MANAGEMENT OF INTENSIVE FORAGE-BEEF PRODUCTION UNDER YIELD UNCERTAINTY

Forage production variability is incorporated into a decision theory framework for a beef producer in East Texas. The results suggest that the least risky, and also the most profitable, approach to intensive forage beef production is to plan for relatively poor weather conditions and low forage production. This results in a more diverse forage system and a smaller herd size than would be found optimal under the assumption of constant average forage production. These results also demonstrate that the assumption of constant average forage production may results in grossly exaggerated estimates of expected net returns.Livestock Production/Industries, Risk and Uncertainty,

Investigation and quality assessment of the Past Weather Code from the Integrated Surface Database

Quantitative SYNOP Code weather variables such as rainfall amount, although of high societal and environmental importance, are frequently subject to recording errors and inhomogeneities resulting in uncertain conclusions. Here we assess the viability of the more qualitative Past Weather Code (PWC) for its use in robust climate analysis in the belief that it is less prone to both random and systematic errors. The Past Weather Code data, from a selection of the National Oceanographic and Atmospheric Administration’s Integrated Surface Database (ISD) (4731 sufficiently long stations), is quality assessed by searching for inhomogeneities in station PWC time series, removing the offending stations and averaging the remaining stations into a global gridded dataset. PWCs 6 (Rainfall), 7 (Snowfall) and 9 (Thunderstorms) are found to robustly exhibit seasonal features, e.g. the Indian monsoon and peak Northern Hemispheric winter snowfall. Precipitation responses to the North Atlantic Oscillation are also detected in winter PWC 6 data over Europe

A roller coaster season

Like most years for Iowa farmers, 2006 was a weather roller coaster ride. The graph shows the weekly departure from 30-year average degree day accumulations from May through September. One way to read the chart is to consider a 1- to 3-week time period and look at the slope of a line at that time. If it was warmer than normal, the line rises; if cooler than normal, the line falls; and if the weather is at the average, it will neither rise nor fall

Not a Bad Week, All in All

The week ending July 13 was close to average in terms of temperature, and crops have generally made slow but steady improvement in condition over the period. Normal daily accumulations of degree days vary throughout the year, with July obviously being warmer than May. An average Iowa mid-July day produces about 24 base-50 degree days in the northern third, around 25 in central counties and 26 to 27 in the southern third of the state. That means that currently, we are about four to five full developmental days behind average for the season from May 1 through July 13. Of course, a late-planted field missed the heat gained while it was in the bag, and is that much more behind in development

Degree Days - Temperature Roller Coaster

Iowa crops continue in good condition as we finish one of the coolest July 4 holidays on record. Each of the last three weeks have alternated between above and below normal temperatures. As of July 5, we have accumulated 87 fewer degree days statewide since May 1 compared with the 30-year average. That is roughly equivalent to 3.5 average July 4 days, so we aren\u27t in terrible shape. The cool-warm-cool pattern appears now to continue as the forecast is for above normal temperatures through the middle of July

Planters are Rolling and Corn is Growing

Today the first weekly report of base 50°F degree-day accumulations is posted for the 2008 Iowa crop season. Statewide, the first four days of May have accumulated degree days at the long-term average, but that follows a cooler-than-normal April

A Cool and Thankfully Dry Week

Some good news this week, with much-needed access to fields gained across Iowa. Also on the positive side, hay harvest progressed rapidly and hay yields were reportedly good. Although the week was a bit cooler than average, the dry weather was a welcome relief

Two Soybean Aphid Field Resources Now Available

Knowing how to manage and speed scout soybean aphids, just got easier, thanks to two new pocket-sized publications authored by Iowa State University Extension entomologists Marlin Rice and Matt O\u27Neal. The companion soybean aphid publications are right off the press and available from ISU Extension. One is a spiral-bound Soybean Aphid Management field guide for 2008, extension publication number CSI 11. The 43-page pocket guide is focused on management of soybean aphid in Iowa. The guide is a handy reference to the history, identification, development and management strategies for this relatively new insect pest for Iowa

Degree Days - Off on a Muddy Track

Today\u27s article is the first weekly post that monitors accumulation of degree days through the 2009 growing season. The map below shows the base 50 degree F days that have accumulated in each of Iowa\u27s nine crop reporting districts, and the departure in accumulations from long-term averages