Fertilizer management and nutrient use efficiency on rice paddy in integrated system

Nitrogen budget under integrated production system in fish farming is one of the acceptable practices in maintaining ecological balance and circulation. This result reveals the patterns of pond water and nutrient flows which were strongly influenced by the main fish farming activities resulting to large amount of nitrogen inputs. The main nutrient input sources of nitrogen into the system were found to be pig manure, feed and maggot while outputs were in water, soil, harvested fish and rice; and also in unaccounted forms as a result to discharge. Nutrient composition of rice paddy in integrated production system records 17% N, 19% P and 64% K. The NPK value recorded in integration production system throughout the period of the experiment showed significant difference (p>0.05). There was a positive correlation between nitrogen in rice and rice growth r=0.8373 and 0.7709. The Increase in nutrient is correlated with the increase in the rating of rice growth. The increase in nutrient of unaccounted forms which accumulate in the sediments absorbed by the plant from the soil plays an important role in balance of an aquaculture system. Thus, in order to ensure sustainable productivity there is need to enhance the management of all the nutrient input channels while minimizing the nutrient output through crop intensification.