By Mary Knapp
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 October 18 – October 24, 2016 from K-State’s Precision Agriculture Laboratory shows only light photosynthetic activity. The growing season is almost over and much of the vegetation is moving into dormancy.
Figure 2. Compared to the previous year at this time for Kansas, the current Vegetation Condition Report for October 18 – October 24, 2016 from K-State’s Precision Agriculture Laboratory shows the largest area of higher vegetative activity is in north central Kansas. Pockets of delayed development continue to be the major contributor to this higher vegetative activity, although emergence of the winter wheat in west central Kansas is visible. Slow establishment of winter wheat in the Southwest into the South Central Divisions is visible as reduced NDVI values there.
Figure 3. Compared to the 27-year average at this time for Kansas, this year’s Vegetation Condition Report for October 18 – October 24, 2016 from K-State’s Precision Agriculture Laboratory shows much of the state has close-to-average vegetative activity. Below-average values are visible in Thomas, Gove, and Ness counties, as abnormally dry conditions continue to expand in the west.
Figure 4. The Vegetation Condition Report for the U.S for October 18 – October 24, 2016 from K-State’s Precision Agriculture Laboratory shows high NDVI values along northern California where mild temperatures and rains have extended the growing season. Low NDVI values are visible in the Corn Belt and along the Mississippi River Valley, where crop maturity is slightly ahead of average.
Figure 5. The U.S. comparison to last year at this time for October 18 – October 24, 2016 from K-State’s Precision Agriculture Laboratory shows that higher NDVI values in the Southern Plains where warmer-than-normal temperatures continue to be an issue. In the Southeast, lower activity is visible as this region missed out on the recent tropical systems and drought continues to intensify. The much lower NDVI values in the Pacific Northwest are due to persistent cloud cover.
Figure 6. The U.S. comparison to the 27-year average for the period October 18 – October 24, 2016 from K-State’s Precision Agriculture Laboratory shows below-average NDVI values in the Pacific Northwest. Persistent rains and cloud cover are the major factors in this area. The deep South continues to have persistent drought conditions, but as photosynthetic activity is typically reduced in that region during this period, the low NDVI values due to the drought are not especially lower than the long-term average. In other seasons, the low NDVI values caused by the drought would show on the map as an area of below-average activity.