Effect of biogas slurry application on N, P and K uptake and utilization characteristics of Zizania latifolia
A filed experiment was conducted to study the effect of biogas slurry application on N,P and K accumulation at different growth stages and utilization rate of Zizania latifolia.It was shown that P and K accumulation at maturity stage were suppressed obviously under treatments of 2.ON and 2.7N,in which the application rate of biogas slurry were 2.0 and 2.7 times the application rate of chemical nitrogen in control (CK) treatment.Compared to CK,P and K accumulation was decreased by 8.73% and 42.0%,and 16.4% and 34.1%,respectively,under these two treatments.N accumulation at maturity stage was decreased significantly only under 2.7N treatment.N and P concentrations in stems and leaves of Zizania latifolia during whole growth stage showed a rising trend generally under 2.ON and 2.7N treatments,especially for 2.7N,which were contrary to K.N concentrations in edible parts of Zizania latifolia were increased with the increase of biogas slurry application rates.K concentrations were increased firstly and then decreased.However,P concentrations kept relatively stable.Biogas slurry application could restrain P translocation in stems,but promote K translocation in both stems and leaves.In addition,2.ON and 2.7N treatments significantly reduced N translocation in leaves.In conclusion,biogas slurry application could affect N,P and K uptake and accumulation in Zizania latifolia and alter nutrient utilization efficiency.Reasonable application rate shall be beneficial to increase nutrient utilization efficiency.