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 July 19- July 25, 2016 from K-State’s Precision Agriculture Laboratory continues to show high NDVI values across the eastern third of the state, as well as in pockets of central and southwest Kansas. It is also interesting to see the higher NDVI values continue along the Republican River Basin in north central Kansas. The areas of lower NDVI values in parts of eastern Kansas, south of the Kansas River, are getting smaller as saturated soils dry.
Figure 2. Compared to the previous year at this time for Kansas, the current Vegetation Condition Report for July 19 – July 25, 2016 from K-State’s Precision Agriculture Laboratory shows much higher photosynthetic activity across most of the state. The greatest increase in photosynthetic activity continues to be in western Kansas. Rainfall has been well distributed in the region and crop progress continues ahead of last year at this time. In eastern Kansas, the rapid switch from wetter conditions to hot dry conditions has had a negative impact on vegetative activity this year.
Figure 3. Compared to the 27-year average at this time for Kansas, this year’s Vegetation Condition Report for July 12 – July 18, 2016 from K-State’s Precision Agriculture Laboratory shows below-average vegetative activity is confined to small pockets in the South Central and East Central Divisions. Intermittent rains and more seasonal temperatures have reduced vegetative stress.
Figure 4. The Vegetation Condition Report for the U.S for July 19 – July 25, 2016 from K-State’s Precision Agriculture Laboratory shows high NDVI values in the western Corn Belt. Favorable rainfall and more seasonal temperatures favored photosynthetic activity across the region. In contrast, the western High Plains of South Dakota, eastern Montana and eastern Wyoming have reduced vegetative activity as drought continues to intensify in these areas. Vegetative activity has recovered in Kentucky as rainfall has moderated.
Figure 5. The U.S. comparison to last year at this time for July 19 – July 25, 2016 from K-State’s Precision Agriculture Laboratory shows that lower NDVI values are most evident in the western High Plains where continued drier-than-average conditions, coupled with extremely hot weather, have stressed vegetation compared to last year. Warm temperatures in the east and south have also reduced vegetative activity as plants are under greater stress than last year.
Figure 6. The U.S. comparison to the 27-year average for the period July 19- July 25, 2016 from K-State’s Precision Agriculture Laboratory shows areas of below-average photosynthetic activity in the western High Plains and the Midwest. Drought conditions continue to expand in New England with severe drought conditions reported in western New York.

Mary Knapp, Weather Data Library

Ray Asebedo, Precision Agriculture

Nan An, Imaging Scientist