Comparative Vegetation Condition Report: April 18 - 24

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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, and 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 18- April 24, 2017 from K-State’s Precision Agriculture Laboratory shows a continued increase in vegetative activity along the Arkansas River in southwest Kansas into south central Kansas. Southeast and east central Kansas are showing the greatest activity. These are also the areas of the state that have consistently been warmer than normal.

Figure 2. Compared to the previous year at this time for Kansas, the current Vegetation Condition Report for April 18 – April 24, 2017 from K-State’s Precision Agriculture Laboratory lower NDVI values are evident in scattered areas of western and central Kansas. The winter wheat is less advanced this year than last, particularly in western Kansas, where dry fall conditions hampered establishment. The greatest increase in vegetative activity is in the eastern portions of the state, where moisture has been more plentiful this April.

Figure 3. Compared to the 27-year average at this time for Kansas, this year’s Vegetation Condition Report for April 18 – April 24, 2017, from K-State’s Precision Agriculture Laboratory much of the state has above-average photosynthetic activity. The highest NDVI values are in the Flint Hills and areas to the east, where precipitation has been more favorable. The lingering impact from the dry conditions last fall is most visible in western Kansas where wheat emergence was uneven.

Figure 4. The Vegetation Condition Report for the U.S for April 18 – April 24, 2017 from K-State’s Precision Agriculture Laboratory shows the highest NDVI values are confined to the Southern Plains, particularly in east Texas and Louisiana. A second area of high vegetative activity is also visible along the West Coast, where the wet conditions continue. Low NDVI values are visible along the central Mississippi River Valley. As of April 1st, the snow depiction has been dropped, since the snow season is largely over.

Figure 5. The U.S. comparison to last year at this time for April 18 – April 24, 2017 from K-State’s Precision Agriculture Laboratory again shows the impact that split in the snow cover has caused this year. Much lower NDVI values prevail in the Pacific Northwest. The Northern Rockies are showing higher NDVI values as the snow pack is rapidly retreating. The South has much lower NDVI values due to persistent clouds in the area this year.

Figure 6. The U.S. comparison to the 27-year average for the period of April 18 – April 24, 2017 from K-State’s Precision Agriculture Laboratory shows an area of below-average photosynthetic activity in the Pacific Northwest, where continuing storm systems have masked vegetative activity. Below-average NDVI values are also present in the South and the Ohio River Valley, where continued cloud cover has also masked vegetative activity. Higher-than-average vegetative activity is present in the Northern Plains and northern Rockies as the snow pack continues to retreat rapidly.


Mary Knapp, Weather Data Library

Ray Asebedo, Precision Agriculture

Nan An, Imaging Scientist