10 Jul 2017
Provincial Potassium Balance of Farmland in China between 1980 and 2010
Abstract
Great changes have been happened over the past 30 years in chemical fertilizer input in China, and thus a gross potassium (K) budget model established to evaluate the variation of farmland K balance for China in 1980 and 2010 at the national scale is important. Results indicated that total K input in 1980 was 6.8 million tonnes, in which chemical fertilizer, organic manure and other sources accounted for 5.6, 77.5 and 16.9% respectively. Total K input in 2010 was 21.6 million tonnes, in which chemical fertilizer, organic manure and other sources accounted for 43.5, 50.4 and 6.1% respectively. Total K output in 1980 was 8.1 million tonnes, in which crops removal and loss accounted for 98.2 and 1.8% respectively. Total K output in 2010 was 19.1 million tonnes, in which crops removal and loss accounted for 99.2 and 0.8%, respectively. Similar to K input, the spatial distribution of K output differed greatly. Total K deficit was 1.3 million tonnes, and the range of K balance in each province was −86.7 to 53.6 kg K2O ha−1 in 1980. Compared with that, total K surplus was 2.5 million tonnes and the range of K balance in each province was −43.0 to 256.6 kg K2O ha−1 in 2010. Chemical fertilizer K application over the past 30 years makes the great changes in average K balance from deficit to surplus in general; however, the great spatial variation in K balance drives urgent need for site-specific K nutrient management.
Liu, Y, Yang, J, He, W, Ma, J, Gao, Q, Lei, Q, He, P, Wu, H, Ullah, S & Yang, F 2017, 'Provincial Potassium Balance of Farmland in China between 1980 and 2010', Nutrient Cycling in Agroecosystems, vol. 107, no. 2, pp. 247-264. doi:10.1007/s10705-017-9833-2