Tillage layer thickness (TLT) of farmland could be regarded as one of physical indexes in assessing soil productivity and quality. In recent years, tillage layer shallowing was found in China in various regions, mainly due to the adoption of non-tillage or rotary tillage practices, but only little rough and non-quantitative information is available so far on the issue. This research took Anhui, a typical agricultural province in Eastern China as an example and compared the TLTs of 87 typical profiles on provincial scale and 210 on county scale from 1980s to 2010s. The results showed that TLTs of 3.7% and 17.2% of samples in 1980s and 2010s respectively were larger than 20 cm. From 1980s to 2010s the mean TLT increased from 16.3 to 17.4 cm on the provincial scale and from 15.0 to 15.5 cm on the county scale respectively. In the middle and southern regions the mean TLTs increased by 0.4-0.7 cm on the provincial scale and 0.3-3.2 cm on the county scale respectively, but decreased by 2.0 cm in northern region on the county scale. The mean TLT increased by 0.8 cm for paddy-field and 1.4 cm for dry-land on the provincial scale. TLT was influenced comprehensively by the factors of soil texture, the depth of rotary tillage and the farming positivity of the farmers. Generally, TLT of farmland with coarse soil texture was higher than that of farmland with fine soil texture, in 1980s TLT in region of poor-economic condition usually was deeper than in region of good-economic condition, and the adoption of rotary tillage led widely TLTs of farmlands to about 15 cm in 2010s.
 Chen, J., Chen, J.Z., Tan, M.Z. and Gong, Z.T. (2002) Soil Degradation: A Global Problem Endangering Sustainable Development. Journal of Geographical Sciences, 12, 243-252. http://dx.doi.org/10.1007/BF02837480
 Wang, S.Q., Zhou, C.H., Li, K.R., Zhu, S.L. and Huang, F.H. (2000) Analysis on Spatial Distribution Characteristics of Soil Organic Carbon Reservoir in China. Acta Geographica Sinica, 55, 533-544.
 Tai, J.C., Yan, M., Cheng, K. and Pan, G.X. (2011) Change in Topsoil Organic Carbon Changes of China’s Cropland: A Statistical Analysis of Sample Data in Chinese Literature from Available on CNCK Network. Journal of Agro-Environment Science, 30, 1816-1821.