Impact of land use, fertilization and seasonal variation on the abundance and diversity of nirS-type denitrifying bacterial communities in a Mollisol in Northeast China

2018 ◽  
Vol 85 ◽  
pp. 4-11 ◽  
Author(s):  
Zhenhua Yu ◽  
Junjie Liu ◽  
Yansheng Li ◽  
Jian Jin ◽  
Xiaobing Liu ◽  
...  
Forests ◽  
2019 ◽  
Vol 11 (1) ◽  
pp. 40 ◽  
Author(s):  
Shi-Jun Wu ◽  
Jiao-Jiao Deng ◽  
You Yin ◽  
Sheng-Jin Qin ◽  
Wen-Xu Zhu ◽  
...  

Soil microorganisms play a vital role in the biogeochemical cycle, whereas land use change is one of the primary factors that affects the biodiversity and functionality of terrestrial ecosystems. The composition and diversity of bacterial communities (by high-throughput sequencing of the bacterial 16S rRNA gene) were evaluated in the soils of the Montane Region of Northeast China, across different land use types, e.g., natural secondary forest (Quercus mongolica, QM), shrubland (SL), coniferous plantation (Larix gmelinii, LG, and Pinus koraiensis, PK), and agricultural land (Zea mays, ZM). Significant differences in the chemical characteristics and bacterial communities in soils under different land uses were observed in this study. Soil resident TC (total carbon) and TN (total nitrogen) were much higher in secondary natural forest soils, than in coniferous plantation and agricultural soils. Compared with forest and shrubland soils, soil bacterial OTUs, the Chao1 index, and the ACE index were the lowest in the ZM. There were high proportions of Proteobacteria, Actinobacteria, Acidobacteria, Chloroflexi, Gemmatimonadetes, Verrucomicrobia, Bacteroidetes, Planctomycetes, Saccharibacteria, and Nitrospirae in agricultural and forest soils, which accounted for over 90% of the reads in each sample. We found that the dominant group in the forest and shrubland soils was Proteobacteria, while the most dominant group in the ZM was Actinobacteria. The results of both heatmap and principal component analyses displayed groups according to land use types, which indicated that the bacterial communities in the areas under study were significantly influenced by long term differently managed land use. Furthermore, redundancy and Pearson correlation analyses revealed that the bacterial communities were primarily regulated by soil characteristics. This suggested that altered land use patterns initiated changes in the chemical properties of the soils, which affected the composition of microbial communities in this area. This provides a scientific basis for the evolutionary mechanism of soil quality, as well as the rational development and utilization of land resources.


2016 ◽  
Vol 74 ◽  
pp. 121-127 ◽  
Author(s):  
Zhenhua Yu ◽  
Junjie Liu ◽  
Judong Liu ◽  
Jian Jin ◽  
Xiaobing Liu ◽  
...  

2021 ◽  
Vol 10 (5) ◽  
pp. 348
Author(s):  
Zhenbo Du ◽  
Bingbo Gao ◽  
Cong Ou ◽  
Zhenrong Du ◽  
Jianyu Yang ◽  
...  

Black soil is fertile, abundant with organic matter (OM) and is exceptional for farming. The black soil zone in northeast China is the third-largest black soil zone globally and produces a quarter of China’s commodity grain. However, the soil organic matter (SOM) in this zone is declining, and the quality of cultivated land is falling off rapidly due to overexploitation and unsustainable management practices. To help develop an integrated protection strategy for black soil, this study aimed to identify the primary factors contributing to SOM degradation. The geographic detector, which can detect both linear and nonlinear relationships and the interactions based on spatial heterogeneous patterns, was used to quantitatively analyze the natural and anthropogenic factors affecting SOM concentration in northeast China. In descending order, the nine factors affecting SOM are temperature, gross domestic product (GDP), elevation, population, soil type, precipitation, soil erosion, land use, and geomorphology. The influence of all factors is significant, and the interaction of any two factors enhances their impact. The SOM concentration decreases with increased temperature, population, soil erosion, elevation and terrain undulation. SOM rises with increased precipitation, initially decreases with increasing GDP but then increases, and varies by soil type and land use. Conclusions about detailed impacts are presented in this paper. For example, wind erosion has a more significant effect than water erosion, and irrigated land has a lower SOM content than dry land. Based on the study results, protection measures, including conservation tillage, farmland shelterbelts, cross-slope ridges, terraces, and rainfed farming are recommended. The conversion of high-quality farmland to non-farm uses should be prohibited.


2020 ◽  
pp. 124996
Author(s):  
Diwu Fan ◽  
Shengyan Wang ◽  
Yanhui Guo ◽  
Jian Liu ◽  
Evgenios Agathokleous ◽  
...  

Author(s):  
Luoman Pu ◽  
Jiuchun Yang ◽  
Lingxue Yu ◽  
Changsheng Xiong ◽  
Fengqin Yan ◽  
...  

Crop potential yields in cropland are the essential reflection of the utilization of cropland resources. The changes of the quantity, quality, and spatial distribution of cropland will directly affect the crop potential yields, so it is very crucial to simulate future cropland distribution and predict crop potential yields to ensure the future food security. In the present study, the Cellular Automata (CA)-Markov model was employed to simulate land-use changes in Northeast China during 2015–2050. Then, the Global Agro-ecological Zones (GAEZ) model was used to predict maize potential yields in Northeast China in 2050, and the spatio-temporal changes of maize potential yields during 2015–2050 were explored. The results were the following. (1) The woodland and grassland decreased by 5.13 million ha and 1.74 million ha respectively in Northeast China from 2015 to 2050, which were mainly converted into unused land. Most of the dryland was converted to paddy field and built-up land. (2) In 2050, the total maize potential production and average potential yield in Northeast China were 218.09 million tonnes and 6880.59 kg/ha. Thirteen prefecture-level cities had maize potential production of more than 7 million tonnes, and 11 cities had maize potential yields of more than 8000 kg/ha. (3) During 2015–2050, the total maize potential production and average yield decreased by around 23 million tonnes and 700 kg/ha in Northeast China, respectively. (4) The maize potential production increased in 15 cities located in the plain areas over the 35 years. The potential yields increased in only nine cities, which were mainly located in the Sanjiang Plain and the southeastern regions. The results highlight the importance of coping with the future land-use changes actively, maintaining the balance of farmland occupation and compensation, improving the cropland quality, and ensuring food security in Northeast China.


Land ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 107
Author(s):  
Ge Song ◽  
Hongmei Zhang

Cultivated land use layout adjustment (CLULA) based on crop planting suitability is the refinement and deepening of land use transformation, which is of great significance for optimizing the allocation of cultivated land resources and ensuring food security. At present, people rarely consider the land suitability of crops when using cultivated land, resulting in an imbalance between crop distribution and resource conditions such as water, heat, and soil, and adversely affects the ecological security and utilization efficiency of cultivated land. To alleviate China’s grain planting structural imbalance and efficiency loss, this paper based on the planting suitability of main food crops (rice, soybean, and maize) to adjust and optimize the cultivated land use layout (CLUL) in the typical counties of the main grain production area in Northeast China, using the agent-based model for optimal land allocation (AgentLA) and GIS technology. Findings from the study show that: (1) The planting suitability of rice, soybean, and maize in the region is obviously different. Among them, the suitability level of soybean and maize is high, and that of rice is low. The current CLUL of the food crops needs to be further optimized and adjusted. (2) By optimizing the layout of rice, soybean, and maize, the planting suitability level of the food crops and the concentration level of the CLUL spatial pattern have been improved. (3) The plan for CLULA is formulated: The study area is divided into rice stable production area, maize-soybean rotation area, maize dominant area, and soybean dominant area, and town or village is identified as the implementation unit of CLULA. The plan for CLULA will be conducive to the concentrated farming of food crops according to the suitable natural conditions and management level. The research realized the optimization of spatial structure and cultivated land use patterns of different food crops integrating farming with protecting land. The significance of the study is that it provides a scientific basis and guidance for adjusting the regional planting structure and solving the problem of food structural imbalance.


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