Submitted to: Agronomy Journal
Publication Type: Peer reviewed journal
Publication Acceptance Date: 2/10/2010
Publication Date: 3/10/2010
Citation: Tolk, J.A., Howell, T.A. 2010. Cotton water use and lint yield in four Great Plains Soils. Agronomy Journal. 102(3):904-910. Interpretive Summary: The production of cotton has expanded from the Southeastern United States with its long, warm growing seasons to the Great Plains with its short, cool growing seasons. While advances in cotton breeding have made cotton more tolerant to cool temperatures, the early and late season cool air temperatures of the Southern Great Plains has made it difficult for cotton to have early season vigorous growth and to complete late season opening of bolls. Low soil temperature can also reduce cotton growth. Soil temperature is affected by a soil's mineral content of sand, silt, and clay. It is also affected by water content such as water applied as irrigation, which is generally needed to produce profitable yields in the Great Plains. Sandy soils, because they hold less water, require less heat to warm when wet compared with the higher water-holding clay and silt soils. This study was conducted to examine the effect of soil type (sandy soil, sandy loam soil, silt loam soil, and clay loam soil) and seasonal variations in air and soil temperatures of the Great Plains on irrigated cotton lint yield in 2005-2007. Because less heat was needed to warm the soil temperature of the sandy soil in the cool early seasons of 2005 and 2007, the crops in that soil most likely had greater early season root development and crop growth. This resulted in larger yields in the sandy soil compared with the crops in the silt and clay soils under both full and limited irrigation. In 2006, however, the early season climate was hotter and drier compared with 2005 and 2007, and the sandy soil dried more quickly compared with the other soils. This reduced early season crop growth in the sandy soil and lint yields were small and did not increase with irrigation. Because of the higher air temperatures and the ability of the clay loam, silt loam, and sandy loam soils to hold more water, the crops in those soils had greater early season growth and produced larger yields compared with 2005 and 2007. This suggests that to achieve the largest yields with the least amount of water, cotton should be grown in sandy soils in the southern Great Plains in most years.
Technical Abstract: The development of earlier maturing and cool temperature tolerant varieties of cotton (Gossypium hirsutum L.) has allowed cotton production to expand northward in the United States Great Plains to regions with shorter, cooler growing seasons. Cotton, as a substitute for the less drought tolerant maize (Zea mays L.), can also help lessen the irrigation water supply burden on the Ogallala Aquifer. The objective of this research was to evaluate the effect of soil type and meteorological conditions on the water use and lint yield of cotton grown in four Great Plains soils under water deficit to full irrigation. Cotton was grown in 2005 through 2007 in 48 weighing lysimeters which contained clay loam, silt loam, sandy loam, or fine sand (12 each) at Bushland, Texas. Climatic conditions were relatively mild in the 2005 and 2007 growing seasons, but the 2006 season began with high air temperatures and evaporative demand. Lint yields averaged across the 2005 and 2007 irrigation treatments were significantly larger in the fine sand (160 g m**-2) than in the other soils (126 g m**-2). In 2006, the lint yield in the fine sand was significantly smaller (101 g m**-2) than the average of the other soils (147 g m**-2). The 2006 lint yield in the fine sand did not increase with increasing irrigation application amounts. Early season warmer soil temperatures in the drier fine sand, compared with the other soils, most likely promoted more root development and crop growth which resulted in larger yields in the mild climates of 2005 and 2007. With the larger evaporative demand in 2006, the low water-holding capacity of the fine sand could not maintain growth while both the higher temperatures and water holding capacities in the other soils promoted growth and resulted in larger yields.