Submitted to: Agronomy Journal
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/1/2006
Publication Date: 10/31/2006
Citation: Felter, D.G., Lyon, D.J., Nielsen, D.C., Baltensperger, D.D., Arkebauer, T.J. 2006. Evaluating crops for a flexible summer fallow cropping system. Agronomy Journal 98:1510-1517. Interpretive Summary: Cropping systems that employ more intense cropping than one crop in two years still require a fallow period to get back to winter wheat planted in September. This fallow period does not store precipitation efficiently and can expose the soil to erosion forces. A short-season spring-planted crop could be planted when available soil water is sufficient to produce a crop. This study evaluated the yield response of four crops (spring triticale for forage, dry pea for grain, proso millet for grain and foxtail millet for forage) to available soil water at planting to determine production functions that might guide a decision to plant a crop vs. leaving a field fallow until winter wheat planting. The study was conducted at both Sidney, NE and Akron, CO. Predictive relationships between soil water and yield were determined for spring triticale and foxtail millet for forage, and for proso millet for grain. No consistent predictive relationship could be determined for dry pea seed yield vs. soil water. Soil water at planting can be a useful tool for determining whether to fallow or grow a crop for some spring-planted crops when growing season rainfall is low.
Technical Abstract: Substituting a short-season spring-planted crop for summer fallow when soil water is sufficient at planting might reduce soil degradation without significantly increasing the risk of crop failure. The objective of this study was to determine the relationship of crop grain or forage yield to plant available soil water at planting. The study was conducted on silt loam soils in 2004 and 2005 at Sidney, NE and Akron, CO. A range of soil water levels was established with supplemental irrigation prior to planting. Four crops [spring triticale (X Triticosecale rimpaui Wittm.) for forage, dry pea (Pisum sativum L.) for grain, proso millet (Panicum miliaceum L.) for grain, and foxtail millet (Setaria italica L. Beauv.) for forage] were no-till seeded into corn (Zea mays L.) residue in a split-plot design with four replications per location. Triticale forage yield increased by 229 kg ha-1 for each cm of soil water available at planting in 2004. Foxtail millet forage yield and grain yield of proso millet increased by 399 kg ha-1 cm-1 and 148 kg ha-1 cm-1, respectively, at Akron in 2004. Spring triticale, foxtail millet, and proso millet did not respond to soil water at planting in 2005, when precipitation was above the long-term average. Dry pea did not demonstrate a consistent positive response to soil water availability at planting. Soil water at planting may be a useful indicator of potential yield for selected short-season spring-planted summer crops, particularly when crop production is limited by growing season precipitation.