|Sudduth, Kenneth - Ken|
|Volkmann, Matthew - Matt|
Submitted to: Precision Agriculture
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/6/2016
Publication Date: 9/27/2017
Citation: Yost, M.A., Kitchen, N.R., Sudduth, K.A., Sadler, E.J., Drummond, S.T., Volkmann, M.R. 2017. Long-term impact of a precision agriculture system on grain crop production. Precision Agriculture. 18(5):823-842. doi:10.1007/s11119-016-9490-5.
Interpretive Summary: Targeting management practices and inputs with precision agriculture has high potential to meet some of the grand challenges of sustainability in the coming century, including simultaneously improving crop yields and reducing environmental impacts. Although the potential is high, few studies have documented long-term effects of precision agriculture on crop production. To better understand these impacts, a 36-ha field in central Missouri was monitored for over a decade as both a conventional (1993-2003) and a precision agriculture system (PAS) (2004-2014). Conventional management was annual rotations of corn and soybean, annual tillage, and uniform chemical inputs. Key aspects of the PAS were the addition of no-tillage, cover crops, winter wheat instead of corn on areas with shallow topsoil and low corn profitability, and variable-rate fertilizer (nitrogen, phosphorus, potassium, and lime) applications. Results showed the PAS maintained, but did not increase, corn or soybean grain yield. However, the PAS did cause less variation in grain yields from year to year in many areas of the field, despite more extreme weather conditions than during the conventional management. These results indicate that yield may be more stable from year to year with precision agriculture and conservation. This information will aid in the further acceptance and use of precision and conservation practices by farmers and farm advisors on claypan landscapes. Increased use of these practices should maintain farmer’s long-term crop yields, reduce variability in their crop yield, and increase the stability of their yields across a range of growing conditions.
Technical Abstract: Research is lacking on the long-term impacts of field-scale precision agriculture practices on grain production. Following more than a decade (1993-2003) of yield and soil mapping and water quality assessment, a multi-faceted, ‘precision agriculture system’ (PAS) was implemented from 2004 to 2014 on a 36-ha field in central Missouri. The PAS targeted management practices that address crop production and environmental issues. It included no-till, cover crops, growing winter wheat (Triticum aestivum L.) instead of corn for field areas where corn was not profitable, site-specific N for wheat and corn using canopy reflectance sensing, variable-rate P, K, and lime using intensively grid-sampled data, and targeting of herbicides based on weed pressure. The PAS assessment was accomplished by comparing it to the previous decade of conventional, whole-field corn (Zea mays L.)-soybean (Glycine max [L.]) mulch-tillage management. In the northern part of the field and compared to pre-PAS corn, wheat in PAS greatly improved relative grain yield and reduced temporal yield variation on shallow topsoil, but reduced relative grain yield on deep soil in the drainage channel. In the southern part of the field where corn remained in production, PAS did not increase yield, but did reduce temporal yield variability. Across the whole field, soybean yield and temporal yield variation were only marginally influenced by PAS. Spatial yield variation of all three crops was not altered by PAS. Therefore, the greatest production advantage of a decade of precision agriculture was reduced temporal yield variation, which leads to greater yield stability and resilience to changing climate.