Two field experiments were carried out at El- Gemmeiza Agricultural Research Station, El-Gharbia Governorate during the two summer growing seasons, 2007 and 2008 to study the effect of nitrogen fertilizer rates, i.e., 15, 30 and 45 kg N/fed and foliar application of compost extract & humic acid on yield components, yield and chemical composition of rice plants and nitrate as well as nitrite content in drainage water at different stages from transplanting.
Results can be summarized as follows:-
Generally, high level of nitrogen fertilizer achieved significantly increases of rice yield and its components as well as N, p & K content of grain and straw compared with low rates in both growing seasons. While, in most cases, the same trend was recorded when second level of 30kg N/fed was practiced.
Spraying humic acid or compost extract led to significant increases in most parameters of yield and its components as well as N, p & K content of grains and straw compared to no addition of such organic compounds in both seasons.
In most cases, the interaction effect between the factors under study was insignificant on rice yield and its components as well as macronutrients content of grains and straw in both seasons.
The high level of nitrogen fertilizer achieved significantly increases of nitrate and nitrite content in drainage water at different stages from transplanting compared to low rates in both stages of two growing seasons. On the other hand, such parameters weren't significant affected by foliar application of humic acid, compost extracts or the interaction between them and nitrogen levels in both seasons.