{"title":"Irrigation expansion shows potential for increased maize yield and reduced nitrogen leaching in the Midwest US","authors":"Kelsie M. Ferin, Christopher J. Kucharik","doi":"10.1016/j.agsy.2024.104055","DOIUrl":null,"url":null,"abstract":"<div><h3>CONTEXT</h3><p>Yield gaps in Midwest US rainfed maize (<em>Zea mays</em> L.) are likely to continue to increase as the frequency of extreme weather events associated with future climate change increase (i.e., high temperatures, precipitation variability). One solution to closing this gap is the expansion of irrigation in regions that currently do not utilize this practice. While irrigation expansion has the potential to increase maize yields and crop productivity, there is also the potential to see improvement in nitrogen loss. However, it remains unclear at what point irrigation should be triggered (i.e., plant available water content (AWC) thresholds) to obtain a balance between crop productivity and environmental improvements.</p></div><div><h3>OBJECTIVE</h3><p>The objective of this study is to assess the effects of irrigation management on maize yield, nitrogen leaching, and water use efficiency under the expansion of irrigation across the entire Midwest US and to determine the optimal plant AWC threshold to trigger irrigation for achieving a substantial increase in maize yield and reduction in nitrogen leaching while using the minimal amount of required irrigation.</p></div><div><h3>METHODS</h3><p>We use an agroecosystem model, Agro-IBIS, to simulate both rainfed and irrigated maize production and nitrogen leaching under likely future climate conditions (i.e., wet-warm, dry-warm). To determine the optimal plant AWC threshold for irrigation, irrigation scenarios were conducted for a range of plant AWC thresholds (0.2 to 0.8) across the entire Midwest US.</p></div><div><h3>RESULTS AND CONCLUSIONS</h3><p>Our results show that Midwest US regions that do not currently utilize irrigation could experience an 11–37% increase in maize yield and a 12–32% decrease in nitrogen leaching when irrigation (39.0 to 96.8 mm yr<sup>−1</sup>) is triggered at the lower end of the plant AWC threshold (e.g., 0.3). Maize grown under dry-warm and wet-warm climate conditions will likely experience increased yields and reduced nitrogen loss with minimal irrigation. While these findings suggest that the expansion of irrigation could help close yield gaps while improving other ecosystem services, future work should focus on simulating these conditions under a wider range of precipitation extremes and fertilizer management to better understand the potential interactions under a changing climate.</p></div><div><h3>SIGNIFICANCE</h3><p>This study outlines the optimal plant AWC threshold for irrigation to maximize maize yields in the Midwest while minimizing nitrogen loss and can provide valuable insights for making informed decisions about landscape management under future conditions.</p></div>","PeriodicalId":7730,"journal":{"name":"Agricultural Systems","volume":null,"pages":null},"PeriodicalIF":6.1000,"publicationDate":"2024-06-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Agricultural Systems","FirstCategoryId":"97","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0308521X24002051","RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"AGRICULTURE, MULTIDISCIPLINARY","Score":null,"Total":0}
引用次数: 0
Abstract
CONTEXT
Yield gaps in Midwest US rainfed maize (Zea mays L.) are likely to continue to increase as the frequency of extreme weather events associated with future climate change increase (i.e., high temperatures, precipitation variability). One solution to closing this gap is the expansion of irrigation in regions that currently do not utilize this practice. While irrigation expansion has the potential to increase maize yields and crop productivity, there is also the potential to see improvement in nitrogen loss. However, it remains unclear at what point irrigation should be triggered (i.e., plant available water content (AWC) thresholds) to obtain a balance between crop productivity and environmental improvements.
OBJECTIVE
The objective of this study is to assess the effects of irrigation management on maize yield, nitrogen leaching, and water use efficiency under the expansion of irrigation across the entire Midwest US and to determine the optimal plant AWC threshold to trigger irrigation for achieving a substantial increase in maize yield and reduction in nitrogen leaching while using the minimal amount of required irrigation.
METHODS
We use an agroecosystem model, Agro-IBIS, to simulate both rainfed and irrigated maize production and nitrogen leaching under likely future climate conditions (i.e., wet-warm, dry-warm). To determine the optimal plant AWC threshold for irrigation, irrigation scenarios were conducted for a range of plant AWC thresholds (0.2 to 0.8) across the entire Midwest US.
RESULTS AND CONCLUSIONS
Our results show that Midwest US regions that do not currently utilize irrigation could experience an 11–37% increase in maize yield and a 12–32% decrease in nitrogen leaching when irrigation (39.0 to 96.8 mm yr−1) is triggered at the lower end of the plant AWC threshold (e.g., 0.3). Maize grown under dry-warm and wet-warm climate conditions will likely experience increased yields and reduced nitrogen loss with minimal irrigation. While these findings suggest that the expansion of irrigation could help close yield gaps while improving other ecosystem services, future work should focus on simulating these conditions under a wider range of precipitation extremes and fertilizer management to better understand the potential interactions under a changing climate.
SIGNIFICANCE
This study outlines the optimal plant AWC threshold for irrigation to maximize maize yields in the Midwest while minimizing nitrogen loss and can provide valuable insights for making informed decisions about landscape management under future conditions.
期刊介绍:
Agricultural Systems is an international journal that deals with interactions - among the components of agricultural systems, among hierarchical levels of agricultural systems, between agricultural and other land use systems, and between agricultural systems and their natural, social and economic environments.
The scope includes the development and application of systems analysis methodologies in the following areas:
Systems approaches in the sustainable intensification of agriculture; pathways for sustainable intensification; crop-livestock integration; farm-level resource allocation; quantification of benefits and trade-offs at farm to landscape levels; integrative, participatory and dynamic modelling approaches for qualitative and quantitative assessments of agricultural systems and decision making;
The interactions between agricultural and non-agricultural landscapes; the multiple services of agricultural systems; food security and the environment;
Global change and adaptation science; transformational adaptations as driven by changes in climate, policy, values and attitudes influencing the design of farming systems;
Development and application of farming systems design tools and methods for impact, scenario and case study analysis; managing the complexities of dynamic agricultural systems; innovation systems and multi stakeholder arrangements that support or promote change and (or) inform policy decisions.