The response of grain production to changes in quantity and quality of cropland in Yangtze River Delta, China.
BACKGROUND
Cropland in Yangtze River Delta has declined drastically since economic reforms in 1978 that led to rapid economic development. Such cropland loss due to population growth has led to a decline in grain production. This study aimed at analyzing the impact of land use changes on grain production. To achieve this, the spatiotemporal dynamics of cropland during 1980-2010 were analyzed. Irrigation and soil fertility data were used as additional lines of evidence.


RESULTS
Cropland loss had negative impacts on grain production. About 80 and 66% of grain production decreased during 1980-2005 and 2005-2010 respectively. This decline was attributed to the conversion of cropland to built-up areas. Abandoned cropland areas were mainly concentrated in regions with high irrigation capability and high soil fertility, while cropland reclamation was mainly in areas with low irrigation and soil fertility, implying that, although cropland was reclaimed, production remained low. The decline in cropland area has reinforced the chronic food insecurity in Yangtze River Delta.


CONCLUSIONS
This study demonstrated the response of grain production to the changes in cropland quantity and quality. It also provides scientific evidence for decision makers to protect cropland and enhance grain production.
State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing, Jiangsu, 210008, China; University of Chinese Academy of Sciences, Beijing, 100049, China; Department of Environmental Remote Sensing and Geoinformatics, University of Trier, D-54286, Trier, Germany.
Guilin
G
Liu
Luocheng
L
Zhang
Qian
Q
Zhang
Zipporah
Z
Musyimi
D057914:Agricultural Irrigation; D000383:Agriculture; D018533:Biomass; D002681:China; D018556:Crops, Agricultural / Q000254:growth & development; D003657:Decision Making; D002523:Edible Grain / Q000254:growth & development*; D005523:Food Supply; D006798:Housing; D006801:Humans; D011158:Population Growth; D045483:Rivers; D012639:Seeds; D012987:Soil; D014867:Water
D012987:Soil; D014867:Water
Yangtze River Delta; cropland change; grain production; irrigation area; soil fertility