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Full-Text Articles in Life Sciences
Effect Of Nitrogen Addition And Weed Interference On Soil Nitrogen And Corn Nitrogen Nutrition, John L. Lindquist, Sean P. Evans, Charles A. Shapiro, Stevan Z. Knezevic
Effect Of Nitrogen Addition And Weed Interference On Soil Nitrogen And Corn Nitrogen Nutrition, John L. Lindquist, Sean P. Evans, Charles A. Shapiro, Stevan Z. Knezevic
John L. Lindquist
Weeds cause crop loss indirectly by reducing the quantity of resources available for growth. Quantifying the effects of weed interference on nitrogen (N) supply, crop growth, and N nutrition may assist in making both N and weed management decisions. Experiments were conducted to quantify the effect of N addition and weed interference on soil nitrate-N (NO3- N) over time and the dependence of corn growth on NO3-N availability, determine the corn N nutrition index (NNI) at anthesis, and evaluate if relative chlorophyll content can be utilized as a reliable predictor of NNI. Urea was applied at 0, 60, …
Simulation Study Of The Competitive Ability Of Erect, Semi-Erect, And Prostrate Cowpea (Vigna Unguiculata) Genotypes, G. Wang, M. E. Mcgiffen Jr., John L. Lindquist, J. D. Ehlers, I. Sartorato
Simulation Study Of The Competitive Ability Of Erect, Semi-Erect, And Prostrate Cowpea (Vigna Unguiculata) Genotypes, G. Wang, M. E. Mcgiffen Jr., John L. Lindquist, J. D. Ehlers, I. Sartorato
John L. Lindquist
Ecophysiological simulation models provide a quantitative method to predict the effects of management practices, plant characteristics, and environmental factors on crop and weed growth and competition. The INTERCOM interplant competition model was parameterized, calibrated by monoculture data for three cowpea (Vigna unguiculata) genotypes that differed in growth habit, common sunflower (Helianthus annuus) and common purslane (Portulaca oleracea), and used to simulate competition of cowpea cover crops with sunflower or purslane. The simulation results were compared with observations from field competition experiments in 2003 and 2004. INTERCOM more accurately simulated actual field data for the competition of cowpea genotypes and sunflower …