Ice Age Epochs and the Sun's Path Through the Galaxy

We present a calculation of the Sun's motion through the Milky Way Galaxy over the last 500 million years. The integration is based upon estimates of the Sun's current position and speed from measurements with Hipparcos and upon a realistic model for the Galactic gravitational potential. We estimate the times of the Sun's past spiral arm crossings for a range in assumed values of the spiral pattern angular speed. We find that for a difference between the mean solar and pattern speed of Omega_Sun - Omega_p = 11.9 +/- 0.7 km/s/kpc the Sun has traversed four spiral arms at times that appear to correspond well with long duration cold periods on Earth. This supports the idea that extended exposure to the higher cosmic ray flux associated with spiral arms can lead to increased cloud cover and long ice age epochs on Earth.Comment: 14 pages, 3 figures, accepted for publication in Ap

Analyzing cropping systems (1983)

In tight financial times, businesses often try to reduce spending and improve their profits. Many farmers are currently operating their businesses under such conditions. Wise management decisions can improve profits in farming while reducing cash flow needs

Nitrogen and phosphorus loads to temperate seepage lakes associated with allochthonous dissolved organic carbon loads

Terrestrial loads of dissolved organic matter (DOM) have increased in recent years in many north temperate lakes. While much of the focus on the “browning” phenomena has been on its consequences for carbon cycling, much less is known about how it influences nutrient loading to lakes. We characterize potential loads of nitrogen and phosphorus to seepage lakes in northern Wisconsin, USA, based on a laboratory soil leaching experiment and a model that includes landscape cover and watershed area. In these seepage lakes, nutrient concentrations are positively correlated with dissolved organic carbon concentrations (nitrogen: r = 0.68, phosphorus: r = 0.54). Using long‐term records of browning, we found that dissolved organic matter‐associated nutrient loadings may have resulted in substantial increases in nitrogen and phosphorus in seepage lakes and could account for currently observed nutrient concentrations in the lake. “Silent” nutrient loadings to brown‐water lakes may lead to future water‐quality concerns. PLAIN LANGUAGE SUMMARY: The color of many temperate lakes is changing; some lakes are becoming more darkly stained brown. The tea‐colored stain is due to dissolved organic matter from the surrounding landscape. Much of the research related to the causes and consequences of increased staining, or “brownification,” relate to its connection to the carbon cycle. However, by examining long‐term lake chemical records, analyzing the properties of the organic compounds, and modeling potential flows of the compounds, we find that carbon is not the only element that is influenced by browning. Nitrogen and phosphorus, two nutrients important to growth of organisms at the base of the food web, may also be increasing in lakes due to brownification."Funding for this research was supported by the Northern Research Station and the Chequamegon-Nicolet National Forest (CNNF) of the United States Department of Agriculture (USDA) Forest Service and a National Science Foundation (NSF) grant to the University of Wisconsin-Madison to support the North Temperate Lakes Long-Term Ecological Research (NTLLTER) Site (DEB-#1440297)."https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2018GL07721

No-till checklist (1993)

Reviewed October 1993

No-till checklist (1984)

Zane R. Helsel, Daryl D. Buchholz, Gary Hoette, and L.E. Anderson (Department of Agronomy), Einar Palm (Department of Plant Pathology), George Thomas (Department of Entomology), Don Pfost (Department of Agricultural Engineering, College of Agriculture)New 1/84/10

No-till planting sytsems

"In no-tillage planting systems, a planting is made directly into an essentially unprepared seedbed. Evaluate the economical and practical feasibility if you consider a no-till planting system. You won't always completely eliminate tillage, and your management ability and experience often determine the economic reward."--First page.Zane R. Helsel, Daryl D. Buchholz, Gary Hoette, and L.E. Anderson (Department of Agronomy), Einar Palm (Department of Plant Pathology), George Thomas (Department of Entomology), Don Pfost (Department of Agricultural Engineering, College of Agriculture)New 7/83/10

No-till checklist (1987)

Zane R. Helsel, Daryl D. Buchholz, Gary Hoette, and L.E. Anderson (Department of Agronomy), Einar Palm (Department of Plant Pathology), George Thomas (Department of Entomology), Don Pfost (Department of Agricultural Engineering, College of Agriculture)Revised 10/87/10

Herbicides for soybeans

"Soybean herbicides can be soil incorporated before planting (PPI). They can be applied to the soil surface at planting time or before crop emergence (preemergence). Or they can be applied in a split application (sequential) where the first product is incorporated and followed by a pre-emergent applied over the row or broadcast. A final application method is post-emergence treatment."--First page.Zane R. Helsel, Harold D. Kerr, E.J. Peters, David Goethle, L.E. Anderson, James A Schaffer, and O'Hale Fletchall (Department of Agronomy College of Agriculture)Revised 12/84/12

Chemical weed control in grain sorghum

"Federal regulations on the use of herbicides change frequently, so stay informed on the status of label registration. To the best of our knowledge, this guidesheet conforms to laws and regulations at the time of writing."--First page.James A. Schaeffer, Harold D. Kerr, David Guethle, O. Hale Fletchall, E.J. Peters, L.E. Anderson, and Zane R. Helsel (Department of Agronomy, College of AGriculture)Revised 1/85/10