Balanced Fertilization of Major Crops in Egypt

There are two objectives for this project: (1) determine the effect of different sources of potassium (K) and balanced fertilization on the yield of the major crops of the common cropping systems in Egypt and (2) promote and extend to farmers the most efficient fertilization and irrigation techniques. For this project, field experiments were conducted on maize with the following treatments investigated: (1) no K fertilizer; (2) 114 kg K₂O/ha as potassium sulfate; (3) 114 kg K₂O/ha as potassium nitrate; and (4) 114 kg K₂O/ha as potassium chloride. Potassium fertilizers were added at three doses: 46, 56, and 66 days after planting.

It was found that all sources of K stimulated vegetative growth, increased yield and its components as compared with the untreated treatment (control). The highest biological maize yield (19 t/ha) was obtained by potassium nitrate, followed by potassium chloride (18.5 t/ha) and then by potassium sulfate (16.4 t/ha). Grain yields were 8.6, 6.9, and 8.2 for potassium nitrate, potassium chloride, and potassium sulfate, respectively. The lowest grain yield (6.5 t/ha) was obtained by the control treatment where no K was added. For the potato crop, 93 kg K₂O/ha were applied. Tuber yields were 46.3, 44.9, 42.0, and 36.9 t/ha for the potassium nitrate, potassium sulfate, potassium chloride, and control treatments, respectively.