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:
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 firstname.lastname@example.org 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, assistant state climatologist:
Figure 1. The Vegetation Condition Report for Kansas for August 18 - 31 from K-State’s Ecology and Agriculture Spatial Analysis Laboratory shows that the highest biomass production is, as typical, in eastern Kansas. The highest NDVI values are in Brown and Doniphan counties along the Missouri River Valley. Favorable soil moisture and moderate temperatures have favored biomass production in these areas. Lower NDVI values are visible in western Kansas, where warmer temperatures have prevailed in the last two weeks.
Figure 2. Compared to the previous year at this time for Kansas, the current Vegetation Condition Report for August 18 - 31 from K-State’s Ecology and Agriculture Spatial Analysis Laboratory shows parts of central and south central Kansas have lower photosynthetic activity. These areas did not have as much moisture in recent weeks as counties farther west, and abnormally dry conditions persist. In contrast the North Central Division has had more favorable conditions this year. Moderate temperatures and favorable moisture have resulted in high photosynthetic activity.
Figure 3. Compared to the 26-year average at this time for Kansas, this year’s Vegetation Condition Report for August 18 – 31 from K-State’s Ecology and Agriculture Spatial Analysis Laboratory shows that most of the state has at or above-average photosynthetic activity. The North Central and Northeastern Divisions have the greatest levels of above-average activity. This continues to be due to a combination of favorable growing conditions and delayed crop development. This delay means more of the vegetation is in the most active growth period, rather than the reduced activity that comes as the crop matures. An area of abnormally dry conditions continues in the Northwest Division edging into North Central and Central Divisions. This is reflected in lower-than-average biomass production in the region.
Figure 4. The Vegetation Condition Report for the Corn Belt for August 18 – 31 from K-State’s Ecology and Agriculture Spatial Analysis Laboratory shows that greatest level of photosynthetic activity is concentrated from northeastern Nebraska through Iowa, southern Minnesota, and into Illinois. Favorable moisture conditions have resulted in high photosynthetic activity. In Iowa, corn is rated as 81 percent good to excellent, while soybeans are 76 percent good to excellent.
Figure 5. The comparison to last year in the Corn Belt for the period for August 18 – 31 from K-State’s Ecology and Agriculture Spatial Analysis Laboratory shows lower photosynthetic activity concentrated in the northern parts of the region, particularly in Wisconsin. Despite recent cool weather, both corn and soybeans are ahead of last year.
Figure 6. Compared to the 26-year average at this time for the Corn Belt, this year’s Vegetation Condition Report for August 18 – 31 from K-State’s Ecology and Agriculture Spatial Analysis Laboratory shows most of the region has average biomass production. Wisconsin stands out with below-average NDVI values, although crop conditions are rated favorably.
Figure 7. The Vegetation Condition Report for the U.S for August 18 – 31 from K-State’s Ecology and Agriculture Spatial Analysis Laboratory shows that the highest photosynthetic activity is centered in the Upper Midwest. Lower NDVI values are noticeable in the Southeastern U.S., particularly in Georgia and South Carolina and the tip of Florida, where drought conditions continue to intensify. Rains from the recent tropical systems were less productive than anticipated. Low NDVI values are also notable along the western Cascades in Oregon.
Figure 8. The U.S. comparison to last year at this time for the period August 18 – 31 from K-State’s Ecology and Agriculture Spatial Analysis Laboratory shows that lower NDVI values are most evident along the East Coast. In the West Coast region, lower NDVI values are visible in Northern California and especially into Oregon. Rains in the early summer were heavier on the California side of the border. Decreased photosynthetic activity is also evident in western Montana, as extreme drought expands in the area.
Figure 9. The U.S. comparison to the 26-year average for the period August 18 – 31 from K-State’s Ecology and Agriculture Spatial Analysis Laboratory shows that the West continues to have lower-than-normal photosynthetic activity, while the greatest increase in NDVI values is in the Central Plains. There is also an area of below-average NDVI values along the lower Great Lakes to Upstate New York and into New England. This marks an area of expanding moisture stress.
Mary Knapp, Weather Data Library
Kevin Price, Professor Emeritus, Agronomy and Geography, Remote Sensing, GIS
Nan An, Graduate Research Assistant, Ecology & Agriculture Spatial Analysis Laboratory (EASAL)