Abstract: Along term experiment was carried out on a damp palm soil about ten years under the condition of nutrient recycling and reutilization. The quantity of crop nutrients transferred from the system,and the nutrient budget of N,Pand Kin soil were studied. The results of a ten-year field experiment indicated that the use of nutrients recycled in the farming systems with appropriate amount of fertilizers applied according to the soil nutrient supplying ability could not only produce high crop yield, but also balance the soil nutrient budget,so that,there were no significant surplus of nutrients (mainly inorganic nitrogen) which might emit or leach out of soil into environment.

Key words: Nutrient recycling and reutilization, Long term field experiment, Soil nutrient budget, tree age, old tree, growth history, dendrochronology