147-1 Evaluation and Classification of Nationwide Arable Land Quality in China.
Poster Number 1120
The results of classification in 2014 revealed that the total area of arable land was approximately 1.4×108 hm2 in China. Only 2.9% of total arable land was classified as 1-4 level, 26.5% of total arable land was at level 5-8, 52.9% of total arable land was at level of 9-12, and 17.7% of total arable land at level 13-15. In general, the area weighted average level is 9.96 and the acreage of level less than the average value accounted for 60.2%. It indicates that the productivity per unit arable land is extremely low. ECALG combined use top-down and bottom-up method. On the one hand, according to top-down method, from national scale- ecological zoning scale-provincial scale, the CP was calculated for 12 ecological zones and 41 sub-ecological zones which can be used for every province of China. On the other hand, based on bottom-up method, the investigation and evaluation results of field plot, village, town and county can be summarized step by step from bottom to top until generate the provincial and national results. The method including country - province - county - town, village - plot multiple evaluation scale, using 1:10 000 large scale, reflects the characteristics of high precision and the summarizing results is nationally comparing through a standard grain transfer coefficient designing. ECALG help China to establish a nationally unified and comparing system of arable land quality and it is of great significance for the service of food security and arable land quality management.
Key words: Agricultural Ecological Zone , crop growth model, land productivity; arable land; evaluation; classification; nationally unified and comparing level; China