Browsing by Author "Lewis, Katie L. (TTU)"
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Item Carbon dioxide mitigation potential of conservation agriculture in a semi-arid agricultural region(2019) McDonald, Mark D. (TTU); Lewis, Katie L. (TTU); Ritchie, Glen L. (TTU); DeLaune, Paul B.; Casey, Kenneth D.; Slaughter, Lindsey C. (TTU)The Texas High Plains (THP) region is one of the largest upland cotton (Gossypium hirsutum L.) producing regions in the world. Cotton is a versatile crop with uses for both food and fiber products. Conservation management practices such as no-tillage and cover crops have been used to reduce wind erosion on the THP but are also associated with mitigating and reducing greenhouse gas (GHG) emissions from soil. Although row-crop agriculture has been linked to GHG emissions across the world, cotton production in the THP ecoregion has not been thoroughly evaluated for its contribution to GHG production. This research quantified the soil flux of carbon dioxide (CO 2 -C) from continuous cotton production systems on the THP after implementing three tillage practices: (1) no-till with a winter wheat cover crop (NTW); (2) no-till winter fallow (NT); and (3) conventional tillage winter fallow (CT). In addition, the timing of nitrogen fertilizer application was evaluated within each tillage system. Five N treatments were implemented: (1) an unfertilized control; (2) 100% pre-plant (PP); (3) 100% side-dressed (SD); (4) 40% PP 60% SD; and (5) 100% PP with a nitrogen stabilizer product (STB). Tillage practice affected CO 2 -C flux rates in spring 2016 and 2017 with the NTW system having greater CO 2 -C flux than the NT and CT systems. In summer 2017, the NTW system had a greater flux of CO 2 -C than the NT or CT systems. In fall/winter 2016, the NTW and CT systems had a greater CO 2 -C flux than the NT system. Cumulative emissions of CO 2 -C were affected by N treatment in 2016, with later season applications of N fertilizer increasing emissions compared to the STB treatment and the control. In 2017, cumulative emissions of CO 2 -C were greater in the NTW system than in the NT and CT system. However, a greater amount of CO 2 -C was assimilated by the wheat cover crop from the atmosphere than was lost from the soil which reduced net C losses from the system. With continued use of no-tillage and a cover crop, lower net soil CO 2 -C losses should result in a greater rate of soil organic C gain, positively impacting the sustainability of cotton production in the THP.Item Carbon sequestration and water management in Texas—One size does not fit all(2023) Bell, Jourdan; DeLaune, Paul B.; Fischer, Bart L.; Foster, Jamie L.; Lewis, Katie L. (TTU); McCarl, Bruce A.; Outlaw, Joe L.Climate-smart agriculture (CSA) is an integrated approach to sustainably meeting food, fiber, and feed production needs. The technical and socioeconomic feasibility of different CSA strategies depends on local conditions, and there is no one-size-fits-all approach. Here, we review two key aspects of CSA with a focus on Texas: soil C sequestration and water management. Carbon sequestration potential is highly variable across Texas as it depends on local biophysical conditions and soil management practices in place, for example, tillage and cover crops. Grasslands also have an important role to play in C sequestration. Important co-benefits of effective soil management for C sequestration, such as reduced CO2 emissions, enhanced soil structure, and increased microbial activity, can positively impact soil fertility and productivity. The economic and political realities of C sequestration will have a strong influence on the implementation of technically feasible strategies. The major challenge for water management is the sustainable allocation of increasingly scarce resources. Expanded irrigation is a short-term solution, but in many cases, the existing water supply is insufficient to meet future demand. A drying Texas, and aquifer depletion, portends lower future supplies. The Panhandle, Llano Estacado, and Rio Grande regions have the greatest projected gaps between future supply and demand. Increasing water-use efficiency and using drought-tolerant crops are important management goals and precision agriculture with site-specific management measures could help improve drought resiliency. Texas’ geographic diversity is reflected in the variety of agricultural commodities produced by the state, and CSA activities are likely to be equally diverse.Item Cotton cultivar response to potassium fertilizer application in Texas’ southern high plains(2021) Kusi, Nana Yaw O. (TTU); Lewis, Katie L. (TTU); Morgan, Gaylon D.; Ritchie, Glen L. (TTU); Deb, Sanjit (TTU); Stevens, Richard D. (TTU); Sintim, Henry Y.Cotton (Gossypium hirsutum L.) and potassium (K) dynamics are not well understood particularly in soils with high K levels. Potassium is important for cotton reproductive development as it influences the number, size, and weight of bolls and can improve fiber quality by mitigating moisture stress. In the case that soil cannot replenish solution K from exchangeable reserves to meet the plant demands, deficiencies may occur leading to decreased yield (lint and seed) and fiber quality, reduced drought and disease tolerance, and premature boll opening. Studies were conducted in 2016 and 2017 in Lubbock (Olton clay loam and Acuff loam) and Lamesa (Amarillo fine sandy loam), TX, to determine the effects of K application rates and timing on lint yield and fiber quality of modern cotton cultivars (DP 1518 B2XF, DP 1522 B2XF, DP 1321 B2XF, and DP 1612 B2XF). Pre-plant soil tests were >250 mg K kg–1 at both locations and years at the 0-to-15-cm soil depths. Potassium treatments were applied at 0 (control), 90, and 180 kg K ha–1 as pre-plant, side-dress, or split applications. Harvest results determined that pre-plant and side-dress K applications produced significantly greater lint yield only for DP 1518 B2XF at both locations, while effects on fiber quality varied by location. The response of DP 1518 B2XF to K fertilizer was due to greater K use efficiency and possibly K demand of this cultivar compared to the others. This research provides evidence for continued investigation of cultivar by environment-based K management.Item Short term cotton lint yield improvement with cover crop and no-tillage implementation(2020) McDonald, Mark D.; Lewis, Katie L. (TTU); Ritchie, Glen L. (TTU)No-tillage has been used for mitigating wind erosion on the Southern High Plains US for decades. This study investigated the effects of tillage and nitrogen (N) fertilizer timing on cotton lint yield, fiber quality, and seed N content during a three-year transition from conventional tillage (CT) to a no-tillage system both with a wheat (Triticum aestivum) cover crop (NTW) and without a cover crop (NT). Lint yield was different between tillage systems within each year with the NTW system producing greater lint yield than the CT system in the second and third year of the transition period. The concentration of cotton seed N was not different within years, although it was decreased in the no N added control in the third year. Cotton fiber strength was increased in the NTW system compared to the CT system in the second year of the study. However, the CT system produced increased fiber strength compared to the other two systems in 2018 and is likely the result of late-season weather conditions. It was determined that implementing a NTW system may increase lint yield within the first few years and has no effect on most fiber quality parameters, especially in environmentally challenging conditions.Item Yield and Economic Response of Modern Cotton Cultivars to Nitrogen Fertilizer(2021) Pabuayon, Irish Lorraine B. (TTU); Mitchell-McCallister, Donna (TTU); Lewis, Katie L. (TTU); Ritchie, Glen L. (TTU)Non-optimal application of nitrogen (N) fertilizer in cotton (Gossypium hirsutum L.) production systems often results from a producer’s uncertainty in predicting the N rate that ensures maximum economic return. Residual soil nitrate-N (NO3-N) is also often unaccounted for in fertilizer management decisions. In this study, the lint yield and profitability of two cotton cultivars (FiberMax FM 958 and Deltapine DP 1646 B2XF) were compared across five N fertilizer treatments [0 kg ha−1 (control), 45 kg ha−1 (N-45), 90 kg ha−1 (N-90), 135 kg ha−1 (N-135), 180 kg ha−1 (N-180)] from 2018 to 2020. For both cultivars, additional N fertilizer on top of the control treatment did not increase the lint yield of cotton. For each year, both control and N-45 treatments resulted in the greatest revenue above variable costs (RAVC) values for all cultivars. The improved N partitioning efficiency in newer cultivars and the high levels of residual soil NO3-N allowed sustained plant growth and yield even with reduced N application. Overall, the results show the advantage of reducing N inputs in residual N-rich soils to maintain yield and increase profits. These findings are important in promoting more sustainable agricultural systems through reduced chemical inputs and maintained soil health.