Maize (Zea mays L.) is one of the most important cereal crops in the world and ranks the third of most important cereal crops in the world. Also, it ranks the third of the world cereal crops which surpassed by wheat and rice. In the USA maize is considered the king of cereal crops. Tillage has traditionally been performed to achieve appropriate seedbed preparation treatments which may lead to favorable changes in the physical and chemical structure of the soil for better microflora soil activities; nutrient availability and absorption which all reflected on the excellent plant perform as, yield and its quality. Meanwhile, nitrogen is a key element for corn productivity as well as in many other field cereal crops. Это и многое другое вы найдете в книге Maize yield asaffected by organic & mineral nitrogen and tillage (El-Saeed El-Gedwy,Mohamed El-Sayed Riad Gomaa and Salah Abbas Hassan Allam)