The soil in the plains of northern Jiangxi is alluvial and permits intensive cultivation. The hilly lands in other parts of the province have red and yellow soils. On farms with clayey red soils, where the rains have washed away the mineral contents as well as the humus, the soil requires working over and the addition of green manure or chemical fertilizers in order to become productive.
Situated in the subtropical belt, Jiangxi has a hot and humid summer lasting more than four months, except in places with high elevation such as the Lu Mountains. High temperatures in Nanchang in July and August average 95 °F (35 °C). In winter temperature variations between north and south are greater. January temperatures in the north at times fall to 25 °F (−4 °C), while those in the south average 39 °F (4 °C). Most of the province has a growing season of 10 to 11 months, thus making possible two crops of rice. Rainfall is plentiful, particularly during May and June. Average annual rainfall is about 47 inches (1,200 mm) in the north and 60 inches (1,500 mm) in the south; in the Wuyi Mountains region it can reach 78 inches (2,000 mm).