Soil Ripping Research Articles

A global review on arid zone restoration: approaches and challenges

Arid environments have become degraded in recent times through human activity highlighting the need for restoration works to reverse this trend. One of the most common forms of restoration works is revegetation. However, revegetation is difficult in the arid zone due to a combination of environmental factors such as low moisture and extreme temperatures, as well as financial and administrative factors. In this review, we investigated the literature describing various methods available for arid revegetation, and assess their utility for revegetation activities. Each of the methods investigated were found to have potential advantages and disadvantages, though some general trends were observed. Two main planting methods were identified, “out‐planting” and “direct seeding.” Which of these methods to use depends on the conditions of the project being undertaken. Out‐planting appeared to be the most suited approach to smaller scale projects with higher budget availability, whereas direct seeding was more suited to large scale, lower budget projects. Weed control prior to planting was identified as being critical for success in most works, whereas soil ripping was beneficial for direct seeding projects. Among the soil amendments investigated, water‐holding gels were most likely to be beneficial, whereas fertilizers were riskier due to their potential to reduce drought tolerance and increase weed invasion. Microbial inoculation with mycorrhiza showed high potential to improve plant performance but may be held back by the lack of suitable commercial sources. Newer seed technologies, such as synthetic seed coats and pellets, show promise, but this issue still requires further research and development.

Carbon‐based pelleting, soil ripping and herbicide application can be used to overcome plant recruitment barriers in Grey Stinkwood (Jacksonia furcellata)

SummarySeed‐based restoration efforts frequently experience limited success due to competition from invasive plant species and poor soil conditions. We aimed to alleviate these plant recruitment barriers through a combination of carbon‐based seed enhancement technologies and commonly applied restoration management practices. Compared to non‐pelleted (control) seeds, we tested seven seed enhancement technologies on Grey Stinkwood (Jacksonia furcellata), a perennial shrub common within the Banksia Woodlands of Western Australia, which included extruded pellets, coating and coins (a novel extrusion method), incorporated with activated carbon or biochar. We tested five management practices including combinations of herbicide and soil ripping at two locations (post‐sand mine and Post‐pine plantation). At the Post‐pine site, coins incorporating biochar had the highest overall mean emergence (53%), and at the Post‐mine site, extruded pellets containing activated carbon had the highest mean emergence (58%). In comparison, emergence was significantly lower from the non‐pelleted seeds (44% and 45% respectively). Survival at the Post‐mine site was also higher from biochar coins (31%) compared to the non‐pelleted seeds (22%), and highest in plots with herbicide application followed by soil ripping (36%), compared to the control, in which no management practice was applied (16%). At the Post‐pine site, survival was poor (<10%), and seed treatment and management practice did not significantly affect seedling survival. Using carbon‐based seed treatments and management practices, such as herbicide application followed by soil ripping, may help to overcome seedling emergence bottlenecks in direct seeding programmes. However, further examination into seedling survival is required, particularly within highly degraded settings, before seed enhancement technologies are used in large‐scale seeding programmes.

Effect of land preparation methods on restoration success of degraded oak forest ecosystems

Estimation of the success of ecosystem restoration through different methods is essential of planning restoration projects, especially nowadays when the world community has declared the target for an effective restoration of 25% of degraded ecosystems in the next years. In the present study, we intro­duce the results of the application of two land preparation methods – soil ripping and land terracing - on ecosystem restoration success twenty years after restoration actions. The study concerns two reforested areas with the species Quercus pubescens, a deciduous oak species. In both reforested areas an estimation of the ecological conditions was carried out as well as stand growth and volume data, based on the following field measurements: soil fertility data, vegetation analysis, tree morphological characteristics, and tree vol­umetric characteristics. The analysis of the results showed that the land preparation method “soil ripping”, greatly improved all the studied ecosystem parameters as well as oak stand characteristics, comparing to the “terracing” method. More specifically, it improved the physical and chemical properties of the soils, the coverage and the composition of flora species, and enhanced the existence of more woody species. It privi­leged the growth of Quercus pubescens trees contributing to a higher stand volume.

Weed community evolution under diversification managements in a new planted organic apricot orchard

Biodiversity conservation and promotion of agroecology (including organic farming) are focused as priorities by European Commission, as reported in the Biodiversity and Farm to Fork Strategies. In this context, agricultural practices can be considered for their contribution to harnessing ecosystem services to sustain agricultural production, while minimising negative environmental effects. Among these, redesigning agricultural systems through diversification practices can be very promising by exploiting the natural biodiversity in space and time, and connecting farms with natural environments. Being an interface between above and belowground, spontaneous plants (i.e., the weeds) are considered valuable agroecosystem components that, if properly managed, provide ecosystem functions and services, and holding key role for biodiversity conservation within agroecosystems. In this study, we explored the response of spontaneous flora communities in terms of abundance, diversity, and functional traits to different soil and agrobiodiversity management strategies (soil ripping vs reduced tillage at orchard planting, soil tillage vs minimum/no tillage in orchard floor management over 5 years) and cover crop introduction in a new planted organic apricot orchard. Our results showed the strong impact of the planting operation on pre-existing spontaneous flora community structure but a resilient trajectory in the following years in recovering the previous community traits distribution. Interannual variability was the main factor affecting communities. However, the reduced tillage condition showed a conservative trend of the incidence of perennials in the community, while the introduction of cover crops generally decreased species richness and abundance. Understanding the mechanisms by which soil management practices affect weed communities can guide the designing of sustainable agroecosystems, preserving their functionality and biodiversity over time.

Going Conservative or Conventional? Investigating Farm Management Strategies in between Economic and Environmental Sustainability in Southern Italy

The European “Green Deal” strategy is aimed at making Europe the first climate-neutral continent by 2050 through integrated actions relying on healthier agricultural systems grounded in (environmental and economic) sustainable practices, including soil carbon management and biodiversity enhancement. In this vein, the present study contrasts the economic-environmental performances of conventional (deep tillage) and conservative (no-tillage and soil ripping) practices for two varieties of durum wheat (Triticum turgidum spp. durum), namely a modern (Anco Marzio) and an ancient landrace (Saragolla Lucana) variety in the Basilicata region (Southern Italy). Field and laboratory analysis (granulometry, mineralogy, and geochemistry) as well as satellite data (RapidEye) were used to characterize the soil and vegetation patterns. The empirical results indicate a higher biomass production and vegetative potential together with higher grain yields in soils managed with conventional deep tillage compared with soil managed with conservative practices. Similarly, the modern wheat variety exhibited better performance with respect to the old landrace. The soils managed with conventional practices had a distribution of exchangeable macro-nutrients characterized by a reduction in Ca+ and an increase in Mg2+ and K+ between pre-sowing and post-harvesting. Such a distribution was also genotype-dependent, with a higher variability for Saragolla Lucana than Anco Marzio, showing a diverging adsorption of macro-elements between the modern and ancient landrace varieties.

TO THE ISSUE OF CREATING MODELS OF PRECISE SOIL COMPACTION DETECTION FOR PRODUCTION SCALE USE

Typical approaches to test soil compaction, along with technical possibilities are assessed with a purpose of scaling best approaches in production. Modern soil works related technologies, GPS accuracy aspirations for precision agriculture are addressed. Two most popular technologies in Ukraine to measure soil compaction are «The Top Soil Mapper» and «CTS-1000», although they function differently, most commonly are used independently. Simple mathematical calculations bringing together timing needed to gather reliable data to form variable depth soil ripping machinery and scale of Ukrainian production demonstrate irrelevance of applying typical mechanical methods. At the same time, sensor technologies have their own limitations. Thus, this article introduces the benefits of the mutual use of «The Top Soil Mapper» and «CTS-1000». Soil compaction models presented in the article include: 1. Smallest possible grid approach of soil compaction data presentation and interpolation for further use to create variable depth soil works assignment proves to provide a very good set of results and can be used as a standard, but at the same time it consumes so much time that production scaling is not achievable. As an example we can state that a grower with 1000 fields would need about 3 years to test all the fields, when production needs are to test all the fields within two or three months (depending on weather and crop rotation). 2. Small, midsize and large grid approach of soil compaction data presentation and interpolation for further use to create variable depth soil works assignment proves to vary from being still time inefficient to having gaps to gather enough data as main approach of any data processing for further interpolation makes an unproven assumption that the sample location is a center of a zone. In case with a smallest possible grid, that difference would be minimal, with a larger distance difference can be significant. 3. Depending on detecting zones to test compaction based other parameters does not prove to work and lacks scientific background. Thus it has been suggested to combine use of «Top Soil Mapper» and «CTS-1000».

Best served deep: The seedbank from salvaged topsoil underscores the role of the dispersal filter in restoration practice

AbstractQuestionsGlobally, ecological restoration is required to restore degraded landscapes and to contribute to biodiversity conservation. Ecological theory suggests that manipulating dispersal, abiotic and biotic filters limiting plant re‐establishment will improve restoration outcomes. Here, we manipulated spread depth of soil containing a salvaged soil seedbank (dispersal filter), soil compaction (abiotic filter) and herbivore grazing (biotic filter) in a topsoil transfer experiment to test their effects on restoration success.LocationBanksiawoodland of the Swan Coastal Plain, Western Australia.MethodsTopsoil (upper ~7 cm) with its seedbank was removed from a donor site (20 ha) of recently cleared native vegetation and transferred to six recipient restoration sites (16 ha). Deep (10 cm thick) and shallow (5 cm thick) layers of topsoil were applied in a fully factorial experiment, with and without soil ripping and fencing, respectively. We analysed emergence, survival and functional types (alien/native, life form, fire response) of all vascular plant species for two consecutive years after topsoil transfer.ResultsThe most successful restoration treatment was deep topsoil with a mean density of 14.3 m−2native perennial germinants in year one and 7.3 m−2in year two. Application of deep topsoil increased native seedling emergence by 34% and decreased weed density by 21% compared with shallow topsoil. Overall seedling survival across the two‐year period was unaffected by filter treatments (range 0.6%–5%). After two years, the resulting plant community was 6%–38% weed species and of native perennial species, 12%–48% were capable of resprouting.ConclusionsManipulation of the dispersal filter alone, that is deep topsoil application, can lead to near‐equivalent native species number emerging on restoration sites as compared to pre‐cleared woodland. However, more research is required to test additional restoration tools to improve survival of biodiverse plant communities. For example, targeted herbicide application coupled with soil ripping to improve weed management and native seedling establishment.

Evaluating support for rangeland‐restoration practices by rural Somalis: an unlikely win‐win for local livelihoods and hirola antelope?

AbstractIn developing countries, governments often lack the authority and resources to implement conservation outside of protected areas. In such situations, the integration of conservation with local livelihoods is crucial to species recovery and reintroduction efforts. The hirola Beatragus hunteri is the world's most endangered antelope, with a population of <500 individuals that is restricted to <5% of its historical geographic range on the Kenya–Somali border. Long‐term hirola declines have been attributed to a combination of disease and rangeland degradation. Tree encroachment—driven by some combination of extirpation of elephants, overgrazing by livestock, and perhaps fire suppression—is at least partly responsible for habitat loss and the decline of contemporary populations. Through interviews in local communities across the hirola's current range, we identified socially acceptable strategies for habitat restoration and hirola recovery. We used classification and regression trees, conditional inference trees, and generalized linear models to identify sociodemographic predictors of support for range‐restoration strategies. Locals supported efforts to conserve elephants (which kill trees and thus facilitate grass growth), seed and fertilize grass, and remove trees, but were opposed to livestock reduction. Locals were ambivalent toward controlled burns and soil ripping (a practice through which soil is broken up to prevent compaction). Livestock ownership and years of residency were key predictors of locals’ perceptions toward rangeland‐restoration practices. Locals owning few livestock were more supportive of elephant conservation, and seeding and fertilization of grass, while longer term residents were more supportive of livestock reduction but were less supportive of elephant conservation. Ultimately, wildlife conservation outside protected areas requires long‐term, community‐based efforts that are compatible with human livelihoods. We recommend elephant conservation, grass seeding and fertilization, manual tree removal and resting range from livestock both to enhance the potential for hirola recovery and to build positive rapport with local communities in the geographic range of this critically endangered species.

The carbon balance of a Scots pine forest following severe windthrow: Comparison of reforestation techniques

Even though windthrows are the main disturbance type in European forests, their impact on forest carbon balance is generally understudied. In order to close this knowledge gap, we took advantage of a tornado event, which occurred in July 2012 in Trzebciny Forest District in northwest Poland. The main objective of this study was to determine how two completely different reforestation techniques in windthrow areas impact net ecosystem production (NEP) of this Scots pine forest ecosystem under similar meteorological conditions. The two techniques were: conventional (“Tlen I” site): uprooted stumps pulled out and removed from the site followed by ploughing, and non-conventional (“Tlen II” site): all stumps left on the site to decompose with no ploughing. Therefore, we measured carbon dioxide (CO2) fluxes using the eddy covariance (EC) technique for four continuous years. Our results indicate that both sites became significant carbon (C) sources after the windthrow (up to 575 ± 56 g C m−2 y-1 in the first year, Tlen I). However, the Tlen I (conventional technique) lost over 30% less C than Tlen II during the 2015–2016 observation period. In contrast to existing knowledge, ploughing as done at Tlen I, did not substantially increase CO2 emission, as compared to local soil ripping (non-conventional technique). The decrease in net C emission, estimated on the basis of linear model parameters, was almost five times greater at Tlen I than at Tlen II. We thus hypothesize that the annual NEP at conventionally reforested windthrow site will reach C neutrality (NEP = 0) six years after windthrow at most, while at the non-conventionally managed area it will probably take ca. 18 years. So far then, the currently widely applied conventional reforestation technique in wind-disturbed Polish forest appeared to be more effective in decreasing C losses than a technique that leaves stumps to decompose and avoids ploughing.

Effects of post-fire management practices and slope-aspect on medium-term Spanish black pine regeneration: implications of using a direct seeding strategy in burnt areas

The natural regeneration of non-serotinous Spanish black pine (Pinus nigra Arn. ssp. salzmannii) is known to be null or limited after severe wildfires. However, it remains challenging to define efficient management strategies within the burnt area, which can help to increase the post-fire resilience of this species. We conducted a direct seeding experiment during 2011–2015 to assess the effect of different post-fire management treatments (control, soil ripping, woodchips, and soil ripping + woodchips) performed in opposite slope-aspects (north- and south-facing) on pine emergence, seed predation, survival, growth, and biomass allocation during the early stages of seedling development (1–5 years) after a severe wildfire. Our results showed that the slope-aspect did not have an important effect in both the seedling emergence and seed predation rates. In contrast, the influence of slope-aspect was significant as both survival and growth of pine seedlings were reduced at the south-facing slope-aspect compared to the north-facing slope-aspect due to harsher environmental conditions. A variable and reduced impact on seedling emergence and seed predation rates was induced by both soil ripping and woodchips treatments. Overall, post-fire management treatments helped to enhance survival rates during early growth stages, although this effect was short-lasting. This knowledge can be used to define post-fire seeding management strategies oriented to enhance the resilience of severely burnt pine forest stands; therefore, while both the soil ripping and woodchips treatments might not be practices leading to increase their post-fire regeneration, direct seeding at north-facing slope-aspects could be a more appropriate management strategy.

Promoting seedling physiological performance and early establishment in degraded Mediterranean-type ecosystems

Mediterranean climate ecosystems (MCEs) are amongst the most heavily degraded ecosystems worldwide. Restoration efforts are challenged by high vulnerability to extreme drought, which is projected to become more frequent with future climate change. The aim of our study was to determine whether restoration efforts could be enhanced through the individual and combined effects of the site preparation technique of soil ripping and the addition of fertilisers. We tested the effects of ripping and fertiliser (±surfactant) on survival, shoot height, crown health, root biomass and leaf physiology of Eucalyptus gomphocephala seedlings in degraded MCEs in Western Australia. Restoration treatments had a much stronger impact under closed canopy (forest) compared to open canopy (woodland) conditions. In the forest, soil ripping doubled seedling survival and together with fertiliser application enhanced shoot height 2.35-fold relative to control seedlings. Ripping resulted in more favourable leaf water potentials and enhanced stomatal conductance suggesting increased water availability compared to unripped soil. In the woodland, fertilisation improved seedling survival and stimulated shoot height (+45 %) and root biomass (>2-fold). Our results demonstrate that restoration techniques targeting the co-limitation by water and nutrients can greatly increase chances of successful restoration in these types of ecosystems.

English

American chestnut (Castanea dentata Marsh. Borkh.) is a once- dominant hardwood species with the potential to be a valuable restoration tree for use on surface mined lands in the Appalachian region. Coupling soil ripping and plowing and disking with plantings of American and backcrossed chestnuts has resulted in high seedling survival on a reclaimed surface mine site in southeast Ohio. The objective of this study was to evaluate flowering, chestnut bur production (seed), and natural cankers caused by chestnut blight fungus (Cryphonectria parasitica) on three chestnut breeding lines, in three soil tillage treatments after seven field seasons. Pure American (Castanea dentata), and two types of C. dentata × C. mollissima hybrids (BC2F1 and BC3F1) were documented. Reproduction potential was measured via flower production in June. Canker incidence was recorded as necrotic bark lesions with the presence of orange spore bearing structures. When reproduction potential was compared among seed types, there were no differences; all chestnuts trees were flowering and producing chestnut burs after 7 seasons. Soil treatment had no impact on flowering incidence; however, hybrid breeding lines had a mild effect. Canker incidence and presence of flowers were not related statistically. When natural canker incidence was compared, pure American chestnut exhibited the most infection (P < 0.0001). There were also notable treatment effects, plots that applied the deep ripping had greater disease incidence on pure American chestnuts (P < 0.0001). Long-term survival and stand stability will depend on chestnut's tolerance to the blight at an age of fruiting and flowering. Results after seven years suggest that hybrids were exhibiting a decrease in blight incidence and were flowering and producing burs. Employing deep ripping methods to backcrossed American chestnut plantings provide a viable method for hardwood seedling establishment in soils impacted by surface mining.

Spatial heterogeneity of soil CO2 efflux after harvest and prescribed fire in a California mixed conifer forest

Spatial variability is a key factor when quantifying soil CO2 efflux and punctual measurements need to be extended to larger stand, ecosystem, or regional scales. Spatial variation also affects comparisons among ecosystems, as when quantifying effects of disturbances on ecosystem carbon dynamics. However, spatial variability of soil CO2 efflux is still unknown and difficult to predict. We quantified the effects of silvicultural practices (prescribed fire and harvesting) on spatial variability of soil CO2 efflux in a mixed conifer forest from the central Sierra Nevada in California, USA. Soil CO2 efflux was measured using a portable chamber system, on 20–29 locations in four treatment sites: an untreated control, a prescribed fire site (burned in 2002 and 2009) and two clear cut sites harvested in 2010. In one of the harvested sites the soils were mechanically ripped to reduce soil compaction, a common practice done on industrial timber forest lands in the Sierra Nevada. Results showed that disturbance increased spatial variability of soil CO2 efflux. Coefficient of variability increased from an annual average of 32% at the control site to 37% at the burned site, and 49–51% at the harvested sites (without and with soil ripping, respectively), mirroring post-disturbance increases in spatial variability of soil temperature and soil water content. Because of the post-harvest increase in spatial variability, the ability to detect differences became lower, and the number of samples needed to obtain a value representative of the full population mean (within a 10% range) increased by 100%, from 60 to 120 samples. To reduce uncertainty in our soil CO2 efflux treatment estimates, more than 10–15 randomly selected locations per study site were necessary. Spatial variability of soil CO2 efflux at our sites was not affected by distance between measurement locations, was correlated to fine root and litter biomass at the control site, negatively correlated to soil bulk density at the fire site, and un-correlated to soil temperature and water content at all sites. The increase of spatial variability in soil CO2 efflux after disturbance and the requirement for a sufficient number of measurement locations should be considered when quantifying carbon dynamics of disturbed ecosystems, or assessing effects of different forest management practices.

Experimental subsoiling by in-line shallow and deep tines

Conventional soil ripping has high fuel consumption because it involves high draft force and may produce large soil clods. This experiment compares the use of shallow leading tines ahead of the main tine with use of a conventional single-tine ripper. The study showed that attaching a single, shallow leading tine ahead of, and in line with, the main tine and 25–40% shallower in depth gave the greatest significant decrease in specific draft force. This led to a fuel reduction from 13.6 to 11.5 L/ha, or a saving of 15% when ripping a moist loamy sand soil to 330 mm depth. Attaching more than one shallow lead tine ahead of the ripper did not significantly affect specific draft forces, whether the shallow lead tines were in line or offset. Other advantages of using the shallow leading tine ripper over the conventional ripper are: improved soil tilth by significantly decreasing soil clod size; potentially a wider moisture range for ripping the soil (as soil clods are smaller and drier soil increases clod size) thus increasing the time available for the operation; and decreased depreciation of ripping components.

Optimising seed broadcasting and greenstock planting for restoration in the Australian arid zone

Vegetation within some parts of Western Australia has been degraded by resource extraction, and ecological restoration is necessary to prevent erosion and reinstate plant biodiversity. Two restoration approaches, seed broadcasting and planting of seedlings, were tested with plant species (Acacia tetragonophylla F. Muell., Atriplex bunburyana F. Muell. and Solanum orbiculatum Poir.) known to have been dominant prior to mining activities in the World Heritage Area at Shark Bay. For broadcast seeding, soil raking and/or ripping increased seedling emergence, but only after sufficient rainfall. Survival of A. bunburyana seedlings (≤92%) was higher than A. tetragonophylla (≤13%) almost two years after planting and soil ripping partly alleviated soil impedance and resulted in increased seedling survival. Shoot pruning, fertiliser and moisture retaining gel had a reduced or detrimental effect on survival. Seedling survival differed between the three experimental sites, with electrical conductivity being the most noted soil difference between the sites. Restoration in the arid environs of the World Heritage Area at Shark Bay in Western Australia is challenging, but this study shows that seedling establishment is technically feasible and provides methodology useful to other arid restoration projects.

Wind-induced leaning (toppling) in young Pinus radiata plantations in Chile

The toppling of young trees considerablyreduces the value of the first log in Pinus radiata plantations.Although wind is the main cause of toppling, the quality and type of plants,planting techniques, soil fertility and soil preparation may play an importantrole in the susceptibility of the species to toppling. This article analyzesthe influence of ripping and soil type on the probability of P. radiatatoppling after severe windstorms in central south Chile. To this aim, pairs ofsimilar trees with and without toppling were selected in 2001 in six soil typeswith and without soil ripping. Root system differences in toppled versusstraight trees were compared to gain better insight into the causes of thephenomenon. Among all root measurements, the quality of thetap root measured through the Menzies scale was significantly correlated with the probability oftoppling. Trees with a strong, dominant and well-developed tap root (Menziesvalue equal to zero) showed a toppling probability of 0.34 (1 of each 3 treesbeing damaged). At the other extreme, trees with a horizontal tap root or withno tap root (Menzies value equal to 10) showed a toppling probability of 0.72 (i.e.,three of each four trees were damaged). A toppling probability of 0.50 (ordamage observed in one of each two trees) was found for trees with a tap rootdistinctly hooked but functional (Menzies value equal to 4). Ripping reducedthe toppling probability from 0.56 to 0.44 by improving the quality of the taproot consistently across all soil types from Menzies 5.7 to Menzies 2.5. Theworst tap root qualities were found for sandy soils (Menzies equal to 7.0,toppling probability of 0.62), followed by metamorphic soils (Menzies equal to4.5, toppling probability of 0.52). Alluvial, granitic, red clay and volcanicash soils did not differ in tap root quality (Menzies equal to 3.3, topplingprobability of 0.47). In conclusion, the study suggests that all measures favoring a strong, dominant andwell-developed tap root, in the nursery and in the field, are likely to considerablyreduce toppling damage in young P. radiata plantations in Chile

Seedbed preparation influence on morphometric characteristics of perennial grasses of a semi-arid rangeland in Kenya

Semi-arid rangelands in Kenya are an important source of forage for both domestic and wild animals. However, indigenous perennial grasses notably Cenchrus ciliaris (African foxtail grass), Eragrostis superba (Maasai love grass) and Enteropogon macrostachyus (Bush rye grass) are disappearing at an alarming rate. Efforts to re-introduce them through restoration programs have often yielded little success. This can partly be attributed to failure of topsoil to capture and store scarce water to meet germination and plant growth requirements. A study was undertaken in the semi-arid environment of eastern Kenya to determine the effects of land treatment on morphometric characteristics of E. superba, C. ciliaris and E. macrostachyus. Seed viability of the grasses was estimated by germination tests. Land treatments involved soil ripping using a tractor and hand-clearing. Thirty-five plants were randomly selected per sub-plot and tagged for sampling. Morphometric characteristics of the grass species were measured weekly. Aboveground biomass was estimated by harvesting standing biomass three months after establishment. Seed viability tests showed significant differences (p<0.05) among the three grass species. This was attributed to intrinsic properties of the grass seeds such as dormancy and tegumental hardness. Seedling survival, foliage cover, plant height, leaf and tiller numbers, and aboveground biomass were significantly higher in ripped plots than hand-cleared plots. It was concluded that soil disturbance influences plant morphometric characteristics and plays an important role in the success rate of restoration attempts in semi-arid rangelands.

Short‐Term and Long‐Term Effects of Soil Ripping, Seeding, and Fertilization on the Restoration of a Tropical Rangeland

Rangeland degradation is a serious problem in semiarid Africa. Extensive areas of bare, compacted, nutrient‐poor soils limit the productivity and biodiversity of many areas. We conducted a set of restoration experiments in which all eight combinations of soil tilling, fertilization, and seeding with native perennial grasses were carried out in replicated plots. After 6 months, little aboveground biomass was produced in plots without tilling, regardless of seeding or fertilization. Tilling alone tripled plant biomass, mostly of herbaceous forbs and annual grasses. Perennial grasses were essentially limited to plots that were both tilled and seeded. The addition of fertilizer had no significant additional effects. After 7 years, vegetation had declined, but there were still large differences among treatments. After 10 years, one tilled (and seeded) plot had reverted to bare ground, but the other tilled plots still had substantial vegetation. Only one seeded grass (Cenchrus ciliaris) was still a contributor to total cover after 10 years. We suggest that restoration efforts on these soils be directed first to breaking up the surface crust, and second to the addition of desirable seed. A simple ripping trial inspired by this experiment showed considerable promise as a low‐cost restoration technique.

English

The use of SMCRA approved practices for mined land reclamation has resulted in arrested succession throughout many areas of central Appalachia. The combination of heavily compacted soils and the addition of aggressive, often non- native, grasses and forbs creates an environment characterized by high soil bulk density and aggressive ground-layer competition. This results in a situation where trees are unable to recruit and thus many lands are unable to return to original forest cover through natural processes of succession. Using the basic principles of the Forestry Reclamation Approach (FRA), we report on two experiments conducted in Ohio: one designed to remediate a 30-yr arrested succession and the other designed to encourage immediate reforestation at the time of reclamation. We conducted these experiments using American chestnut (Castanea dentata) to explore the potential for using these sites as part of the national restoration plan under development by the American Chestnut Foundation (ACF). The first experiment utilized deep soil ripping and a combination of plowing and disking treatments. After three years, the results are clear. Simply planting chestnut into untreated existing habitat is ineffective. Some type of surface treatment to reduce soil bulk density and competition is necessary for seedling establishment. The more significant the disturbance, the better the survival and growth of chestnut. The second experiment utilized loose end-dumping at the time of reclamation. Various methods of chestnut deployment and planting were evaluated including direct seeding and bare-root seedlings. Plantings were done with and without protection from predators in different microsites. While survival of seedlings was greater than seeds, the most noticeable enhancement to survival was the addition of a tree shelter, which nearly doubled the survival rate. In summary, American chestnut appears to thrive on mine land reclamation sites—this may prove to be a useful focal point for restoration of the species while aiding in the reforestation of old and new reclamation sites.

English

In the semiarid West, establishing perennial vegetation is often difficult on newly constructed natural gas drill pads because of harsh site conditions. Southern Wyoming is characterized by low precipitation and sites can have saline and/or sodic soil and steep slopes. Twenty-five combinations of reclamation techniques were evaluated on six Devon Energy Corporation natural gas drill pads in the Washakie Basin near Baggs, Wyoming. Treatments included combinations of soil ripping, fertilizer applications, gypsum or sulfur application, chopped straw or woodchip amendments, imprinting, pitting, mulch, irrigation, fencing and site-specific seed mixes. Grass density was measured ten months after treatment implementation on five drill pads and six weeks after implementation on one drill pad. Irrigation during plant establishment was beneficial on all sites, increasing grass density 92 % on average compared to areas not irrigated. Wood chips, gypsum and fertilizer; and chopped straw, sulfur and fertilizer treatments, both with and without irrigation significantly increased grass establishment on saline-sodic soils. Irrigation and fertilizer, and fertilizer alone produced little to no grass establishment on saline-sodic soils, suggesting some treatment for the saline-sodic condition was necessary for grass establishment. Imprinting significantly increased grass densities on both saline and non-saline soils and on sloped sites by providing protected microclimates for seedling growth. Pitting produced lower grass density than imprinting, and most likely cut through the topsoil and exposed lower quality subsoil material. Straw mulch increased grass density when used in combination with irrigation, but did not increase density when used with other treatments on a site with low salinity and sodicity. On the same site, grass density was 89 % higher on average when treatments did not include fertilizer. At least one reclamation treatment on each site produced grass density of at least 80 % of that found in the adjacent native range. These reclamation techniques can significantly decrease the time required to reach plant re-vegetation requirements.