hand, high ground contact pressures may occur under a more loaded section of the crawler track if the active length of the crawler track is shortened. As it was shown in the case of a weak track tension, the course of ground contact pressures exerted on the soil deviates from the assumed usually homogeneous impact over the entire length of the crawler

Influence of soil compaction on the growth of silver fir (Abies alba Mill.) under a forest canopy

In the study, the influence of soil compaction on the growth of silver fir seedlings (Abies alba Mill.) was evaluated; the soil compaction being measured using a cone penetrometer. The studies were conducted under a forest canopy, where the exploratory units with different soil compactions exerting a unit pressure of 50, 100, 150, 200, and 250 kPa, as well as the control units (without pressure), were prepared. Selected units were sown with seeds of silver fir, and from the remaining units, the soil samples were collected and their compaction measured using a cone penetrometer. After 5 months, the seedlings were collected and their growth analyzed. Increasing the unit pressure resulted in soil compaction characterized by the compaction in the layer up to 15 cm, in which the roots of the growing seedlings were found. Different variants of the pressure significantly affected the analyzed parameters of seedlings. Negative and statistically significant correlation was reported between increasing compaction of the soil, the length of the primary root, and the total length of seedlings (-0.46 and -0.35, respectively), while the positive correlation was found for the length of the stem (+0.32). Similarly, there was a statistically significant negative correlation between the increased soil compaction and the dry weight of the root system (-0.29), and positive correlation in the case of the stem dry weight (0.26). Increasing soil compaction, however, did not affect significantly the size of assimilation apparatus

Design of a Planting Module for an Automatic Device for Forest Regeneration

Forest regeneration by means of seedlings grown in container nurseries is usually performed manually with the use of the standard dibble bar or the tube dibble. Manual placement of a large number of seedlings in the soil requires a lot of work. Manual removal of the soil cover and digging the soil in spots with a diameter of 0.4 m requires, under average conditions, about 38 man-hours/ha, while planting with a dibble bar requires about 34 man-hours/ha. Additional work time is needed to carry seedlings over an area that is being afforested. At present, forestry does not have automatic planters that would enable the establishment of forest cultures. The aim of the paper is to present the concept of an autonomous robot and an innovative technology of performing forest regeneration and afforestation of former agricultural and reclaimed areas. The paper also presents the design solutions of the key working unit, which is a universal, openable dibble, cooperating with a three-toothed shaft to prepare a planting spot. The solution proposed enables continuous operation of the machine, i.e. without the need to stop the base vehicle

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

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

Analysis of Surface Deformation and Physical and Mechanical Parameters of Soils on Selected Skid Trails in the Gorce National Park

Skidding is considered to be one of the most stressful works for the forest environment. This paper presented the results obtained from the analysis of soil deformation and selected physical and mechanical parameters of soils on skid trails in the Gorce National Park. The study analyzed two horse and tractor skid trails that are in continuous use in the park. Measurements of parameters were recorded before (summer) and after (autumn) a total of 81 skidding cycles, using a profilometer and a penetrometer, and soil samples were collected for analysis. The measurements obtained from the horse trails indicated that soil compactness was considerably higher in the lower sections of the trails and on the side more loaded by horse traffic and the transported load, which was related to the trail course in the field. The values of penetration resistance were high in the middle of those trails, reaching 6.8 MPa in the layer up to 10 cm. In the tractor trail the values of soil compactness reached 7.62 MPa in the layer up to 10 cm deep and were similar across the width of the trail and deep into the soil profile, with only slight changes observed in the monitored period. As a result of skidding, there were increases in the maximum depth of ruts reaching up to 4.6% on horse trails and up to 10.8% on tractor trails. Soil erosion per 10 m of trail caused by skidding and other natural factors during the study reached 1.314 and 0.390 m3 for the tractor and horse trail, respectively, wherein volume of skidded wood on the tractor trail was 180.1, and 18.1 m3 on horse trails. This confirms that the volume of eroded soil on the trails is determined by the type of skidder used and volume of skidded wood, so it is important to choose the right kind of skidder based on the conditions in which the skidding work will be carried out

Quality of Scots pine, European beech and pedunculate oak grown from sowing on soil with different compaction levels

In this study, we explore the effect of soil compaction on the growth of seedlings of Scots pine Pinus sylvestris L., European beech Fagus sylvatica L. and pedunculate oak Quercus robur L. On the experimental plots, ground contact pressures ranging from 0 to 250 kPa was applied on the soil. The applied pressure resulted in an increase in soil compaction between 1.02 to 1.19 g cm–3, which reflected pressures exerted by the undercarriage of vehicles used in logging. We then measured the seedlings as well as the dry weight of the roots and the above-ground parts. Using this data, we calculated the following quality indicators for each seedling: SQ – sturdiness quotient, S/R – shoot to root dry mass, DQI – Dickson quality index. For pedunculate oak, the SQ value significantly improved with increasing soil compaction, whereas no differences in the other two indicators were observed. In case of the European beech, the best value of SQ and DQI were observed at a soil density of 1.11 g cm–3, whilst no significant difference for the S/R coefficient could be found. Completely different results were obtained for Scots pine. The most favorable growth was observed when no pressure was applied. However, the SQ and S/R ratios even exceeded the values commonly considered acceptable. Our results therefore indicate that the values of seedling quality indicators are indeed influenced by soil compaction. At a soil compaction of 1.11 g cm–3, the share of seedlings with the SQ value below the critical level was the highest, but a similar relationship could not be confirmed for the other indicators. The response of the seedlings to compaction is likely to be species specific

Influence of substrate compaction in nursery containers on the growth of Scots pine (Pinus sylvestris L.) seedlings

The paper presents research on influence of nursery soil compaction, composed of peat (90%) and perlite (10%), on the growth of seedlings of Pinus sylvestris grown in containers. Polyethylene nursery are containers used for the seedling production. These containers were filled with three different densities of the peat and perlite substrate (0.3, 0.5 and 0.7 g·cm-3). During the experiment, nursery containers were initially placed in a plastic tent for a period of two months, and then for three months further months in an open nursery field. Growth measurements for individual plants were the length of shoots and the root system, root collar diameter, root and shoot dry weight and photosynthetic rate. There was a relationship between the extent of compaction of the soil substrate and all analyzed growth parameters of seedlings. A more compact substrate adversely affected on the number of grown seedlings and their length but positively influenced the dry mass of pine seedlings

Visualization and quantification of peat substrate moisture by fully automated moisture controlling system (SMCS) in forest container nursery

This study explores the use of fully automatic monitoring system of peat moss substrate moisture under pine seedlings at Rudy Raciborskie forest nursery in the Silesian Upland. A brand new multipoint system for this study was created. The multichannel electronic recorder MPI-DN Metronic was the main part of the project. Twelve HD3910.2 probes (three electrodes) for volumetric water content measurement were used in a distributed configuration. Modbus RTU protocols were used for data transmission and the results were archived into an internal memory. One probe delivers 1440 measurements a day. Based on the average substrate moisture data from the field, the recorder controls the watering system according to the precisely defined parameters. Proper placement of sensors in the field allows for accurate analysis of the temporal and spatial variability of peat moss substrate moisture. Results of the statistical analysis have confirmed that the peat moss moisture is significantly differentiated within the homogeneous production field of the forest seedlings. The study findings suggest that irrigation systems should be adapted to specific situation of substrate moisture at the nursery surfaces aimed at optimised water management

Macronutrient Content in European Beech (Fagus sylvatica L.) Seedlings Grown in Differently Compacted Peat Substrates in a Container Nursery

The macroelement (nitrogen, phosphorus, potassium, sulfur, calcium, and magnesium) contents in individual parts of 1-year-old seedlings (leaves, shoots, root system) of the common beech (Fagus sylvatica L.) were investigated. The seedlings were grown in nine different densities of peat substrate (0.196&ndash;0.317 g cm&minus;3) in 265 cm3 containers. It was found that substrate compaction influenced macroelement content in the seedlings. With an increase in substrate compaction, there was a decrease in macroelement content in the leaves (except for N). The macroelement contents derived from this study were compared to the optimal contents indicated in the literature. Studies have shown that the availability of Mg is of great importance for the growth of beech seedlings. The least-compacted substrate allowed for the best root growth in the seedlings, which translated into a higher Mg uptake, resulting in a better dry-mass shoot to root ratio. Our findings confirmed that the lowest compaction of a peat substrate (0.196 g cm&minus;3 actual density) containing dolomite is the best for cultivating common beech under foliar fertilization in 265 cm3 containers