Cattle trampling and soil compaction on loamy sands

Abstract. Field investigations on loamy sand soil showed that compaction by cattle trampling increased soil bulk density and cone penetrometer resistance. Trampling produced very dense zones at depths of 7–10.5 cm, which impeded drainage, despite the presence of large macropores. Soil structural and hydrological changes caused by hoof compaction can result in serious pasture management problems. Compaction simulation experiments on saturated turf indicated that most severe structural damage occurs on initial compaction.     

Temporal variation of soil compaction and deterioration of soil quality in pasture areas of Colombian Amazonia

In the Amazon basin, tropical rainforest is being slashed and burned at accelerated rates for annual crops over a couple of years, followed by forage grasses. Because of poor management, the productivity of established pastures declines in a few years so that grazing plots are abandoned and new areas are deforested. Previous studies in the region report higher bulk density in soils under pasture than in similar soils under forest. The objective of this study was to detect changes in the physical quality of the topsoil of nutrient-poor Typic Paleudults in the colonisation area of Guaviare, Colombian Amazonia, and analyse the effect of soil deterioration on pasture performance. Temporal variation of soil compaction under pasture was analysed by comparing natural forest taken as control and pasture plots of Brachiaria decumbens (Stapf) grouped into three age ranges (<3, 3–9, >9 years). Evidence of soil compaction through cattle trampling, after clearing the primary forest, included the formation of an Ap horizon with platy structure and dominant greyish or olive colours, reflecting impaired surface drainage, the increase of bulk density and penetration resistance, and the decrease of porosity and infiltration rate. From primary forest to pastures older than 9 years, bulk density of the 5–10 cm layer increase was 42% in fine-textured soils and 30% in coarse-textured soils. Penetration resistance ranged from 0.45 MPa under forest to 4.25 MPa in old pastures, with maximum values occurring at 3–12 cm depth in pastures older than 9 years. Average total soil porosity was 58–62% under forest and 46–49% under pasture. Basic infiltration dropped from 15 cm h⁻¹ in the original forest conditions to less than 1 cm h⁻¹ in old pastures. Crude protein content and dry matter yield of the forage grass steadily decreased over time. No clear relationship between declining protein content as a function of pasture age and changes in chemical soil properties was found, but there was a high negative correlation (r=−0.81) between protein content and bulk density, reflecting the effect of soil compaction on pasture performance. After about 9–10 years of use, established grass did no longer compete successfully with invading weeds and grazing plots were abandoned. As land is not yet a scarcity in this colonisation area, degraded pastures are seldom rehabilitated.     

Earthworms in New Zealand sheep- and dairy-grazed pastures with focus on anecic Aporrectodea longa

Earthworms play an important role as primary decomposers in the incorporation and initial mixing of plant litter. This study explored the response of earthworms to increasing fertiliser inputs, pasture production and livestock numbers (and their influence on food availability and soil physical condition) on six different managements in sheep-grazed and fifteen different managements in dairy-grazed pastures in a variety of New Zealand soils.Native earthworms were only found in some low-fertility pastures. Accidentally introduced peregrine earthworms, when present, dominate pasture soils. Of these, endogeic earthworms dominated the earthworm community and were positively associated with soil types with higher bulk densities. Peregrine anecic earthworms were absent from most hill-country sheep-grazed pastures, however in more fertile and productive dairy-grazed pastures they reached a biomass of up to 2370 kg ha^?1. Only anecic earthworms showed a positive response to the increasing pressures associated with higher potential dry matter inputs and liveweight loadings of grazing livestock on soil, while epigeic earthworms declined. The positive response of anecic earthworms probably reflects the combined effect of the increase in food resources, including dung and plant litter, available on the soil surface, and their lower susceptibility to livestock treading pressure. Anecic species may be a suitable substitute for incorporation of surface litter in those soils where livestock treading limits epigeic earthworm populations.This study confirmed previous observations of limited distribution of the introduced Aporrectodea longa in pastoral hill-country soils in the North Island, and their near absolute absence from the South Island of New Zealand. This would suggest that large areas of New Zealand pastoral farmed soils could benefit from the introduction of anecic species from other parts of New Zealand which already contain A. longa.     

Shape and intraporosity of topsoil aggregates under maquis and pasture in the Mediteranean region

The clearing of Mediterranean maquis along with the creation of new pasture land has been an important factor of soil and land degradation in the Mediterranean region. The present research compared soil aggregates and their intraporosity in paired pasture/maquis plots in central E Sardinia (Italy), to study the impact of land use change on soil structure. Undisturbed surface horizons were sampled for thin‐section analysis. Aggregate shape was compared and intraporosity was studied for representative aggregates at different depths. Furthermore, the interaction of root activity and grazing under pasture and maquis cover was discussed. The outcomes revealed a complex interplay of trampling and root activity effects. A decrease (–44%) in total voids (regular pores), along with higher aggregate regularity, was observed under pasture in the 0–2 cm layer, and an increase (+261%) in 50–100 μm planar (elongated) pores was determined in the 2–4 cm layer, suggesting a possible surface compaction due to trampling and an increased subsurface fine root activity by the grassland vegetation.     

The effect of trampling on neutral grassland

This paper presents an analysis of the intensity of trampling on the soils and the vegetation on three transects which reached from the bank of the River Thames, across a footpath and into a grazed water meadow. Soil bulk density, penetration resistance, water content and the height above the water table were all strongly correlated with trampling. The correlations between the occurrence of the common species and the intensity of trampling and the soil qualities were investigated by means of linear regression analysis. Poa annua, Plantago major, Poa pratensis and Lolium perenne were positively correlated with trampling intensity and Holcus lanatus, Agrotis stolonifera and Phleum bertolonii had negative correlations. The effect of trampling on neutral grassland was broadly similar to other situations but there is evidence which suggests that the relative trampling tolerance of different species cannot be considered in isolation from the habitat in which they are growing.     

Cattle trampling alters soil properties and changes soil microbial communities in a Swiss sub-alpine pasture

Stock farming plays an important role in the agriculture of alpine regions although deleterious effects on the soils are most pronounced here. We investigated the effects of cattle trampling on soil physical, chemical and microbial properties in a Swiss sub-alpine pasture. About 10% of the study site was bare of vegetation as a result of repeated cattle trampling and the bulk density of these bare steps was 20% higher than of the soils unaffected by trampling. In the upper 25 cm, soil organic carbon (SOC) concentrations and total SOC stocks were 35% and 20% respectively lower than on the vegetated slope. As compared with the vegetated slope, topsoils of the bare steps featured narrower C:N-ratios and were more enriched in the ¹⁵N isotope, with typical values of deeper soil layers. This indicates that bare soils primarily evolved by erosion and not by a compaction, which might, together with the reduced litter input, explain the lower SOC contents. The abundances of soil microbes, estimated by the concentrations of phospholipid fatty acid (PLFA), were 30% smaller in the bare soils than in the vegetated areas. This depletion was most pronounced for fungi as expressed in the lower concentrations of the fatty acid 18:2ω6.9 (45%) and ergosterol (50%). The lower fungal abundance very likely has negative consequences for the stability of the bare soils, since fungi play an important role in the formation of soil aggregates. In summary, our results show that cattle trampling decreases soil carbon storage and alters soil microbial community structure.     

Earthworm activity as a determinant for N2O emission from crop residue

Earthworm activity may have an effect on nitrous oxide (N₂O) emissions from crop residue. However, the importance of this effect and its main controlling variables are largely unknown. The main objective of this study was to determine under which conditions and to what extent earthworm activity impacts N₂O emissions from grass residue. For this purpose we initiated a 90-day (experiment I) and a 50-day (experiment II) laboratory mesocosm experiment using a Typic Fluvaquent pasture soil with silt loam texture. In all treatments, residue was applied, and emissions of N₂O and carbon dioxide (CO₂) were measured. In experiment I the residue was applied on top of the soil surface and we tested (a) the effects of the anecic earthworm species Aporrectodea longa (Ude) vs. the epigeic species Lumbricus rubellus (Hoffmeister) and (b) interactions between earthworm activity and bulk density (1.06 vs. 1.61 g cm⁻³). In experiment II we tested the effect of L. rubellus after residue was artificially incorporated in the soil. In experiment I, N₂O emissions in the presence of earthworms significantly increased from 55.7 to 789.1 μg N₂O-N kg⁻¹ soil (L. rubellus; p<0.001) or to 227.2 μg N₂O-N kg⁻¹ soil (A. longa; p<0.05). This effect was not dependent on bulk density. However, if the residue was incorporated into the soil (experiment II) the earthworm effect disappeared and emissions were higher (1064.2 μg N₂O-N kg⁻¹ soil). At the end of the experiment and after removal of earthworms, a drying/wetting and freezing/thawing cycle resulted in significantly higher emissions of N₂O and CO₂ from soil with prior presence of L. rubellus. Soil with prior presence of L. rubellus also had higher potential denitrification. We conclude that the main effect of earthworm activity on N₂O emissions is through mixing residue into the soil, switching residue decomposition from an aerobic and low denitrification pathway to one with significant denitrification and N₂O production. Furthermore, A. longa activity resulted in more stable soil organic matter than L. rubellus.     

Earthworms bring compacted and loose soil to a similar mechanical state

We tested the hypothesis that earthworms stabilise loose soil and loosen compacted soil to a similar mechanical state. Casts collected from initially loose soil (980 kg m⁻³) had 10-fold greater viscosity (31 kPa s) and 5-fold greater yield stress (200 Pa) than a control soil without worms. Lumbricus terrestris; Dendrobaena sp. and Aporrectodea longa were all investigated, with no difference found between species. In compacted soils (1300 kg m⁻³), A. longa produced casts with similar mechanical properties to loose soil, with viscosity and yield stress decreased by 45% compared to the control without worms. Earthworms were shown to bring initially loose and compacted soil to an intermediate mechanical state that is more favourable for structural stability and root growth.     

Does the deep-burrowing earthworm,Aporrectodea longa,compete with resident earthworm communities when introduced to pastures in south-eastern Australia?

Pastures in southern Australia are dominated by endogeic earthworms such as Aporrectodea caliginosa (Sav.). Introductions of the anecic earthworm, A. longa (Ude), which is mostly restricted to Tasmania at present, are likely to increase the functional diversity of local communities and thereby enhance plant production and agricultural sustainability. However, the potential impact of A. longa on resident earthworm communities first needs assessing. Glasshouse and field experiments reported here suggested that A. longa can reduce the abundance and biomass of A. caliginosa, but that these effects are likely to be offset by overall increases in worm abundance. There was no evidence to suggest that species richness was reduced by A. longa introduction.     

Short-term and long-term effects of human trampling on above-ground vegetation, soil density, soil organic matter and soil microbial processes in suburban beech forests

Understanding the effects of disturbance by human trampling on ecosystem processes is essential for the management of recreational areas. Discussions on recreational impacts are based either on data from trampling experiments or on field survey data from sites subjected to long-term recreational use, but rarely on a combination of both. We examined whether results from a short-term trampling experiment reflect the impact of long-term trampling around frequently used fire places. We compared short- and long-term effects of human trampling on above-ground forest vegetation and soil physical, chemical and microbial characteristics. We found both similarities and differences in short- and long-term trampling effects. Both short- and long-term trampling reduced plant cover, plant height and species density, though long-term effects were more pronounced than short-term effects. In both approaches, leaf litter biomass decreased, whereas soil density increased with trampling intensity. Other soil characteristics including soil moisture, total soil organic matter content and total organic nitrogen content were not or only marginally affected by short- and long-term trampling. Furthermore, soil microbial biomass and the activity of dehydrogenase did not change in both approaches. In contrast, the activity of β-glucosidase was only reduced by short-term trampling, whereas activity of phosphomonoesterase was reduced only by long-term trampling. Soil compaction was one factor reducing microbial activities at low and medium trampling intensities in our experiment and in the highly compacted area around the fire rings. We conclude that it could be problematic to use the results of short-term trampling experiments to predict general long-term trampling effects. Our results imply also that the restoration of degraded sites might be hampered by the low nutrient turnover resulting from the reduced litter layer and changes in enzyme activities, mitigating a successful re-establishment and growth of plants.     

C and N turnover of fermented residues from biogas plants in soil in the presence of three different earthworm species (Lumbricus terrestris,Aporrectodea longa,Aporrectodea caliginosa)

A soil microcosm experiment was performed to assess (1) the C- and N- turnover of residues from biogas plants in soils in the presence of three earthworm species (Lumbricus terrestris, Aporrectodea longa and Aporrectodea caliginosa) and (2) the resulting changes in soil chemical and microbiological properties when using these residues as fertilizer in comparison to conventional slurry. Earthworms were exposed in soils, fertilized with an equivalent amount of 120 kg of NH₄-N ha^?1 from: (1) conventional cattle slurry and (2) a fermented residue derived from cattle slurry, grass (silage) and maize. Additional treatments without slurry and earthworms were used as controls.There was considerable evidence that soils fertilized by fermented slurry comprised fewer amounts of readily available nutrients for microbial C and N turnover. We observed significant stimulation of microbial biomass, basal respiration and nitrification in treatments with conventional slurry, especially in the presence of earthworms. However, the stimulation of microbial activity by manure and earthworms were significantly lower in treatments with fermented slurry. Moreover, the results showed clear interactions between different earthworm species and manures. While the biomass of the anecic species (L. terrestris and A. longa) increased in both slurry treatments, the biomass of A. caliginosa (endogeic) decreased, with a significantly stronger biomass decline in treatments with fermented slurry. The metabolic quotients revealed microbial stress metabolism in fermented slurry treatments, predominantly in treatments with A. caliginosa. We conclude that particularly A. caliginosa and soil microorganisms competed for labile C sources in treatments with fermented slurry. An application of these residues as fertilizer might result in a reduction of microbial activity in agricultural soils and in a decline of endogeic earthworms.     

Tillage and crop management impacts on soil loss and crop yields in northwestern Ethiopia

Lack of appropriate agronomic practices is one of the major causes for soil erosion and low yields in teff (Eragrostis tef [Zucc.]) production in Ethiopia. A 3-yr study was conducted at the Aba Gerima watershed in northwestern Ethiopia, to investigate the effects of two tillage practices (reduced tillage [RT] and conventional tillage [CT]), two planting methods (row planting [RP] and broadcast planting [BP]), and two compaction options (with [+T] and without [–T] trampling) on soil loss and teff yields in a split-split plot arrangement. Sediment concentration ranged from 0.01 to 5.37 g L^?1 (mean, 0.25 g L^?1) in our study. Accordingly, the estimated total (August–October) soil loss ranged from 0.2 to 0.5 t ha^–1 (mean, 0.3 t ha^–1). The sediment concentration and total soil loss were significantly influenced (P < 0.05) by tillage, planting methods, and trampling only in the third monitoring year. RT reduced soil loss by 19% relative to that of CT, whereas RP resulted in a 13% reduction in soil loss over BP. The ?T plots showed a 15% reduction in soil loss as compared to + T plots. Results revealed significant increase in soil total carbon and nitrogen in RT and –T. Less soil loss and greater teff grain yield were obtained in plots with improved agronomic practices (RT and RP) compared to conventional ones (CT and BP). Based on our findings we conclude that the use of RT, RP, and –T practices can effectively minimize soil loss without any crop yield penalty.     

Associations between soil texture,soil water characteristics and earthworm populations in grassland

Abstract

The aim of the present study was to investigate the relationships between soil physical characteristics and earthworms in a regional-scale field study in Denmark. The earthworm populations along within-field gradients in soil texture were quantified at five field sites, representing dominant soil types of Denmark. Eleven earthworm species were found, but populations were mainly dominated by Aporrectodea tuberculata and A. longa. Despite considerable variation in soil parameters across the five study sites the results suggest that the biomass of anecic worms (or A. longa as a species) was not causally associated with the soil parameters studied. This indicates that there must be other causal factors associated with the abundance (and composition) of anecic worms that are not among the soil texture and structure parameters studied. On the other hand, soil texture (Coarse sand) was associated with the abundance of the dominant endogeic species, A. tuberculata, but not endogeic worms in general. It was hypothesized that anecic and endogeic earthworms might respond to local soil water characteristics rather than soil texture, but this hypothesis could not be confirmed with the present data.     

Burrowing ability of the earthworm Aporrectodea longa limited by soil compaction and water potential

Summary Adult earthworms (Aporrectodea longa) were maintained for 199 days in soil columns (h=30 cm; ø=10 cm) where the water potential ranged from -7 to-65 kPa and compaction from 50 to 350 kPa. The weight of casts on the soil surface was measured at the end of two periods of activity (spring and autumn). Cast production increased with bulk density, but the activity of earthworms was limited both by the mechanical strength of the soil and by decreasing water potential. The results obtained in the laboratory conditions of this study were consistent with field observations on casting and burrowing activities. The effects of water potential and soil compaction on these activities were estimated.     

Using arbuscular mycorrhiza to reduce the stressful effects of soil compaction on corn (Zea mays L.) growth

Soil compaction is of great importance in agriculture, because its high levels may adversely affect plant growth and the environment. Since mechanical methods are not very efficient and economical, using biological methods to alleviate the stress of soil compaction on plant growth may be beneficial. The objectives of this study were to: (1) evaluate the effects of soil compaction on corn (Zea mays L.) growth, and (2) test the hypothesis that applying arbuscular mycorrhiza (AM) with different origins can partially or completely overcome the stressful effects of soil compaction on corn growth under unsterilized and sterilized conditions. Corn was planted in unsterilized and sterilized compacted soils, while treated with three species of AM including, Iranian Glomus mosseae, Iranian Glomus etunicatum, and Canadian Glomus mosseae, received from GINCO (Glomales in vitro Collection), Canada. Plant growth variables and soil resistance parameters were determined. AM significantly increased root fresh (maximum of 94% increase) and dry (maximum of 100% increase) weights in the compacted soil. AM with different origins may improve corn growth in compacted soils, though its effectiveness is related to the level of compaction and also to the interaction with other soil microorganisms.     

Quantitative image analysis of earthworm-mediated soil displacement

The way soil is disrupted and deformed by earthworm movement is hard to quantify non-destructively. Two anecic earthworm species, Aporrectodea longa (Ude) and Lumbricus terrestris L., were compared in their effect on the soil around them as they burrow. Image analysis (particle image velocimetry, PIV) was used successfully to quantify the distance and direction of soil particle displacement by earthworm locomotion giving a unique insight into their effect on the soil structure development. The data collected from both species using PIV show a decline in soil displacement at increasing distance from the earthworm’s body. The quantity of soil being displaced was more to the sides of the earthworms (radially) than in front of the prostomium (axially). Also, L. terrestris displaced more soil than A. longa both axially and radially. The findings from this study suggest that PIV image analysis is a viable tool for examining soil displacement by earthworms and the method used has the potential to be applied to other soil organisms.     

Trampling effects on coastal dune vegetation in the parker river national wildlife refuge,Massachusetts, USA

Long-term human trampling on coastal dune vegetation was analysed using eight 100 × 100 m study areas ranging in trampling intensity from little or no past trampling pressure to severe trampling pressure. All trampling levels significantly reduced species diversity. Total vegetation cover was significantly reduced only in areas with severe and heavy trampling pressure. Where long-term moderate trampling did not affect total cover, it appears to have favoured Ammophila breviligulata over other more sensitive species. The data suggest that long-term trampling pressure has caused a shift in the horizontal pattern of vegetation, i.e. expanding the width of the foredune plant community, while restricting the interdune community to a narrow strip at the base of the backdune ridge.     

Changes of pore morphology, infiltration and earthworm community in a loamy soil under different agricultural managements

Earthworm activity produces changes at different scales of soil porosity, including the mesoporosity (between 1.000 and 30 μm eq. dia.) where both water retention and near-saturated infiltration take place. At this scale, the structural changes are poorly described in temperate agricultural systems, so we do not yet fully understand how these changes occur. The present study was conducted to determine the relationships between the morphology of the mesopores, which is mainly affected by earthworm activity, and the hydrodynamic behaviour (near-saturated infiltration) of topsoil under different agricultural managements inducing a large range of earthworm populations.Investigations were carried out at the soil surface in three fields under different management practices giving rise to three different earthworm populations: a continuous maize field where pig slurry was applied, a rye-grass/maize rotation (3/1 year, respectively) also with pig slurry, and an old pasture sown with white clover and rye-grass.Pore space was quantified using a morphological approach and 2D image analysis. Undisturbed soil samples were impregnated with polyester resin containing fluorescent pigment. The images were taken under UV light, yielding a spatial resolution of 42 μm pixel⁻¹. Pores were classified according to their size (which is a function of their area) and their shape. Hydraulic conductivity K(h) was measured using a disc infiltrometer at four water potentials: −0.05, −0.2, −0.6, and −1.5 kPa. The abundance and ecological categories groups of earthworms were also investigated.Continuous soil tillage causes a decrease in both abundance and functional diversity (cf. maize compared with old pasture) when soil tillage every 4 years causes only a decrease in abundance (cf. rotation compared with old pasture). There were no relationships between total porosity and effective porosity at h=−0.05 kPa. Image analysis was useful in distinguishing the functional difference between the three managements. Fewer roots and anecic earthworms resulted in fewer effective tubular voids under maize. There were fewer packing voids in the old pasture due to cattle trampling. Greater hydraulic conductivity in the pasture phase of rotation may arise from a greater functional diversity than in the maize and absence of cattle trampling compared with the pasture. We point to some significant differences between the three types of agricultural management.A better understanding is required of the influence of agricultural management systems on pore morphology. This study provides a new methodology in which we consider the earthworm activity as well as community in order to assess the effects of agricultural management on soil structure and water movement.     

Impact of five different tillage systems on soil organic carbon content and the density,biomass, and community composition of earthworms after a ten year period

To assess the impact of different types of soil tillage on the density, biomass, and community composition of earthworms, a long-term field study was performed in which soils were tilled in different ways for ten years. This study included five different types of tillage: (i) plough, (ii) grubber, (iii) disc harrow, (iv) mulch sowing, and (v) direct sowing. At the end of the experiment the earthworm density, biomass, and community composition, and the SOC (soil organic carbon) content were determined. The results show that density, biomass, and community composition of earthworm populations varied in relation to the type of soil tillage used. The density of anecic earthworm species decreased when soils were managed by conventional ploughing, relative to reduced tillage practices, whereas conversely the density of endogeic species increased. Additionally, the varying types of soil tillage influenced the abundance and biomass of different earthworm species in different ways. The density of Aporrectodea caliginosa was positively influenced by ploughing, whereas Aporrectodea longa, Lumbricus castaneus, and Satchellius mammalis showed a positive relationship to the grubber and Allolobophora chlorotica to direct sowing. We attribute these changes to modifications in the vertical distribution of SOC and varying potentials for mechanical damage of earthworms by tillage. A decrease in tillage intensity modified the vertical SOC distribution in the topsoil and consequently revealed positive effects on earthworm biodiversity, thus sustaining soil functioning.