Jiangnan in Spring Rain, by Mei Qilin. [Photo/artron.net]

Water as precious as oil

According to an old Chinese saying, the rainfall in spring is as precious as oil. In northern China, the spring drought is common and the precipitation of this season accounts for only 10 to 15 percent of annual average rainfall.

Therefore, Rain Water is considered as a key period for irrigation when the day gets warmer and rainfall increases.