Maize water use and yield in the solar corridor system: A simulation study

Authors: Timlin, Dennis; KIM, SOO-HYUNG - University Of Washington; Fleisher, David; WANG, ZHUANGJI - University Of Maryland; Reddy, Vangimalla

Submitted to: Book Chapter
Publication Type: Book / Chapter
Publication Acceptance Date: 6/5/2019
Publication Date: 6/20/2019
Citation: Timlin, D.J., Kim, S.-H., Fleisher, D.H., Wang, Z., Reddy, V.R. 2019. Maize water use and yield in the solar corridor system: A simulation study. In: C. L. Deichman and R. Kremer (ed.) The Solar Corridor Crop System: Implementation and Impacts. Elsevier Science. pp. 57-78

Interpretive Summary:

Technical Abstract: The solar corridor system is an agronomic approach to increase crop yields by using wide row spacings that allow light to penetrate into the lower areas of the canopy thus increasing photosynthesis per unit ground area. Wide rows may have some advantages including earlier warming of the soil in the spring and water conservation during drought. Intercropping in the interrow space could also potentially increase overall production per unit area. Row spacing interacts with plant population and the arrangement of plants within the row. There have been a large number of studies to address plant population and row spacing effects on yield and water use in maize but the results are sometimes conflicting and depend on other factors such as climate, hybrid, irrigation and planting date. The objective of this study was to use a maize simulation model with a 2D soil process model (MAIZSIM) to investigate the interactive effects of maize hybrid, climate and plant population on water use efficiency and yield of maize for a site in the maize growing area of Johnson County, Iowa. The simulations used soil properties for two soils found in Iowa with contrasting water holding capacities, two plant populations (3.7 and 6.2 plants m-2), two row spacings (0.75and 1.20 m), and three hybrids (early maturing, medium and late maturing). Thirty years of daily weather date were generated by the program CLIGEN. The model was tested for response to plant population against data from the literature. The model was validated by comparing simulated yields for the thirty year period to yields recorded by the National Agricultural Statistics Service for Johnson County, Iowa for the last 24 years. The means and ranges of the two were similar. The simulations showed that row spacing did not significantly affect yield, WUE, or transpiration. For the same plant population, intercepted light was lower for the wider row spacing. These results were similar to those found in the literature. Yields were higher for the high population treatments but only for the short and mid-season varieties. Yields for the long season hybrid were not different from the midseason suggesting that the longer period of grainfill for the long season hybrid was not an advantage because of decreasing daylength and cooler temperatures. There were only a few years of weather data with strong water stress. When filtered for these years, there was a slight yield advantage to the wider spacing. This research suggests that, for the conditions used here, wider row spacing (to 1.2m) and higher plant populations generally result in higher yields. The model was useful for the purposes of this study and could be used to explore a wider range of management, soil, and climate conditions.