Sustainability

#Sustainability | 来源: 网络整理| 查看: 265

Next Article in Journal Research on the Sustainable Development of Enterprises That Evoke Industrial Heritage—A Case Study of Taoxichuan Previous Article in Journal Undrained Shear Properties of Shallow Clayey-Silty Sediments in the Shenhu Area of South China Sea Journals Active Journals Find a Journal Proceedings Series Topics Information For Authors For Reviewers For Editors For Librarians For Publishers For Societies For Conference Organizers Open Access Policy Institutional Open Access Program Special Issues Guidelines Editorial Process Research and Publication Ethics Article Processing Charges Awards Testimonials Author Services Initiatives Sciforum MDPI Books Preprints Scilit SciProfiles Encyclopedia JAMS Proceedings Series About Overview Contact Careers News Blog Sign In / Sign Up Notice clear Notice

You are accessing a machine-readable page. In order to be human-readable, please install an RSS reader.

Continue Cancel clear

All articles published by MDPI are made immediately available worldwide under an open access license. No special permission is required to reuse all or part of the article published by MDPI, including figures and tables. For articles published under an open access Creative Common CC BY license, any part of the article may be reused without permission provided that the original article is clearly cited. For more information, please refer to https://www.mdpi.com/openaccess.

Feature Papers represent the most advanced research with significant potential for high impact in the field. Feature Papers are submitted upon individual invitation or recommendation by the scientific editors and undergo peer review prior to publication.

The Feature Paper can be either an original research article, a substantial novel research study that often involves several techniques or approaches, or a comprehensive review paper with concise and precise updates on the latest progress in the field that systematically reviews the most exciting advances in scientific literature. This type of paper provides an outlook on future directions of research or possible applications.

Editor’s Choice articles are based on recommendations by the scientific editors of MDPI journals from around the world. Editors select a small number of articles recently published in the journal that they believe will be particularly interesting to readers, or important in the respective research area. The aim is to provide a snapshot of some of the most exciting work published in the various research areas of the journal.

Journals Active Journals Find a Journal Proceedings Series Topics Information For Authors For Reviewers For Editors For Librarians For Publishers For Societies For Conference Organizers Open Access Policy Institutional Open Access Program Special Issues Guidelines Editorial Process Research and Publication Ethics Article Processing Charges Awards Testimonials Author Services Initiatives Sciforum MDPI Books Preprints Scilit SciProfiles Encyclopedia JAMS Proceedings Series About Overview Contact Careers News Blog Sign In / Sign Up Submit Journals Sustainability Volume 15 Issue 2 10.3390/su15021173

Submit to this Journal Review for this Journal Edit a Special Issue ► ▼ Article Menu Article Menu Academic Editor

Bo Jiang Subscribe SciFeed Recommended Articles Related Info Link Google Scholar More by Authors Links on DOAJ Liu, S. Zhang, Q. Li, Z. Tian, C. Qiao, Y. Du, K. Cheng, H. Chen, G. Li, X. Li, F. on Google Scholar Liu, S. Zhang, Q. Li, Z. Tian, C. Qiao, Y. Du, K. Cheng, H. Chen, G. Li, X. Li, F. on PubMed Liu, S. Zhang, Q. Li, Z. Tian, C. Qiao, Y. Du, K. Cheng, H. Chen, G. Li, X. Li, F. /ajax/scifeed/subscribe Article Views Citations - Table of Contents Altmetric share Share announcement Help format_quote Cite question_answer Discuss in SciProfiles thumb_up ... Endorse textsms ... Comment Need Help? Support

Find support for a specific problem in the support section of our website.

Get Support Feedback

Please let us know what you think of our products and services.

Give Feedback Information

Visit our dedicated information section to learn more about MDPI.

Get Information clear JSmol Viewer clear first_page settings Order Article Reprints Font Type: Arial Georgia Verdana Font Size: Aa Aa Aa Line Spacing:    Column Width:    Background: Open AccessArticle Soil Salinity Weakening and Soil Quality Enhancement after Long-Term Reclamation of Different Croplands in the Yellow River Delta by

Shanbao Liu 1,2,3 ORCID

Qiuying Zhang 4,*,

Zhao Li 1,2 ORCID

Chao Tian 1,2,

Yunfeng Qiao 1,2,

Kun Du 1,2,

Hefa Cheng 5 ORCID

Gang Chen 6 ORCID

Xiaoyan Li 3 ORCID

and

Fadong Li 1,2,* ORCID

1 Shandong Yucheng Agro-Ecosystem National Observation and Research Station, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China 2 College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, China 3 State Key Laboratory of Earth Surface Processes and Resource Ecology, Faculty of Geographical Science, Beijing Normal University, Beijing 100875, China 4 Chinese Research Academy of Environmental Sciences, Beijing 100012, China 5 College of Urban and Environmental Sciences, Peking University, Beijing 100871, China 6 Department of Civil & Environmental Engineering, College of Engineering, Florida A&M University—Florida State University, Tallahassee, FL 32310, USA * Authors to whom correspondence should be addressed. Sustainability 2023, 15(2), 1173; https://doi.org/10.3390/su15021173 Received: 25 November 2022 / Revised: 5 January 2023 / Accepted: 6 January 2023 / Published: 8 January 2023 (This article belongs to the Section Soil Conservation and Sustainability) Download Download PDF Download PDF with Cover Download XML Browse Figures Review Reports Versions Notes

Abstract: Saline soils are of great concern globally. Selecting the Yellow River Delta as a model site, the influence of reclamation on soil salinity and saline soil quality was investigated. Soil quality index (SQI) was applied to statistically analyze 210 soil profile samples collected at seven depth layers in 30 sampling sites among native saline soils and three croplands (peanut, cotton, and wheat) in May 2020. After reclamation, the soil salt content (SSC) reduced from 4.52 g/kg to 1.44 g/kg after reclamation, with the degree of soil salinity reducing from severe to slight. The nitrate nitrogen (NO3−-N) contents of peanut, cotton, and wheat croplands were 1.90, 2.02, and 4.29 times higher and the available phosphorus (AP) contents were 5.43, 3.57, and 8.77 mg/kg higher than that of the saline soils, respectively, while the soil ammonium nitrogen (NH4+-N) and available potassium (AK) contents were decreased. The NO3−-N, AN, and AP contents of the three croplands showed a significant surface aggregation at depth of 0–30 cm. SQI increased by 0.10, 0.09, and 0.02 after the reclamation with the enhancement effect of wheat and cotton was more pronounced. It was discovered that reclamation notably improved the soil quality as a result of crop growth and field management of fertilization and irrigation. Keywords: reclamation; cropland; saline soil; soil quality; Yellow River Delta 1. IntroductionSoil salinity is one of the main types of soil degradation, which is attributed to the combined effects of natural processes and human activities. Currently, it is a serious global threat to agricultural production and sustainable development, affecting more than 100 countries worldwide [1]. Saline soils cover 833 million hectares globally, occupying 8.7% of the earth’s surface area. Of irrigated soils on the continents, 20–50% are saline soils, and more than 1.5 billion people worldwide face major challenges to food security [2,3]. The causes of soil salinity include poor human management, improper fertilization, deforestation, soil erosion, sea level rising, saltwater intrusion, etc. Global climate change also intensifies soil salinity with significant negative impacts on the agriculture and local economy. For instance, damming of the Mississippi River prevents sediment supply and coastal resource development activities, especially oil and gas extraction, result in groundwater level decline and seawater intrusion, leading to increased soil salinity of farmlands [4,5]. In the Nile Delta of Egypt, the coastline constantly changes and seawater erosion results in high soil saline content [6,7]. The Mekong Delta in Vietnam has been invaded by the natural backwash of seawater in the southern region due to improper human development, and the high soil saline content has seriously affected local households and the good production [8,9]. With the construction of gates and dams in India, flooding in the rainy season, and flow in the dry season have caused increased seawater intrusion and reduction of agricultural irrigation [10,11]. With the increase in global food demand and the continuous decrease of available arable land, reclamation of salinized land becomes important globally.The Yellow River Delta, as one of the major estuarine deltas in China, serves as an excellent example of saline soil reclamation. The Yellow River Delta is an alluvial plain formed by the sediment carried by the Yellow River into the Bohai Sea and deposited at the estuary of the sea [12,13,14]. Large areas of the Yellow River Delta are low-quality saline soils with low nutrient contents. The Yellow River Delta is significantly affected by seawater intrusion and extreme weather events induced by global climate change. Since the area is highly mineralized with shallow water, table salts are easily enriched on the soil surface, resulting in large and widely distributed saline soils in the region [15,16,17]. Soil salinity leads to poor soil physical and chemical properties, low nutrients, decreased freshwater resources, and eventually poor crop yields. In recent years, resulting from the influence of climate change and intensified farming, soil salinity in the Yellow River Delta has become an increasingly prominent problem of wide concern to local and state governments, and is also believed to be the primary factor limiting local land development and utilization as well as sustainable agricultural development and food security [18,19]. The reclamation of saline soils in this region has become more difficult because of the relatively high soil salinity in the offshore areas and the different degrees of salinity in different locations. It is crucial to develop salinized saline soil rationally to improve soil conditions, increase crop yield, enhance sustainable use, and optimize the management of saline soil resources. Reclamation and planting of salt-tolerant crops can not only raise ground cover and effectively inhibit soil reversion to salt, but also significantly ameliorate soil nutrient content and soil structure and promote agricultural production and sustainable development [20,21,22].Soil quality, as an inherent property of soil, is a comprehensive reflection of soil’s physicochemical properties and plays an important role in maintaining soil productivity and promoting plant and animal health within the ecosystem [23,24]. Soil physical and chemical property characteristics are also an indicator of soil quality, which reflect the stability of the ecosystem. Therefore, the selection of appropriate evaluation methods is important for the accurate evaluation of soil quality [25]. At present, although there is no unified standard for soil quality evaluation, soil quality is typically analyzed using principal component analysis, cluster analysis, gray correlation analysis, fuzzy comprehensive evaluation, and the comprehensive index method. Soil quality index (SQI), a combination of physical, chemical, and biological indicators, has been widely and successfully applied in many studies at various scales and locations to assess soil quality visually and accurately. SQI can be used to fully consider measured soil indicators, which are framed through principal component analysis with both ascending and descending functions to determine the weight of each indicator in a unified system and calculate the index through scoring equations to compare the final values and soil quality [26].The global deltas are facing the problems of land degradation and soil quality deterioration. The Yellow River Delta, as an important land resource in China, serves as an excellent example, which has undergone changes in soil salinity and soil quality after long-term reclamation. Previous studies assessing the effects of reclamation on soil salinity degree and nutrients by positioning observation or remote sensing, and most of the results are only based on visual characteristics of multiple indicators, so that few studies have used SQI to carry out such assessment and the comprehensive analysis of the overall characteristics of soil quality is still limited [27]. This study thus seeks to advance an understanding in this regard using the Yellow River Delta of China as a case study. Therefore, this study selected four land use types of reclaimed croplands in the Yellow River Delta and explored the influences of different land use types on physical and chemical soil properties at different depth layers to provide a reference for field management and the sustainable development of land productivity in saline soils. It was hypothesized that different land use types had different reclamation effects on soil reclamation. It was further hypothesized that the reclamation results varied with soil depth. The specific objectives of this research were: (1) to compare the distinct characteristics in soil physical and chemical properties at different soil depths of four land use types, (2) to analyze the influence of the reclamation on soil salt content and nutrients, and (3) to evaluate the soil quality of four land use types using SQI and identify the influence of reclamation to native saline soils. 2. Materials and Methods 2.1. Study AreaThe Yellow River Delta is located in northeast Shandong Province, China, which has a warm temperate continental monsoon climate with cold winters and hot summers, an average annual temperature of 12.8 °C, interannual variable precipitation (average annual precipitation of 555.9 mm), and elevated evaporation (average annual potential evaporation of 2049 mm) [28]. The native water table depth of this region is shallow. The mineralization of the region is above 5 g/L and the soil texture is mainly slit and fine clay. The soil type is influenced by the sediment of the Yellow River and mostly is formed as coastal tidal soil. Most of the natural vegetation comprises salt-tolerant species, mainly Phragmites communis, Suaeda heteroptera Kitog, Imperata cylindrica, etc. and the artificial vegetation comprises mainly Black Locust, Fraxinus chinensis, Populus L., etc. The saline land has been reclaimed for more than 50 years in the Yellow River Delta, which is now suitable for wheat, corn, cotton, sorghum, rice, and other crops after tillage improvement [13]. In addition to being rainfed, the irrigation relies on water from the Yellow River with an annual average annual irrigation amount of about 2250 m3/hm2 [29]. The fertilization contains nitrogen, phosphorus, and potassium compound fertilizers as well as organic fertilizers. 2.2. Soil CollectionBased on the current land use of the Yellow River Delta and field surveys, soil samples were collected in May 2020 throughout Dongying City, Shandong Province, China. A total of 210 soil samples were collected at 7 depth layers of 0–5 cm, 5–10 cm, 10–20 cm, 20–40 cm, 40–60 cm, 60–80 cm, and 80–100 cm in 30 sampling sites of different land use types in the Yellow River Delta (Figure 1). Based on the main crop types and planting areas in spring, we selected winter wheat (a major food crop), cotton, and peanuts (major cash crops) as model crops with widely distributed native saline soils as reference background values. In total, 9 saline soils, 11 wheat, 6 cotton, and 4 peanut sample plots were selected from randomly distributed standard farmlands throughout Dongying City.Soil water content (SWC), pH, electrical conductivity (EC), sand content, slit content, clay content, ammonium nitrogen (NH4+-N), nitrate nitrogen (NO3−-N), available nitrogen (AN), available phosphorous (AP), and available potassium (AK) were analyzed and determined. SWC was determined using the drying method in an oven at 105 °C for 24 h to constant weight; pH and EC were determined by portable water quality analyzer (HACH, USA) according to the soil to water ratio (1:5) leaching; sand, slit, and clay content was determined using the pipetting method; NH4+-N and NO3−-N were determined using potassium chloride immersion–UV spectrophotometry; AN was determined by the alkaline diffusion absorption method; AP was determined using the sodium bicarbonate immersion–molybdenum antimony anti-colorimetric method; and AK was determined by ammonium acetate immersion–flame photometry [30].Soil salt content (SSC) was converted from the empirical relationship in Equation (1) between SSC (g/kg) and EC (dS/m) established by a related study in the Yellow River Delta [19]: SSC = 2.18 × EC + 0.727, R2 = 0.9387 Sodium adsorption ration (SAR) was based on the determination of Na+, Ca2+, and Mg2+ and calculated according to Equation (2) [31]: SAR (m/mol)0.5 = Na+/[(Ca2+ + Mg2+)/2]0.5 2.3. Data AnalysisArcGIS 10.2 was used to map the distribution of the study area and sampling locations, and Excel 2019 software was used to organize the data. Pearson correlation analysis was performed using SPSS 23.0 to explore the correlation between physical and chemical properties of soils and to discern the significance of differences between different land use types. Origin 2021 software was used for graphical plotting, and the vertical distribution characteristics of soil samples were categorized and analyzed by principal component analysis. One-way ANOVA was used to analyze the variability for significance, and the least significant difference (LSD) multiple comparison method was used to analyze the variability between different soil types with 95% reliability. 2.4. Soil Quality AssessmentSoil quality was evaluated using the soil quality index (SQI), which was not simply additive but weighted additive when compared to other methods. In detail, SQI was constructed through downscaling and quantifying the different kinds of soil indicators putting each indicator in the same reference system for weighted calculation by principal component analysis (PCA) with ascending and descending functions, and calculating the quantitative results by weighted average [32,33]. SQI combines a variety of soil information to provide an intuitive and accurate assessment of soil quality.(1)Calculation of affiliation valueThe affiliation value was determined by the affiliation function to which the evaluation index belonged. The affiliation function includes an ascending affiliation function and a descending affiliation function, which mainly depends on the positive and negative effects of soil physicochemical indicators of soil quality. The ascending type, which is applicable to soil chemical and biological properties, is used in the evaluation of soil nutrient indicators with more being better. The descending type, which is applicable to soil physical property, is used in the evaluation of soil salt indexes with less being better.The ascending membership function formula is: F ( x ) = { 1.0 ( x ≥ b ) 0.9 ( x − a ) b − a + 0.1 ( a 150>40>200Level II120–15020–40150–200Level III90–12010–20100–150Level IV60–905–1050–100Level V30–603–530–50Level VI

【本文地址】

公司简介

联系我们