Precision mapping technology in dryland cropping system

Authors: Mikha, Maysoon; Barnard, David; Mankin, Kyle

Submitted to: Proceedings Great Plains Soil Fertility Conference
Publication Type: Proceedings
Publication Acceptance Date: 3/9/2022
Publication Date: 3/9/2022
Citation: Mikha, M.M., Barnard, D.M., Mankin, K.R. 2022. Precision mapping technology in dryland cropping system. Proceedings Great Plains Soil Fertility Conference.

Interpretive Summary: Precision Agriculture is a farming concept that accounts for spatial and temporal variability in crop production and soil resources. This can be done by using global positioning system (GPS) to coordinate collection of soil, site, and plant information; generating maps and relationships between spatial variability of soil and site properties and the resulting crop yield; and applying those relationships to guide variable-rate inputs for seed, fertilizer, and pesticides. The objective of this study is to evaluate spatial variability and precision management decisions using mapping technology in dryland cropping system. The study was initiated in 2018 in Akron, Colorado on field size plots ranged from 2.4 to 4.5 ha (6-11 acres) with substantial production variability. The cropping system consists of (i) Business-As-Usual (BAU) management with wheat-fallow cropping under reduce tillage (WF-RT) and (ii) Aspirational (ASP) with four-year cropping of winter wheat-corn-millet-flex under no tillage (WCMFlex-NT). Soil samples in each field were taken in a 30-m (100-ft) georeferenced grid. Two or three management zones were defined in each field by yield, soil properties, and elevation. Yield differences between high and low yielding zones within each field varied by as much as 135 bu ac-1 (8.5 Mg ha-1) for corn and 85 bu ac-1 (5.3 Mg ha-1) for wheat. Information generated from this study could improve the application of precision farming in this region. Overall, this project provides a unique opportunity to evaluate precision farming practices for the dryland cropping system in the Central Great Plains Region.

Technical Abstract: Increasing availability of cropland geospatial data are providing farmers with opportunities but also challenges in interpreting these data for precision cropland management decisions. The objective of this study is to evaluate spatial variability and precision management decisions using mapping technology in dryland cropping system. The study was initiated in 2018 in Akron, Colorado on field size plots ranged from 2.4 to 4.5 ha (6-11 acres) with substantial production variability. The cropping system consists of (i) Business-As-Usual (BAU) management with wheat-fallow cropping under reduce tillage (WF-RT) and (ii) Aspirational (ASP) with four-year cropping of winter wheat-corn-millet-flex under no tillage (WCMFlex-NT). Each phase of each rotation was included in each year of the study with three replications. Soil samples in each field were taken in a 30-m (100-ft) georeferenced grid. Two or three management zones were defined in each field by yield, soil properties, and elevation. Veris-EC/pH was used as a tool to evaluate some aspects of soil properties. Two eddy covariance towers were installed to estimated carbon and water fluxes. High-resolution topographical maps reveal elevation changes of more than 2 m (6.5 ft) in some fields. Yield differences between high and low yielding zones within each field varied by as much as 135 bu ac-1 (8.5 Mg ha-1) for corn and 85 bu ac-1 (5.3 Mg ha-1) for wheat. Preliminary geospatial analyses are showing promise in guiding precision farming decisions and could provide a unique opportunity to dryland farmers for optimizing crop production, reducing inputs, and enhancing economic return in the central Great Plains Region.