Cropland soil organic matter content change inNortheast China, 1985-2005

Abstract

Soil organic matter (SOM) content is one of themost important indicators of soil quality and hence theproductive capacity of soils. Northeast China (NEC) is themost important region in grain production in China. Inthis study,we assessed the spatiotemporal change of croplandSOM content in NEC using sampling data of 2005 andsurvey data of 1985. We also analysed the driving forcesbehind the SOM content change. Our results showed thatSOM content decreased in 39% of all the cropland in NEC,while increase in SOM content was only detected on 16%of the cropland. SOM remained unchanged in nearly half(i.e. 45%) of the cropland. Our results also revealed thatcropping intensity and fertilizer application were the twomost important factors driving SOM change. Overall, resultsfrom this research provided novel details of the spatiotemporalpatterns of cropland SOM content change inNEC which was not revealed in earlier assessments. Thedatasets presented here can be used not only as baselinesfor the calibration of process-based carbon budget models,but also to identify regional soil quality hotspots andto guide spatial-explicit soil management practices.

Keywords

• agriculture
• geostatistics
• kriging
• soil quality
• organic carbon
• change attribution