Rice productivity and its inner quality as affected by anhydrous ammonia rates with foliar application of organic acids

A field experiment was carried out at El- Gemmeiza Agricultural Research Station, El-Gharbia Governora te during the two summer growing seasons, 2011 and 2012 locat ed at lat. 30.47, long 31.00 and 14.80 m above the mean sea level to study the effect of nitrogen fertilizer rates, i.e., control (without N fertilizer),25, 50 and 75 kg N/fed., and foliar application of humic and fulvic acids togeth er or individually on yield, chemical composition o f rice plants and nitrate as well as nitrite content in drainage water at 60 days from transplanting as well as of safter harvesting. High level of nitrogen fertilizer (75 k g N /fed.,) achieved significantly increases of ric e yield and N, P & K content of grain and straw as well as NO 2 and NO 3 of grain and straw . While, the lowest significant values of such parameters were recorded by low rates(without addition of nitrogen fertilizer )followed by 25 kg N/fed.,in both growing seasons. Foliar application of humic and fu lvic acids together led to significant increases of rice yield and N, P & K content of grain and straw as well as NO 2 and NO 3 of grain and straw, whereas, the lowest significan t ones were obtained when sole foliar application of fulvic acid in both seasons. In most cases, the hig hest significant values of rice yield and N, P & K content of grain and straw as well as NO 2 and NO 3 of grain and straw were obtained when foliar application of humic and fulvi c acids together under the high levels of nitrogen fertilizer was added. While, the lowest ones were recorded with so le foliar spray of fulvic acid under the low level of N in both seasons. The high level of nitrogen fertilizer ach ieved significantly increases of nitrate and nitrite content in drainage water at 60 days from transplanting as we ll as nitrate, nitrite and ammonium of soil after h arvesting compared to low rates in both seasons. While, the sparameters were increased significantly by sole application of humic and /or fulvic acidc, but the lowest ones were achieved by foliar spray of both organic acid s together in both seasona. On the other hand, such parameters w ere significantly increased by sole foliar applicat ion of humic or fulvic acids with high levels of nitrogen fertilizer. Whereas, the lowest ones were observed by fol iar spray of humic and fulvic acisd together with no addition of nitrogen fertilizer in both seasons.