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ARS Home » Midwest Area » Columbia, Missouri » Cropping Systems and Water Quality Research » Research » Publications at this Location » Publication #68099


item Sudduth, Kenneth - Ken

Submitted to: Missouri Soil Fertility and Fertilizers Research Update
Publication Type: Experiment Station
Publication Acceptance Date: 3/7/1996
Publication Date: N/A
Citation: N/A

Interpretive Summary: Site-specific management, or precision farming, is a strategy in which cropping inputs such as fertilizers are applied at varying rates across a field in response to variations in crop needs. Variations in productivity from point to point, especially those related to the water-supplying capacity of the soil, are important in developing variable fertilizer application plans. An inexpensive and accurate method for measuring these productivity differences would allow more efficient and economical adoption of precision farming methods. In this study, we report on the use of an electromagnetic induction (EM) sensor for estimating crop productivity differences on claypan and alluvial soils in Missouri. The measurements obtained from the sensor were able to explain a portion of the variation in crop productivity seen in most crop years on both soil types. Although differences in crop production within fields are also related to a number of other variables, EM sensor measurements can be a valuable tool for understanding soil variability relative to precision farming. Adoption of this sensing technology can potentially impact production agriculture by improving profits and benefiting the environment through tailoring of crop inputs to the productivity potential at each point within a field.

Technical Abstract: An inexpensive and accurate method for measuring water-related, within field soil productivity variation would greatly enhance site-specific crop management strategies. This paper reports on investigations to use an electromagnetic induction (EM) sensor to map claypan (Udollic Ochraqualfs) and alluvial (Typic and Aquic Udipsamments and Aeric Fluvaquents) soil conductivity variations and to evaluate the relationship of EM measurement to grain crop production. Grain yield measurement was obtained by yield monitoring. While yield by EM model r**2 values were fairly low, EM sensing helped explain some crop productivity variability for most crop years on both soil types. A theoretical relationship between EM and production was proposed. With several crop-years of data, the theoretical relationship was supported. This tool for measuring field variability of soils will be most useful for predicting productivity variability where the erange in EM variability is large (> 30 mS/m).