Browsing by Author "Udeigwe, Theophilus K."

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Crop water use and stage-specific crop coefficients for irrigated cotton in the mid-south, United States
(2015-07) Kumar, Vipan; Udeigwe, Theophilus K.; Clawson, Ernest L.; Rohli, Robert; Miller, Donnie K.
Regional variations in environmental conditions, cultivars, and management practices necessitate locally derived tools for crop water use estimation and irrigation scheduling. A study was conducted in northeast Louisiana (mid-south US) aimed at estimating daily crop evapotranspiration (ETc) and reference evapotranspiration (ETo) and thus, developing local crop coefficient (Kc) curves for irrigated upland cotton. ETc was determined using paired weighing lysimeters installed near the middle of a 1-ha cotton field and planted with cotton as in the rest of the surrounding field, while ETo was calculated using the Standardized Reference Evapotranspiration Equation (SREE) developed by the American Society of Civil Engineers (ASCE), using estimates of weather variables from a nearby standard reference weather station. Stage-specific Kc values averaged over 2 years were 0.42, 1.25 and 0.70 for initial, midseason, and end season stages of cotton, respectively. The initial-stage Kc value was approximately 26% lower than the Food and Agricultural Organization (FAO)-adjusted initial Kc value. The mid- and end-season Kc values obtained in the study were approximately 6% and 11% greater, respectively, than the FAO-adjusted Kc values for the corresponding stages. The observed differences among the local stage-specific Kc values (especially at initial growth stage of cotton) and the FAO-adjusted initial Kc values could be attributed to regional variations in environmental conditions, cultivars, and management practices. The ETc and Kc values obtained from this study provide research-based information for future studies and the development of Kc-based irrigation tools in this region.
Implications of leading crop production practices on environmental quality and human health
(2015-03) Udeigwe, Theophilus K.; Teboh, Jasper M.; Eze, Peter N.; Stietya, M. Hashem; Kumar, Vipan; Hendrix, James; Mascagni, Henry J.; Ying, Tang; Kandakji, Tarek
Globally, much weight is currently being placed on agriculture to provide food for the growing population as well as feedstock for the bioenergy industry. Unfortunately, the intensification of agricultural operations to satisfy these growing needs has been associated with a number of environmental and human health risks. A review of publications on the subject was conducted and emphasis was placed on articles focusing on agriculture, environment, and public health as well as their interactions. Supporting information was also gathered from publications of various agricultural and environmental agencies. Agricultural practices with potential negative implications on the environment and human health were identified broadly as: (a) utilization of biosolids and animal manures, (b) use of agricultural chemicals, (c) management of post-harvest residue, (d) irrigation, and (e) tillage operations. Soil, water, and air contamination by nutrients, heavy metals, pathogens, and pesticides, as well as air contamination by particulate matters, noxious gases, and pathogens were among the leading environmental impacts. Some of the human-health impacts identified included neurological and reproductive defects, cardiovascular risks, cancers and other diseases (of kidney, liver, lung, and skin), skin allergies, gastroenteritis, and methemoglobinemia. Continual awareness on the impacts of the reviewed agricultural practices on environmental quality and human health and the implementation of experimentally-backed best management practices in agricultural systems remain indispensable. Keywords Bioenergy; Biosolids; Agricultural chemicals; Biomass burning; Pathogens; Nutrients; Metals; Noxious gases; Public health