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Full-Text Articles in Life Sciences

Statistical And Machine Learning Methods Evaluated For Incorporating Soil And Weather Into Corn Nitrogen Recommendations, Curtis J. Ransom, Newell R. Kitchen, James J. Camberato, Paul R. Carter, Richard B. Ferguson, Fabián G. Fernández, David W. Franzen, Carrie A. M. Laboski, D. Brenton Myers, Emerson D. Nafziger, John E. Sawyer, John F. Shanahan Aug 2019

Statistical And Machine Learning Methods Evaluated For Incorporating Soil And Weather Into Corn Nitrogen Recommendations, Curtis J. Ransom, Newell R. Kitchen, James J. Camberato, Paul R. Carter, Richard B. Ferguson, Fabián G. Fernández, David W. Franzen, Carrie A. M. Laboski, D. Brenton Myers, Emerson D. Nafziger, John E. Sawyer, John F. Shanahan

John E. Sawyer

Nitrogen (N) fertilizer recommendation tools could be improved for estimating corn (Zea mays L.) N needs by incorporating site-specific soil and weather information. However, an evaluation of analytical methods is needed to determine the success of incorporating this information. The objectives of this research were to evaluate statistical and machine learning (ML) algorithms for utilizing soil and weather information for improving corn N recommendation tools. Eight algorithms [stepwise, ridge regression, least absolute shrinkage and selection operator (Lasso), elastic net regression, principal component regression (PCR), partial least squares regression (PLSR), decision tree, and random forest] were evaluated using a dataset …


Rethinking Invasion Impacts Across Multiple Field Sites Using European Swallowwort (Vincetoxicum Rossicum) As A Model Invader, Grant L. Thompson, Terrence H. Bell, Jenny Kao-Kniffin Aug 2018

Rethinking Invasion Impacts Across Multiple Field Sites Using European Swallowwort (Vincetoxicum Rossicum) As A Model Invader, Grant L. Thompson, Terrence H. Bell, Jenny Kao-Kniffin

Grant Thompson

European swallowwort [Vincetoxicum rossicum (Kleopow) Barbarich] is found in the northeastern United States and southeastern Canada. It forms dense growth patterns that reduce plant and insect biodiversity, and lab assays show that it produces allelopathic compounds that affect microbial activity. Consequently, we hypothesized that V. rossicum alters soil microbiome composition and activity in invaded habitats, which may impact
ecosystem properties and processes. We sampled soil from a similar time point within a growing season at each of five sites in New York State where V. rossicum was both present and absent. We measured bacterial and fungal microbiome composition, available soil …


Long-Term Tillage Frequency Effects On Dryland Soil Physical And Hydraulic Properties, Andrew W. Lenssen, J. D. Jabro, U. M. Sainju, W. B. Stevens, R. G. Evans Jan 2008

Long-Term Tillage Frequency Effects On Dryland Soil Physical And Hydraulic Properties, Andrew W. Lenssen, J. D. Jabro, U. M. Sainju, W. B. Stevens, R. G. Evans

Andrew W. Lenssen

Soil tillage is considered one of most important practices in agricultural production due to its influence on physical, chemical, and biological properties of the soil environment. The effect of a long-term tillage [no-till (NT), spring till (ST), and fall and spring till (FST)] was investigated on soil penetration resistance (PR), bulk density (BD), gravimetric water content (GWC) and saturated hydraulic conductivity (Ks) under dryland conditions. Tillage effects on these physical properties were tested after 22 years on a Dooley sandy loam (fine-loamy, mixed Typic Argiborolls) derived from glacial till parent material. The statistical design used was a randomized complete block …


Sheep Grazing Wheat Summer Fallow And The Impact On Soil Nitrogen, Moisture, And Crop Yield, Andrew W. Lenssen, E. E. Snyder, H. B. Goosey, P. G. Hatfield Jan 2007

Sheep Grazing Wheat Summer Fallow And The Impact On Soil Nitrogen, Moisture, And Crop Yield, Andrew W. Lenssen, E. E. Snyder, H. B. Goosey, P. G. Hatfield

Andrew W. Lenssen

In typical dryland farming areas of Montana, annual precipitation is not sufficient for annual harvest of small grains. Summer fallow in alternate years, is a common method of conserving soil moisture to produce a crop in the following season. Current methods of fallow management are primarily mechanical tillage and spraying with herbicides. Although these methods are effective, they are expensive, making fallow management the highest variable cost associated with dryland grain production. The objectives of this study were to compare the impact of grazing small grains stubble with sheep, as a fallow management tactic, against traditional management practices of chemical …