2008 Joint Annual Meeting (5-9 Oct. 2008): Skip Row Planting and Tie-ridging to Improve Sorghum Yield in Semi-arid Ethiopia.

Water deficit stress during grain fill often results in low grain yield, small kernel size, and low harvest index values for grain sorghum in Ethiopia and may reduce sorghum grain production by 350,000 Mt per year. Skip row planting is a means of saving soil water for the grain fill period, often resulting in increased mean yields in water deficit environments as well as reduced probability of complete crop loss. Tie-ridging is a micro-basin tillage practice intended to reduce runoff. Seven trials were conducted in semi-arid sorghum production areas of central and northern Ethiopia. The mean grain yield increase for three trials conducted in northern Ethiopia was 33% for planting two rows and omitting the third compared to conventional planting while there was no yield increase or decrease in skipping every other row. There was no yield increase with skipping alternate rows in central Ethiopia, and yield was reduced in some trials with planting 2 rows and skipping 2 rows. Tie ridging increased yield in the northern and central Ethiopia trials. Skip row planting and tie ridging have potential to improve sorghum yield if well targeted to suitable environments. The practices appear to be more appropriate in northern Ethiopia, possibly due to a shorter rainfall season.