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Full-Text Articles in Life Sciences

Remote Estimation Of Nitrogen And Chlorophyll Contents In Maize At Leaf And Canopy Levels, Michael Schlemmer, Anatoly A. Gitelson, James S. Schepers, Richard B. Ferguson, Y. Peng, J. Shanahan, Donald Rundquist Dec 2013

Remote Estimation Of Nitrogen And Chlorophyll Contents In Maize At Leaf And Canopy Levels, Michael Schlemmer, Anatoly A. Gitelson, James S. Schepers, Richard B. Ferguson, Y. Peng, J. Shanahan, Donald Rundquist

Department of Agronomy and Horticulture: Faculty Publications

Leaf and canopy nitrogen (N) status relates strongly to leaf and canopy chlorophyll (Chl) content. Remote sensing is a tool that has the potential to assess N content at leaf, plant, field, regional and global scales. In this study, remote sensing techniques were applied to estimate N and Chl contents of irrigated maize (Zea mays L.) fertilized at five N rates. Leaf N and Chl contents were determined using the red-edge chlorophyll index with R2 of 0.74 and 0.94, respectively. Results showed that at the canopy level, Chl and N contents can be accurately retrieved using green and red-edge Chl …


High Yield Soybean Management: Planting Practices, Nutrient Supply, And Growth Modification, Evan Sonderegger Aug 2013

High Yield Soybean Management: Planting Practices, Nutrient Supply, And Growth Modification, Evan Sonderegger

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

Growers are constantly seeking ways to improve yield in soybean [Glycine max (L.) Merr.]. There has been much interest in the use of selected alternative practices to maximize soybean yield. These practices include planting soybean at higher than recommended seeding rates, planting soybean in narrow rows, breaking apical dominance to induce branching, application of strobilurin fungicides prophylactically to minimize disease and extend the seed filling period, the use of N fertilizer both in furrow and foliar applied, and the use of seed treatments to promote early stand establishment and health. Field studies were conducted at the University of Nebraska …


Decomposition And Nutrient Release Of Different Cover Crops In Organic Farm Systems, Jianru Shi Jun 2013

Decomposition And Nutrient Release Of Different Cover Crops In Organic Farm Systems, Jianru Shi

School of Natural Resources: Dissertations, Theses, and Student Research

Cover crops act as green manure adding organic matter to agricultural-soils. For legume green manures to be an effective nitrogen (N) source for organic farming systems, their N release must be in synchrony with crop N demand. The objectives of this study were 1) determine the decomposition rates of three common cover crops (white clover, (Trifolium repens,L ) red clover (Trifolium pratense L.) and soybean (Glycine max L) in order to determine when most N was released and its synchrony with subsequent corn crop uptake; 2) we focused on the effect of cover crops on soil …