Soil Disturbance Research Articles

Environmental impact of mechanical site preparation on mineral soils in Sweden and Finland — a review

Mechanical site preparation (MSP) is deliberate soil disturbance which is undertaken to improve the conditions for forest regeneration. Disc trenching and mounding are the dominant MSP practices currently used in Sweden and Finland. In this paper, the impacts of MSP on the soil, water quality, greenhouse gas (GHG) emissions and ground vegetation of mineral soil sites in Sweden and Finland are reviewed. The practices considered are patch scarification, mounding, inverting, disc trenching, and ploughing, which together represent a wide range of soil disturbance intensity. The environmental effects of MSP in this region have not been studied extensively. The environmental impact of MSP derives from the process of creating microsites which involves horizontal and/or vertical redistribution of soil and soil mixing. This typically affects decomposition, element circulation and leaching, vegetation coverage and uptake of nutrients and water, and possibly erosion and sediment exports. Following disc trenching or mounding the effects on GHG emissions appear to be minor over the first two years. For a few years after disc trenching concentrations in soil water collected below ridges are higher than that below furrows for some elements (e.g., NO3-, NH4+, Mg2+, and total or dissolved organic C). The physical and chemical effects of ploughing remain detectable for several decades. There is little evidence about how the effects of forestry activities in upland areas on soil-water chemistry are transferred to adjacent surface water bodies, including what role streamside discharge areas play. MSP increases the tree biomass C store and may increase the total ecosystem C store. The impact of MSP on the cover and abundance of ground vegetation species depends on the composition of the original plant community, MSP intensity, and the establishment rate of different species. Species cover generally seems to decline for late succession understory species, while pioneer and ruderal species can benefit from the microsites created. Areas containing lichens which are used for reindeer forage require special consideration. More research is needed on the environmental effects of MSP, particularly regarding its long-term effects. Further efforts should be made to develop efficient site-preparation practices which better balance the disturbance intensity with what is needed for successful regeneration.

Badania archeologiczne domniemanej mogiły powstańca styczniowego z 1863 r. w miejscowości Lipe, gm. Blizanów, pow. kaliski, woj. Wielkopolskie

Archaeological Research of the Alleged Grave of a January Insurgent from 1863 in the village of Lipe, Blizanow Commune, Kalisz County, Greater Poland Voivodeship In July 2023, verification archaeological research was conducted at the site of the alleged grave of a January insurgent in the village of Lipe, Blizanow Commune, Kalisz County, Greater Poland Voivodeship. On May 30, 1863, there was a skirmish between the tsarist army and insurgent units commanded by Colonel Edmund Callier. The violent clash, which broke out in the village of Borowiec, resulted in 14 deaths and left seven insurgents wounded. The fallen were buried at the local cemetery in Grodziec and the wounded found help and shelter among local people. According to oral history, one of the wounded allegedly reached the village of Jarantow Kolonia, where he was taken care of by the Mikolajczak family, but died of his wounds. His body was supposedly transferred near Pisko- Lipe and laid to rest in a nameless grave. A GPR survey undertaken before excavation works revealed soil disturbances in the vicinity of the wooden cross. The archaeological research did not confirm the existence of a grave in this area. There were modern destructions in the area where GPR detected soil disturbances, which indicates attempts to dig up the alleged grave. The insurgent may have been buried near the symbolic gravesite.

Exploring Resistance Reduction of Subsoiling Through Sandfish (Scincus scincus) Inspired Sinusoidal Locomotion

Highlights Biomimetic design, inspired by sandfish locomotion, decreased subsoiling resistance. Penetration tests and simulations showed bioinspired tines outperforming traditional ones in resistance reduction. DEM-MBD co-simulation effectively modeled the sandfish's movement, revealing the mechanisms of soil interactions. Simulations confirmed that sinusoidal subsoiler movement significantly reduced soil resistance. Abstract. This study addresses the issue of high resistance and low efficiency in subsoiling operations by employing a novel method inspired by the unique locomotion of the sandfish (scincus scincus), aimed at reducing forward resistance. The unparalleled adaptability of the sandfish in navigating granular media, such as desert sand, offers valuable insights for enhancing agricultural machinery. This research employs sandfish’s movement principles to propose innovative strategies for improving subsoiling efficiency. A sandfish inspired prototype, created through reverse engineering, served as the basis for the analysis. The models of both traditional (T-S) and bioinspired (B-S) subsoiler tines for comparative assessment were developed. The EDEM simulation model’s performance was calibrated using soil penetration tests and integrated with multibody dynamics (MBD) to analyze the sandfish’s variable locomotion in sandy soil. The impact of linear and sinusoidal locomotion at velocities of 0.8 m/s, 1.0 m/s, and 1.2 m/s on resistance and soil disturbance were investigated and contrasted. The congruence between measured and simulated resistance-depth curves for T-S and B-S models was desirable, with maximum resistance errors of 2.54% and 2.47%, respectively, confirming the simulation model’s accuracy in predicting mechanical interactions. A comparison of characteristic angles validated the close correlation between simulated and actual sandfish locomotion in soil. Stress analysis during soil locomotion of the sandfish head indicated a 25.1% reduction in resistance with sinusoidal motion compared to linear motion. At the specified velocities, sinusoidal locomotion of the subsoiler tine showed resistance reductions of 6.75%, 7.39%, and 9.40%, respectively, relative to linear locomotion. The mechanism of resistance reduction in sinusoidal locomotion was further verified through soil compression force analysis, supporting the adoption of sandfish-inspired sinusoidal behavior as an innovative approach to enhance efficiency in agricultural practices. Keywords: Bioinspired design, DEM-MBD simulation, Sandfish (Scincus scincus), Sinusoidal locomotion, Subsoiling.

Soil Stockpile Age Does Not Impact Vegetation Establishment in a Cold, Arid Natural Gas Field

Abstract Land reclamation is critical to ensure surface disturbance associated with natural gas development is not permanent. Soil management is critical to reclamation success, especially in arid environments. Typically, natural gas well pad construction involves stripping topsoil to allow for equipment to be on level ground and placing it into a stockpile. After well pad construction, soil is respread and seeded to initiate interim reclamation. Previous research has shown that soil disturbance during natural gas well pad construction and subsequent reclamation in cold, arid environments is highest at the stripping and respreading phases, with minimal soil activity occurring during the stockpile phase. Other research has shown that additional soil disturbances after reclamation is initiated may exacerbate soil damage, limiting revegetation potential. Here, we examine soil stockpiles that are 1 to 7 years old in the Jonah Infill natural gas field for vegetation emergence and vegetation cover using an image analysis software called SamplePoint. In a 10-week greenhouse experiment, we found vegetation cover across stockpile age classes increased uniformly during the study period but that there was no significant difference in the rate of vegetation cover increase or percentage vegetation cover over time. These findings suggest it may be better to keep soil stockpiled in cold, arid natural gas fields when it is uncertain if additional construction activities will be required on a well pad location rather than respreading soil with a chance that redisturbance is necessary.

Channel Attention GAN-Based Synthetic Weed Generation for Precise Weed Identification.

Weed is a major biological factor causing declines in crop yield. However, widespread herbicide application and indiscriminate weeding with soil disturbance are of great concern because of their environmental impacts. Site-specific weed management (SSWM) refers to a weed management strategy for digital agriculture that results in low energy loss. Deep learning is crucial for developing SSWM, as it distinguishes crops from weeds and identifies weed species. However, this technique requires substantial annotated data, which necessitates expertise in weed science and agronomy. In this study, we present a channel attention mechanism-driven generative adversarial network (CA-GAN) that can generate realistic synthetic weed data. The performance of the model was evaluated using two datasets: the public segmented Plant Seedling Dataset (sPSD), featuring nine common broadleaf weeds from arable land, and the Institute for Sustainable Agro-ecosystem Services (ISAS) dataset, which includes five common summer weeds in Japan. Consequently, the synthetic dataset generated by the proposed CA-GAN obtained an 82.63% recognition accuracy on the sPSD and 93.46% on the ISAS dataset. The Fréchet inception distance (FID) score test measures the similarity between a synthetic and real dataset, and it has been shown to correlate well with human judgments of the quality of synthetic samples. The synthetic dataset achieved a low FID score (20.95 on the sPSD and 24.31 on the ISAS dataset). Overall, the experimental results demonstrated that the proposed method outperformed previous state-of-the-art GAN models in terms of image quality, diversity, and discriminability, making it a promising approach for synthetic agricultural data generation.

Changes in soil properties of xerophytic forests in Southern Russia after anthropogenic impact

Anthropogenic influences negatively affect the soil properties and woody vegetation in the xerophytic forests and the rare forests of the northern coastal area of the Black Sea. The study was carried out at the properties of soils in the Utrish State Nature Reserve (Russia), which was previously under the influence of anthropogenic impact. Fires, deforestation, and recreational load were selected as the prioritised types of anthropogenic impact in long-term studies with soil (Cambisols) in the Utrish State Nature Reserve, which rapidly lead to the degradation of ecosystems and biodiversity reduction. Soil samples were taken from the 0–10-cm layer in triplicate from each study site. The study site after recreational load has been investigated in 2013, 2015, 2018, 2019, and 2020. The parameters pH, organic carbon content, enzyme activity were studied. Biological properties of soils were found to be more sensitive to changes in characteristics than other soil parameters. For all the studied parameters, there was a decrease in the organic carbon content from 18% to 59% relative to the control. The highest decrease in the indicator was noted for soils after deforestation. Enzymes from the oxidase class recover faster than the hydrolases. Catalase activity for all disturbed soils decreased on average by 13%. Non-significant differences from the control were observed for soils after deforestation and fires. Inhibition of invertase activity was established in soils by an average of 52% after fires and recreational exposure, with an increase in enzyme activity of 77% observed after deforestation. The results can be used to assess effects of the anthropogenic impacts on forests. Biological indicators are good markers of the condition of disturbed soils that could be implicated to determine the prioritised anthropogenic load in the soils of xerophytic forests.

Technosols as a resource for restoration of soil and vegetation cover during disturbed land reclamation in the forest-steppe zone

Technogenically disturbed soils of the Kedrovsky coal mine dumps, a branch of JSC MC Kuzbassrazrezugol, located in the forest-steppe of the Kuznetsk Basin, Kemerovo region (Russia), are investigated. The physicochemical characteristics of young soils were studied using the facilities of an experimental polygon for disturbed land reclamation technologies. The following soil variants were studied: typical technosol (technogenic eluvium), organogenic technosol (with application of a potential fertile soil layer, PFSL), and humusogenic technosol (with application of a fertile soil layer, FLS). The humusogenic technosol was found to possess a higher starting lithogenic potential in terms of soil formation, when restoring disturbed soils and their vegetation cover with an increase in species diversity by zonal type. Under favorable climatic conditions and the use of proper agrotechnical technologies, FSL technosols promote the development of grassy ecosystems and activate the process of soil formation. Over time, these soils can approach zonal soil types in terms of their main physical and chemical parameters, including organic matter.

Longitudinal vibration characteristics of a tapered pipe pile considering the vertical support of surrounding soil and construction disturbance

Longitudinal vibration characteristics of a tapered pipe pile considering the vertical support of surrounding soil and construction disturbance

Agroecological assessment of spatial variability of carbon content in the conditions of disturbed sod-podzolic soils

Soil carbon is one of the main carbon pools of terrestrial ecosystems. The carbon of arable soils is the most labile. In this regard, rapid and accurate methods for determining soil carbon in different forms are of great interest to researchers. Therefore, in this paper we decided to conduct a comparative analysis of the results of organic carbon determination using the Walkley-Black method (colorimetric method), the Dumas dry combustion method (using the CN Vario El Cube analyzer)) and the remote method using the Valeeva approach (Valeeva, Aleksandrova, Koposov, 2016) according to the values of the red channel of the spectrum, on the images obtained using an RGB camera mounted on a DJI Phantom 4 drone. For laboratory analysis, 100 soil samples of the arable horizon were collected at regular grid points, georeferenced using RTK. The correlation between the Dumas dry combustion method and potassium dichromate oxidation was 0.24 (for n = 100, significant p=0.195), allowing comparison at the trend level. The highest correlation (R = 0.39 was observed between the data obtained using the Dumas method and the Valeeva-Alexandrova approach, indicating that it can be used to estimate soil carbon dynamics from RGB images. Correlation analysis showed relationships (R = 0.63) between total carbon and microrelief, which is reflected by the drone-derived digital elevation model.

Hillslope and vegetation response to postglacial warming at Bear Meadows Bog, Pennsylvania, USA

AbstractConnecting changes in erosion and vegetation is necessary for predicting topographic and ecologic change in thawing permafrost landscapes. Formerly periglacial landscapes serve as potential analogs for understanding modern permafrost landscape change, yet compared to paleoenvironmental records at these sites, less is known about concurrent geomorphic processes, particularly their rates and relationships to climate change. Here, we target sediments preserved in a central Appalachian peat bog to reconstruct sedimentation across the last deglacial warming. We use ground-penetrating radar and geochemistry of cored bog sediments to quantify sedimentation timing, style, and provenance. Using 14C dating of sedimentary and geochemical shifts, we connect depositional changes to global climate and local vegetation change. We show that deglacial warming promoted deep soil disturbances via solifluction at ca. 14 ka. In contrast, relatively wetter conditions from ca. 10–9 ka promoted shallow disturbance of hillslopes via slopewash, which corresponds to a time of vegetation change. Our results highlight climate-modulated erosion depth and processes in periglacial and post-periglacial landscapes. The existence of similar erosion and vegetation records preserved regionally implies these dynamics were pervasive across unglaciated Appalachian highlands, aiding in reconstructing erosion responses to warming at a resolution with implications for predicting high-latitude landscape responses to disturbance.

Listening to tropical forest soils

Acoustic monitoring has proven to be an effective tool for monitoring biotic soundscapes in the marine, terrestrial, and aquatic realms. Recently it has been suggested that it could also be an effective method for monitoring soil soundscapes, but has been used in very few studies, primarily in temperate and polar regions.We present the first study of soil soundscapes using passive acoustic monitoring in tropical forests, using a novel analytical pipeline allowing for the use of in-situ recording of soundscapes with minimal soil disturbance. We found significant differences in acoustic index values between burnt and unburnt forests and the first indications of a diel cycle in soil soundscapes.These promising results and methodological advances highlight the potential of passive acoustic monitoring for large-scale and long-term monitoring of soil biodiversity. We use the results to discuss research priorities, including relating soil biophony to community structure and ecosystem function, and the use of appropriate hardware and analytical techniques.

The influence of a soil amendment on the abundance and interaction of arbuscular mycorrhizal fungi with arable soils and host winter wheat.

Arbuscular mycorrhizal (AM) fungi have been shown to be associated with an estimated 70 % of vascular terrestrial plants. Such relationships have been shown to be sensitive to soil disturbance, for example, tillage in the preparation of a seed bed. From the application of arable soil management, AM fungal populations have been shown to be negatively impacted in abundance and diversity, reducing plant growth and development. The present study aims to utilise two sources (multipurpose compost and a commercial inocula) of mycorrhizal fungi for the amendment of arable soils supporting Zulu winter wheat under controlled conditions and quantify plant growth responses. A total of nine fields across three participating farms were sampled, each farm practicing either conventional, reduced, or zero tillage soil management exclusively. Soil textures were assessed for each sampled soil. Via the employment of AM fungal symbiosis quantification methods, AM fungi were compared between soil amendments and their effects on crop growth and development. The present study was able to quantify a mean 6 cm increase to crop height (P<0.001), 10 cm reduction to root length corresponding with a 2.45-fold increase in AM fungal arbuscular structures (P<0.001), a 1.15-fold increase in soil glomalin concentration corresponding to a 1.26-fold increase in soil carbon, and a 1.32-fold increase in the relative abundance of molecular identified AM fungal sequences for compost amended soils compared to control samples. Mycorrhizal inocula, however, saw no change to crop height or root length, AM fungal arbuscules were reduced by 1.43-fold, soil glomalin was additionally reduced by 1.55-fold corresponding to a reduction in soil carbon by 1.31-fold, and a reduction to relative AM fungal species abundance by 1.26-fold. The present study can conclude the addition of compost as an arable soil amendment is more beneficial for the restoration of AM fungi beneficial to wheat production and soil carbon compared to the addition of a commercial mycorrhizal inocula.

Moving conservation agriculture from principles to a performance-based production system

Abstract Conservation agriculture (CA) is an approach to farming that is defined by three principles: (1) minimal soil disturbance (no-till), (2) crop diversity in time and space, and (3) soil coverage by crop residues and/or cover crops. These principles provide a roadmap to protect and improve soil. However, the narrow criteria for defining CA may fail to account for tradeoffs between soil health and other ecosystem services. A literature review of meta-analyses dealing with CA and an online survey in France were conducted to explore the implementation and performances of CA. Research on CA systems has focused on crop productivity and soil quality whereas research on other dimensions of cropping system sustainability are lacking. The effects of CA on other aspects of sustainability such as biodiversity and profitability are less prevalent in the literature. The online survey results show that 63% of respondents thought that CA helps reduce pesticide use, 91% that CA improves water use efficiency, and 77% that CA helps to store carbon and achieve the objectives of the 4 per 1000 international initiative. Given the prevalence and widespread support for CA, we advocate for moving CA from its current definition based on the means toward a definition that includes performance-based metrics that address different ecosystem services. CA has potential to help address challenges associated with climate change, biodiversity loss, and water pollution, but opportunities may be missed without developing performance targets that go beyond soil conservation.

Conservation tillage facilitates the accumulation of soil organic carbon fractions by affecting the microbial community in an eolian sandy soil.

Conservation tillage (CT) is an important agronomic measure that facilitates soil organic carbon (SOC) accumulation by reducing soil disturbance and plant residue mulching, thus increasing crop yields, improving soil fertility and achieving C neutrality. However, our understanding of the microbial mechanism underlying SOC fraction accumulation under different tillage practices is still lacking. Here, a 6-year in situ field experiment was carried out to explore the effects of CT and traditional tillage (CK) practices on SOC fractions in an eolian sandy soil. Compared with CK, CT increased the particulate OC (POC) content in the 0-30 cm soil layer and the mineral-associated OC (MAOC) content in the 0-20 cm soil layer. Moreover, tillage type and soil depth had significant influences on the bacterial, fungal and protistan community compositions and structures. The co-occurrence network was divided into 4 ecological modules, and module 1 exhibited significant correlations with the POC and MOC contents. After determining their topological roles, we identified the keystone taxa in the network. The results indicated that the most common bacterial taxa may result in SOC loss due to low C use efficiency, while specific fungal (Cephalotrichum) and protistan (Cercozoa) species could facilitate SOC fraction accumulation by promoting macroaggregate formation and predation. Therefore, the increase in keystone fungi and protists, as well as the reduction in bacteria, drove module 1 community function, which in turn promoted SOC sequestration under CT. These results strengthen our understanding of microbial functions in the accrual of SOC fractions, which contributes to the development of conservation agriculture on the Northeast China Plain.

Sediments and morphology of deep lakes of Central Tunguska Plateau (Krasnoyarsk krai, Evenkia): on the problem of the Tunguska Event at 1908

The shape of the bottom and the thickness of sediments of small lakes Zapovednoye and Peyungda, located 50-60 km from the supposed epicenter of the “Tunguska Event” of 1908, were studied using echo-sounding and seisimo-acoustic profiling, and their age was estimated using 137Cs, 210Pb, 14C. It was revealed that both lakes have funnel shape with a depth of 60 and 34 m, respectively, and are similar in shape and size to Lake Cheko, which, according to some researchers, is an impact crater formed by a celestial body as a result of the “Tunguska Event 1908”. The examples of lakes Zapovednoye and Peyungda show that the shape of Lake Cheko is not unique to this area. The age of the bottom sediments of lakes Zapovednoye and Peyungda exceeds several thousand years. In the sediments of lakes Zapovednoe and Peyungda, a layer with a high content of terrigenous elements was identified, presumably formed due to the input of disturbed soil layer as a result of the massive fall of trees after the “Tunguska 1908”. Thus, the presence of two deep funnel-shaped lakes near the epicenter of the “Tunguska 1908” much older than 1908, casts doubt on the uniqueness of Lake Cheko, and therefore its impact origin. In addition, according to our estimate, the age of Lake Cheko is no less than 300 years, which contradicts the hypothesis of its origin as a result of the “Tunguska 1908”.

Organic carbon and short-range order minerals responsible for cementation of the spodic horizon (ortstein): a new proposal of chemical extractions in undisturbed samples

Context The cementation of spodic horizons (ortstein) has long been studied through chemical analysis in disturbed soil samples of &lt;2 mm (soil structure destructuring). Aims Use of the undisturbed samples and selective chemical extractions to study the soil organic matter (SOM) and short-range order phase (SROP) cementing the spodic horizon. Methods The study was carried out in a Spodosol (ortstein) from southern Brazil in undisturbed cubes (1.5 cm × 1.5 cm × 1.5 cm). The undisturbed cubes were separated in two visual colour standards (yellow colour (YC – 10YR 6/8) and yellow dark colour (YDC – 10YR 4/3)) and were submitted to four SROP chemical extractions (pyrophosphate (PYR), ammonium oxalate (AO), NaOH 0.5 mol L−1, and water). Key results The choice of selective SROP extraction in two colour standards of undisturbed samples enabled the identification of cementation details of the ortstein : (1) SOM illuviation also increases Fe, Al, Mn, Si, Ca, and Mg contents; (2) the SRO-Fe and Al oxides cover the SOM and/or there is a larger proportion of mineral in relation to OC in the organo/mineral association; (3) SRO-Al oxides were the main compounds responsible for cementation; and (4) the illuvial SOM associated with SRO-Fe oxides did not contribute to ortstein physical stability. Conclusions and implications The best extractions to study the samples were AO for YC colour and NaOH for YDC colour. We recommend the use of undisturbed samples and the inclusion of NaOH 0.5 mol L−1 in the chemical protocol for analysis to better understand which organic and mineral phases clog the ortstein pores in different pedogenetic conditions around the world.

Optimization Design and Experiment of High-Speed Drag-Reducing Trencher Based on Conservation Tillage

In the realm of high-speed precision broadcasting, the existing seeder opener proves inadequate for the speed of the seeding operation. We focus on the duckbill opener and employ the quadratic regression orthogonal rotation combination test design method to optimize the structural parameters of the opener. Throughout the experiment, the primary performance metrics encompassed the opener’s working resistance and the side dumping distance. The selected experimental factors comprised the penetration angle, the angle of soil entry gap, the shovel body width, and the shovel length. The optimal arrangement of structural parameters has been determined: a penetration angle, a soil entry gap angle, a shovel body width of 21 mm, and a shovel length of 142 mm. These parameters contribute to increased velocity, reduced operational resistance, and minimal soil disturbance. Under this combination, the relative deviations between the recorded measurements and the theoretical outcomes for working resistance and the side dumping distance stand at 4.24% and 1.06%, respectively; these confirm the credibility of the optimization results. We performed adaptability testing and conducted a comparative analysis under various operational conditions to assess the innovative opener’s ability to reduce force, minimize soil disruption, and maintain depth stability. The findings are as follows: At a depth of 5 cm and velocities ranging from 6 km/h to 8 km/h, an average working resistance reduction of 19.73%, a 5.64% decrease in the side dumping distance, and an average depth stability of 89.5% were observed. When operated at a speed of 7 km/h with a depth ranging from 3 cm to 5 cm, an average reduction of 19.66% in operational resistance, a 2.59% decrease in the side dumping distance, and an average depth stability of 91.1% were recorded. These results illustrate the innovative opener’s capacity to significantly reduce working resistance and side dumping distance while satisfying the depth stability requisites.

Physical Conditions That Limit Chickpea Root Growth and Emergence in Heavy-Textured Soil

The tillage method determines several soil physical parameters that affect the emergence of post-rice chickpea (Cicer arietinum L.) in the Indo-Gangetic Plain of South Asia. Mechanised row-sowing with minimum soil disturbance and crop residue retention in medium-to-heavy-textured soils will alter the seedbed when compared to that prepared after traditional full tillage and broadcast sowing. Whilst minimum soil disturbance and timely sowing may alleviate the soil water constraint to crop establishment, other soil physical properties such as soil strength, bulk density, and aggregate size may still inhibit seedling emergence and root elongation. This study’s objective was to determine the limitations to chickpea crop establishment with increasing bulk density and soil strength, and different aggregate sizes below and above the seed. In two growth cabinet studies, chickpea seed was sown in clay soil with (i) a bulk density range of 1.3–1.9 Mg m−3 (Experiment 1) and (ii) the combination of bulk densities (1.3 and 1.8 Mg m−3) and aggregate sizes (&lt;2 mm and &gt;4 mm) above and below the seed (Experiment 2). Root length was significantly reduced with increasing bulk density (&gt;1.4 Mg m−3), and soil strength impeded early root growth at &gt;1 MPa. Where main root growth was impeded due to high bulk density and soil strength, a greater proportion of total root growth was associated with the elongation of lateral roots. The present study suggests that the soil above the seed needs to be loosely compacted (&lt;1.3 Mg m−3) for seedling emergence to occur. Further research is needed to determine the size of the soil aggregates, which optimise germination and emergence. We conclude that soil strength values typical of field conditions in the Indo-Gangetic Plain at sowing will impede the root growth of chickpea seedlings. This effect can be minimised by changing tillage operations to produce seedbed conditions that are within the limiting thresholds of bulk density and soil strength.

Evaluation of tractor traffic on soil physical properties and their relationship with white oat yield in no-tillage

In a no-tillage system, the absence of soil disturbance combined with increased machine traffic has led to soil compaction in the top layer, negatively affecting its physical quality and hampering crop growth and production. This experiment aimed to assess the impact of tractor traffic, occurring under a no-tillage system, on soil physical properties and their relationship with the growth and yield of white oat crops. The research was conducted in an Oxisol, utilizing a randomized block design with five replications. The treatments consisted of ten consecutive years of no-tillage and additional traffic by 2, 4, 6, and 8 passes of a tractor wheel across the entire plot area. Various soil parameters were evaluated in two soil layers, including soil bulk density, total porosity, macroporosity, and soil resistance to penetration. Additionally, plant height, stem diameter, dry plant mass, mass of one thousand grains, and grain yield were determined. The collected data were analyzed using analysis of variance and linear regression. The results indicated that higher tractor traffic intensity led to increased soil bulk density and reduced macroporosity and soil resistance to penetration in the 0-0.10 m layer compared to the 0.10-0.20 m layer. In the 0-0.10 m layer, bulk density values exceeding 1.44 Mg m-3 were found to restrict the growth and yield of white oat crops, while in the 0.10-0.20 m layer, grain yield was limited when soil bulk density surpassed 1.35 Mg m-3. Our results show that farmers should be aware of the consequences of machine traffic on soil properties as it can have negative effects on crop yields, especially those of white oats grown in clayey soil similar to the one evaluated in this experiment.

Soil failure characteristics and loosening effectivity of compacted grassland by subsoilers with different plough points

Mechanical disturbance of compacted grassland soil can reduce the compaction level. This paper aimed to provide recommendations for optimising plough point design and the formulation of grassland loosening operation standards by analysing the disturbance degree and loosening effectivity of compacted grassland soil. A grassland disturbance test was conducted by using different types of plough points (straight, chisel, diamond, and arrow), tillage depths (50, 100, and 150 mm), and shank spacings (250, 300, and 350 mm). A soil disturbance model was established to determine the disturbance threshold of the compacted soil. The results showed that the straight point cut through the grassland soil along the edge of the shank, the chisel point sheared it into strips and blocks, the diamond and arrow point produced furrows in the grassland. The disturbance degree of the grassland soil increased as the tillage depth increased for all four points and as the shank spacing decreased for the chisel, diamond, and arrow point. The average values of the soil disturbance index (SDI) were 1.19, 1.34, 1.30, and 1.22 for the straight, chisel, diamond, and arrow point, respectively. The significance analysis showed that the loosening effectivity of the chisel and diamond point was significantly better than that of the straight and arrow point. The chisel point plot had the highest mean SDI, indicating it was more effective than the other three points in loosening the compacted grassland soil. The optimum loosening effectivity was achieved at a soil disturbance rate of 26%.