2015-02-20

Authors: Mary Knapp, Kevin Price, Nan An

K-State’s Ecology and Agriculture Spatial Analysis Laboratory (EASAL) produces weekly Vegetation Condition Report maps. These maps can be a valuable tool for making crop selection and marketing decisions.

Two short videos of Dr. Kevin Price explaining the development of these maps can be viewed on YouTube at:
http://www.youtube.com/watch?v=CRP3Y5NIggw
http://www.youtube.com/watch?v=tUdOK94efxc

The objective of these reports is to provide users with a means of assessing the relative condition of crops and grassland. The maps can be used to assess current plant growth rates, as well as comparisons to the previous year and relative to the 26-year average. The report is used by individual farmers and ranchers, the commodities market, and political leaders for assessing factors such as production potential and drought impact across their state.

NOTE TO READERS: The maps below represent a subset of the maps available from the EASAL group. If you’d like digital copies of the entire map series please contact Nan An at nanan@ksu.edu and we can place you on our email list to receive the entire dataset each week as they are produced. The maps are normally first available on Wednesday of each week, unless there is a delay in the posting of the data by EROS Data Center where we obtain the raw data used to make the maps. These maps are provided for free as a service of the Department of Agronomy and K-State Research and Extension.

The maps in this issue of the newsletter show the current state of photosynthetic activity in Kansas, the Corn Belt, and the continental U.S., with comments from Mary Knapp, service climatologist:

Figure 1. The Vegetation Condition Report for Kansas for February 3 – 16 from K-State’s Ecology and Agriculture Spatial Analysis Laboratory shows that southwest and south central Kansas missed the snow events during this two-week period. Moderate snowfall was reported in northeast Kansas.
Figure 2. Compared to the previous year at this time for Kansas, the current Vegetation Condition Report for February 3 – 16 from K-State’s Ecology and Agriculture Spatial Analysis Laboratory shows that the greatest increase in NDVI readings is in extreme northeastern Kansas. Last year, this area had much higher snow totals than this. For example, Lawrence reported 12.1 inches of snow during this two-week period in 2014. This year, the report was just 2 inches.
Figure 3. Compared to the 26-year average at this time for Kansas, this year’s Vegetation Condition Report for February 3 – 16 from K-State’s Ecology and Agriculture Spatial Analysis Laboratory shows that greater-than-average NDVI values are confined to extreme southwest Kansas and parts of south central Kansas. Sumner County, in particular, has higher-than-average photosynthetic activity. Warmer temperatures have favored development in these areas.
Figure 4. The Vegetation Condition Report for the Corn Belt for February 3 – 16 from K-State’s Ecology and Agriculture Spatial Analysis Laboratory shows that snow during this two-week period missed southwestern and south central Kansas, as well as most of Kentucky. This does not reflect the snow that fell in the eastern portions of the Corn Belt from Wednesday night into Thursday, Feb. 18-19.
Figure 5. The comparison to last year in the Corn Belt for the period February 3 – 16 from K-State’s Ecology and Agriculture Spatial Analysis Laboratory shows that there is a sharp gradient with less snow to the south. Louisville, on the border between Indiana and Kentucky, reported just 3 tenths of an inch of snow this year. Last year, it reported 7.1 inches of snow in the same period.
Figure 6. Compared to the 26-year average at this time for the Corn Belt, this year’s Vegetation Condition Report for February 3 – 16 from K-State’s Ecology and Agriculture Spatial Analysis Laboratory shows that there is an area of below-average NDVI readings from eastern Nebraska across southern Iowa and into northern Ohio. This corresponds with the areas of greatest snow cover.
Figure 7. The Vegetation Condition Report for the U.S. for February 3 – 16 from K-State’s Ecology and Agriculture Spatial Analysis Laboratory shows that light snow cover continues to be a problem in the West. Snow water equivalents are averaging less than 20 percent along the Cascades.
Figure 8. The U.S. comparison to last year at this time for the period February 3 – 16 from K-State’s Ecology and Agriculture Spatial Analysis Laboratory shows that higher NDVI readings correspond mostly to areas of lower snow cover this year. South Texas is the exception. Mild temperatures and favorable moisture have resulted in higher NDVI values this year.
Figure 9. The U.S. comparison to the 26-year average for the period February 3 – 16 from K-State’s Ecology and Agriculture Spatial Analysis Laboratory shows that the area of greatest above-average NDVI levels is in the West. This indication of higher photosynthetic activity, coupled with lower snow pack, brings concerns of increasing drought in the coming months.

Mary Knapp, Weather Data Library
mknapp@ksu.edu

Kevin Price, Professor Emeritus, Agronomy and Geography, Remote Sensing, GIS
kpprice@ksu.edu

Nan An, Graduate Research Assistant, Ecology & Agriculture Spatial Analysis Laboratory (EASAL)
nanan@ksu.edu