Increasing nutrient utilization and crop production in the red soil regions of China

Red soils belong to Oxisols, Ultisols, and some of the Alfisols in the soil order of the United States soil taxonomy. These soils had and continue to play an important role in the economic development of China. Non-judicious use of red soil resources, particularly deforestation, has caused severe so il erosion, resulting in the degradation of the environment and reduced agr icultural production in the red soil regions. Various approaches have been developed to restore the fertility of degraded red soils. These include: 1) reclamation of the surface and subsurface soil by a mixture of lime, manur es, and chemical fertilizers; 2) improvement of the entire rooting depth of citrus and other deeply-rooting crops using trench-planting and soil chise ling techniques; 3) increased input of organic materials applied alone or t ogether with chemical fertilizers or Iii-ne; 4) integrated utilization of r ed soil resources to minimize soil erosion and water losses; and 5) diversi fied crop production systems to increase economic return. These efforts hav e proved to be effective in sustaining agricultural production and further improving nutrient utilization efficiency and environmental quality in the red soil regions of China.