Effect of 5-year rapeseed cake fertilization and straw mulching on tea plantation soil ecosystem.

In the Baili Tea Gallery of Changsha County,field experimentation for five years was conducted to explore the impacts of rapeseed cake fertilization and straw mulching on the soil ecosystem of hilly tea plantations.The results show that soil pH,organic matter content,total N content and available P content are all higher under rapeseed cake with straw mulching (T1) than those under inorganic fertilizers (T3) alone.While soil bulk density in the 0～40 cm soil profile drops significantly,water content in the 0～60 cm soil profile,quantity and biomass of earthworm,amounts of microorganisms such as amino bacteria,aerobic in-situ nitrogen-fixing bacteria,anaerobic in-situ nitrogen-fixing bacteria,actinomycetes,fungi and bacteria in the 0～20 cm soil profile significantly increase in T1 than in T3.Rapeseed cake fertilization in conjunction with straw mulching significantly improves soil ecological functions in hilly tea plantations.Combined rapeseed cake and chemical fertilizer along with straw mulching (T2) to some extent improves soil ecosystem.Zero long-term fertilization results in overall decline in soil nutrient stock in tea plantations.