Regenerative agriculture (RA) crop production systems have recently been popularized in many agricultural communities. Claims are often made that RA systems are better than conventional agriculture (CA) crop production systems, which are commonly considered to be input intensive.

The definition of an RA system is highly dependent on the practitioner, and many definitions can be found. In general, RA is a principles-based approach that aims to restore and enhance soil health, biodiversity, and ecosystem services through practices such as reduced tillage, cover cropping, diverse rotations (including fallow or resting periods), crop residue retention. In some cases, it includes agroforestry and/or the integration of livestock.

Proponents of RA argue that it can increase soil organic carbon (SOC), which is a proxy measurement related to stable soil organic matter (SOM). They also contend that RA practices improve soil water-holding capacity and soil systems resilience (which is an extremely broad category).

Regenerative agriculture systems have the basic objective of increasing on-farm biodiversity and delivering long-term improvement in productivity and soil health as compared to conventional crop production systems.

Recent reviews of the literature have addressed the overall trends in field research associated with RA systems in comparison to CA crop production systems. Some studies have demonstrated some positive effects of RA systems on soil condition and soil health.

Research reviews clearly illustrate that the context of the studies is very important in interpretation and there is clear evidence of major gaps in describing and quantifying effects from RA systems (Montgomery and Biklé, 2021 and Khangura, et al., 2023).

BLUF (Bottom Line Up Front) Statement:
Regenerative systems promote crop and soil management practices that have been recognized and utilized for many years, hundreds of years in fact. Current research comparing RA and CA systems are highly variable. All asserted benefits of RA systems are highly dependent on climate conditions and the CA systems used for comparison.

Overall, RA practices generally contribute positively to soil health. However, there is no definitive evidence of RA systems being superior to CA crop production systems.

Pros – Objectives of RA systems:

• Soil carbon and structure. A meta-analysis of temperate systems found that reduced tillage and inclusion of grass-based rotation and resting/fallow periods could increased SOC relative to CA. Studies in cooler and humid climates show that RA practices can build SOC stocks over several decades (Jordan, et al., 2022). This does not transfer to other agroecosystems in drier and warmer environments.
• Soil health and resilience. Practices that increase incorporation into soil crop residues (organic material), crops with different types of root systems, and crop rotations that include legume crops can improve soil aggregate stability, infiltration, internal soil drainage, and retention has been found in some studies and reviews (Khangura, et al., 2023).
• Biodiversity and ecosystem services. Diversified crop rotations, the use of cover crops, and crop–livestock integration can increase soil biodiversity. It is also contended that crop pollination and pest-regulation (insects, weeds, and diseases) can be improved with RA systems versus CA. However, these effects are commonly poorly quantified in most studies (Sher, et al., 2024). Thus, some of these benefits are quite speculative.
• Co-benefits and livelihoods. There are some publications that conclude that RA systems can be more profitable or financially resilient for farmers. But from these studies it is only possible for RA superiority to CA systems when there are price premiums, reduced input costs, or ecosystem payment schemes that are available. Highly variable yields, the need for policy support and payment mechanisms are commonly needed to make RA systems viable at scale (Reuters, 2024).

Cons / limitations compared to conventional cropping systems:

• Yield uncertainty and trade-offs. In most studies, RA practices do not consistently or significantly change crop yields relative to CA systems, particularly in short-term studies, anything less than a decade. Overall, review of the literature shows no consistent or general “win-win” RA situation that will reliably increase yields while increasing SOC. Yield responses are highly variable by crop, region, and the time elapsed since RA systems were adopted. In many cases, the transition years into RA systems cause yield reductions. The site-specific constraints can be quite variable it is difficult to identify consistent positive trends in RA system benefits over CA systems (Jordan, et al., 2022).
• Greenhouse gas and livestock trade-offs. RA systems that integrate livestock or increasing manure inputs can boost SOC and encourage soil biodiversity. These

types of RA systems have been shown to raise methane and nitrous oxide emissions. As a result, any net climate benefits are dependent on whole-system greenhouse-gas accounting, which is often not done or effectively included in most RA studies (Sher, et al., 2024).

• Evidence gaps and heterogeneity. Most of the cases found in the current literature on RA systems evaluation address single practices such as no-till versus conventional tillage, the use of cover crops, and animal manure application regimes. There is a substantial absence of long-term, fully integrated RA/CA systems comparisons. Accordingly, the results found in the current literature are highly variable and context dependent (soil type, climate, access to RA-friendly market benefits, etc.). As a result, generalization is extremely limited in comparing RA and CA systems (Jordan, et al., 2022).
• Adoption barriers. Moving to RA systems often requires new knowledge, increased and different levels of labor reallocation, equipment changes, and often many upfront investments to access unique markets and secure technical support. Incentive structures (i.e., subsidies) are commonly needed to make RA system transitions from CA systems and without that, adoption can be slow and highly variable (Reuters, 2024).

Regenerative systems promote crop and soil management practices that have been recognized and utilized for many years, hundreds of years in fact. Current research comparing RA and CA systems are highly variable. All asserted benefits of RA systems are highly dependent on climate conditions and the CA systems used for comparison.

There is a definite need for long-term, system-level experiments. The appropriate measurement and quantification of RA and CA system management comparisons and soil health parameters are essential priorities to help resolve the many remaining uncertainties associated with RA systems (Jordan, et al., 2022).

Overall, RA practices can potentially improve soil health. However, there is no definitive evidence of RA systems being superior to CA crop production systems.

References:
Jordon, M. W., K. J. Willis, P. C. Bürkner, N. R. Haddaway, P. Smith, & G. Petrokofsky. 2022. Temperate regenerative agriculture practices increase soil carbon but not crop yield — a meta-analysis. Environmental Research Letters 17(9):093001. doi:10.1088/1748-9326/ac8609.  

Khangura, R., D. Ferris, C. Wagg, & J. Bowyer. 2023. Regenerative agriculture—A literature review on the practices and mechanisms used to improve soil health. Sustainability 15(3):2338. doi:10.3390/su15032338.  

Montgomery, D. R., & A. Biklé. 2021. Soil health and nutrient density: Beyond organic vs. conventional farming. Frontiers in Sustainable Food Systems 5:699147. doi:10.3389/fsufs.2021.699147.  

Sher, A., H. Li, A. Ullah, Y. Hamid, B. Nasir, & J. Zhang. 2024. Importance of regenerative agriculture: Climate, soil health, biodiversity and its socioecological impact. Discover Sustainability 5:462. doi:10.1007/s43621-024-00662-z.  

Reuters. 2024. Rewarding farmers for regenerative agriculture is 'critical for decarbonising the food sector'. Reuters, June 10, 2024. (news article).  

Guardian (news). 2024. Cows help farms capture more carbon in soil, study shows. The Guardian, Sept. 28, 2024. (news article).  

Click here and hit ‘download’ for a PDF version of this article. 

It’s been anything but a smooth Spring melon season this year. Mild winter temperatures have contributed to the persistence of weeds and whitefly populations culminating in high viral pressure observed from the very first melon plantings onward. Through a collaborative effort between the University of California, USDA, and University of Arizona we would like to invite growers, PCAs, farm managers, researchers, and other stakeholders from the desert melon production regions in California, Arizona, and Mexicali to join us for a stakeholder meeting to discuss field observations and disease management research priorities.  

This meeting will provide an opportunity to review this season’s observations and trends across production areas, hear research and strategy updates from plant pathology specialists, and, most importantly, create space for discussion among stakeholders to better understand what is happening and give input on the disease management research priorities you want to see pursued moving forward. Topics and invited speakers include:

• Bill Wintermantel (USDA-ARS) – Overview of cucurbit viruses affecting desert melon production
• Arun Babu (UCCE Imperial)– Whitefly populations and insecticide efficacy trials in Imperial Valley
• Samuel Discua (University of Arizona, Yuma) – Whitefly populations and insecticide efficacy trials in Yuma, Arizona
• Chris Detranaltes (University of Arizona, Yuma)– Viruses and other pathogens recovered from symptomatic melon plants in Yuma, Arizona
• Ana M. Pastrana (UCCE Imperial) – Viruses and other pathogens recovered from symptomatic melon plants in Imperial Valley, California

Meeting details:
Where: AgWest Imperial 485 Business Pkwy, Imperial, CA 92251
When: June 2, 2026 10:30 am – 12:30 pm (lunch to follow until 1:00 pm)

Lunch will be provided. Please register here if you plan to attend so we can have an accurate food count and seating estimate: Registration Survey

If you have any concerns regarding the health of your plants/crops please consider submitting samples to the Yuma Plant Health Clinic for diagnostic service or booking a field visit with me:

Christopher Detranaltes, Ph.D. Cooperative Extension – Yuma County
Email: cdetranaltes@arizona.edu
Cell: 602-689-7328
6425 W 8th St Yuma, Arizona 85364 – Room 109 

Last week, we initiated an on-farm demonstration of soil steaming of the season with our self-propelled steam applicator. The machine is designed to inject steam into the soil and raise soil temperatures to levels sufficient to kill weed seed and soil borne pathogens (roughly 150°F for > 20 minutes). After the soil cools (< ½day), the crop is planted into the disinfested soil.

In this trial, we are examining the viability of soil steaming for controlling weeds in spinach at the field scale level (plot size > 1/3^rd ac). The machine performed well in that it was able to reach target soil temperatures at reasonable travel speeds (> 0.25 mph) in cold soil (roughly 50°F), provide uniform temperature distribution across the bed and form nicely shaped beds suitable for subsequent planting. Stay tuned for reports of weed control efficacy, crop yield and overall profitability as compared to the grower standard.

If you are interested in seeing the machine operate at the field scale level on a commercial farm, we are conducting additional trials this week! Please contact me for further information.

Fig. 1. On-farm demonstration of a self-propelled steam applicator for weed and
diseasecontrol video. We are conducting additional trials this week. Contact me if
you are interested in seeing it.

Acknowledgements
This project is sponsored and funded in part by the Arizona Specialty Crop Block Grant Program and the Propane Education and Research Council (PERC). We greatly appreciate their support.

1. Precision Robotic Weeding and Thinning Trial
We are approaching the final steps of our ongoing robotic weeding and thinning trial for head lettuce. As the crop approaches maturity, we will soon conduct a comprehensive comparison of lettuce marketable yield between robotic-treated and handweeded/thinned plots.

These results will provide evidence-based insights into the efficacy and viability of robotic technologies in specialty crop production. Our preliminary observations suggest promising results, and we anticipate that detailed findings will be valuable for adoption decisions across the region.

Southwest Ag Summit Presentation
Join us at the Southwest Ag Summit on February 19th for a detailed presentation of our results. This session will provide the complete analysis to support grower decision making.

Funding Acknowledgment: This research was made possible through support from the Arizona Iceberg Lettuce Research Council (AILRC).

2. Precision Chemigation Trial
In parallel with robotic thinning and weeding research, we are advancing precision chemigation through the utilization of a custom injection assembly designed to accurately deliver chemicals like herbicides and pesticides into sprinkler irrigation systems for research purposes.

The chemigation assembly enables consistent, controlled injections at different rates, allowing for optimized chemical efficacy.

The chemigation trial will evaluate the efficacy of Kerb and Prefar herbicides applied at different rates through the chemigation system for head lettuce. This research will provide weed control efficacy optimized for chemigation delivery methods. We will present details on the chemigation system and herbicide efficacy during the IPM Session at the Southwest Ag Summit.

Funding Acknowledgment: This project was funded in part by the USDA National Institute of Food and Agriculture through the Western Integrated Pest Management Center.

Both projects represent important steps forward in the adoption of precision agriculture technologies for sustainable crop production. Results from both trials will be presented at the Southwest Ag Summit on February 19th.

Bagrada bug (Bagrada hilaris) is an invasive stink bug recently established in the desert Southwest of the U.S. It has become a major economic pest of many cruciferous vegetable crops cultivated in fall and winter in the agricultural valleys of Arizona and southern California. Crop injury caused by Bagrada bug feeding has resulted in major economic losses. Depending on the crop species, Bagrada bugs may cause yield losses of 15-35%. Effective options for controlling Bagrada bug infestations in organic crops are limited, creating a significant challenge for organic growers. The objective of this study was to evaluate selective organic-approved insecticides to identify new tools that organic vegetable producers in the desert can use to manage Bagrada bugs effectively.

This fall growing season, we conducted a field trial to evaluate several organic-approved insecticides against the Bagrada bug in broccoli. The results of our trial show that M-Pede and a tank mix of M-Pede and Entrust can provide approximately a 60% reduction in Bagrada bugs relative to the untreated check. Captiva Prime and Neemix also resulted in a nearly 50% reduction in Bagrada bug numbers. Aza-Direct, Entrust alone, and Botanigard each resulted in about a 30% reduction in Bagrada bugs relative to the untreated check (Fig. 1). Our observations indicate that the insecticides evaluated are unlikely to provide quick knockdown. Tank mix of M-Pede and Entrust, Neemix, and Captiva Prime resulted in 39, 35, and 34% reduction in damage caused by Bagrada bug feeding. Entrust alone and M-Pede resulted in Bagrada bug feeding damage reductions approaching 25% (Fig. 2). Previous research trials conducted in Yuma also show that mixture of Entrust and M-Pede, Entrust alone, Aza-Direct, and Pyganic can fairly suppress the pest (Palumbo 2022).

Figure 1. Number of Bagrada bugs per 10 broccoli plants as affected by biological
insecticide applications, Fall 2025. All insecticide treatments included Nu-Film
P at 1 pt./ac.




Figure 2. Percentage of broccoli plants with damage caused by Bagrada bug
feeding, Fall 2025. All insecticide treatments included Nu-Film P at 1 pt./ac.

Additional Reading Material:
Palumbo, J.C. 2024. Bagrada Bug Management Tips - 2024. Veg IPM Newsletter, Vol. 15, No. 18 University of Arizona, Department of Entomology. http://hdl.handle.net/10150/676902

Keith, M., & Calvin, W. 2025. The Evolution of Bagrada Bug Management in Desert Cole Crops: The Legacy of John C. Palumbo (2010–2025). Veg IPM Newsletter, Vol. 16, No. 21. University of Arizona, Department of Entomology. http://hdl.handle.net/10150/678668

In Yuma Valley, precipitation is not the primary driver of crop water supply; irrigation is. Yet rainfall still matters because it can act like a biological “switch,” briefly reshaping field conditions in ways that influence weeds and plant disease. A single storm can alter soil surface moisture, stimulate germination, increase canopy humidity, and adjust access and irrigation timing. For Integrated Pest Management (IPM), these short windows often have outsized consequences compared with the annual total. Using annual precipitation totals from AZMET (Yuma Valley station), 1987–2025, the long-term trend is slightly upward, but the signal is extremely weak relative to the natural variability.

Figure 1 summarizes annual precipitation over time and includes a fitted linear trendline (the red line). The long-term mean annual precipitation is 2.63 inches (the yellow line), emphasizing how arid this production system is. The most recent year provides useful context: 2025 annual precipitation was 5.91 inches, which is substantially above the long-term mean (by 3.28 inches). That single year does not redefine the long-term trajectory by itself, but it illustrates the central message of the dataset: large departures from the mean can occur even when the multi-decadal trend is weak.

Figure 1. Annual total precipitation at the AZMET Yuma Valley station (1987–2025). Points/line represent annual totals; the horizontal reference indicates the long-term mean (2.63 in). The fitted linear regression trendline indicates a slight increasing tendency over the period.

The trendline equation shown on the figure is:  

• y = 0.0111x − 19.58
• R² = 0.0074

The slope (0.0111 inches per year) corresponds to roughly 0.11 inches per decade, which is small in magnitude. Meanwhile, R² = 0.0074 indicates the linear trend explains less than 1% of the year-to-year variability, meaning annual precipitation is dominated by irregular storm years and interannual fluctuations, not a strong flat wetting or drying signal.

Why this matters for IPM

For pest management, the most relevant feature of Yuma Valley precipitation is not the weak long-term slope but the timing and periodicity of rainfall and the biological responses it triggers:

• Rainfall pulses can rapidly activate weed germination in disturbed soils.
• Microclimate shifts and disease favorability. Even modest rainfall can elevate leaf wetness and near-canopy humidity, creating short infection windows for moisture sensitive pathogens (crop- and growth-stage dependent).
• Rain-driven changes in host availability and microclimate can influence insect survival, dispersal, and population growth. The post-rain window is often when scouting provides the highest informational value because conditions shift quickly.
• Rain seldom replaces irrigation in Yuma, but it can affect field access and irrigation timing, indirectly shaping canopy structure and pest habitat.

The key message from Figure 1 is straightforward: annual rainfall in Yuma Valley does not exhibit a strong long-term linear trend from 1987 to 2025, and any increase suggested by the trendline is minor relative to variability. Years like 2025 (5.91 inches) sit far above the long-term mean (2.63 inches), highlighting that single-year abnormalities can be operationally meaningful even when the multi-decadal trend is weak.