Where Is Your Soil Water? Crop Yield Has the AnswerJuly 02, 2008Crop yield is highly dependent on soil plant-available water, the portion of soil water that can be taken up by plant roots. Quantitative determination of the maximum amount of plant-available water in soil using traditional methods on soil samples remains challenging, especially at the scale of an entire field. However, a map of plant-available water capacity for a field would be instrumental in yield potential assessment and site-specific soil and water management, making the search for improved methods of soil plant-available water quantification an important step towards improved crop productivity and management. One of the alternative methods designed to rapidly and economically estimate plant-available water capacity for a field is the Simple Inverse Yield Model (SIYM). The SIYM first simulates crop yield using a water-budgeting algorithm and growing season weather conditions such as radiation, temperature, and rainfall. As such, yield values can be simulated for a range of levels of soil plant-available water. In the following model step, plant-available water values can subsequently be obtained by matching measured crop yield with the closest simulated yield on a yield map. A group of researchers at the University of Missouri and the USDA-ARS (Cropping Systems and Water Quality Research Unit) investigated the applicability and performance of the SIYM for poorly-drained claypan soils in Central Missouri, and compared them to well-drained soils where the model was first developed and tested. For the study, a total of nine corn yield maps were generated using data collected from two fields in Central Missouri during 1993 to 2005. Soil samples were taken to determine plant-available water capacity using traditional laboratory methods. This research was published in the May-June issue of Agronomy Journal. Results showed that measured plant-available water capacity correlated with corn yield better in dry years than in normal or wet years. Agreement between measured plant-available water and SIYM estimates was weaker in the claypan soils than well-drained soils, especially at locations where the claypan layer was shallow or exposed at the surface. At these locations, plants cannot utilize all the plant-available water in the soil, due to slow water transport in clay-rich soils. As a result, yields simulated by SIYM tended to be higher than measured yields, and thus SIYM-estimated plant available water capacity tended to be lower than measured plant-available water capacity. The lead author, Pingping Jiang, stated "Compared to the measured plant-available water using traditional methods, the SIYM estimates may be more useful in assessing soil productivity and making site-specific management decisions. SIYM is based on actual yield measurements, and less strongly on conventional soil measurement techniques, which do not take crop-soil-water interactions into account." This research was a part of continuing research at the USDA-ARS Cropping Systems and Water Quality Research Unit to assess field variability for site-specific management. The American Society of Agronomy (ASA) |
|||||||||||||||||||||
| Related Crop Yield Current Events and Crop Yield News Articles Herbicide diversity needed to keep Roundup effective Using a diverse herbicide application strategy may increase production costs, but a five-year Purdue University study shows the practice will drastically reduce weeds and seeds that are resistant to a popular herbicide. Iowa State University researcher looks at the future of agriculture Dramatic price fluctuations, increasing demand, the food vs. fuel debate, and other events of the past year may have food producers wondering which way is up. NASA uses satellite to unearth innovation in crop forecasting Soil moisture is essential for seeds to germinate and for crops to grow. But record droughts and scorching temperatures in certain parts of the globe in recent years have caused soil to dry up, crippling crop production. Industrialization of China increases fragility of global food supply Global grain markets are facing breaking point according to new research by the University of Leeds into the agricultural stability of China. Tillage, Rotation Impacts Peanut Crops The increasing popularity of reduced tillage on crops has not only been an important development in combating soil erosion, but it has also been associated with increasing organic material and producing high crop yields. A Little Nitrogen Can Go a Long Way Varying the rate of crop production inputs such as fertilizer and seed makes intuitive sense, as farmers have long observed differences in crop yield in various areas of a single field. The availability of spatial yield information from combines equipped with yield monitors has provided a good resource for improved management. Measuring Calcium in Serpentine Soils Serpentine soils contain highly variable amounts of calcium, making them marginal lands for farming. Successful management of serpentine soils requires accurate measurement of the calcium they hold. Research published this month in the Soil Science Society of America Journal shows that multiple measurement techniques are needed to accurately measure calcium content in serpentine soils. How to build a plant Walking through a tropical or temperate forest immediately impresses us with the myriad forms and soaring structures of the plant world, but our knowledge of how plants are actually built, cell by cell, is still incomplete. Researcher works with European Space Agency to test moisture satellite Europeans want to peek into our soil and see how dry we are. And an Iowa State University professor is eager to help, and even check their results. Increased carbon dioxide in atmosphere linked to decreased soil organic matter A recent study at the University of Illinois created a bit of a mystery for soil scientist Michelle Wander - increased carbon dioxide in the atmosphere was expected to increase plant growth, increase plant biomass and ultimately beef up the organic matter in the soil -- but it didn't. More Crop Yield Current Events and Crop Yield News Articles |
|||||||||||||||||||||
|
|||||||||||||||||||||
|
|||||||||||||||||||||