Authors: Mary Knapp, Ray Asebedo, Nan An

The weekly Vegetation Condition Report maps below can be a valuable tool for making crop selection and marketing decisions.

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 27-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.

The Vegetation Condition Report (VCR) maps were originally developed by Dr. Kevin Price, K-State professor emeritus of agronomy and geography. His pioneering work in this area is gratefully acknowledged.

The maps have recently been revised, using newer technology and enhanced sources of data. Dr. Nan An, Imaging Scientist, collaborated with Dr. Antonio Ray Asebedo, assistant professor and lab director of the Precision Agriculture Lab in the Department of Agronomy at Kansas State University, on the new VCR development. Multiple improvements have been made, such as new image processing algorithms with new remotely sensed data from EROS Data Center.

These improvements increase sensitivity for capturing more variability in plant biomass and photosynthetic capacity. However, the same format as the previous versions of the VCR maps was retained, thus allowing the transition to be as seamless as possible for the end user. For this spring, it was decided not to incorporate the snow cover data, which had been used in past years. However, this feature will be added back at a later date. In addition, production of the Corn Belt maps has been stopped, as the continental U.S. maps will provide the same data for these areas. Dr. Asebedo and Dr. An will continue development and improvement of the VCRs and other advanced maps.

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

Figure 1. The Vegetation Condition Report for Kansas for April 12 – 18, 2016 from K-State’s Precision Agriculture Laboratory continues to show continued expansion of the area of highest plant production. The highest NDVI values are still in Sumner and Harper counties. The Flint Hills continue to show relatively low photosynthetic activity. Recent rainfall is likely to accelerate the green up in this region.
Figure 2. Compared to the previous year at this time for Kansas, the current Vegetation Condition Report for April 12 - 18, 2016 from K-State’s Precision Agriculture Laboratory shows a smaller portion of the state with lower productivity. Dry conditions in March and early April have contributed to this slowed production. In contrast, above-normal moisture in February in the Northwest and North Central Divisions has buffered vegetation in these areas.
Figure 3. Compared to the 27-year average at this time for Kansas, this year’s Vegetation Condition Report for April 12 – 18 from K-State’s Precision Agriculture Laboratory shows that the area of above-average photosynthetic activity continues to decline. The largest areas with the greatest increase are in central Kansas. Even with the recent cool weather, temperatures continue above normal across the state. An exception to the generally above-average photosynthetic activity can be seen in western Barber County. Lack of precipitation has slowed the plant recovery from the fire in that area. The Flint Hills are also showing lower plant productivity.
Figure 4. The Vegetation Condition Report for the U.S for April 11 – 18 from K-State’s Precision Agriculture Laboratory shows high NDVI values along much of the West Coast, and in northern Idaho. Favorable moisture continues to drive active photosynthesis in these areas. A pocket of lower photosynthetic activity can be seen in east Texas and Louisiana, where flooding is an issue.
Figure 5. The U.S. comparison to last year at this time for the period April 12 – 18 from K-State’s Precision Agriculture Laboratory shows that lower NDVI values are most evident in Minnesota and Wisconsin, thanks to a late-season snow event. This is also true in Colorado and Wyoming, although to a lesser degree. In contrast, much higher NDVI values are visible in New England. Despite the recent snows in this area, the overall snow depth is less than last year, and more vegetation is active.
Figure 6. The U.S. comparison to the 27-year average for the period April 12 – 18 from K-State’s Precision Agriculture Laboratory shows above-average photosynthetic activity across the Pacific Northwest, where winter moisture has reduced drought impacts. Snow pack from the late-season storms in the central Rockies has reduced photosynthetic activity in that areas. Persistent cloud cover from the heavy rains in southeastern Oklahoma, east Texas, Louisiana, and eastward has masked photosynthetic activity in those regions.

Mary Knapp, Weather Data Library

Ray Asebedo, Precision Agriculture

Nan An, Imaging Scientist