1.School of Geographic and Oceanographic Sciences, Nanjing University, Nanjing 210023, Jiangsu, China 2.The Key Laboratory of the Coastal Zone Exploitation and Protection, Ministry of Land and Resources, Nanjing 210023, Jiangsu, China
Reclaiming coastal wetlands for cultivate lands transformed the wetland soil to agricultural soil, soil properties changed a lot. To explore the effects of soil ecological environment due to the reclamation activities in coastal zone and determine the key modified factors, it can provide guidance for soil improvement. In this article, soil samples collected from reclamation area under different years and tidal flats in Rudong Country of Jiangsu Province were analyzed. ANOVA was used to test the difference among soil indicators in different reclamation area(LSD test). The method of soil quality index (SQI) is used to evaluate the soil quality. The model of limiting factors diagnosis is used to analyze the key improvement factors of soil quality. The result shows that since 60 years from reclamation, the trajectory of soil quality change in study area is “improve sharply-relative stability-improve sustainability”. SQI increased sharply from 0.19 to 0.37 at the first 10 years after reclamation, average annual rate of growth is 11.84%,the difference is significant; SQI increased from 0.37 to 0.42 between 10 years to 30 years after reclamation and average annual rate of growth is 0.54%; SQI increased from 0.42 to 0.45 between 30 years to 40 years after reclamation and average annual rate of growth is 0.71%, there has no obvious difference. Therefore soil quality is in a relatively stable state after reclamation at 30 years. While SQI increased sustainability from 0.45 to 0.56 between 40 years to 60 years after reclamation and average annual rate of growth is 1.22%, the difference is significant. The limiting factors diagnosis showed that the lower TOC, TN and clay content are the major limiting factors of soil quality and have significant negative correlation with pH and salt, therefore decreased salinization is the basic reason for improving soil quality after reclamation. The improvement of fertility as well as soil texture are the key to further improve soil quality.
. 沿海滩涂围垦区土壤质量演变研究——以江苏省如东县为例[J]. 地理科学,
2016, 36(2): 256-264.
Ming Zhu et al
. Soil Quality Evolution in Coastal Reclamation Zones：A Case Study of Rudong County of Jiangsu Province[J]. SCIENTIA GEOGRAPHICA SINICA,
2016, 36(2): 256-264.
[ZhaoHaidi,LiuShiliang,DongShikui,et al.Relationship between human interference and wetland spatial variationin three-river headwaters region.,2014,12(1):22-28.]
Sun YG,Li XZ,ÜloMander,et al.Effect of reclamation time and land use on soil properties in Changjiang River Estuary,China.,2011,21(4):403-416.
The objective of this study is to analyze soil physical and chemical properties, soil comprehensive functions and impact factors after different years of reclamation. Based on the survey data taken from 216 soil sampling points in the Fengxian Reclamation Area of the Changjiang (Yangtze) River Estuary, China in April 2009 and remotely sensed TM data in 2006, while by virtue of multivariate analysis of variance (MANOVA), geo-statistical analysis (GA), principal component analysis (PCA) and canonical correspondence analysis (CCA), it was concluded that: 1) With the increase in reclamation time, soil moisture, soil salinity, soil electric conductivity and soil particle size tended to decline, yet soil organic matter tended to increase. Soil available phosphorous tended to increase in the early reclamation period, yet it tended to decline after about 49 years of reclamation. Soil nitrate nitrogen, soil ammonia nitrogen and pH changed slightly in different reclamation years. Soil physical and chemical properties reached a steady state after about 30 years of reclamation. 2) According to the results of PCA analysis, the weighted value (0.97 in total) that represents soil nutrient factors (soil nitrate nitrogen, soil organic matter, soil available phosphorous, soil ammonia nitrogen, pH and soil particle size) were higher than the weighted value (0.48 in total) of soil limiting factors (soil salinity, soil electric conductivity and soil moisture). The higher the F value is, the better the soil quality is. 3) Different land use types play different roles in the soil function maturity process, with farmlands providing the best contribution. 4) Soil physical and chemical properties in the reclamation area were mainly influenced by reclamation time, and then by land use types. The correlation (0.1905) of the composite index of soil function (F) with reclamation time was greater than that with land use types (-0.1161).
[SiGuicai,WangJian,XiaYanqing,et al.Change characteristics of microbial communities and enzyme activitiesin soils of marshes in Nyaiqentanglha mountainswith heights above sea level.,2014,12(3):340-348.]
[JinWenhui,YangJingsong,WangXiangping.Spatial distribution of organic carbon in coastal saline soil and itscorrelation with reclamation age.,2013,29(5):89-94.]
Li JG,Pu LJ,ZhuM,et al.Evolution of soil properties following reclamation in coastal areas:A review[J].,2014,226(1): 130-139./s?wd=paperuri%3A%28874edd620fdab9e86b3902395cf1789f%29&filter=sc_long_sign&sc_ks_para=q%3DEvolution%20of%20soil%20properties%20following%20reclamation%20in%20coastal%20areas%3A%20A%20review&sc_us=2761085231134554606&tn=SE_baiduxueshu_c1gjeupa&ie=utf-8
[ZhangYan,PengBuzhuo,GaoXiang,et al.Impact on soil erosion and soil properties by human disturbance—case of the low mountains and hills of Yixing,south Jiangsu Province.,2002,22(1): 336-341.]
Meng QF,Yang JS,Yao RJ,et al.Soil quality in east coastal region of China as related to different land use types[J].,2013,13(4):664-676.
Abstract<br/><h3 class="a-plus-plus">Purpose</h3><p class="a-plus-plus">The impacts of different land use practices on soil quality were assessed by measuring soil attributes and using factor analysis in coastal tidal lands. The study provided relevant references for coastal exploitation, land management and related researches in other countries and regions.</p><h3 class="a-plus-plus">Materials and methods</h3><p class="a-plus-plus">Measured soil attributes include physical indicators [bulk density (<em class="a-plus-plus">ρ</em><sub class="a-plus-plus">b</sub>), total porosity (<em class="a-plus-plus">ƒ</em><sub class="a-plus-plus">t</sub>) and water-holding capacity (WHC)], chemical indicators [pH, electrical conductivity (EC), total nitrogen (TN), soil organic matter (SOM), available N, available P and available K] and biological indicators (urease activity, catalase activity and phosphatase activity), and 60 soil samples were collected within five land use types [(1) intertidal soils, (2) reclaimed tidal flat soils, (3) farmland soils, (4) suburban vegetable soils, (5) industrial area soils) in Jianggang village of Dongtai county, Jiangsu province of China.</p><h3 class="a-plus-plus">Results and discussion</h3><p class="a-plus-plus">The results from the investigation indicated that selected soil properties reduced to three factors for 0–20-cm soil depth; “Soil fertility status” (factor 1), “Soil physical status” (factor 2) and “Soil salinity status” (factor 3). For the first factor, the measured soil attributes with higher loadings were TN and SOM, which represented soil fertility feature, and for the second and third factors, the measured soil attributes with higher loadings were <em class="a-plus-plus">ρ</em><sub class="a-plus-plus">b</sub> and available K as well as EC, which reflected soil physical properties and soil salinity feature, respectively.</p><h3 class="a-plus-plus">Conclusions</h3><p class="a-plus-plus">Changes in different land use types due to plants (corn, wheat and green vegetable) and application of fertilizers were characterized by promoted soil quality, including improvements in chemical properties (increasing SOM concentration, TN and nutrient available to plants; decreasing EC), improvements in soil physical properties (decreasing <em class="a-plus-plus">ρ</em><sub class="a-plus-plus">b</sub>; increasing <em class="a-plus-plus">ƒ</em><sub class="a-plus-plus">t</sub> and WHC) and enhancements in soil enzyme activities. Judging from the soil quality indices, the soil quality was affected by different land use practices and decreased in sequence of suburban vegetable soils, farmland soils, industrial area soils, reclaimed tidal flat soils and intertidal soils in the study area.</p><br/>
<p>以安庆沿江农田不同退耕还湖方式——低坝高网式水产养殖和湿地自然恢复区的湿地土壤为研究对象，并以邻近的水田和旱地土壤作为参照，研究退耕还湖后湿地土壤生物化学性质变化。结果表明，退耕还湖18 a（1991～2009 年)后，在湿地自然恢复区，湿地土壤(深度为0～30 cm)微生物量碳含量、土壤磷酸酶活性和过氧化氢酶活性增大，土壤脲酶活性和蔗糖酶活性减小；由水田退耕18 a 的湿地亚表层土壤(深度为15～30 cm)脲酶活性和表层土壤(深度为0～15 cm)过氧化氢酶活性与由旱地退耕18 a 的湿地无明显差异，由水田退耕18 a 的湿地表层土壤脲酶活性和亚表层土壤过氧化氢酶活性、表层和亚表层土壤微生物量碳含量、蔗糖酶活性和磷酸酶活性都明显高于由旱地退耕18 a 的湿地。退耕还湖18 a 后，进行低坝高网式水产养殖的湿地土壤微生物量碳含量、土壤脲酶活性、蔗糖酶活性和磷酸酶活性减小，而过氧化氢酶活性增大；由水田退耕18 a 的湿地表层和亚表层土壤微生物量碳含量与由旱地退耕18 a 的湿地无明显差异，由水田退耕18 a 的湿地表层和亚表层土壤脲酶活性、表层土壤蔗糖酶活性和亚表层土壤磷酸酶活性明显高于由旱地退耕18 a 的湿地，而其亚表层土壤蔗糖酶、表层土壤磷酸酶、表层和亚表层土壤过氧化氢酶活性均显著低于由旱地退耕18 a 的湿地。天然湿地土壤微生物量碳含量、土壤脲酶活性、蔗糖酶活性和磷酸酶活性明显低于已退耕还湖的湿地和参照农田土壤。退耕还湖后，湿地的不同利用方式及其历史利用方式影响湿地土壤生物化学性质；湿地土壤有机质等养分含量和水文<br />条件变化是导致湿地土壤生物化学性质变化的主要原因。</p>
[ZhangPingjiu,ZhaoYongqiang,MengXiangdong.Biochemical properties of soils in wetlands of returning farmland to lakefor 18 Years along the Yangtze River in Anqing.,2012,10(3):299-305.]
[GuoJixun,JiangShicheng,LinHaijun,et al.Enzymic activity of alkaline meadow soil with different grassland vegetations.,1997,8(4):412-416.]
Ramos ME,BenitezE,Garcia PA,et al.Cover crops under different managements vs.frequent tillage in almond orchards in semiarid conditions:Effects on soil quality[J].,2010,44(1):6-14./s?wd=paperuri%3A%287838c2e16d03eff6a47567f03f3a39ce%29&filter=sc_long_sign&sc_ks_para=q%3DCover%20crops%20under%20different%20managements%20vs.%20frequent%20tillage%20in%20almond%20orchards%20in%20semiarid%20conditions%3A%20Effects%20on%20soil%20quality&sc_us=17863041773474912898&tn=SE_baiduxueshu_c1gjeupa&ie=utf-8
GarciaC,HernandezT,CostaF.Potential use of dehydrogenase activity as an index of microbial activity in degraded soils[J]. ,1997,28(1-2):123-134.http://www.tandfonline.com/doi/pdf/10.1080/00103629709369777
Soils from many portions of the Mediterranean region are subjected to progressive degradation as a result of erosion by wind and water. As a consequence, the fertility level of these degraded soils is declining. This report studied the dehydrogenase activity of 18 soils, all of which were subjected to processes of erosion, in order to ascertain whether such activity could serve as a marker of the microbial activity of a degraded soil. The dehydrogenase activity of the soils studied was not correlated with their organic matter content, indicating that total organic matter was not representative of the microbial activity of degraded soil. An analysis of principal components showed a similar behavior between other indices of microbial activity (basal respiration and biomass carbon) and the dehydrogenase activity values. This data confirmed that dehydrogenase activity can be used as a sensitive marker of soil degradation and soil microbial activity.