scholarly journals Identifying the Relationship between Soil Properties and Rice Growth for Improving Consolidated Land in the Yangtze River Delta, China

2018 ◽  
Vol 10 (9) ◽  
pp. 3072 ◽  
Author(s):  
Xiaoxiao Li ◽  
Man Yu ◽  
Jing Ma ◽  
Zhanbin Luo ◽  
Fu Chen ◽  
...  

China has widely implemented land consolidation, which was expected to increase the amount of cultivated land and enhance grain yields. Key components of land consolidation include filling mall waterbodies and leveling land, both of which have strong impacts on the environment in the Yangtze River Delta. The impacts of land consolidation on soil ecology and agricultural production are not yet clear. Here, we conducted a field survey of soil properties and rice growth to detect the effects of land consolidation in the first growing season. The normalized difference vegetation index (NDVI) was used to analyze the remote sensing data. We found significant differences in the soil properties under different types of land leveling, with a general NDVI pattern of: control > borrowed topsoil area > filled waterbodies area > topsoil cutting area. We found significant heterogeneity in rice NDVI after land consolidation. The NDVI of rice had extremely significant positive correlations with soil organic matter and available zinc. The spatial variation in soil properties caused by land consolidation was a dominant factor leading to the heterogeneity of rice NDVI. Fertilizing soil and strengthening field management should be adopted to provide more ecological services while increasing quantity.

Author(s):  
Shufeng She ◽  
Bifeng Hu ◽  
Xianglin Zhang ◽  
Shuai Shao ◽  
Yefeng Jiang ◽  
...  

Potentially toxic elements (PTEs) pollution in the agricultural soil of China, especially in developed regions such as the Yangtze River Delta (YRD) in eastern China, has received increasing attention. However, there are few studies on the long-term assessment of soil pollution by PTEs over large regions. Therefore, in this study, a meta-analysis was conducted to evaluate the current state and temporal trend of PTEs pollution in the agricultural land of the Yangtze River Delta. Based on a review of 118 studies published between 1993 and 2020, the average concentrations of Cd, Hg, As, Pb, Cr, Cu, Zn, and Ni were found to be 0.25 mg kg−1, 0.14 mg kg−1, 8.14 mg kg−1, 32.32 mg kg−1, 68.84 mg kg−1, 32.58 mg kg−1, 92.35 mg kg−1, and 29.30 mg kg−1, respectively. Among these elements, only Cd and Hg showed significant accumulation compared with their background values. The eastern Yangtze River Delta showed a relatively high ecological risk due to intensive industrial activities. The contents of Cd, Pb, and Zn in soil showed an increasing trend from 1993 to 2000 and then showed a decreasing trend. The results obtained from this study will provide guidance for the prevention and control of soil pollution in the Yangtze River Delta.


Land ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 804
Author(s):  
Bo Niu ◽  
Dazhuan Ge ◽  
Rui Yan ◽  
Yingyi Ma ◽  
Dongqi Sun ◽  
...  

In recent years, the impact of land-use systems on global climate change has become increasingly significant, and land-use change has become a hot issue of concern to academics, both within China and abroad. Urbanization, as an important socioeconomic factor, plays a vital role in promoting land-use transition, which also shows a significant spatial dependence on urbanization. This paper constructs a theoretical framework for the interaction relationship between urbanization and land-use transition, taking the Yangtze River Delta as an example, and measures the level of urbanization from the perspective of population urbanization, economic urbanization and social urbanization, while also evaluating the level of land-use morphologies from the perspective of dominant and recessive morphologies of land-use. We construct a PVAR model and coupled coordination model based on the calculated indexes for empirical analysis. The results show that the relationship between urbanization and land-use transition is not a simple linear relationship, but tends to be complex with the process of urbanization, and reasonable urbanization and land-use morphologies will promote further benign coupling in the system. By analyzing the interaction relationship between urbanization and land-use transition, this study enriches the study of land-use change and provides new pathways for thinking about how to promote high-quality urbanization.


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