Application Research of Restoration Materials on Degraded Land

[Objective] The paper aimed at researching on the ecological remediation materials and related technologies in degraded land.[Method] Pointing at the specific reasons for degradation of soil moisture and fertility conditions,the ecological remediation materials and related technologies for soil moisture had been studied using layered silicates as substrate materials and using straw turnover as the method.The application research had been carried out in degraded cultivated land,compacted land,saline-alkali soil and laboratory of nine provinces and regions on 26 species and 48 varieties.[Result] The materials and related technologies are environment-friendly in formula,processing,application with no hidden trouble as secondary pollution,which can be used for the restoration of positive balance of soil moisture conditions（water,fertilizer,gas,and heat）,establishment of the core of a stable circle and improving food production steadily.The materials are more suitable for plant growth than chemical fertilizers,applying of which helps plants obtain better adversity resistance.[Conclusion] The ecological remediation materials for soil moisture can reduce the application of chemical fertilizers effectively and improve the production and quality of crops remarkably.

Effects of the vegetation restoration years on soil microbial community composition and biomass in degraded lands in Changting County,China

We evaluated the effects of the number of years of restoration of vegetation on soil microbial community structure and biomass in degraded ecosystems.We investigated the microbial community structure by analyzing their phospholipid fatty acids then examined microbial biomass carbon and nitrogen by chloroform fumigation extraction of restoration soils over several years.The data were compared with those of highly degraded lands and native vegetation sites.The results show that the duration of vegetation on the sites substantially increased microbial biomass and shifted the microbial community structure even after only 4 years.However,microbial communities and biomass did not recover to the status of native vegetation even after 35 years of vegetation cover.A redundancy analysis and Pearson correlation analysis indicated that soil organic carbon,total nitrogen,available potassium,soil water content,silt content and soil hardness explained 98.4%of total variability in the microbial community composition.Soil organic carbon,total nitrogen,available potassium and soil water content were positively correlated with microbial community structure and biomass,whereas,soil hardness and silt content were negatively related to microbial community structure and biomass.This study provides new insights into microbial community structure and biomass that influence organic carbon,nitrogen,phosphorus and potassium accumulation,and clay content in soils at different stages of restoration.

Assessment of land degradation in Inner Mongolia between 2000 and 2020 based on remote sensing data

Achieving land degradation neutrality(LDN)worldwide is a significant target of the Sustainable Development Goal(SDG15.3).Inner Mongolia,as a typical dryland region in northern China,has carried out several large-scale ecological restoration programs to combat land degradation.However,there is a lack of comprehensive assess-ment of its land degradation situation after ecological programs implementation,which is of great significance to supporting SDG15.3 in China.This study analyzed the land degradation situation using the improved SDG15.3.1 calculation framework based on fine resolution data in Inner Mongolia from 2000 to 2020,and finally compre-hensively evaluated the land status of the whole region and those subject to ecological programs.The results show that net land restoration proportion of various ecological project regions and whole region continues to increase.The scope of the Grain for Green Program(GGP)had the largest proportion of net land restoration while the Natural Reserve Program(NRP)had the lowest proportion from 2000 to 2020.The net land restoration area of Inner Mongolia during 2000-2010 and 2010-2020 was 35,800 km 2 and 65,300 km 2,respectively.Overall,Inner Mongolia has achieved statistically zero growth in land degradation under the governance of ecological restora-tion programs.Therefore,reasonable planning,well monitoring,and timely assessment of ecological restoration programs are crucial to support SDG15.3.

Characteristics of change of humic substance in soil in degraded grass lands

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Performance and Adaptation of the Vallerani Mechanized Water Harvesting System in Degraded Badia Rangelands

Rainwater harvesting in micro-catchments such as contour ridges and semicircular bunds is an option for utilizing the limited rainfall, improving productivity and combating land degradation in dry rangeland areas （Badia）. However, implementation of this practice using manual labor or traditional machinery is slow, tedious and costly, and often impractical on a large scale. These limitations can be overcome using the ＂Vallerani＂ plow for quickly constructing continuous and intermittent ridges. The plow （model Delfino （50 MI/CM）, manufactured by Nardi, Italy） was tested and adapted to dry steppe （Badia） conditions in Jordan. The performance of the machine, its weaknesses and potential improvements were assessed in the 2006/07 season at three sites on 165 hectares of various terrain, slope and soil conditions. The performance parameters included effective field capacity （EFC）, machine efficiency （ME） and fuel consumption （FC）. Field tests were carried out at different tractor （134 HP） traveling speeds, pit sizes and contour spacings. Overall mean performance indicators gave an EFC of 1.2 ha/h, 51% ME and an average FC of 5.15 liter/ha. Increasing ridge spacing had a small effect on ME where, increasing traveling speed had a greater effect. A guide table was developed, relating performance parameters with ridge spacing, speed, and bund size setting. This could be a useful reference for the implementation and management of mechanized micro-catchment construction in the Badia. The system performed well in the construction of continuous ridges. However, it was unable to construct intermittent ridges at speeds over 4km/h; problems were encountered in properly staggering the bunds at successive contours.

Impacts of Agricultural Activities on Land Degradation along the Bomboré River in Burkina Faso

Land along the Bomboré River in the rural commune of Mogtédo in Burkina Faso is experiencing degradation. The explanatory causes of this degradation constitute the subject of this study. To do this, a survey was conducted among agricultural producers deployed along the watercourse. Soil profiles were described and samples were taken to analyze pH, soil organic carbon, soil organic matter, total nitrogen, and texture. The RUSLE model approach based on landstat8 OLI/TIRS and SRTM satellite images dated December 17, 2021 with fairly good radiometric, spatial, and spectral resolution was used to calculate the land loss rate. In terms of results, the potentially irrigable areas that spread out on both sides of the banks of the river cover 209.23 ha with a perimeter of 6.16 km. The number of irrigators is 26 producers and they grow 17.92 ha of vegetables. Soil analyzes indicate the presence of a moderate acid on the vertisol with a pH between 5.57 and 5.86. On the depth 0 - 30 cm of the horizon, the color of the horizons ranges from 5YR4/2 on the talweg and on the right bank to 7.5YR3/2 on the left bank and presents no risk of salinity because the electrical conductivity measured is less than 1dS/cm. The diagnosis of hydromechanical equipment shows that producers use 46 motor pumps for irrigation, of which 15 motor pumps run on gasoline and 31 motor pumps on butane gas with a ratio of 1.7 motor pumps per producer. The number of Polyvinyl Chloride (PVC) pipes used by producers in combination with a motor pump gives an average of 44 per farmer. In terms of mineral fertilization, the gross doses used by producers are 415.53 kg/ha of NPK and 201.55 kg/ha of urea, while the quantities of phytosanitary products are 3.99 l/ha of pesticides and 1.42 l/ha of herbicides. Agricultural activities emit about 222,436.66 kgCO2eq into the atmosphere, whose emissions from motor pumps represent 84.52% of these total emissions. The land loss estimate gives an average rate of 2.30 t/ha/year of land loss. This loss is due to the effects of poor agricultural practices, water erosion, and the drainage channels and gullies created by the anarchic installation of dwellings around the edges of the river. This study calls for more monitoring actions to sustainably safeguard the soil and water resources of this river which contribute to the survival of more than 73,214 inhabitants.

Analysis of Land Degradation in Ethiopia and Countermeasures

In Ethiopia soil conservation is primarily meant to improve agriculture production.Therefore,assessment of the existing erosion hazards and classifying the land according to its capability are essential.This paper depicts the land degradation status and causes,through an integrated assessment,and some measures to alleviate the problem are proposed.

Restoration and Conservation of Deteriorated Arid Land by a Native Thorny Shrub Lycium shawii

Land degradation is of great concern in the desert environment of Kuwait, as it has a negative impact on the natural resources. In response to this situation, Kuwait conserves their natural environment by setting aside areas of significant natural ecosystem, such as wild life center at the Liyah area. The area suffered during the past four decades from severe environmental pressures due to the excessive exploitation of natural resources of sand and gravel as well as overgrazing and military activities. Re-vegetation and restoration programs were applied in the degraded areas in Liyah in December 2003. A large variety of native plants were used for the restoration, however, in this research, only one native perennial drought resistant plant Lycium shawii （Awsaj） was highlighted. Tissue cultured thorny shrub planted at experimental site showed high adaptation on gravel hill side with harsh field condition. Their survival rate was 100% under drip irrigation only 10% was the mortality rate due to improper fixation of irrigation system. The average length of the main stem and the number of branches gradually increased by year from 42 cm with three branches in 2011 to 170 cm with seven branches in 2014. Since Lycium shrubs have the ability to grow in severely degraded areas, with extreme condition of prolonged drought, high temperature and poor nutrient soil as well as their ability to form nabkha, it is considered to be most suitable shrub used for rehabilitation program at Liyah area.

Evaluation of soil loss severity and ecological restoration approach for sustainable agriculture in the Hindu Kush, Karakoram and Himalaya region

Soil erosion has resulted in removal of the topsoils containing fine soil particles and plant nutrients, causing decrease in soil fertility in the Hindu Kush, Karakoram and Himalaya(HKH) region. The existing production of cereal crop grains has been reduced to one third of the potential crop grains production owing to land degradation and poor farming practices. It is necessary to assess risk of soil loss and identify appropriate controlling measures to address issues of low agriculture productivity and water insecurity in the region. In the present study, severity of soil loss was predicted using Revised Universal Loss Equation(RUSLE) and ecological measures were identified for sustainable mountain agriculture in the HKH region of Upper Indus Basin, Pakistan. Overall 62.6% area was found to have very low risk of soil loss, i.e., <5 t/(ha·yr), 15.8% area low risk, i.e., 5-25 t/(ha·yr) and 7.5% area moderate risk, i.e., 25-50 t/(ha·yr) in the region. The risk was high, i.e., 50-100 t/(ha·yr) and very high, i.e., >100 t/(ha·yr) in about 6.8% and 7.4% areas respectively. The mean rate of soil loss was about 41.9 t/(ha·yr) in the Hindu Kush, 31.1 t/(ha·yr) in the Himalayas, 18.8 t/(ha·yr) in the Karakoram and overall 29.7 t/(ha·yr) in the three HKH ranges. As such no considerable measures have been adopted by the communities for restoration of the degraded areas except raising fruit/farm trees and supporting limited social forestry for their livelihoods. The slopes cleared for cultivation and susceptible to erosion may be stabilized through sowing/planting of multi-purpose plant species and formation of proper bench terraces. The conservation of forest ecosystem and pastures at higher elevations would help in reducing overland water flow, risk of flash flood hazard and minimizing sediment loads in the downstream. It is essential to adopt site-specific resource conservation techniques and restore possible ecosystem health for sustainable agriculture and economic development in the region in future.

Establishment of Monitoring and Assessment Index System of Land Degradation of Farmland Ecosystems at Small-scale

The research established land degradation monitoring and assessment in- dex system of farmland ecosystem under influence of human activities, including farming system, measures, mulch residuals, fertilizer pollutions, pesticide pollution, irrigation method, salt content of soils, engineering measures of discharging alkali, agricultural protection forests and poverty. The indices of the system are accessible, and convenient for operation, which is suitable for land managers self-monitoring, re- ducing irrational farming activities, improving farmland productivity and preventing farmland degradation.

Human induced dryland degradation in Ordos Plateau,China,revealed by multilevel statistical modeling of normalized difference vegetation index and rainfall time-series

Land degradation causes serious environmental problems in many regions of the world, and although it can be effectively assessed and monitored using a time series of rainfall and a normalized difference vegetation index （NDVI） from remotely-sensed imagery, dividing human-induced land degradation from vegetation dynamics due to climate change is not a trivial task. This paper presented a multilevel statistical modeling of the NDVI-rainfall relationship to detect human-induced land degradation at local and landscape scales in the Ordos Plateau of Inner Mongolia, China, and recognized that anthropogenic activities result in either positive （land restoration and re-vegetation） or negative （degradation） trends. Linear regressions were used to assess the accuracy of the multi- level statistical model. The results show that： （1） land restoration was the dominant process in the Ordos Plateau between 1998 and 2012; （2） the effect of the statistical removal of precipitation revealed areas of human-induced land degradation and improvement, the latter reflecting successful restoration projects and changes in land man- agement in many parts of the Ordos; （3） compared to a simple linear regression, multilevel statistical modeling could be used to analyze the relationship between the NDVI and rainfall and improve the accuracy of detecting the effect of human activities. Additional factors should be included when analyzing the NDVI-rainfall relationship and detecting human-induced loss of vegetation cover in drylands to improve the accuracy of the approach and elimi- nate some observed non-significant residual trends.

Distribution and Assessment of Soil and Land Degradation in Subtropical China—A Case Study of the Dongxi River Basin, Fujian Province *1

Some alternative methods for estimating soil erosion rates rapidly were used to elucidate the relationship between the land use types and land degradation. The 137 Cs content, magnetic susceptibility, aggregate stability, and soil properties were studied in the Dongxi River Basin, a mountainous area of western Fujian. A plot of 137 Cs inventory (Y) against slope angle (X) shows a strong inverse log log relationship ( r = -0.83 ), indicating that much more soil erosion occurs on steeper slopes. Average soil loss (in thickness of top soil per year) in the past 30 years for arable slope crest, arable slopes and tea plantation slopes are 1.6 , 10.4 and 8.0 mm year -1 respectively. The surface layer enrichment factor of magnetic susceptibility (Y) in soil also shows an inverse log log relationship ( r =-0.63), indicating a similar tendency with the relationship between the 137 Cs inventory (Y) against slope angle (X). The physical and chemical properties of soils among different land use types show different degraded characteristics at different significant levels.

Mechanism and regulation of land degradation in Yulin district

Yulin district is located in the transitional zone between Mu Us Desert and Loess Plateau of northern Shaanxi Province, thus it is particularly vulnerable to degradation due to its fragile ecosystem and intense human activities there. The purpose of this study is to explore the mechanism, process and driving force of land degradation in area with vulnerable eco-environment within the context of increasing population and intensifying human economic activities, and then find out the patterns and countermeasures of how to control them using the economic and technological ways. In detail, this study includes three main sections: the first section analyzes the mechanism, causes and characteristics of land degradation, which can be achieved by the typical field investigations and systematical analysis within the regional natural, social and economic context. Based on the technologies of remote sensing and GIS, and combined with the modeling methods, the second section reveals the change characteristics of land use and its driving force from 1990 to 2000; As to the third section, feasible countermeasures of how to prevent the degradation and rehabilitate the regional ecology are proposed, which are studied from the perspective of harmony between nature and economy, and the conception of regional sustainable development.

Land use change and its ecological effect in Qian’an County of Jilin Province

Based on GIS and statistical methods, with the help of searching historical literatures and calculating the landscape indices, the land use changes of Qian'an County in both spatial and temporal aspects from 1945 to 1996 has been analyzed in this paper. And the driving forces of land use changes and their ecological effects are discussed too. The main findings of this study are as follows: (1) Land use changed greatly in Qian'an during 1945-1996, characterized by a decrease in grassland, wetland and water bodies, and an increase in cultivated land, saline-alkali land, and the land for housing and other construction purposes. Grassland decreased by 175,828.66 ha, and cultivated land increased by 102,137.23 ha over the half century. Accordingly, the main landscape type changed from a steppe landscape to a managed agricultural ecosystem. (2) Results of correlation analysis show that the land use change in the study area was mainly driven by the socioeconomic factors. (3) The ecological effects of land use change in the area are characterized by serious salinization, degression of soil fertility and the weakening of landscape suitability.

Land Degradation Due to Salinization in Arid and Semi-arid Regions with the Aid of Geo-information Techniques

This study applied a computerized parametric methodology to monitor, map, and quantify land degradation by salinization risk detection techniques at a 1：250 000 mapping scale using geo-information technology. The northern part of the Shaanxi province in China was taken as a case. Multi-temporal remotely sensed materials of both Landsat TM and thematic maps （ETM＋） were used as the bases to provide comprehensive views of surface conditions such as vegetation cover and salinization detection. With ERDAS ver. 9.1 software, the Normalized Differential Salinity Index （NDSl） and Salinity Index （S.I.） were computed and then evaluated for land degradation by salinization. Arc/Info ver. 9.2 software was used along with field observation data （GPS） for analysis. Using spatial analysis methods, results showed that 19 973.1 km^2 （72%） of land had no risk of land degradation by salinization, 3 684.7 km^2 （13%） had slight land degradation by salinization risk, 2 797.9 km^2 （10%） had moderate land degradation by salinization risk, and 1 218.9 km^2 （4%） of the total land area was at a high risk of land degradation by salinization. The study area, in general, is exposed to a high risk of soil salinization.

Land degradation, government subsidy, and smallholders＇ conservation decision： the case of the loess plateau in China

Land degradation is one of the severe environmental problems in China. In order to combat land degradation, a soil conservation program was introduced since 2000 to reduce soil erosion by converting slope-cultivated land into forestry and pasture. This paper represents the first systematic attempt to investigate the impact of the soil conservation program on land degradation in the loess plateau. The results indicate that the soil conservation program to convert slope fields into forest or pasture is an effective way to combat soil erosion. However, a subsidy that is higher than profit of land use activity of slope fields before their conversion into forest and pasture is needed to encourage farmers to join the conservation program. A policy measure to encourage and assist farmers to develop sedentary livestock by using crops produced from fields as well as fodder and forage grass from the converted slope fields might contribute to combat soil erosion. Increase in off-farm job opportunities may encourage households to reduce cultivation in slope fields. That implies a policy measure to encourage rural urbanization might contribute to combat soil erosion.

Element and mineral characterization of dust emission from the saline land at Songnen Plain, Northeastern China

Recent observations of Asian dust storms show an eastern expansion of the source area to degraded lands, where dust emissions have been little studied. The dust concentrations over the saline land of the western Songnen Plain （SSL）, Northeastern China, are circumstantially higher than those from the northwestern Chinese deserts. These concentrations are sensitive to the surface soil conditions and wind velocity on the ground. The dust samples collected during dust storm events on the SSL contain abundant Na, Mg, A1, K, Ca, Fe and Ti, as well as toxic elements such as Cu, V, Zn and Ba. Individual particle analysis reveals that fine saline particles （〈 10 μm in diameter） on the saline land, consisting largely of carbonate, halite and sulfate together with lithogenic minerals such as SiO2 and aluminosilicate, are eventually uplifted during the interval from spring to autuum. The predominantly fine saline particles uplifted from the SSL are likely transported eastward by the winter monsoon circulation and westerlies. Recent degradation of saline lands in Northeastern China would not only increase the frequency of dust storm events in the downwind area, but also might change the chemical composition of the Asian dust emissions.

Land degradation in the subtropical hilly andmountain regions of South China

Land degradation, caused by water erosion. closely related to inherent vulnerabilities of itseco-environment in South China. Spatial variation of land degradation from top to foot of a slope wasmainly induced by differentiation of surface materials and their erodibility, nutrient and moisture dueto downslope variation of land erosion. It was showed by comparing maps of land degradationbetween the 1950s and the 1980s that changes of land degradation varied from one area to anotherbecause of differences of human activities, including land reclamation and vegetation depletion.

Evaluation of Land Degradation and So-cio-Environmental Issues: A Case Study of Semi Arid Watershed in Western Rajasthan

The present work attempts to assess the land cover changes at watershed level and status of land degradation in Mithri Watershed lying in the semi-arid tracts of Western Rajasthan, using time series climate data and remote sensing data and GIS techniques. The study also has a strong field component in the form of village wise surveys to record observations on climatic changes, agriculture, socio-economic condition of the community, water availability etc. Integration of remote sensing technique along with climate data analysis and household surveys, Group discussion and Participatory rural appraisal (PRA) was conducted to record land use/land cover changes and its impact on socio-economic condition of the people. Degradation mapping of the area reveals that area is affected by forest degradation, scrub erosion and salinization. Anthropogenic factors like fuel wood and timber extraction, livestock grazing etc. are also responsible for forest degradation. People have shifted from cash crops such as cotton to maize, barley and cereal during the last two decades.

Comparing Land Degradation and Regeneration Trends in China Drylands

The aim of this paper is to offer a statistically sound method to make a precise account of the speed of land degradation and regeneration processes.Most common analyses of land degradation focus instead on the extent of degraded areas,rather than on the intensity of degradation processes.The study was implemented for the Potential Extent of Desertification in China(PEDC),composed by arid,semi-arid,and dry sub-humid regions and refers to the period 2002 to 2012.The metrics were standard partial regression coefficients from stepwise regressions,fitted using Net Primary Productivity as the dependent variable,and year number and aridity as predictors.The results indicate that:①the extension of degrading lands(292896 km 2 or 9.12%of PEDC)overcomes the area that is recovering(194560 km 2 or 6.06%of PEDC);and②the intensity of degrading trends is lower than that of increasing trends in three land cover types(grassland,desert,and crops)and in two aridity levels(semi-arid and dry sub-humid).Such an outcome might pinpoint restoration policies by the Chinese government,and document a possible case of hysteresis.