INFLUENCE OF COMPOST, N-MINERAL an‎d HUMIC ACID ON YIELD an‎d CHMICAL COMPOSITION OF WHEAT PLANTS

Two field experiments were carried out at the experimental farm of El-Ismailia Agric. Research station, during two successive winter seasons of 2007/2008- 2008/2009 to study the effect of different levels of nitrogen fertilizers 0,25, 50, 75 and 100kg N/fed. from recommended dose (100kg/fed) with or without composted rice straw and / or humic acid on yield, yield components, chemical composition of wheat plant and its attributes as well as NPK uptake of wheat grain and straw, and protein content. A three way randomize complete block (Factorial) design with three replicates was used. The obtained results could be summarized as follow;- 1- Raising mineral nitrogen fertilizer level from 25 to 50, 75 and 100 kg N/fed resulted in significant increases in plant height, spike length, grain and straw yields/fed and protein content of grain and straw. Also, NPK uptake of grain and straw were significantly increased. 2- The wheat grain and straw yields as well as their NPK contents and grain protein were significantly increased by application of compost and humic acid treatments. 3- Raising the nitrogen rate along with compost application increased the quantity and quality of wheat yield. 4- Addition of humic acid markedly increased plant height, spike length, 1000-grain weight, grain and straw yield/fed., protein content of grain, NPK uptake of both grain and straw. 5- The interaction between compost, mineral nitrogen level and humic acid had significant effects on grain yield/fed. and N,P and K uptake of straw and 1000-grain weight. 6- The highest values for yield and its components were obtained by humic acid, under the highest level of nitrogen fertilizer and compost treatment. Therefore, it could be concluded that the application of compost+ 100 kg N/fed + humic acid was the most compatible and economical, since it has the highest wheat yield.