Wednesday, November 15, 2006

Skip-Row Planting as a Drought Avoidance Strategy in the West Central Great Plains.

Merle Vigil1, Brien Henry1, David Nielsen1, Francisco Calderon1, Joseph Benjamin1, and Robert Klien2. (1) USDA-ARS, 40335 County Rd GG, Akron, CO 80720-1029, (2) Univ of Nebraska, North Platte, NE 69101

The Central Great Plains Region is a net importer of feed grains. This market provides an incentive to develop stable dryland corn and sorghum yields. The lack of adequate moisture during silking/pollen shed is a major limitation to dryland feed-grain production in the region. Here we investigate strategies to circumvent the water limitation during silking/pollen shed using a “skip-row” technique. The idea here is that a wider row arrangement changes the timing of soil-water availability and use. Three alternative planting schemes were investigated and compared to planting in conventional 0.76m rows. These were plant 2 rows, skip 2 rows (P2S2); plant 1, skip 1 (P1S1); and a plant 2, skip 1 (P2S1).   Plots were seeded with a roundup ready hybrid in 2004 and in 2005. Variable plant population was also investigated in combination with alternative planting arrangements. There exists a trend for the alternative planting arrangements to yield higher than conventionally planted corn and sorghum. The effect is not always statistically significant. In a preliminary analysis, it seems the alternative planting arrangements show an advantage in the 2500-4500 kg/ha yield range (40-70 bushel/acre), but do not show a disadvantage or an advantage if yields potentials are greater than this up to at least 5500 kg/ha (90 bushels/acre). An analysis of these data would suggest, that the alternative planting arrangements show potential for greater yields in dryer areas and/or in dry years where yields are less than 4500 kg/ha (70 bushel/acre).