A long fertilization experiment has been conducted on red soil upland for 13years. It was found that soil organic matter content increased from 11.5 g/kg to 24.3 g/kg

the most of soil organic matter increased was easy to oxidize

and less was stable. Applying fertilizer P in red soil for long term increased soil available P content and improved significantly the ability of soil on supplying P. Applying organic fertilizer decreased P fixation in soil and enhanced the utilization efficiency of P fertilizer. The soil became acid obviously

the exchangeable Al in soil increased significantly

crop grew poorly and the yield decreased after applying sole chemical fertilizer for long term. Applying organic chemical fertilizer decreased significantly exchangeable Al in soil

increased soil nutrients content

and kept the high and stable yield of crops.