China has just experienced a unusual clod winter in history. It is said that the possibility of such coldness was one in fifty years. Southern China, including Hunan, Hubei, Jiangxi, Anhui, Guzhou, Guangxi and Sichuan, suffered most from the low temperatures. The cold spells lasted from late January to the end of mid-March with continuous snow mixed with frozen rains. A number of crops that are used to mild winters could not stand the coldness and were damaged (Fig. 1 and Fig. 2).


Fig. 1 Frozen leafy vevgetable Fig. 2 Frozen rape plants

In the less frozen area such as on the Chengdu Plain and the hilly areas in Sichuan province, the low temperatures caused serious phosphorus (P) deficiency on winter wheat. Leaf yellowing resembling nitrogen (N) deficiency occurred on the wheat that received about 60-75 kg P2O5/ha as usual years (Fig. 3).
These P application rates are commonly used for wheat in Sichuan and no such P problem had occurred on large scale before. Thanks for the field experiments that contained both +P and - P treatments, the nutrient deficiency problem could be correctly identified. In those fields received higher P rates or the areas with higher temperatures, this problem was not observed.

Fig. 2