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Wang J.,Key Laboratory of Land Consolidation and Rehabilitation | Dun Y.,University of Science and Technology of China | Guo Y.,Key Laboratory of Land Consolidation and Rehabilitation | Dou S.,Jilin Agricultural University
Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering

Songnen plain is the main grain strategy reserve area of China, and it is also one of the three largest soda saline-alkali soil regions in the world. Soil salinization severely restricts the sustainable development of agriculture and the improvement of people's living standards. The land consolidation major projects officially launched in the west of Jilin Province in 2007 provides an effective way for comprehensive controlling salinity land. In the process of land consolidation, one of the most important problems need to be addressed was how to combine land consolidation with soil improvement to realize the purpose of increasing cultivated land areas and improving salinity soil. In order to study the Western Songnen Plain land consolidation effect on improving salinity soil, this paper took the land consolidation project in Zhenlai county of Jilin Province as study area, selected the original cultivated land, saline-alkali land and newly-added cultivated land as plots, adopted the methods of classical statistical analysis and canonical correspondence analysis to comparative study the differences of soil physical and chemical properties and soil ionic composition of different plots. And then we put forward related suggestions for land consolidation and improving salinity soil. The results showed that, in 0-20 and >20-40 cm soil layer, soil electrical conductivity of newly-added cultivated land was significantly decreased by 44.9% and 37.0% than saline-alkali land (P<0.05), but significantly higher than original cultivated land by 35.7% and 58.6%. The total actions and total anions of newly-added cultivated land were significantly lower than saline-alkali land (P<0.05). The exchange sodium percentage of saline-alkali land was around 38% and pH value was close to 10.0, that was classified to severe salinity soil. While the newly-added cultivated land soil exchange sodium percentage was 18.0% and 21.6%, and soil pH value was less than 9.0, that was classified to moderate salinity soil and close to the original cultivated land. Newly-added cultivated soil organic matter was higher than saline-alkali land by 33.4% and 61.3% significantly (P<0.05), but it was significantly lower than original cultivated 21.5% in 0-20 cm soil layer. Newly-added cultivated soil cation exchange capacity was increased by 16.7% and 25.1% than saline-alkali land (P>0.05), and it's slightly higher than original cultivated land. Canonical correspondence analysis results showed that soil physical and chemical properties and ionic composition had significant correlation with plot type distribution. Plot type changed from saline-alkali land to newly-added cultivated land was the process of soil salinization indices decreasing and fertility indices rising in the level of soil physical and chemical properties, and also the process of bicarbonate ion, carbonate ion and sodium ion content reduction in the level of soil ionic composition. Overall, the land consolidation project in Western Songnen Plain could improve salinity soil effectively, but the soil quality of newly-added cultivated land is still lower than the original cultivated land. Therefore, we suggest to improve salinity soil better through improvement of irrigation and drainage system, reasonable land leveling measure and scientific farming. Source

Wang J.,University of Science and Technology of China | Yang R.,Shihezi University | Bai Z.,Key Laboratory of Land Consolidation and Rehabilitation
Ecological Engineering

Drastically disturbed minesoils can result in a significant loss of soil organic carbon (SOC) and total nitrogen (TN). To assess the effect of mining activities on minesoils and to track the changes in reclaimed soil quality, the variability of SOC and TN concentrations in the Shanxi Pingshuo Antaibao opencast coal-mine inner dump after dumping and before reclamation was analyzed using geostatistics, and a number of soil monitoring points were evaluated after land reclamation. Soil samples were collected from depths of 0-20cm, 20-40cm, 40-60cm and 60-80cm at 78 sampling sites in the study area over an area of 0.44km2. The coefficient of variation (CV) for TN was the least at <15% for depths of 0-40cm and 60-80cm. For TN at a depth of 40-60cm and the SOC at all depths, the CV was moderate at 15-35%. Interpolation using kriging displayed a high heterogeneity of TN and SOC, and the spatial structure of the original landform was partially or completely destroyed. Revegetation was an important measure for increasing the accretion of C and N compared to an unmined site. The kriging-interpolated maps were a very valuable tool in monitoring soil properties after land reclamation at the field scale, and RMSE can be used to determine the number of sampling point for soil properties. © 2015 Elsevier B.V. Source

Wang Y.Z.,University of Science and Technology of China | Zhao Z.Q.,University of Science and Technology of China | Zhao Z.Q.,Key Laboratory of Land Consolidation and Rehabilitation | Jiang G.Y.,University of Science and Technology of China
Applied Mechanics and Materials

The effects of phosphates rock (PR) with different particle sizes {D97<4.26 (the diameters of 97% of the particles are less than 4.26 μm.), <36.83, <71.12 and <101.43 μm} and different concentration (2.5% and 5% content of try soil weight) on immobilizing heavy metal-contaminated soils by a perennial ryegrass greenhouse experiment are conducted. Results indicate that remediation effect of applying 5% content is more significant than 2.5%. Ryegrass biomass in shoots in the former applying content is much larger than the latter and for both roots and shoots, PR reduces the absorption and accumulation of Pb, Cu and Zn, but no significant influence on Cd. While adding the same amount of different sizes of PR doesn't show significant differences between these treatments. Pb content at 5% level of the finest size of PR is the minimum, decreased by 33% and 56% compared to the control in roots and shoots respectively, which was also suitable for Zn, decreased by 12.65% and 39.61% respectively. © (2014) Trans Tech Publications, Switzerland. Source

Zhao Z.,University of Science and Technology of China | Zhao Z.,Key Laboratory of Land Consolidation and Rehabilitation | Jiang G.,University of Science and Technology of China | Mao R.,University of Science and Technology of China
Journal of Soil Science and Plant Nutrition

Phosphate-induced immobilization is recognized as one of effective in situ remediation methods for heavy metal contaminated soils. Phosphate-based minerals that adsorb, chelate, or complex heavy metals in soil were greatly concerned as effective heavy metals immobilizing materials. Effects of particle sizes of rock phosphate on immobilizing heavy metals in Pb-Zn mine soils by a greenhouse experiment was conducted. Rock phosphate was added to a Pb-Zn mine soil with four different particle sizes, D97<101.43 μm (UP), D97<71.12 μm (P1), D97<36.83 μm (P2) and D97< 4.26 μm (P3) (the diameters of 97% of the particles were less than 4.26 μm.), and 2 rates (2.5% and 5%). Lolium prenne, L. were grown in the treated soils. Compared to the control, addition of rock phosphate (RP) decreased metal contents in both roots and shoots significantly. Pb contents in shoots decreased by 19.59%-37.80% by different particle sizes at the rate of 5%, reaching lowest level at lowest particle size P3. Zn contents in shoots decreased by 13.47%-13.75%, Cu in roots was decreased by 18.46%-67.98% and in shoots by 16.82%-32.61%, and Cd in roots decreased by 31.03%-74.23%. The results indicated that, RP can reduce the phytoavailability of Pb, Zn, Cu and Cd in soil significantly by immobilization and the effects strengthened with the decrease of particle size and increasing the rate of addition. Source

Hu X.,University of Science and Technology of China | Bai Z.,University of Science and Technology of China | Bai Z.,Key Laboratory of Land Consolidation and Rehabilitation
Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering

Mine reclamation has become a worldwide problem recently and has similar research directions both in China and abroad, including ecological restoration, mining technology, bioremediation technology, soil reconstruction techniques, soil quality testing, plant species selecting. The key target is to restore the ecological system and improve the environment. One of the main purposes of reclamation is to restore farmland, which is scarce in China. In addition, resettlement of residents and their living environment need to be taken into account. In this paper, the study area is the Pingshuo open-pit mine, which is located in Shuozhou City, Shanxi Province, China, and belongs to super-large open-pit mine with modern production. Mining activities began in 1987, and have lasted for 28 years until now. Fourteen rural settlements have moved, and resettlement population has reached 8400 by 2013. From the perspective of farming radius, buffer analysis of rural settlements was used to contrast the difference of farming radius before and after the open-pit mining by geographic information system (GIS) technology. Considering the impact of topography on farming radius, this paper calculated the terrain correction coefficient of farming radius in the study area using the achievements about relief amplitude, and the mean change-point analysis method was adopted to determine the best statistics grid unit to reflect terrain. Through buffer analysis, the result of spatial farming radius showed that the farming radius had a great change from 1986 to 2013 because of open-pit mining. Therefore, the best farming radius should be determined based on the result in 1986. Using the equation of farming radius, per capita arable land and the number of population were calculated through combining the method of "the ratio of arable land area to settlements land area" Finally, optimal farming radius was determined according to the calculation result about the terrain correction coefficient and the scale of arable land. We predicted the size and number of rural settlements after completing reclamation. The results showed that: 1) Affected by mining, the farming radius has expanded by 1500 m from 1986 to 2013, and the largest farming radius was 4500 m; 2) Determining the optimal statistics grid unit to calculate the value of relief amplitude, the result showed that 550 m × 550 m was the optimal statistics grid unit to reflect terrain in study area; 3) Based on the buffer analysis, digital elevation map neighbourhood analysis and forecasting, the terrain correction coefficient of farming radius was 1.6836, and the optimal actual farming radius was 1500 m, and therefore, the optimal spatial farming radius was 891 m. 4) On the premise of guaranteeing the arable land quantity unchanged, the total area of relocated rural settlements was about 651.24 hm2, and there were 67 rural settlements in total. Individual rural settlement area was predicted to be 9.72 hm2, and the control area of arable land was about 109.68 hm2. 5) The total relocated population would be about 29521 (7380 families). The results of this study can provide the reference for the implementment of relocating rural settlements and the reuse of reclaimed arable land in Pingshuo mining area. © 2016, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved. Source

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