Abstract: To advocate for reduced use of chemical nitrogen fertilizers and explore scientific fertilization patterns and finally to achieve the planting goals of green, stable and high yield, an experiment with two factors of nitrogen reduction ratio and organic fertilizer application were conducted for two years, with blank treatment (CK₀) and routine nitrogen application rate (CK₁) as two controls. There were two levels of nitrogen reduction ratios, 20% (A₁) and 40% (A₂), and three levels of organic fertilizer, without organic fertilizer (B₀), common organic fertilizer (B₁), and bioorganic fertilizer (B₂). We examined the effects of nitrogen reduction with application of different organic fertilizers on the accumulation, allocation, and transport of dry matter and on the yield of maize. The results showed that the accumulation of dry matter and maize yield decreased with decreasing nitrogen application. Application of organic fertilizer significantly increased dry matter accumulation, allocation ratio in grain, contribution rate of dry matter to grains after silking, and yield. Treatments A₁B₁ and A₁B₂ increased dry matter accumulation in two years on average by 31.38% and 46.29%, and yield by 19.57%, 23.78%, respectively (P<0.05), compared with A₁B₀; and increased yield by 7.15% and 10.95%, respectively, compared with CK₁. Treatments A₂B₁ and A₂B₂ increased dry matter accumulation in two years on average by 19.68% and 35.13%, and yield by 6.33% and 7.48% (P<0.05), respectively, compared with A₂B₀; while decreased yield by 10.42% and 9.44%, respectively, compared with CK₁. Appropriate reduction of nitrogen fertilizer combined with application of organic fertilizer could improve dry matter accumulation, improve panicle traits, and ultimately increase yield of maize. In this study, application of 1500 kg·hm^-2 organic fertilizer with 20% reduction of chemical nitrogen fertilizer increased maize yield, which shows the best effect of bio-organic fertilizer application on the yield.

Key words: small hydropower substitute fuel project, forest ecology, service function value.