Abstract: The results from an eight years field experiment on cinnamon soil in western Liaoning indicatethat the recycled nutrients in compost made by 60% of the harvested products from the Plotsapplied with different fertilizers every year could increase crop yields by 29.6 % (no fertilizer),15.2 % (N), 11.1 % (NP) and 9.2 % (NPK)respectively, or give an averaxe increase of 1.33,0.99, 0.79 and 0.64 t·hm^-2 respectively. There was a trend that the effect of recycled nutrients in compost on crop ytelds was significantly increased during the period of experiment, implying the existence of accumulative residual effect from recycled comopt. Therefoe, a real effectiveness of recycled nutrients on crop yields could only be estimated by a long term field experiment.

Key words: Agro-ecosystem, Nutrients cycle, Crop yield, cotton fiber quality, GGE biplot, regional crop trial, ecological regiona-lization, cotton (Gossypium hirsutum), major cotton-producing area