skip to main content
US FlagAn official website of the United States government
dot gov icon
Official websites use .gov
A .gov website belongs to an official government organization in the United States.
https lock icon
Secure .gov websites use HTTPS
A lock ( lock ) or https:// means you've safely connected to the .gov website. Share sensitive information only on official, secure websites.

Explore Research Products in the PAR
It may take a few hours for recently added research products to appear in PAR search results.


Title: How does building healthy soils impact sustainable use of water resources in irrigated agriculture?
As blue water resources become increasingly scarce with more frequent droughts and overuse, irrigated agriculture faces significant challenges to reduce its water footprint while maintaining high levels of crop production. Building soil health has been touted as an important means of enhancing the resilience of agroecosystems to drought, mainly with a focus in rainfed systems reliant on green water through increases in infiltration and soil water storage. Yet, green water often contributes only a small fraction of the total crop water budget in irrigated agricultural regions. To scope the potential for how soil health management could impact water resources in irrigated systems, we review how soil health affects soil water flows, plant–soil–microbe interactions, and plant water capture and productive use. We assess how these effects could interact with irrigation management to help make green and blue water use more sustainable. We show how soil health management could (1) optimize green water availability (e.g., by increasing infiltration and soil water storage), (2) maximize productive water flows (e.g., by reducing evaporation and supporting crop growth), and (3) reduce blue water withdrawals (e.g., by minimizing the impacts of water stress on crop productivity). Quantifying the potential of soil health to improve water resource management will require research that focuses on outcomes for green and blue water provisioning and crop production under different irrigation and crop management strategies. Such information could be used to improve and parameterize finer scale crop, soil, and hydraulic models, which in turn must be linked with larger scale hydrologic models to address critical water-resources management questions at watershed or regional scales. While integrated soil health-water management strategies have considerable potential to conserve water—especially compared to irrigation technologies that enhance field-level water use efficiency but often increase regional water use—transitions to these strategies will depend on more than technical understanding and must include addressing interrelated structural and institutional barriers. By scoping a range of ways enhancing soil health could improve resilience to water limitations and identifying key research directions, we inform research and policy priorities aimed at adapting irrigated agriculture to an increasingly challenging future.  more » « less
Award ID(s):
1824871
PAR ID:
10454034
Author(s) / Creator(s):
; ; ; ; ;
Date Published:
Journal Name:
Elementa: Science of the Anthropocene
Volume:
10
Issue:
1
ISSN:
2325-1026
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
More Like this
  1. ; ; ; ; ; (, Journal of Advances in Modeling Earth Systems)
    Abstract Correctly calculating the timing and amount of crop irrigation is crucial for capturing irrigation effects on surface water and energy budgets and land‐atmosphere interactions. This study incorporated a dynamic irrigation scheme into the Noah with multiparameterization land surface model and investigated three methods of determining crop growing season length by agriculture management data. The irrigation scheme was assessed at field scales using observations from two contrasting (irrigated and rainfed) AmeriFlux sites near Mead, Nebraska. Results show that crop‐specific growing‐season length helped capture the first application timing and total irrigation amount, especially for soybeans. With a calibrated soil‐moisture triggering threshold (IRR_CRI), using planting and harvesting dates alone could reasonably predict the first application for maize. For soybeans, additional constraints on growing season were required to correct an early bias in the first modeled application. Realistic leaf area index input was essential for identifying the leaf area index‐based growing season. When transitioning from field to regional scales, the county‐level calibrated IRR_CRI helped mitigate overestimated (underestimated) total irrigation amount in southeastern Nebraska (lower Mississippi River Basin). In these two heavily irrigated regions, irrigation produced a cooling effect of 0.8–1.4 K, a moistening effect of 1.2–2.4 g/kg, a reduction in sensible heat flux by 60–105 W/m2, and an increase in latent heat flux by 75–120 W/m2. Most of irrigation water was used to increase soil moisture and evaporation, rather than runoff. Lacking regional‐scale irrigation timing and crop‐specific parameters makes transferring the evaluation and parameter‐constraint methods from field to regional scales difficult. 
    more » « less
  2. ; (, Water Resources Research)
    Abstract Irrigated agriculture depends on surface water and groundwater, but we do not have a clear picture of how much water is consumed from these sources by different crops across the US over time. Current estimates of crop water consumption are insufficient in providing the spatial granularity and temporal depth required for comprehensive long‐term analysis. To fill this data gap, we utilized crop growth models to quantify the monthly crop water consumption ‐ distinguishing between rainwater, surface water, and groundwater ‐ of the 30 most widely irrigated crops in the US from 1981 to 2019 at 2.5 arc min. These 30 crops represent approximately 95% of US irrigated cropland. We found that the average annual total crop water consumption for these 30 irrigated crops in the US was 154.2 km3, 70% of which was from irrigation. Corn and alfalfa accounted for approximately 16.7 and 24.8 km3of average annual blue crop water consumption, respectively, which is nearly two‐fifths of the blue crop water consumed in the US. Surface water consumption decreased by 41.2%, while groundwater consumption increased by 6.8%, resulting in a 17.3% decline in blue water consumption between 1981 and 2019. We find good agreement between our results and existing modeled evapotranspiration (ET) products, remotely sensed ET estimates (OpenET), and water use data from the US Geological Survey and US Department of Agriculture. Our data set and model can help assess the impact of irrigation practices and water scarcity on crop production and sustainability. 
    more » « less
  3. ; ; ; ; ; (, Scientific Reports)
    Abstract Agricultural fields in drylands are challenged globally by limited freshwater resources for irrigation and also by elevated soil salinity and sodicity. It is well known that pedogenic carbonate is less soluble than evaporate salts and commonly forms in natural drylands. However, few studies have evaluated how irrigation loads dissolved calcium and bicarbonate to agricultural fields, accelerating formation rates of secondary calcite and simultaneously releasing abiotic CO2to the atmosphere. This study reports one of the first geochemical and isotopic studies of such “anthropogenic” pedogenic carbonates and CO2from irrigated drylands of southwestern United States. A pecan orchard and an alfalfa field, where flood-irrigation using the Rio Grande river is a common practice, were compared to a nearby natural dryland site. Strontium and carbon isotope ratios show that bulk pedogenic carbonates in irrigated soils at the pecan orchard primarily formed due to flood-irrigation, and that approximately 20–50% of soil CO2in these irrigated soils is calcite-derived abiotic CO2instead of soil-respired or atmospheric origins. Multiple variables that control the salt buildup in this region are identified and impact the crop production and soil sustainability regionally and globally. Irrigation intensity and water chemistry (irrigation water quantity and quality) dictate salt loading, and soil texture governs water infiltration and salt leaching. In the study area, agricultural soils have accumulated up to 10 wt% of calcite after just about 100 years of cultivation. These rates will likely increase in the future due to the combined effects of climate variability (reduced rainfall and more intense evaporation), use of more brackish groundwater for irrigation, and reduced porosity in soils. The enhanced accumulation rates of pedogenic carbonate are accompanied by release of large amounts of abiotic CO2from irrigated drylands to atmosphere. Extensive field studies and modelling approaches are needed to further quantify these effluxes at local, regional and global scales. 
    more » « less
  4. ; (, Journal of environmental management)
    Land use change and climate variability have significantly altered the regional water cycle over the last century thereby affecting water security at a local to regional scale. Therefore, it is important to investigate how the climate, land use change, and water demand potentially influence the water security by applying the concept of water footprint. An integrated hydrological modeling framework using SWAT (Soil and Water Assessment Tool) model was developed by considering both anthropogenic (e.g. land use change, water demand) and climatic factors to quantify the spatio-temporal variability of water security indicators such as blue water scarcity, green water scarcity, Falkenmark index, and freshwater provision indicators in Savannah River Basin (SRB). The SRB witnesses a significant change in land use land cover (e.g. forest cover, urban area) as well as water demand (e.g. irrigation, livestock production). Overall our results reveal that, SRB witnessed a significant decrease in blue water due to the climate variability indicating that the precipitation has more control over the blue water resources. Whereas, green water was more sensitive to changes in land use pattern. In addition, the magnitude of various water security indicators are different within each county suggesting that water scarcity are controlled by various factors within a region. An integrated assessment of water footprint, environmental flow, anthropogenic factors, and climatic variables can provide useful information on the rising (how and where) of water related risk to human and ecological health. 
    more » « less
  5. ; ; ; ; ; ; ; (, Earth's Future)
    Abstract Groundwater extraction in the United States (US) is unsustainable, making it essential to understand the impacts of limited water use on irrigated agriculture. To improve this understanding, we integrated a gridded crop model with satellite observations, recharge estimates, and water survey data to assess the effects of sustainable groundwater withdrawals on US irrigated agricultural production. The gridded crop model agrees with satellite‐based estimates of evapotranspiration (R2 = 0.68), as well as survey data from the United States Department of Agriculture (R2 = 0.82–0.94 for county‐level production and 0.37–0.54 for county‐level yield). Using the optimistic assumption that groundwater extraction equals effective aquifer recharge rate, we find that sustainable groundwater use decreases US irrigated production of maize, soybean, and winter wheat by 20%, 6%, and 25%, respectively. Using a more conservative assumption of groundwater availability, US irrigated production of maize, soybean, and winter wheat decreases by 45%, 37%, and 36%, respectively. The wide range of simulated losses is driven by considerable uncertainty in surface water and groundwater interactions, as well as accounting for the many aspects of sustainability. Our results demonstrate the vulnerability of US irrigated agriculture to unsustainable groundwater pumping, highlighting the difficulty of expanding or even maintaining irrigated food production in the face of climate change, population growth, and shifting dietary demands. These findings are based on reducing pumping by fallowing irrigated farmland; however, alternate pumping reduction strategies or technological advances in crop genetics and irrigation could produce different results. 
    more » « less
  • Citation Formats
  • MLA
  • APA
  • Chicago
  • BibTeX
  • Save / Share this Record
  • Send to Email