Mapping soil and pasture variability with an electromagnetic induction sensor

The general objective of this study was to test a non-contact electromagnetic induction probe to evaluate the soil and pasture variability in a precision agriculture project. Assessment of the variability of soil and vegetation in a permanent pasture is the basis for management of variable rate fertilization, which is the main instrument used by farmers for improvements in permanent pasture in Alentejo, Portugal. The traditional process of sampling and evaluation of the soil is very demanding in terms of time, labour and reagents, and can derail a project of precision agriculture. This paper describes the major steps followed by the authors to simplify the methodology of soil evaluation in a permanent pasture based on measuring the apparent soil electrical conductivity. Tests were carried out in a parcel of approximately 6ha, which was subdivided into 28mx28m squares. The soil samples and the evaluation of apparent electrical conductivity were geo-referenced with a global positioning system. The geospatial data were processed by ArcGIS software and the statistical analysis resulted in significant correlation coefficient values between apparent electrical conductivity and altitude, soil pH and pasture dry matter yield.

[1]  Ancha Srinivasan,et al.  Handbook of Precision Agriculture: Principles and Applications , 2006 .

[2]  Dennis L. Corwin,et al.  Characterizing soil spatial variability with apparent soil electrical conductivity Part II. Case study , 2005 .

[3]  John Tenhunen,et al.  Application of a geographically‐weighted regression analysis to estimate net primary production of Chinese forest ecosystems , 2005 .

[4]  A. Mauromoustakos,et al.  Soil phosphorus variability in pastures: implications for sampling and environmental management strategies. , 2001, Journal of environmental quality.

[5]  Matthias Rothmund,et al.  Precision agriculture on grassland : Applications, perspectives and constraints , 2008 .

[6]  J. M. Silva,et al.  Delineation of management zones using mobile measurements of soil apparent electrical conductivity and multivariate geostatistical techniques , 2010 .

[7]  Antonio P. Mallarino,et al.  Efficacy of Grid and Zone Soil Sampling Approaches for Site-Specific Assessment of Phosphorus, Potassium, pH, and Organic Matter , 2004, Precision Agriculture.

[8]  J. S. Bailey,et al.  Within and between-field spatial variation in soil phosphorus in permanent grassland , 2009, Precision Agriculture.

[9]  J. Serrano,et al.  Evaluation of spatial and temporal variability of pasture based on topography and the quality of the rainy season , 2008, Precision Agriculture.

[10]  Chris Brunsdon,et al.  Geographically Weighted Regression: The Analysis of Spatially Varying Relationships , 2002 .

[11]  Clyde W. Fraisse,et al.  Delineation of Site-Specific Management Zones by Unsupervised Classification of Topographic Attributes and Soil Electrical Conductivity , 2001 .

[12]  R. M. Lark,et al.  Mapping Potential Crop Management Zones within Fields: Use of Yield-map Series and Patterns of Soil Physical Properties Identified by Electromagnetic Induction Sensing , 2005, Precision Agriculture.

[13]  S. Searcy,et al.  Apparent Electrical Conductivity, Soil Properties and Spatial Covariance in the U.S. Southern High Plains , 2005, Precision Agriculture.

[14]  Andreas G. Lazari,et al.  Soil electrical conductivity as a function of soil water content and implications for soil mapping , 2006, Precision Agriculture.

[15]  Andreas Persson,et al.  Topographical data for delineation of agricultural management zones. , 2005 .

[16]  Huiquan Bi,et al.  Modeling spatial variation in tree diameter–height relationships , 2004 .

[17]  Donald G. Bullock,et al.  Improving Map Accuracy of Soil Variables Using Soil Electrical Conductivity as a Covariate , 2005, Precision Agriculture.

[18]  R. G. V. Bramley,et al.  Precision Viticulture: A new era in vineyard management and wine production , 2006 .

[19]  Walter Jetz,et al.  Local and global approaches to spatial data analysis in ecology , 2005 .

[20]  J. R. Landis,et al.  The measurement of observer agreement for categorical data. , 1977, Biometrics.

[21]  Dennis L. Corwin,et al.  Apparent soil electrical conductivity: applications for designing and evaluating field-scale experiments , 2005 .

[22]  Dennis L. Corwin,et al.  Characterizing soil spatial variability with apparent soil electrical conductivity , 2005 .

[23]  A. O. A. Netto,et al.  Características químicas e salino-sodicidade dos solos do Perímetro Irrigado Califórnia, SE, Brasil , 2007 .