Georeferenced field yield and soil variable data collected and processed through precision agriculture technologies

Abstract

Data were collected from a 60-hectare agricultural production field under continuous agriculture with annual crop rotation, located in the southeastern Pampas, Argentina. The Argentine Humid Pampas region is one of the world's best areas for grain crop production. The major soil types in this region are Typic Argiudolls, with a loam texture at the surface layer, loam to clay loam at subsurface layers, and sandy loam below 110 cm in depth, and Petrocalcic Paleudolls, which present discontinuous layers of a petrocalcic horizon between 50 and 100 cm and greater clay contents at subsurface layers than Typic Argiudolls. According to the Thornthwaite moisture index, the climate is sub-humid/humid, with annual rainfall of 880 mm and a mean annual temperature of 13.3 °C. Georeferenced measurements of apparent electrical conductivity (ECa) were taken at two depths: 0-30 cm (ECa30) and 0-90 cm (ECa90), as well as elevation (Elev) and soil depth (Sd). Soil ECa measurements were taken using a Veris 3100 (Veris 3100, Division of Geoprobe Systems, Salina, KS) calibrated following the manufacturer's instructions. The sensor was pulled across the field in a series of parallel transects spaced at 15-20 m intervals, the appropriate spacing to avoid measurement errors and information loss. ECa was simultaneously measured and georeferenced using a Differential Global Positioning System (DGPS) (Trimble R3, Trimble Navigation Limited, USA) with sub-meter measurement accuracy and set up to record position once per second. A total of 6425 sites were measured. Terrain elevation data were processed with a vertical accuracy of 3-5 cm. Soil depth was measured using a hydraulic penetrometer (Gidding) on a 30 x 30 m regular grid. Eight georeferenced soil sampling points were taken within delineated management zones (MZ) to validate zoning. Each sampling point consisted of three subsamples centered in the MZ. Soil cores were taken to a depth of 90 cm using a 5-cm diameter hydraulically driven soil tube (Giddings Machine Co., Windsor, CO). As the soil profile is not uniform through the 0-90 cm depth, soil in each core was carefully mixed to homogenize the sample. To validate the created MZ, we used soil organic matter (SOM) content measured from the 0-30 cm stratum, particle-size distribution determined using the Bouyoucos method, and wheat grain yield recorded using calibrated commercial yield monitors mounted on combines equipped with DGPS. Data for ECa30, wheat yield, samples, and boundary field area are available in the files data0.txt, WheatYield.txt, sample.txt, and Bound.txt. Additionally, ECa30, ECa90, elevation, and soil depths were processed and interpolated using geostatistical techniques on a regular 10 x 10 m grid generated within the field boundaries. These interpolated data are available in the file Pred.txt.