Given the increasing dairy and poultry industries, cowdung (CD) and poultry manure (PM) might become alternative sources of nitrogen (N) for rice production in South Asia. A field experiment was conducted during dry season (Nov-April) in Chhiata clay loam soil. The experiment aimed to evaluate the effect of N from organic and inorganic sources on dry matter and N uptake pattern of rice. We compared (i) N-control, ii) Optimum dose of nitrogen (164 kg N/ha) from urea, iii) 50% N from urea and 50% N from CD, iv) 50% N from urea and 50% N from PM, v) 100% N from CD and vi) 100% N from PM. Two mega varieties BRRI dhan28 and BRRI dhan29, were used as test crops. Application of N from urea, urea + PM and absolute PM increased dry matter significantly both in BRRI dhan28 and BRRI dhan29. The combination of urea and PM, absolute urea and absolute PM gave greater N uptake compared to other treatments in different growth stages of rice. The urea + PM treatment gave similar yield to that of urea in both the varieties, however, BRRI dhan29 gave about 1.17 t /ha higher yield than BRRI dhan28. The PM treatment gave similar yield to that with urea + PM in BRRI dhan28, but BRRI dhan29 gave significantly lower yield in PM than the urea + PM. Sole cowdung or poultry manure application produced significantly lower grain yield than urea + PM treatment and sole urea application. Because of insufficient mineralization of N from CD and PM, sole organic sources of N were not as good as combined use of organic and inorganic fertilizer amendments.
