The soil reference materials.
| Sample ID | Sampling area | Soil types |
|---|---|---|
| GBW07401a (GSS-1a) | Yichun, Heilongjiang | Dark brown earths |
| GBW07402a (GSS-2a) | Bayan Obo, Inner Mongolia | Castanozems |
| GBW07403a (GSS-3a) | Laizhou, Shandong | Yellow-brown earths |
| GBW07404a (GSS-4a) | Yizhou, Guangxi | Limestone soil |
| GBW07405a (GSS-5a) | Liuyang, Hunan | Yellow-red earths |
| GBW07406a (GSS-6a) | Yangchun | Yellow red earths |
| GBW07407a (GSS-7a) | Xu Wen, Guangdong | Humid-thermo ferralitic |
| GBW07408a (GSS-8a) | Luochuan, Shaanxi Province | Loess |
| GBW07427 (GSS-13) | North China Plain | Soil of cultivation |
| GBW07428 (GSS-14) | Sichuan Basin | Soil of cultivation |
| GBW07446 (GSS-17) | Wulate, Inner Mongolia | Shahist |
| GBW07447 (GSS-18) | Hangmianhou Banner, Inner Mongolia | Saline soil |
| GBW07448 (GSS-19) | Haiyan County, Qinghai | Brown desert soil |
| GBW07449 (GSS-20) | Shanshan, Xinjiang | Saline soil |
| GBW07450 (GSS-21) | Shihezi, Xinjiang | Sierozems |
| NSA-1 | Suihua, Heilongjiang | Phaeozem |
| NSA-5 | Changsha County, Hunan | Paddy soil |
| NSA-6 | Shaoguan, Guangzhou | Red earths |
| HTSB-2 | Luochuan, Shaanxi | Dark loessial soils |
| HTSB-5 | Qinghai mutual assistance | Castanozems |