Reduce Wind Erosion Research Articles

Ecological restoration enhances dryland carbon stock by reducing surface soil carbon loss due to wind erosion

Enhancing terrestrial carbon (C) stock through ecological restoration, one of the prominent approaches for natural climate solutions, is conventionally considered to be achieved through an ecological pathway, i.e., increased plant C uptake. By conducting a comprehensive regional survey of 4279 1 × 1 m2 plots at 517 sites across China's drylands and a 13-y manipulative experiment in a semiarid grassland within the same region, we show that greater soil and ecosystem C stocks in restored than degraded lands result predominantly from decreased surface soil C loss via suppressed wind erosion. This biophysical pathway is always overlooked in model evaluation of land-based C mitigation strategies. Surprisingly, stimulated plant growth plays a minor role in regulating C stocks under ecological restoration. In addition, the overall enhancement of C stocks in the restored lands increases with both initial degradation intensity and restoration duration. At the national scale, the rate of soil C accumulation (7.87 Tg C y-1) due to reduced wind erosion and surface soil C loss under dryland restoration is equal to 38.8% of afforestation and 56.2% of forest protection in China. Incorporating this unique but largely missed biophysical C-conserving mechanism into land surface models will greatly improve global assessments of the potential of land restoration for mitigating climate change.

Carbon Sequestration Characteristics of Typical Sand-Fixing Plantations in the Shiyang River Basin of Northwest China

A predominant management practice to reduce wind erosion in the arid deserts of northwest China is the planting of shrubs. However, the carbon sequestration capacity of these sand-fixing plantations has not received much attention. In this study, the carbon sequestration capacity of six typical sand-fixing plantations (Haloxylon ammodendron (C. A. Mey.) Bunge, Caragana korshinskii Kom., Tamarix ramosissima Ledeb., Calligonum mongolicum Turcz., Artemisia desertorum Spreng. and Hedysarum scoparium Fisch. & C. A. Mey.) in the Shiyang River Basin were compared and analyzed. We evaluated how carbon sequestration may vary among different species, and examined if plantation age or management style (such as the additional construction of sand barriers, enclosure) positively or negatively influenced the carbon storage potential of these plantation ecosystems. Our results showed that all six plantations could store carbon, but plant species is the controlling factor driving carbon stock accumulation in plantations. The actual organic carbon stored beneath 25-year-old T. ramosissima, H. ammodendron, C. korshinskii, H. scoparium, C. mongolicum and A. desertorum plantations was 45.80, 31.80, 20.57, 20.2, 8.24 and1.76 Mg ha−1, respectively. Plantations using a clay–sand barrier had 1.3 times the carbon sequestration capacity of plantations that only used wheat straw and sand barriers. Similarly, enclosed plantations had 1.4 times the carbon storage capacity of unenclosed plantations. Plantation age greatly impacts carbon sequestration capacity. A 25-year-old H. ammodendron plantation has a carbon sequestration capacity three times greater than that of 3-year plantation. We conclude that while afforesting arid areas, H. ammodendron and T. ramosissima should be prioritized, and priority also should be given to using clay–sand barrier and enclosure.

Cover Crop Species Selection, Seeding Rate, and Termination Timing Impacts on Semi-Arid Cotton Production

By improving soil properties, cover crops can reduce wind erosion and sand damage to emerging cotton (Gossypium hirsutum L.) plants. However, on the Texas High Plains, questions regarding cover crop water use and management factors that affect cotton lint yield are common and limit conservation adoption by regional producers. Studies were conducted near Lamesa, TX, USA, in 2017–2020 to evaluate cover crop species selection, seeding rate, and termination timing on cover crop biomass production and cotton yield in conventional and no-tillage systems. The no-till systems included two cover crop species, rye (Secale cereale L.) and wheat (Triticum aestivum L.) and were compared to a conventional tillage system. The cover crops were planted at two seeding rates, 34 and 68 kg ha−1, and each plot was split into two termination timings: optimum, six to eight weeks prior to the planting of cotton, and late, which was two weeks after the optimum termination. Herbage mass was greater in the rye than the wheat cover crop in three of the four years tested, while the 68 kg ha−1 seeding rate was greater than the low seeding rate in only one of four years for both rye and wheat. The later termination timing produced more herbage mass than the optimum in all four years. Treatments did not affect cotton plant populations and had a variable effect on yield. In general, cover crop biomass production did not reduce lint production compared to the conventional system.

Stabilizers based on nanoclay and blast furnace slag to reduce wind erosion of sandy soil green stabilization of sandy soil

Stabilizers based on nanoclay and blast furnace slag to reduce wind erosion of sandy soil green stabilization of sandy soil

First Report of Karelinia caspia (Pall.) Less as a new host of Orobanche cumana Wallr. in Xinjiang, China.

Sunflower broomrape (Orobanche cumana Wallr.) is a holoparasitic plant species which mainly parasitizes a few species of the Asteraceae in the wild and is exclusively found growing on sunflower in agricultural fields (Fernández-Martínez et al. 2015). O. cumana is a serious threat to sunflower production in Xinjiang and Inner Mongolia (Shi et al. 2015). Karelinia caspia (Pall.) Less. (Asteraceae) is an ecologically important plant species occurring across the desert ecosystems of Russia, Central Asia, and northwest China. It plays an important role in reducing wind erosion and desertification (Xu et al. 2018). During the 2018 and 2019 growing seasons, sunflower broomrape was observed parasitizing K. caspia in non-cultivated areas adjacent to sunflower fields near Beitun city (87°51'E, 47°15'N) in Xinjiang, China. Sunflower broomrape plants were identified morphologically as O. cumana according to Pujadas-Salvà and Velasco (2000). The host plants were identified morphologically as K. caspia according to Lin et al (1979). The ribosomal DNA internal transcribed spacer (ITS) and the trnL-F region of the parasite were amplified by PCR using primer pairs ITS1/ITS4 and trnL-FF/trnL-FR, respectively (Taberlet et al. 1991; Anderson et al. 2004). The ITS sequence of the parasite (Accession No. MT795725.1) showed 100% identity (675bp out of 689bp) to that of O. cernua var. cumana (KC811228.1). The trnl-F sequence of the parasite (Accession No. ON843707) showed 98% identity (675 of 689 bp) to O.cernua var. cumana (KT387722.1). Multi-locus phylogenetic analysis of the two sequences showed clustering with sunflower broomrape. The ITS region of the parasite and host was were amplified by PCR using the primer pair ITS1F/ITS4R (Taberlet et al.1991), and the ITS sequences of the host (Accession No. MT791995.1) showed 99.86% identity (728bp of 802bp) to that of K. caspia (LN607483.1). Rhizotron and pot experiments were carried out to assess the parasitic relationship between O. cumana and K. caspia. In the rhizotron experiment, 2-week-old seedlings of K. caspia were inoculated with sterilized 400 O. cumana seeds in a 15-cm petri dish filled with a sponge overlaid with glass fiber filter paper. The parasitic state of O. cumana was observed 9 days after inoculation. In another trial, seeds of K. caspia were sowed in 2-L and 4-L pots containing sand-vermiculite-compost (1:1:1 v:v:v). These pots were artificially inoculated with 50 mg of O. cumana seeds per 1 kg of substrate. After 20 and 70 days, corresponding to the early parasitic and flowering stages, respectively, of O. cumana, K. caspia plants were uprooted from the media and washed carefully. The parasitic relationship was confirmed by the attachment position of the broomrape to the K. caspia root. To our knowledge, this is the first report of O. cumana parasitizing K. caspia in Xinjiang, China. This phenomenon means that sunflower broomrape can raise up seed on a newly recognized host. Weed eradication in and near sunflower fields is a key measure to control sunflower broomrape.

Dynamics of soil wind erosion in the Mu Us sandy land (in northern China) affected by cropland reclamation from 2000 to 2020

In recent decades, the wind speed displayed an obvious declining trend in northern China. Under this background, large amounts of grassland and sandy land have been reclaimed into cropland in the Mu Us Sandy Land (MUSL), and whether cropland reclamation will cause an increase in wind erosion has aroused widespread concern. Additionally, there are two reclamation patterns including croplands reclaimed by herdsmen and enterprises in this round of cropland reclamation, whether the different reclamation patterns will induce differential wind erosion is also a scientific question. These questions have influenced the policy of cropland reclamation. Consequently, the Revised Wind Erosion Equation (RWEQ) validated by field observations was applied to simulate the wind erosion of the MUSL from 2000 to 2020. Furthermore, by simulating the wind erosion modulus (WEM) under different scenarios, the climatic fluctuations and cropland reclamation effects on the WEM were distinguished. The results showed that the WEMs of the MUSL decreased during the simulated period. Moreover, the average annual WEM of croplands reclaimed by herdsmen was higher than that reclaimed by enterprises by 18.49% and 12.85% during the 2015 phase (during 2013 to 2017) and 2020 phase (during 2018 to 2020), respectively. The average WEM of the newly reclaimed croplands (reclaimed after 2013) increased 42% relative to the old croplands (reclaimed before 2013), but compared with the original land use types, the WEM of newly reclaimed cropland decreased by 134.55 and 158.94 t/km2/a (annum) during the 2015 phase and 2020 phase, respectively. During the fallow period of the cropland reclaimed by enterprises, the WEM was two times as high as that during planting, so corresponding measures to reduce wind erosion during fallow should be implemented. This study resolves the question of whether cropland will lead to an increase in wind erosion and provides valuable information for reclamation in the MUSL.

Trade-offs and synergistic relationships in wind erosion in Central Asia over the last 40 years: A Bayesian Network analysis

Wind erosion may have significant effects on both the environment and human activities. Central Asia, a prominently affected region by wind erosion on a global scale, has been the focus of a significant number of studies employing fundamental linear equations to establish causal relationships among the driving factors of wind erosion. However, such approaches neglect the imperative need for comprehensive analysis accounting for the intricate non-linear interactions among multiple factors, thereby potentially leading to distorted assessment outcomes. This study evaluated the multidimensional gradients (temporal, spatial, and vertical) of wind erosion in Central Asia over the last four decades using an enhanced version of the Revised Wind Erosion Equation (RWEQ) model. The Wind Erosion Modulus – Bayesian Network (WIEM-BN) model was developed by incorporating the Wind Erosion Modulus (WIEM) calculated by the RWEQ model as the parent node of the Bayesian Network (BN) and integrating multiple factors that influence the occurrence of wind erosion. The findings revealed a synergistic relationship between precipitation and the Normalized Difference Vegetation Index (NDVI), snowy days, and the Human Influence Index (HII), with trade-off correlations between temperature and precipitation and NDVI and soil moisture. The lowest overall WIEM level in Central Asia was associated with high HII and temperature (10–19 °C) as well as moderate precipitation (180–280 mm) and NDVI (0.18–0.24). Wind erosion in Central Asia varied substantially with Land Use Cover Change (LUCC), with the following drivers receiving precedence: wind speed > windy days > elevation > surface roughness (K') > HII > snowy days. Wind erosion was primarily caused by climate conditions (R = 0.741), with human activities (R = 0.629) acting as a suppressor. This study offered strategies to reduce wind erosion by up to 647.06 t km2 yr−1 in Central Asia, including a greater emphasis on ecological conservation programs and increased plant cover.

Effects of conservation practices on global wind erosion control: Evidence from experimental data

AbstractWind erosion represents one of the major land degradation forms that significantly threatens sustainable development across the globe. A series of conservation practices have been widely developed and tested in order to effectively reduce wind erosion rates in non‐irrigated dry and semi‐dry lands. However, a comprehensive investigation regarding the efficacy of conservation practices and potential impacting factors on erosion control at the global scale has not been undertaken. In this study, a synthesis was conducted, based on data from global experimental plots, to comprehensively examine the efficacy of varying conservation practices, and their effectiveness at reducing erosion, in different geographical regions, under varying climatic conditions, and with different soil properties. The results showed that conservation practices were able to reduce wind erosion rates by over 52% globally. Straw use and soil stabilizer were the most effective measures in wind erosion control, which could reduce erosion rates by over 70%. Wind erosion control efficacy of conservation practices differed among climatic zones, continents, and countries. Notably, the lowest efficacy was observed in dry climatic zones. Erosion control efficacy highly depended on climatic conditions, such as mean annual precipitation (MAP), mean annual temperature (MAT), wind speed, and soil properties, such as water content and clay content. We further observed a positive correlation between wind erosion reduction rates and straw mulching rates, suggesting a straw mulching rate of at least 40% was necessary in order to reach a potential erosion reduction rate of 70%. To sum up, this study illustrates that the overall efficacy of conservation practices in wind erosion control is highly effective at the global scale, but the specific effects vary among different regions, and depend on conservation practice type, climatic condition, and soil property. The lower erosion reduction rate of dry regions at high erosion risk suggests the high erosion control pressure, and more effective measures should be considered and developed. The results of this study are, importantly, complementary to existing wind erosion control guidelines.

Great Green Walls: Hype, Myth, and Science

Visions of planting walls of trees to block the expansion of the desert have long been promoted but never realized. The green wall myth persists today even though it is premised on outdated understandings of desertification. We review the history of the idea of green walls and focus on two sets of contemporary initiatives to assess their outcomes: peri-Saharan programs (Algeria's Green Dam and Great Green Wall in sub-Saharan Africa) and China's Three Norths Shelterbelt Program. This review reveals a mixed record of technical success with low rates of the establishment of monocultures of fast-growing trees vulnerable to disease. While there is evidence for reduced wind erosion in some areas, afforestation is also associated with reduced soil moisture and lowering of water tables. Social impacts include increased water scarcity for people and livestock in some cases, and resource enclosures that particularly work against pastoralist livelihoods.

New non-ureolytic heterotrophic microbial induced carbonate precipitation for suppression of sand dune wind erosion

The detrimental effects of sand storms on agriculture, human health, transportation network, and infrastructures pose serious threats in many countries worldwide. Hence, wind erosion is considered a global challenge. An environmental-friendly method to suppress wind erosion is to employ microbially induced carbonate precipitation (MICP). However, the by-products of ureolysis-based MICP, such as ammonia, are not favorable when produced in large volumes. This study introduces two calcium formate-bacteria compositions for non-ureolytic MICP and comprehensively compares their performance with two calcium acetate-bacteria compositions, all of which do not produce ammonia. The considered bacteria are Bacillus subtilis and Bacillus amyloliquefaciens. First, the optimized values of factors controlling CaCO3 production were determined. Then, wind tunnel tests were performed on sand dune samples treated with the optimized compositions, where wind erosion resistance, threshold detachment velocity, and sand bombardment resistance were measured. An optical microscope, scanning electron microscope (SEM), and X-ray diffraction analysis were employed to evaluate the CaCO3 polymorph. Calcium formate-based compositions performed much better than the acetate-based compositions in producing CaCO3. Moreover, B. subtilis produced more CaCO3 than B. amyloliquefaciens. SEM micrographs clearly illustrated precipitation-induced active and inactive bounds and imprints of bacteria on CaCO3. All compositions considerably reduced wind erosion.

Root biomechanical features and wind erosion resistance of three native leguminous psammophytes for coastal dune restoration

Taiwan is a subtropical mountainous island with fragile geological conditions and about 1566 km of coastline. Monsoon usually bring severe coastal erosion and dust storms. Canavalia lineata, Canavalia rosea and Vigna marina, three native pioneer leguminous psammophytes occurring on coastal sand dune areas, play important roles in reducing wind erosion in coastal regions. Nonetheless, its root biomechanical properties and wind erosion resistance are still unexplored. In this study, the root biomechanical properties of these plants were inspected using uprooting and tensile tests. Wind erosion resistance was estimated by wind tunnel tests. Our results showed that the growth charactersitics of C. lineata are superior than those of C. rosea and V. marina. Furthermore, the root pullout force of C. lineata (0.36 ± 0.04 kN) and C. rosea (0.36 ± 0.05 kN) are remarkably higher than that of V. marina (0.22 ± 0.02 kN). Root tensile strength of C. rosea (291.24 ± 11.89 MPa) plants is significantly greater than those of C. lineata (231.33 ± 9.47 MPa) and V. marina (95.78 ± 8.83 MPa) plants. Moreover, wind tunnel tests show that C. lineata has superior wind erosion resistance than C. rosea and V. marina. Altogether, these results clearly demonstrate that the priority species order for coastal dune restoration is: C. lineata > C. rosea > V. marina. These results contribute important strategy for ecological engineering of coastal management in sand dune areas.

Land Suitability and Characterization Study of Soils, Natural Vegetation Cover in Wahat Elnukhila area, Northern Darfur State, Sudan

This study was conducted in the Wahat Elnukhila area, about 600 km northeast of El-fashier town, northern Darfur State, to produce broad–base data on the geographical distribution of soils, characterization of soils using some soil indicators (ECe, pH and SAR), explore the natural land cover and evaluate the soil suitability for agricultural activities in the study area. The study area covers (20000 feddans). This research was based on the data and information extracted from the soil survey, remote sensed landsat, Enhanced Thematic Mapper (ETM+) images dated 2018, in addition to field observation aided by GPS receivers and geographic information system were used to generate soil map in the study area. By using the American soil classification system (FAO, 1990 and 2006) study area may be classified into three units, the total area of the three units and natural vegetation cover decreased in the following order: unit1 (12734 feddans) > unit 2 (3994 feddans) > unit 3 (3272 feddans), green covers as a result of the availability of quantities of ground and surface water, which distinguishes it from the rest of the surrounding desert lands. The predominant vegetation cover is Imperata cylindrica (halfa), Tamarix (Tarfa), phragmites (communist)“ Alboes”, Citrullus Colocynthis (Hanzal), Ischaemum muticum and p. dactylifera (date palm). Regarding soil texture, drainage, soil depth, and fertility status for units 1, unit 2, and unit 3, can be described as follows: sandy to loamy sand, well-drained, shallow and low fertile, coarse texture to moderate, moderately drained, shallow to moderate and low fertile, gravelly surface, moderatly drained, shallow to moderate and very low fertile respectively. Soil analysis reveled that there was high inherent risk of soil salinity and sodicity, especially unit 1. In general, the result showed that there were clear aspects of wind erosion represented as large areas affected by the sand encroachment form of crescent dunes and rocks interspersed with hills and plateaus. Furthermore, soils of the targeted area were formed from the accumulation of creeping and portable aeolian sands. The research site lies in the southeastern part of the border triangle between Sudan, Egypt, Libya and Chad, which is severely affected by wind erosion because the site was bare, open with no wind barriers or shelter belts, also this area falls under the sand moving winds of the Sahara. These are the northerly winds that prevail in Northern Darfur State. Furthermore, the prevalent climatic conditions including high temperature, rainless area and relatively high wind speed are conducive to high wind erosion. The area in danger unless serious measures carried out to reduce wind erosion. The area has very low potential suitability for agriculture. The study area was rich in wild life such as deer, rabbits, birds, many insects and snakes.

Changes in land management practices have reduced wind erosion in the cropping areas of far south-western NSW, Australia

Since the mid-1970s, approximately 250 000 ha of rangelands in semi-arid far south-western NSW, Australia, have been converted to cropping land use, resulting in substantial wind erosion. Wind erosion is of concern because of its adverse impacts on soils, agricultural production, aviation, energy supply, human health and ecosystem function. Over recent decades, multi-faceted extension programs have promoted sustainable land management practices to reduce wind erosion. Repeated biannual paddock surveys were undertaken between 2003 and 2022 to determine (1) the best land management practices (BMPs), that is, those that would reduce erosion while maintaining productivity and profitability, and (2) whether the use of the BMPs changed over time. The BMPs that reduce wind erosion included chemical fallow, standing stubble, and perennial pastures. Between 2003 and 2022, the proportion of sites with BMPs increased from 14% to 75%, and the proportion of sites with wind erosion fell from 23% to 9%. Practices that reduced ground cover and led to frequent erosion have declined, including tilled pasture, tilled stubble and grazed stubble. In drier years, livestock grazing crop stubble exacerbated the erosion hazard. In an attempt to understand where landholders obtain their information for land management practice change, the Western Local Land Services (LLS) conducted a social benchmarking survey in 2020 that indicated that the LLS was the third source of information for practice change after neighbours and other landholders, and stock and station agents. Although the LLS is a source of information, this study could not determine a causal link between LLS programs and practice change. Further research is required to test whether extension programs can reduce the overgrazing of stubble.

Promoting vegetation coverage using fertilization treatments in abandoned farmland in Mongolia

AbstractWe investigated the changes in vegetation responses following fertilization in abandoned farmland in Mongolia. Nitrogen (N), phosphorus (P) and potassium were sprayed alone or in combination on abandoned farmland on a typical steppe in Mongolia, and changes in soil nutrients, species composition and vegetation cover were investigated. Abandoned farmland had lower vegetation cover and soil N and P levels than natural grassland. Phosphorus fertilization significantly affected soil phosphate levels. Nitrogen fertilization in abandoned farmland effectively increased vegetation cover. Moreover, combined N and P fertilization increased plant cover over either element alone, possibly via improved uptake of nitrate ions and the promotion of growth. The effect of increasing cover following fertilization was primarily observed in the genus Artemisia. These results suggest that fertilization of abandoned farmland might not contribute to a return to natural steppe vegetation but rather increase the vegetation cover of annual forbs such as field weeds. Species composition did not appear to be affected by fertilization. This speaks to the difficulty of promoting species regeneration in abandoned farmland using fertilization alone. However, combining fertilization with the introduction of native plant material, e.g., seed sowing, may be beneficial in early restoration treatments, given the promotion of plant growth via fertilization and the importance of reducing wind erosion via the establishment of ground cover.

Effects of Shelterbelt Transformation on Soil Aggregates Characterization and Erodibility in China Black Soil Farmland

Farmland shelterbelts are widely used to reduce wind erosion, maintaining the ecological and food security of the black soil plain region of northeast China. In recent years, the protective effect of shelterbelts has been reduced due to tree degeneration. Efforts have been made to transform the construction of shelterbelts to conserve the stability of soil aggregates and enhance protection against erosion, however, the results are not well understood. To evaluate the impact of shelterbelt transformation on the stability of farmland soil aggregates and soil erodibility, three transformation modes of shelterbelts were selected, including pure Pinus sylvestris var. mongolica (ZC), pure Picea asperata (YS), and mixed Populus × xiaohei–Pinus sylvestris var.mongolica (ZY), with a degraded Populus × xiaohei shelterbelt (TYC) used as a control. We set up soil sampling points at 0.5H, 1H, 1.5H, 3H, 5H, 7H, and 9H from the shelterbelts and analyzed aggregate composition, mean weight diameter (MWD), geometric mean diameter (GMD), fractal dimension (D), soil erodibility (K-value), and their relationships to soil properties of the 0–10 cm, 10–20 cm and 20–40 cm soil layers and the shelterbelt structure by using dry and wet sieving and equation estimation methods. The results show that dry (d) sieved soil samples from the transformed shelterbelt-protected farmlands are mainly composed of 2–5 mm and >5 mm grain size aggregates; the sum of the two particle sizes ranged from 48.67% to 51.27%, significantly larger than in the degraded shelterbelts (15.37%), decreasing with increasing distance from the shelterbelts. The effect is most obvious in the 0–10 cm soil layer. Wet (w) sieved soil samples are all dominated by <0.25 mm and 0.25–0.5 mm grain size aggregates; the sum of the two particle sizes ranged from 78.25% to 80.82%, which do not vary significantly with the mode of shelterbelts. The dMWD and dGMD show significantly higher mean values in samples from transformed shelterbelt-protected farmland than in soil from degraded shelterbelt-protected farmland; their magnitudes differ depending on the transformation mode, showing a pattern of ZC > ZY > YS and decreasing with increasing distance from shelterbelts, while the opposite is true for D and K. The difference between wMWD and wGMD for different shelterbelts protected farmland is not significant and is significantly lower than that between dMWD and dGMD. Clay and silt content was highly significantly positively correlated with aggregates dMWD and dGMD, weakly positively correlated with wMWD, wGMD and wD, and highly significantly negatively correlated with dD and K values. This shows that particle composition parameters can be used to reflect the sensitivity of agricultural soils to wind erosion. Farmland shelterbelt porosity is the main factor driving changes in soil aggregates stability, soil erodibility, and other soil properties. The transformation of degraded farmland shelterbelts can decrease the porosity and reduce wind speed, resulting in improved stability and erosion resistance of the farmland soil aggregates by increasing the clay content of the farmland soils. These results are useful in renovating degraded shelterbelts, providing novel insights into how to regulate the stability of soil aggregates and soil erodibility characteristics at the shelterbelt network scale.

Agroforestry Systems for Soil Health Improvement and Maintenance

Agroforestry integrates woody perennials with arable crops, livestock, or fodder in the same piece of land, promoting the more efficient utilization of resources as compared to monocropping via the structural and functional diversification of components. This integration of trees provides various soil-related ecological services such as fertility enhancements and improvements in soil physical, biological, and chemical properties, along with food, wood, and fodder. By providing a particular habitat, refugia for epigenic organisms, microclimate heterogeneity, buffering action, soil moisture, and humidity, agroforestry can enhance biodiversity more than monocropping. Various studies confirmed the internal restoration potential of agroforestry. Agroforestry reduces runoff, intercepts rainfall, and binds soil particles together, helping in erosion control. This trade-off between various non-cash ecological services and crop production is not a serious constraint in the integration of trees on the farmland and also provides other important co-benefits for practitioners. Tree-based systems increase livelihoods, yields, and resilience in agriculture, thereby ensuring nutrition and food security. Agroforestry can be a cost-effective and climate-smart farming practice, which will help to cope with the climate-related extremities of dryland areas cultivated by smallholders through diversifying food, improving and protecting soil, and reducing wind erosion. This review highlighted the role of agroforestry in soil improvements, microclimate amelioration, and improvements in productivity through agroforestry, particularly in semi-arid and degraded areas under careful consideration of management practices.

Reducing Wind Erosion through Agroforestry: A Case Study Using Large Eddy Simulations

Wind erosion is seen as one of the main risks for modern agriculture in dry and sandy regions. Shelterbelts and agroforestry systems are known for their ability to reduce wind speed and, consequently, wind erosion. The current study considers temperate alley cropping agroforestry systems, where multiple tree strips (shelterbelts) are interleaved with either annual rotating crops or perennial grassland. The aim was to quantify the potential wind erosion reduction by alley cropping agroforestry systems and the effect of design decisions for a case study in Germany. By combining wind measurements and Large Eddy Simulations, the wind speed and potential wind erosion inside an agroforestry system were estimated. Our model simulations result in an average reduction in wind speed between 17% and 67%, and a reduction of average potential wind erosion between 24% and 97%. The most optimal reduction of the average potential wind erosion was larger than 92% for tree strips orientated perpendicular to the main wind direction, whereas for a diagonal orientation of the tree strips to the main wind direction we found an average reduction of 86%. Parallel orientated tree strips reduce wind erosion on average by less than 35%. Tree strips planted with ≤48 m distance provide a strong and constant reduction of wind erosion, even for tree strips of 2 m height the average reduction was 86%, when the tree strips were orientated optimal to the dominant wind direction. Our model simulations showed that alley cropping agroforestry systems in a temperate climate have a large potential to reduce wind erosion by more than 80% when the system is well-designed and managed.

Accounting for land use in an analysis of the spatial and temporal characteristics of ecosystem services supply and demand in a desert steppe of Inner Mongolia, China

Assessing the relationships between ecosystem services supply and demand is crucial to support sustainable planning and human well-being. In the present study, we analyzed the ecosystem services supply and demand, synergies and trade-offs among services, as well as the spatial relationships between supply and demand, for four services in a desert steppe of Inner Mongolia. In terms of the balance between supply and demand, the grass production and carbon stock supply exceeded the demand, whereas the demand of water yield and windbreak and sand fixation services surpassed the supply. The degree of demand in windbreak and sand fixation service was met increased from 14.7% in 2000 to 20.6% in 2017, versus a decrease from 18.0% to 8.2% in water yield. The spatial distributions of the water yield and carbon stock demand were similar, and there was a significant synergy between them. The grass production supply and demand were not spatially matched, with higher supply in the eastern part of the study area and higher demand in the western part. Areas with high demand for the windbreak and sand fixation service also had a high supply. The water supply and demand in the low-coverage grassland were relatively balanced, and the deficiency of carbon stock supply was mainly found in construction land. In summary, for the sustainable development of animal husbandry and to reduce wind erosion, each county should establish an appropriate livestock density standard based on local constraints. Furthermore, it is also crucial for policymakers to develop water-saving industries to improve water utilization efficiency, and to set targets for CO2 emissions to reduce the impact on climate change.

Design and Test of the Clearing and Covering of a Minimum-Tillage Planter for Corn Stubble

Conservation tillage technology can reduce wind erosion and soil erosion, improve soil fertility, avoid straw burning and relieve ecological pressure. It is an important measure to achieve sustainable agricultural development. In northeast China, there is a large amount of straw covering the ground after the corn machine harvest, which can easily lead to the blockage of the soil-touching parts during no-tillage seeding, affecting sowing quality and crop yield. In order to solve the above problems, the clearing and covering of a minimum-tillage planter for corn stubble was developed. The machine can complete multiple processes, such as seedbed preparation, seeding, fertilization, covering and suppression, straw covering, etc., in a single entity. This paper focuses on the design of the straw cleaning device and uses discrete element method software (EDEM 2018, Altair Engineering, Troy, MI, USA) to establish the straw cleaning device–straw–soil discrete element simulation model. The quadratic-regression orthogonal center-of-rotation combination test method is used to optimize the parameter combination of the machine, using the operating speed, the speed of the knife roller and the penetration depth of the knife as the test factors and using the rate of cleaning straw and the equivalent power consumption as the evaluation index. The results show that each factor has a significant influence on the performance evaluation indices, and the order of influence of each factor on the rate of cleaning straw is operation speed > penetration depth of knife > speed of knife roller, and the order of influence of each factor on the equivalent power consumption is penetration depth of knife > speed of knife roller > operation speed. The optimal combination of parameters is a 5.5–6.2 km/h operation speed, a 500 rpm speed of the knife roller, a 40 mm penetration depth of the knife, a straw-cleaning rate of more than 90% and an equivalent power consumption of less than 8 kW. This study provides technical and equipment support for the promotion of conservation tillage technology in Northeast China.

Impact of the Beijing-Tianjin sandstorm source control project on ecosystem services and an evaluation of economic benefits

<p indent="0mm">The Beijing-Tianjin sandstorm source control project (BTSSCP) is a large and famous ecological construction project with enormous investment that aims to improve and optimize the ecological condition of Beijing-Tianjin and the surrounding areas. Since the implementation of the BTSSCP in 2000, profound changes have occurred in the region regarding land use, vegetation cover, soil, wind and water erosion, and the supply of regional ecosystem services (ESs). Changes in regional ESs are influenced not only by human activities but also by natural factors such as climate change. Distinguishing and quantifying the roles of climate change and land-use change on regional ES changes can better serve sustainable land-use management decisions at the regional and national levels. Additionally, information is needed on the economic benefits caused by sandstorm control and ecological restoration, such as the value change of the regulating ESs since the BTSSCP began, the variation in the spatial patterns of ESs and their integration, and the contribution of sand control and vegetation restoration to regional ES changes. Moreover, a landscape-level ES multifunctionality concept and measurement framework provided deep insight into the spatial supply-benefit relationship of ESs, and this information is crucial for sustainable ecosystem management and land-use planning. In this study, a set of ES indicators that represent ecological provisioning (<italic>n</italic>=2), regulating (<italic>n</italic>=4), and supporting (<italic>n</italic>=2) services at the county scale in the BTSSCP were calculated based on a field survey, Normalized difference vegetation index (NDVI) data, land-use data, meteorological data (i.e., temperature, precipitation, wind speed, and direction) and socioeconomic census data. Then, the ES multifunctionality of each county was assessed using the multiple ES landscape index (MESLI) and the ES Shannon diversity index (ESHDI). Variation partitioning was used to distinguish the contributions of land-use area composition and major climatic conditions (annual average temperature, annual precipitation, and average wind speed) to various ESs, and the MESLI and ESHDI in different periods were measured and compared. Partial least squares path modeling (PLS-PM) was applied to determine the direct and indirect effects of the BTSSCP on the regional ecological supply, ecological regulation, habitat support services and multifunctional indicators of ESs and their changes. The results showed that (1) the implementation of the BTSSCP effectively improved the regulating ESs in Beijing, Tianjin and surrounding areas and promoted the overall improvement of the comprehensive benefits of regional ESs while effectively improving the integration and diversity of ESs in the core areas of wind and sand management. The MESLI increased in 94.8% of all counties in 2015 compared to 2000. (2) Both land-use composition and climatic factors had impacts on the regional ES provisions, but the influence of land use on the regulating and provisioning ESs was significantly higher than that of climatic factors. The direct effect of land use on ES provision, regulation, and support was enhanced, the multifunctionality of regional ESs was dramatically improved, and the role of climatic factors markedly declined as the project proceeded. (3) The economic benefits of the BTSSCP were positive, with a 415300 yuan/km² increase in the content of regulating ESs, and 82.7% of counties had reduced wind erosion after BTSSCP implementation, which indicated that the comprehensive economic benefits of BTSSCP implementation were significant. These results provide a scientific basis for evaluating the benefits of the BTSSCP and serve as a reference for developing new national management strategies.