scholarly journals Cropland heterogeneity changes on the Northeast China Plain in the last three decades (1980s–2010s)

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e9835
Author(s):  
Xiaoxuan Liu ◽  
Le Yu ◽  
Qinghan Dong ◽  
Dailiang Peng ◽  
Wenbin Wu ◽  
...  

The Northeast China Plain is one of the major grain-producing areas of China because of its fertile black soil and large fields adapted for agricultural machinery. It has experienced some land-use changes, such as urbanization, deforestation, and wetland reclamation in recent decades. A comprehensive understanding of these changes in terms of the total cropping land and its heterogeneity during this period is important for policymakers. In this study, we used a series of cropland products at the 30-m resolution for the period 1980–2015. The heterogeneity for dominant cropland decreased slowly over the three decades, especially for the large pieces of cropland, showing a general trend of increased cropland homogeneity. The spatial patterns of the averaged heterogeneity index were nearly the same, varying from 0.5 to 0.6, and the most heterogeneous areas were mainly located in some separate counties. Cropland expansion occurred across most of Northeast China, while cropland shrinking occurred only in the northern and eastern sections of Northeast China and around the capital cities, in the flat areas. Also, changes in land use away from cropland mainly occurred in areas with low elevation (50–200 m) and a gentle slope (less than 1 degree). The predominant changes in cropland were gross gain and homogeneity, occurring across most of the area except capital cities and boundary areas. Possible reasons for the total cropland heterogeneity changes were urbanization, restoration of cropland to forest, and some government land-use policies. Moreover, this study evaluates the effectiveness of cropland policies influencing in Northeast China.

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.


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.


1999 ◽  
Vol 16 (2) ◽  
pp. 82-88 ◽  
Author(s):  
Thomas E. Mauldin ◽  
Andrew J. Plantinga ◽  
Ralph J. Alig

Abstract Data on land use in Maine are assembled from USDA Forest Service inventories, the Census of Agriculture, and other sources. Regression analysis is used to estimate the relationships between land use and determinants of land use such as land rents and soil characteristics. The fitted models are used to project changes in land use to 2050. We project declines in private timberland area, though these losses are small on a percentage basis. Continued declines in agricultural land area and increases in urban land area also are projected. Land use policies that influence land rents such as preferential tax assessment programs can be used to deter socially undesirable land use changes. North. J. Appl. For. 16(2):82-88.


1983 ◽  
Vol 10 (3) ◽  
pp. 213-224 ◽  
Author(s):  
Shiu-Hung Luk

In the Maowusu Desert—which in the south-east encompasses part of the Yulin Region, Shaanxi Province, and in the north-west the Ih Ju League, Inner Mongolia Autonomous Region—desertification trends in relation to the impact of droughts and land-use changes were investigated. Data derived from Earth resources technology satellites (LANDSAT I and LANDSAT II, 1974–1978), and Chinese documentary sources, were used for the analysis. It was found that desert ‘expansion’ occurred during 1953–76, but the rates of expansion varied over time and space, relatively rapid desertification being observed for 1959–63 and 1971–76. The bulk of the expansion was located in the more arid Ih Ju League. The mean annual rate of areal expansion was 6.4% during 1958–71. By comparing the desertification rates with precipitation and land-use information, it was established that droughts have only accentuated the desertification process. The primary cause of desert expansion is the excessive clearing of land for rain-fed agriculture as well, of course, as overgrazing. Another contributory factor was culling of vegetation for fuel and raw materials for handicraft industries.Efforts have been expended on desert control since the mid-1950s, resulting in the arresting of desertification in some local areas. The individual success stories demonstrate that, with mass participation, effective desert control can be achieved by using low-level technology. However, the Chinese programme of desert control was not conceived as a comprehensive programme. Control activities relied almost exclusively on vegetational methods, and they were seldom coordinated with land-use policies as well as with the planning of energy supplies. The negligence of the fundamental conflict between expanding agricultural activities and desert control has led to a net desert expansion in the last 30 years. Recognition of this fundamental conflict and implementation of mitigative land-use policies, would be a major step towards resolving the desertification problem in the Maowusu Desert.


2019 ◽  
Vol 99 (4) ◽  
pp. 406-419 ◽  
Author(s):  
Haiqiang Li ◽  
Xiaolin Liao ◽  
Hansong Zhu ◽  
Xiaorong Wei ◽  
Mingan Shao

Black soil is inherently productive and fertile but is subject to soil erosion. Understanding the distribution of soil physical and hydraulic properties of the soil profile under various land uses would help reveal the mechanism behind the degradation of black soil. In this study, we investigated the variation in soil physical and hydraulic properties with land uses and soil depths in the black soil area of Northeast China. Disturbed samples and undisturbed soil cores were collected from 0–100 cm soil depths under agricultural land (AL), forestland (FL), and shrub land (SL). Our results showed that the land use and soil depth significantly affected the soil bulk density (BD), field capacity (FC), capillary moisture capacity (CMC), saturated hydraulic conductivity (Ks), and soil water retention curve (θs and α). Small macroaggregates accounted for most of the soil mass and were significantly higher in FL but lower in AL for the 0–50 cm of the soil samples. The FC, CMC, and Ks decreased, but the BD increased with the soil depth across the three land-use types. In addition, the soil in AL had a higher BD but lower CMC and Ks than the soil in FL and SL for most soil depths. These results indicated that land use can influence the variation in soil physical and hydraulic properties within the 0–100 cm soil depth, and agricultural use is a major reason for soil degradation in this black soil region.


2012 ◽  
Vol 50 (5) ◽  
pp. 888-899 ◽  
Author(s):  
Fanghua Hao ◽  
Xuehui Lai ◽  
Wei Ouyang ◽  
Yiming Xu ◽  
Xinfeng Wei ◽  
...  

2021 ◽  
Vol 13 (17) ◽  
pp. 9563
Author(s):  
Yan Qu ◽  
Chulin Pan ◽  
Hongpeng Guo

Taking the conservation tillage influences of black soil in Northeast China as the research object, the paper is written according to the advice of relevant experts and technicians in Northeast China, the study also calculates the weight of each influencing factor through the Delphi and Analytic Hierarchy Process (AHP) method. Then, the significance of the factors affecting the benefit of conservation tillage is analyzed. The results show that, based on the comprehensive analysis, it is concluded that the economic factor is the primary factor affecting the benefit of black soil conservation tillage in Northeast China. Among the twelve influencing factors, eight of them have a significant impact on the development of conservation tillage benefits on black soil in Northeast China. Such as the degree of government subsidy; the adaptability of agricultural machinery; the input of new technology; relevant policies, laws and regulations; the quality of conservation tillage; the income of agricultural machinery farmers; practical application capacity; government publicity. Therefore, in the process of implementing the black soil conservation tillage, we should focus on these influencing factors, which will effectively promote the sustainable development of agriculture in Northeast China.


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