Effects of chemical and biological fertilizer on yield and nitrogen uptake of rice

A factorial experiment was applied to evaluate the effect of chemical and biological fertilizer on nitrogen uptakes, nitrogen use efficiencies of grain yield and biomass (NUEg and NUEb respectively), yield and yield components of rice. Four biological treatments including:(M1:no fertilizer), ( M2:10 ton/ha cow dung ),(M3:20 ton/ha cow dung) and (M4:5 ton/ha azolla compost) and four chemical fertilizer treatments including: (S1: no fertilizer),(S2:40 kg N /ha),(S3:60 kg N /ha) and ( S4:80 kg N /ha ) were compared. Results showed that highest rate of yield (3387 kg/ha), grain nitrogen uptake (45.1 kg/ha) and total nitrogen uptake (81.4 kg/ha) were reached the highest value at M4. Among the chemical fertilizers the highest grain yield (3373 kg/ha), straw nitrogen uptake (42.9 kg/ha) and total nitrogen uptake (87.7) belonged to highest nitrogen level (S4). Interaction effect of chemical × biological fertilizers didn't show significant difference between all parameters except of yield and grain nitrogen uptake, as the most grain nitrogen uptake and grain yield were obtained in M4S4. So it can be concluded that using of biological fertilizers at appropriate rate and type, considering plant requirement, may improve grain yield, nitrogen uptake in rice.