Impacts of Tethered Logging Equipment on Soil Compaction, Moisture and Seedling Growth.

Spatial variability in soil compaction properties associated with field traffic operations

Effect of vapor pressure deficit on the photosynthesis, growth, and nutrient absorption of tomato seedlings

Penetration resistance (PR), soil bulk density (BD), and volumetric water content (VWC) are important determinants of crop production. The objectives of this study were to: (1) evaluate the effect of conventional (S1), conservation (S2), and reduced tillage (S3) systems on BD, PR, and VWC shortly after soil tillage; and (2) characterise the spatial variations of these soil properties before the seedbed preparation for the second crop in Taşliçiftlik clay loam (medium, mixed, mesic Ustic Fluvents) located in north‐central Anatolia, Turkey. Tillage effect was evaluated at two different soil depths (0–10 cm and 10–20 cm). Soil BD and VWC measurements were conducted on undisturbed soil samples and PR was measured with a hand‐pushing penetrometer. All three tillage systems increased the variation in the PR; S1 and S3 decreased and S2 increased the variation in BD; and S2 and S3 increased, and S1 decreased the variation in soil VWC in 0–10 cm depth. Spatial structure of PR in 0–10 cm was not affected by the tillage systems. Slight changes occurred in spatial structure of PR in 10–20 cm after the tillage. Spatial structure of BD in 0–10cm was considerably affected by S1 compared to both S2 and S3. In 10–20 cm depth, chiseling considerably altered the BD as indicated by semivariograms. However, tillage effect on BD was negligible in S1 and S3 in the same depth. Although the spatial structure of VWC in 0–10 cm depth was highly altered in S1, S2 and S3 had smaller effects on VWC in 0–10cm. Both S1 and S3 resulted in more uniform volumetric water content in 10–20 cm depth.

Irrigation and surface characteristics are important for managing professional turfgrass pitches. This study evaluated irrigation depth, volumetric water content (VWC), penetration resistance (PR), and normalized difference vegetation index (NDVI) on a Mirage bermudagrass (Cynodon dactylon) stadium football pitch in Lima, Peru, in 2019. The pitch, constructed with 10 cm of loamy sand soil, was irrigated by six pop‐up impact gun sprinklers. Data on irrigation depth, VWC, PR, and NDVI were collected from June to September using a 10.0 m × 5.0 m grid across 154 sample locations to create spatial maps. Correlation, regression, and spatial analyses evaluated relationships and variability among variables. The VWC lower quarter distribution uniformity was higher (72.0%) than that of irrigation depth (49.0%). A negative correlation was found between PR and VWC (r = −0.30, p < 0.001), with PR being the most significant predictor of VWC (p < 0.001). VWC and PR site‐specific management units indicated that the pitch center was compacted, resulting in lower VWC. These findings highlight that spatial data can enhance understanding of variability and relationships among surface characteristics, supporting data‐driven, site‐specific management for stadium pitches.

Growing media that contain organic materials can provide nutrients and water for plants. This study analyzed the availability and effects of nutrients and water, N and P resorption, and growth of teak seedlings under drought stress. The growing medium was made from ultisol soil (M1), ultisol soil with husk charcoal (M2), ultisol soil with chicken manure (M3), and ultisol soil with compost (M4), then planted with teak seeds. Maintenance was conducted by field capacity watering for 30 days. Teak seedlings were treated with drought stress for 90 days. Based on the analysis, growing media total N ranged from 0.19 to 0.28%, total P ranged from 0.10 to 0.17%, and water ranged from 11.40 to 16.20%. Teak seedling leaves contain N nutrient ranging from 0.34 to 0.95 % and P nutrient ranging from 0.04 to 0.16 %. The N resorption ability of teak seedlings ranged from 26 to 31%, and P resorption was around 20 to 25 %. The height growth of teak seedlings ranged from 80 to 115cm, the stem diameter from 1.4 to 1.8cm, the leaf area from 630 to 650cm2, and the thickness of the leaves from 545 to 462µm. Growing media made from ultisol soil and chicken manure (M3) produced the best water content, N and P resorption, and the growth of teak seedlings after 3 days of drought stress.

Abstract--Ultisol soil has low organic matter content, high levels of leaching and evaporation, high Al saturation, and low nutrient availability. To overcome several ultisol soil problems, it is necessary to apply vermicompost fertilizer. Vermicompost is compost from soil used to raise worms, which affects soil structure and contains N, P, K, CA, Mg, S, and Fe. The research aimed to determine the characteristics of ultisol soil after applying vermicompost fertilizer and the growth of cocoa seedlings. Implementation of Research at the Pijoan Experimental Garden, Batanghari Regency. The experiment used a Completely Randomized Design (CRD). Observation data were analyzed using analysis of variance and the Duncan New Multiple Range Test (DNMRT) at the 5% level. The treatment tried was vermisol fertilizer with four dose levels, K0: 100% ultisol soil, K1: 85% ultisol soil + 15% vermisol fertilizer, K2: 75% ultisol soil + 25% vermisol fertilizer, K3: 65% ultisol soil + 35 % vermicompost per polybag. Providing vermicompost fertilizer with K2 and K3 treatment can increase N-total, P-Bray 1, and C-organic soil, increasing the pH of ultisol soil. Fertilizing vermicompost on ultisol soil had a significant effect on shoot dry weight and cocoa plant quality index. However, it had no significant effect on plant height, stem diameter and root dry weight.

Cone penetration resistance (PR) is an important index of soil physical restriction to root growth in agriculture. Spatio-temporal variability of soil water content (SWC) makes PR data less comparable. Our objective was to normalise spatio-temporal PR measurements to a standard SWC, thus allowing comparison across New Zealand’s agricultural regions. We geo-referenced 497 measurements of PR and SWC from two depths (0–15 and 15–30 cm) in multiple agricultural regions between 2002 and 2007. Power, exponential, and logarithmic models were used for fitting PR as a function of SWC. A power function relating PR to gravimetric water content (GWC) provided the best-fit model for normalising PR for variation in SWC. Low relative errors (<10 %) and absolute errors (<0.2 MPa) were obtained at both depths for GWC values of 0.16–0.26 g g−1. We recommend GWC of 0.16–0.26 g g−1, with 0.20 g g−1 preferred for its proximity to the midpoint and its associated lower relative error (5 %). Specific models for different land use categories were unnecessary, while soil-depth-specific models for different soil orders (Allophanic cf. Non-Allophanic) improved the PR normalisation. Normalised PR values (GWC = 0.20 g g−1) for pastoral soils were higher than for cropping soils, particularly at 0–15 cm. About 65 % and 75 % of the sampled sites had normalised PR values exceeding 2.5 MPa at 0–15 and 15–30 cm depths, respectively, indicating the potential for adverse effects from widespread soil compaction. This study highlights the importance of normalising PR data for soil moisture variation to better assess potential adverse effects of land use and management on soil.

Soil compaction affects crop yield in many ways. Knowing its spatial variability provides possibilities for site-specific soil treatments that can increase the profitability and sustainability of crop production. The purposes of this study were (1) to investigate the spatial variability of particle size distribution, gravimetric water content, bulk density, and penetration resistance using classical and geostatistical methods in a field in which conventional soil tillage methods and a particular crop rotation were applied, and (2) to evaluate the spatial relations among soil properties in the field studied. Topsoil (0 to 20 cm) and subsoil (20 to 40 cm) were separately sampled at each of 94 predetermined sampling points based on an irregular grid design in a 45 ha areaypic Ustifluvents). Bulk density showed the lowest variability (CV = 9.09% for topsoil and 6.00% for subsoil), and the penetration resistance showed the highest variability among the soil properties investigated (CV = 64.08% and 42.69%, for topsoil and subsoil, respectively). Gravimetric water content and bulk density showed high correlation particularly with clay and sand content, whereas no significant correlation occurred between penetration resistance and any of the textural components. Spatial correlation ranges varied from 72 to 510 m. Clay content had strong spatial dependence in topsoil, whereas, only moderate spatial dependence occurred in subsoil. Spatial dependence classes of other soil properties evaluated did not change with depth. Strong spatial dependence occurred for penetration resistance and sand content, and a moderate spatial dependence occurred for bulk density, gravimetric water content, and silt content. Comparisons of kriged maps of bulk density, penetration resistance, and textural components revealed that greater penetration resistance and bulk density were associated with greater sand content. However, most of the soils of study area had a clayey texture. Therefore, farmers need to be careful in application of soil tillage and other management practices that could cause compaction.

The purpose of this study was to characterize spatial and temporal variations in soil physical properties and to examine possible differences that might occur when the crop rotation shifted to rice cultivation. Soil samples from 0-20 cm and 20-40 cm depth were collected on a 100×100 m grid basis over a 45 ha field, in May 2005 and May 2011. The geostatistical methods were used to model the variance structure of gravimetric water content (GWC), soil bulk density (BD), penetration resistance (PR) and aggregate stability (AgS). The coefficient of variations were 17.5% for GWC, 7.1% for BD, and 25.0% for PR at surface and 12.8% for GWC, 6.7% for BD, and 17.1% for PR at subsurface. PR at subsurface (>2MPa) and BD at surface and subsurface soils (1.47 g cm-3) exceeded the threshold values in some fields of the study area. Temporal variations of GWC and PR at 0-20 cm and 20-40 cm depths were significant (P<0.01) while BD was significantly varied only at 20-40 cm. Spatial correlation ranges of GWC, BD and PR varied from 72 m to 433 m in 2005 and 40 to 1524 m in 2011. The spatial dependences of GWC, BD and PR at surface were moderate, and AgS had strong dependency at this depth. The spatial distribution maps of soil physical attributes are useful in identifying the limiting factors and take necessary precaution to prevent further loss of soil quality.

Comparison of compaction induced by conventional and zero tillage in two soils of the Rolling Pampa of Argentina

Temperate hardwood floodplain forests (HFF) are highly heterogeneous and productive ecosystems threatened by anthropogenic influence and effects of global warming. Quercus robur (oaks) and Ulmus laevis (elms) are acknowledged in literature as the two highest the highest and second highest aboveground carbon biomass stores along the lower middle Elbe floodplain. Both species are adapted to the hydrological fluctuations of floodplain soils. However, in Central Europe, these hydrological fluctuations &amp;#160;are threatened by the IPCC (2022) expected increase of streamflow drought, soil moisture drought and lower groundwater levels, hindering key ecosystem services provided by HFF. Thus, we wanted to assess the water use patterns of both species under water limiting conditions and high vapor pressure deficit (VPD).The study was conducted during the vegetation period of 2020 in the active floodplain of the Elbe. To understand the influence of soil texture in the soil water dynamics, two sites were selected, a sandy site located in the &amp;#160;high sand embankments and a loamy site, representing the low positioned sites of the floodplains. Sap flow was measured in 5 trees per species per site, using heat-ratio method devices. Additionally, 3 soil profiles per site were instrumented with volumetric water content and water tension sensors in defined depths up to 1.60 meters below ground. One week in June was selected to represent high soil water availability and one in August with less soil water availability, both periods shared similar VPD.Both species show different reactions to soil type and water availability. Elms kept higher mean daytime sap velocity than oaks even under low water availability (~50% higher). Nonetheless, a steep decrease was recorded for the elms during August in sandy soils, what could be evidence of loss of conductivity due to cavitation. In both, the loamy and the sandy site, oaks had significantly lower mean daytime sap flow velocity than elms (E.g. in loamy soils: 13cm/h and 6cm/h, for elms and oaks respectively). &amp;#160;Intraspecific variability was observed for the oaks when the influence of the soil texture was considered. The oak reduced sap velocity in sandy soils significantly by approximately 50% compared to loamy soils. This indicates higher sensitivity of this species to soil texture and associated soil water potential. Furthermore, to understand the impact of soil texture on tree water use, the Jarvis model was applied. In the sandy site, under drought, the model was not able to explain the reduction in sap velocity considering potential evapotranspiration, thus under this condition soil water potential plays a stronger role in sap velocity regulation.These results provide insights to the function that different adaptations by species and the influence of site-specific abiotic conditions could have over increased drought periods, providing information that may increment the success of restoration efforts of this ecosystem.

Prevention and estimation of soil erosion from forest roads requires an understanding of how road design and maintenance affect sediment production. Seventy‐four plots were installed on forest roads in the Oregon Coast Range to examine the relationship between sediment production and road attributes such as distance between culverts, road slope, soil texture, and cutslope height. An additional comparison was made between road segments with cutslopes and ditches freshly cleared of vegetation and segments with established vegetation on cutslopes and in ditches. All road segments were 5 m wide and insloped with aggregate surfacing, light traffic, and no overhanging forest cover. Sediment production was correlated to the product of segment length times road slope squared. Sediment production from aggregate covered roads on a silty clay loam was about 9 times greater than that from roads constructed on a gravelly loam. Sediment production was not correlated to the cutslope height. Road segments where vegetation was cleared from the cutslope and ditch produced about 7 times as much sediment as road segments where vegetation was retained, showing the potential reduction in erosion by revegetation following construction and the potential impact of ditch cleaning during maintenance. Relationships and estimates from this study provide a basis for improved erosion estimates by commonly used empirical procedures.

The crucial aspect of cocoa cultivation is ensuring the availability of seedlings with robust growth. Ultisols, a type of soil with potential for cocoa plant propagation, necessitate materials to enhance fertility when used as a growing medium. This includes the application of liquid smoke derived from coconut shells. To further study on this aspect this research aimed to determine the role of liquid coconut shell smoke on the growth of cocoa seedlings in Ultisols soil. The research was conducted in the laboratory and greenhouse of the Faculty of Agriculture, Panca Bhakti University, Pontianak, for 90 days from July to October 2023. The research used a complete randomized block design (CRBD) with four replications. The treatment concentrations of liquid coconut shell smoke (%) consisted of six levels: 0.00, 0.25, 0.50, 0.75, 1.00, and 1.25%. Each replication consisted of three cocoa plant seedling samples, resulting in a total of 72 plants for the entire research unit. The observed parameters included plant height increase (cm), the increase in the number of leaves (leaves), and the increase in stem diameter (mm). The research results found a very significant influence on all observed parameters. The treatment of liquid coconut shell smoke at a concentration of 0.75% yielded the highest results in terms of seedling height increase (29.09 cm), the number of leaves (14.08 leaves), and stem diameter (9.87 mm) compared to the control. This research finding shows that a concentration of 0.75% liquid coconut shell smoke can maximize the growth of cocoa seedlings in Ultisols soil through soil fertility improvement.

Soil compaction is recognized as an increasingly challenging problem with regard to root growth and yield reduction in agricultural production in Thailand. The aim of this research was to study the effect of soil texture, moisture content and organic matter on the compaction properties of silty soils. Three soils with different silt contents were studied-loam, silty clay loam and silt loam. The study showed that compacting silt loam soil using the modified Proctor test resulted in a higher bulk density than from the oedometer test at 200 kPa. Statistical analysis showed that soil type and the moisture content significantly affected both the bulk density and penetration resistance. However, organic matter showed a significant effect only on the bulk density. The bulk density increased with increased moisture content. The bulk densities of compacted soils were higher in the order of loam, silt loam and silty clay loam. The penetration resistance seemed to increase with increased silt content. The differences in the bulk density and penetration resistance among these three soils decreased as the moisture content increased. Adding organic matter at 5% by weight to soils resulted in lower bulk densities of the soil using the oedometer test, with reductions of 3.9, 3.8 and 7.7% for loam, silty clay loam and silt loam, respectively. In order to avoid effects on root growth, it is recommended that machines with 200 kPa of tire contact pressure should only work in fields with a moisture content not exceeding 20.27, 18.74 and 17.88% for loam, silt loam and silty clay loam, respectively.

Frequent occurrences of soil compaction damage resulting from high raindrop impact energy, and from human and animal trafficking during field operations pose a problem to farmers around the tropics. We studied the effect of some crop and soil management practices (manure, mulch, NPK applications, tillage and crop type) on some soil compactibility indices (dry bulk density, cone index, total soil porosity, gravimetric soil water content) in a Typic Paleustult in southeastern Nigeria. The study was carried out for three consecutive planting seasons using two tillage systems and four other soil management practices (poultry droppings + NPK, mulch + NPK, NPK alone and no amendment). These were laid out as split-plot in a RCB design replicated three times and using maize (Zea mays L.) and groundnut (Arachis hypogea) as test crops. Results indicate that the different soil management techniques adopted influenced dry bulk density, penetration resistance, total soil porosity and gravimetric soil water content at 44 and 66 days after planting (DAP) whereas only gravimetric soil water content was affected at 90 DAP. The dry bulk density of tilled maize and groundnut plots increased significantly (P<0.05) by between 2 and 14% relative to no-till plots at 44 and 66 DAP. In both maize and groundnut plots, dry bulk density decreased significantly (P<0.05) in plots amended with poultry droppings +NPK relative to the control plots by 3–10% at 44 and 66 DAP. Tilled maize and groundnut plots had 37–45% lower (P< 0.05) penetration resistance than their corresponding no-till plots at both 44 and 66 DAP. Penetration resistance measurements were lower by 16.5–25% in plots amended with poultry droppings + NPK relative to unamended plots at 44 and 66 DAP. Cumulative (1996, 1997, 1998) data indicate that gravimetric soil water content in maize and groundnut plots generally increased significantly (P<0.05) in no-till plots relative to tilled plots by 18–27% at both 44 and 66 DAP. Plots amended with poultry droppings + NPK had between 24 and 111% increase (P<0.05) in soil gravimetric soil water content at both 44 and 66 DAP. Results are indicative that all soil compactibility indices measured were not affected at 90 DAP except for soil gravimetric soil water content in 1996 and 1998. Results from this work demonstrate that some crop and soil management practices could be used to reduce soil compactibility problems thus increasing productivity of such soils.