|Baumhardt, Roland - Louis|
|Evett, Steven - Steve|
|HOWELL, TERRY - Retired ARS Employee|
Submitted to: ASABE Annual International Meeting
Publication Type: Proceedings
Publication Acceptance Date: 3/23/2015
Publication Date: 11/10/2015
Citation: Baumhardt, R.L., Schwartz, R.C., Evett, S.R., Colaizzi, P.D., Howell, T.A. 2015. Crop rotation and residue management effects on deficit irrigated cotton and corn. ASABE Annual International Meeting. CDROM:Paper#152143137.
Interpretive Summary: Irrigation water for the southern High Plains comes from the Ogallala Aquifer. It has negligible recharge South of Nebraska. No-tillage (NT) residues cover the soil and has the potential to capture more rain to reduce irrigation from the falling Ogallala Aquifer. ARS scientists, (Bushland, TX) compared NT and disk tillage (DT) effects on fallow water storage and the yield of irrigated corn or cotton grown after wheat at the USDA-ARS in Bushland, TX increased soil water stored during fallow about 2 inches over DT soil. Compared with DT, NT increased corn yield 86% at the low irrigation rate and 25% at the high rate. The NT cotton yields increased nearly 40% over DT. Greater corn and cotton yield with NT residue was due to lower evaporation and more transpiration. Fallow water savings and efficient use can help preserve the Ogallala Aquifer.
Technical Abstract: Compared with disk tillage (DT), no-tillage (NT) retains residue and increases precipitation capture, which has the potential to reduce irrigation withdrawals from the declining Ogallala Aquifer. Our objective was to quantify DT and NT effects on water conservation during fallow and the subsequent yield of deficit irrigated corn (Zea mays L.) or cotton (Gossypium hirsutum L.) grown in rotation with wheat (Triticum aestivum L.). On a Pullman clay loam (fine, mixed, superactive, thermic Torrertic Paleustoll) at the USDA-ARS Conservation and Production Research Laboratory, Bushland, TX (35.183 degrees N, 102.1 degrees W), we seeded separate blocks of cotton and corn at 12 and 9 plants m-2, respectively, in 0.76-m rows following a 10-month fallow during 2006-2009. Using a lateral move mid-elevation sprinkler system, crops were irrigated every 10 days with nominal 25 or 50 mm amounts to mimic limited well capacities of the region. No-tillage increased soil water stored during fallow by approximately 50 mm over bare DT soil. Although evapotranspiration (ET) increased with increasing irrigation for both corn and cotton, only the shorter cotton crop realized consistently greater ET with residue retaining NT practices. Compared with DT, NT residue management increased mean corn yield by 1.25 Mg ha-1 or 86% at the 2.5 mm d-1 irrigation rate and 25% from 3.86 to 4.82 - Mg ha-1 for the 5.0 mm d-1 irrigation rate. Cotton lint yields did not vary by irrigation rate during any year, but NT increased 4-year mean lint yield 0.35 Mg ha-1 or nearly 40% over DT cotton. We conclude that residue retaining NT conservation tillage increased soil water storage during fallow compared with DT. We attributed greater corn and cotton yield with NT to a continued residue benefit during the growing season to repartition ET for less soil water evaporation and increased crop transpiration, which increased crop water use efficiency.