While those of us in the midwest have a relatively easy time coaxing our corn to grow, farmers and researchers in the Texas High Plains face almost continuous drought. This area is the most intensively irrigated region in the state, according to the Texas High Plains Evapotranspiration Network. How can corn be grown in this region and other drought prone areas to maximize yield while reducing the amount of water that is applied? We can find an answer in Growing maize in clumps as a strategy for marginal climatic conditions.
Corn tillers, by Joel Ransom, Extension Agronomist at NDSU.
Researchers from Texas A&M University and USDA-ARS found that “growing maize in clumps compared with equidistant spacing reduced the number of tillers, early vegetative growth, and [leaf area index]. This conserved more soil water for use during the grain filling stage resulting in increased grain yield. The increased yield was primarily due to higher kernel mass and higher Harvest Index values although total aboveground biomass was also higher for the clump treatments.”
Tillers on corn may not have any effect on yield, according to Extension documents like: Tillers or “Suckers” in Corn: Good or Bad? and studies by However, tillers may be an unnecessary sink for precious water in places like the Texas High Plains. It would be interesting to see a study of the effect of tillers on yield under normal and drought conditions.
One problem with adoption of this method is that maize planted in clumps may not be easily harvested with commercial harvesters as they are currently configured. Still, it will be immediately useful for anyone who harvests by hand. Is this planting method being used in drought-prone areas of Africa and Central America? If not, clump planting may be something to try.
Full abstract of Growing maize in clumps as a strategy for marginal climatic conditions:
Under dryland conditions of the Texas High Plains, maize (Zea mays) production is limited by sparse and erratic precipitation that results in severe water stress particularly during grain formation. When plant populations are reduced to 2.0–3.0 plants m−2 to conserve soil water for use during grain filling, tillers often form during the vegetative growth and negate the expected economic benefit. We hypothesized that growing maize in clumps spaced 1.0 m apart would reduce tiller formation, increase mutual shading among the plants, and conserve soil water for grain filling that would result in higher grain yield. Studies were conducted during 2006 and 2007 at Bushland, TX. with two planting geometries (clump vs. equidistant), two irrigation methods (low-energy precision applicator, LEPA, and low-elevation spray applicator, LESA) at three irrigation levels (dryland, 75 mm and 125 mm in 2006; and dryland, 50 mm and 100 mm in 2007). For dryland plots in 2007, clump plants had only 0.17 tillers (0.66 tillers m−2) compared with 1.56 tillers per plant (6.08 tillers m−2) for equidistant spacing. Tillers accounted for 10% of the stover for the equidistant plants, but less than 3% of the grain. Clump planting produced significantly greater grain yields (321 g m−2 vs. 225 g m−2 and 454 g m−2 vs. 292 g m−2 during 2006 and 2007, respectively) and Harvest Indexes (0.54 vs. 0.49 and 0.52 vs. 0.39 during 2006 and 2007, respectively) compared with equidistant plants in dryland conditions. Water use efficiency (WUE) measurements in 2007 indicated that clumps had a lower evapotranspiration (ET) threshold for initiating grain production, but the production function slopes were 2.5 kg m−3 for equidistant treatments compared to 2.0 kg m−3 for clump treatments. There was no yield difference for method of irrigation on water use efficiency. Our results suggest that growing maize in clumps compared with equidistant spacing reduced the number of tillers, early vegetative growth, and Leaf Area Index (LAI) so that more soil water was available during the grain filling stage. This may be a useful strategy for growing maize with low plant populations in dryland areas where severe water stress is common.
Strange that these researchers do not mention that Native Americans have grown maize this way for as long as they’ve been growing corn in the American Southwest.