Alternate furrow irrigation for maize production in an arid area

A new irrigation method for maize production was designed and tested for yield and water use efficiency (WUE). A field experiment was conducted in an arid area, with seasonal rainfall of 80 mm, over 2 years (1997 and 1998). Irrigation was applied through furrows in three ways: alternate furrow irrigation (AFI), fixed furrow irrigation (FFI), and conventional furrow irrigation (CFI). AFI means that one of the two neighboring furrows was alternately irrigated during consecutive watering. FFI means that irrigation was fixed to one of the two neighboring furrows. CFI was the conventional way where every furrow was irrigated during each watering. Each irrigation method was further divided into three sub-treatments with different irrigation amounts: 45, 30 and 22.5 mm water at each application. Results showed that root development was significantly enhanced by AFI treatment. Primary root numbers, total root dry weight, and root density were all higher in AFI than in FFI and CFI treatments. Less irrigation significantly reduced the total root dry weight and plant height in both FFI and CFI treatments but not as substantially with AFI treatments. The most surprising result was that AFI maintained high grain yield with up to 50% reduction in irrigation amount, while FFI and CFI all showed a substantial decrease in yield with reduced irrigation. As a result, WUE for irrigated water was substantially increased. We conclude that AFI is a way to save water in arid areas where maize production relies heavily on repeated irrigation.