323-2 Maize Water Use In Biomass Production Systems.



Wednesday, October 19, 2011: 1:00 PM
Henry Gonzalez Convention Center, Room 206A, Concourse Level

ABSTRACT WITHDRAWN

Constraints to maize stover biomass harvest may be mitigated by using a living mulch (LM) to offset C exports and control soil erosion. Living mulches can compete with the main crop for resources, particularly water. The objectives of this research were to quantify soil water dynamics and maize water use in continuous maize with stover removal. Continuous soil water content (SWC) and reproductive whole-plant water use were measured in no-till maize growing in LM’s of creeping red fescue (CF)(Festuca rubra L.), Kentucky bluegrass (KB) (Poa pratensis L.), and a no LM control between 2008 and 2010 near Ames, IA. In two years with excessive rainfall (2008 and 2010), LM’s increased SWC compared with the control at 15 cm. Excessive SWC in the no-till LM treatments lowered grain yield in 2008 and 2010, although a KB strip-till treatment had similar yields all three years. Reproductive water use efficiency for no-till KB in 2008 and 2009 (51 and 42 g grain cm water-1) was 21 and 14% greater than the control (42 and 37) but 24% lower in 2010 (41 vs. 51). Maize water use in the control during reproductive growth exhibited a bimodal response averaged across the three study years with peak water use occurring at the R1-2 growth interval (0.58 cm d-1) and declining to 0.26 cm d-1 during R5-6. In contrast, no-till KB exhibited a simple negative linear relationship with water use rates declining from a high of 0.47 cm d-1 during the R1-2 growth interval to 0.22 cm d-1 during R5-6. These results indicate LM’s may increase SWC and utilize water more effectively, particularly when combining strip-till and herbicide management.
See more from this Division: C02 Crop Physiology and Metabolism
See more from this Session: Optimizing Yield & Quality of Conventional and Bioenergy Crops