Author: Bob Whitney

Extension Organic Program Specialist, Texas A&M AgriLife Extension

Insights on inter-row electrical weeding as a non-chemical weed management tool in organic cotton.

by Ryan Hamberg – Graduate Research Assistant and PhD Candidate at Texas A&M University working in weed control research.

Inter-row cultivation is a “go-to” tool in organic production systems. However, repeated soil disturbance is bad for soil health, leading to erosion, organic matter loss, and more. Practices that maintain or enhance soil health are at the forefront of organic production systems. The problem is that few non-chemical tools exist to manage inter-row weeds organically without soil disturbance.

Figure 1. The Zasso inter-row electrical weeding prototype. (Left) The generator is located at the back of the tractor and the front applicator attachment. (Right) This unit is designed for small plot research and covers just two rows

Research is underway at the Texas A&M University Research Farm, where a “first-of-its-kind” prototype inter-row electrical weeder (EW) in cotton is being tested (Figure 1). This prototype unit was designed through collaboration with Zasso (Indaiatuba, Brazil) and purchased through the support of AgriLife Research and Cotton Incorporated. The prototype includes a large generator and transformer that is powered by the tractor PTO, with the applicator attached to the front loader (Figure 1). Many growers may already be familiar with the Weed Zapper or similar tools that can manage weeds present above the canopy (Figure 2). Though both technologies use electricity, this EW prototype uses a distinctly different delivery method and can kill weeds present between the rows, allowing for control of weeds present below the crop canopy.

Figure 2. A more common electrical weeder design that only targets weeds taller than the crop canopy.

Numerous experiments are currently being conducted to test this prototype unit to determine the feasibility of using this technology in organic row crops, including cotton. The study highlighted in this article aims to determine how EW compares to traditional cultivation methods. Treatments were applied at the early post-emergence timing, when cotton was at the 4-leaf stage. The treatment structure was as follows:

  • One pass EW @ 0.8 mph
  • Two-pass (double-knock) EW @ 0.8 mph – 2nd pass immediately after
  • Two-pass (double-knock) EW @ 0.8 mph – 2nd pass 3 days after
  • One pass EW @ 2 mph
  • Two-pass (double-knock) EW @ 2 mph – 2nd pass immediately after
  • Two-pass (double-knock) EW @ 2 mph – 2nd pass 3 days after
  • One pass inter-row cultivation
  • One pass EWC @ 3.5 mph
  • Two-pass (double-knock) EW @ 3.5 mph – 2nd pass immediately after
  • Two-pass (double-knock) EW @ 3.5 mph – 2nd pass 3 days after
  • Nontreated control

The field tested in this experiment was infested with hophornbeam copperleaf, ivyleaf morningglory, Palmer amaranth, Johnsongrass, and Texas panicum. Weeds ranged in height from 5 to 10 cm at the time of application. Between-row weed control was evaluated at 3 and 14 days after treatment (DAT). Broadleaf weed control exceeded 95% across all treatments at both evaluation timings (Figures 3 & 4). In general, electrical weeding performed comparably to cultivation for broadleaf control, except for a single pass at 3.5 mph. Control of grasses varied across treatments at both timings. Grass control at 0.8 and 2 mph was slightly higher (~ 3%) with two passes of EW compared to a single pass of cultivation. Electrical weeding at 3.5 mph reduced grass control to 70% with one pass. Even with two passes at 3.5 mph, control ranged from 74% to 81% (Figure 3). Some concerns over potential current transfer into crop roots were raised, and therefore, cotton injury was also assessed at 3 and 14 DAT. Cotton injury never exceeded 1% of the plot and was generally <1% overall (Data not shown). The cotton injury observed was always due to contact with the electrode of the EW and there was no indication that root transfer was occurring.

The present study indicates that inter-row EW holds promise as a non-chemical weed control option in row crop systems. The EW performed as well as inter-row cultivation on broadleaf weeds while minimizing soil disturbance. Reduced grass control at faster travel speeds suggests that slower applications are necessary when grass weeds are present. Previous research has found grasses as more tolerant to other thermal weed control tools such as flaming (Ulloa et al., 2010). Overall, the feasibility of the EW has been demonstrated. Ongoing and future research will assess the potential role of this tool within integrated weed management programs specifically designed for organic cropping systems.

Figure 3. Visual control ratings of broadleaf and grass weeds following electrical weeding at varying travel speeds compared to cultivation. The red dashed line represents the 90% control threshold.

Figure 4. Plots showing weed control treatments three days after application.

Planning Organic Production with a Practical Price Index

In Extension, we’re often asked to help farmers and food businesses plan for the future—whether it’s transitioning acreage to organic, developing budgets, or evaluating the economics of new practices. One of the most common challenges we face is this: how do you plan for prices in an unpredictable market?

While no one can forecast future prices with certainty, that doesn’t mean we’re flying blind. We base our planning on something measurable, reliable, and rooted in history—and in organic agriculture, one of the most useful tools for this is a broad price index or multiplier.

Why Use a Price Multiplier?

Organic markets—like all markets—fluctuate. Prices are affected by everything from weather and input costs to consumer demand and global trade. But when we look at long-term trends, we begin to see patterns that can inform sound decision-making.

When we have access to strong market data—such as for organic corn, cotton, dairy, and many fruits and vegetables—we can use that data to create benchmarks. These help answer practical questions:

  • What kind of price can I reasonably expect if I go organic?
  • How much more can I budget for input costs and still break even?
  • Will this transition pencil out?

To answer these questions, we need a reference point—and that’s where a 1.6 multiplier comes in.

What Is the 1.6 Organic Multiplier?

The 1.6 multiplier means that organic farmgate prices tend to average about 1.6 times higher than conventional prices for many major commodities over the long run. That’s a 60% premium, based on real market data and USDA price tracking over the past decade or more. I happened to stumble onto this idea when I read an article in Progressive Dairy about conventional milk price forecasts through 2025. (Click to Read) This article made me wonder if I could use historical organic dairy milk prices in relation to conventional dairy milk prices and use this ratio to predict future organic prices. It was amazing to see what I kind of knew, that organic prices do follow with conventional prices for the most part!

So, this is not a guess. It’s backed by:

  • USDA AMS organic market summaries for corn (1.6 is pretty stable for corn) and cotton (less stable as prices have been higher making the index 1.6-2.0 or higher).
  • National organic dairy price reports, which show organic milk regularly selling at 1.5 to 1.65 times the price of conventional.
  • Industry-wide organic vegetable and fruit pricing that shows farmgate premiums in the 1.5 to 1.7 range across categories like tomatoes, lettuce, and apples.

Whether you’re planning production, analyzing risk, or applying for a grant or loan, this index provides a realistic baseline. It is not too optimistic or too pessimistic and is useful for planning purposes.

When This Index Works—and When It Doesn’t

The 1.6 multiplier is a planning tool, not a crystal ball. It works best:

  • When building enterprise budgets for row crops, dairy, and produce.
  • When discussing profitability potential with transitioning farmers.
  • When negotiating contracts or thinking through insurance or risk tools.
  • In extension workshops, to help audiences grasp market potential quickly.

However, this index doesn’t capture every situation. Local sales, direct markets, specialty crops, and extreme weather or supply chain issues can cause premiums to fall below or rise above the average. Sometimes, organic produce in a saturated market may only bring in a 10–20% premium, while other times a rare variety or short supply can push that number above 2x (or higher) the conventional price.

Why It’s Still Useful

Despite those swings, planning requires a number—and the 1.6 index is a solid, evidence-based starting point.

When I help producers set up organic systems, I don’t want to promise the moon. Instead, it is better to offer realistic projections grounded in long-term national trends.

Always I encourage producers to:

  • Adjust their projections up or down depending on crop, region, and market access.
  • Keep checking updated USDA-AMS, Argus Media, or buyer data each year.
  • Use the 1.6x benchmark as a baseline, not a guarantee.

Final Thoughts

As organic agriculture continues to grow, tools like this price index become more and more valuable. They help all of us in organic talk apples to apples with producers, gins, co-ops, lenders, and buyers. They also help demystify what can sometimes feel like a complex or volatile market.

My plan and my job is to keep helping farmers make decisions that are smart, sustainable, and rooted in good data.

Avian Influenza H5N1 Hits Dairy Herds Hard: What the New Study Reveals

A recent study in Nature Communications1 investigates the impact of highly pathogenic avian influenza (HPAI) H5N1 on dairy cattle—highlighting concerning health and economic consequences that warrant attention in organic and conventional dairy farming alike.

What Happened on the Farm

  • Researchers examined a 3,876‑cow dairy herd in Ohio affected by H5N1 in Spring 2024.
  • About 20% of cows showed clinical signs—such as fever, reduced feeding, and mastitis, leading to a dramatic milk loss lasting around 7 days, with many cows quarantined.

Substantial Milk Production Declines

  • Clinically infected cows experienced a steep drop: from ~77 lbs./day to ~24 lbs./day, persisting at reduced levels for up to 60 days after diagnosis.
  • Over 60 days, milk output per cow fell by nearly ~2,000 lbs., a huge hit to productivity.

Hidden Infections: Subclinical Cases Are Common

  • Serum tests on 637 cows found 89% had been exposed to H5N1.
  • Among these, around 76% never showed clinical signs, maintaining normal milk yields despite infection.
  • This suggests widespread but often unnoticed infection—highlighting the need for proactive monitoring.

Economic Impact: Nearly $1,000 Loss per Cow

  • Clinical infection led to an estimated $950 loss per cow, accounting for lost milk, culling, and replacement costs.
  • The total for this one herd was a staggering ~$737,500.

Why This Matters

  • Extended milk loss even after cows recover points to lasting damage—likely from virus replication in mammary tissue causing severe mastitis.
  • Subclinical infection prevalence underscores the importance of surveillance and early detection tools (e.g., monitoring rumination and milk yield trends).
  • Risk factors: cows in mid-to-late lactation and higher-parity animals were most affected.
  • Transmission during milking is suspected—pointing to milking hygiene and protocols as possible control points.

From the Field: Cornell’s Perspective

Cornell University highlighted in Phys.org2 that pasteurization kills the virus, so consumer milk remains safe. However, at the farm level, the outbreak is an economic crisis—on par with the large losses seen in poultry, though less government support exists for dairy.

Take‑Home Messages for Farmers

  1. Vigilant monitoring: Falling rumination or milk yield—especially during HPAI outbreaks—may signal infection before symptoms appear.
  2. Review milking biosecurity: Strengthen cleaning protocols between cows to reduce spread.
  3. Prepare economically: Understand that even a few cases can cascade into massive financial losses.
  4. Surveillance matters: Regular serology can detect infections early in both lactating and dry cows.

Start Early Protecting Organic Dairy Replacements

To help protect calves from H5N1 infection through contaminated waste milk, organic producers have a practical tool: citric acid acidification. I wrote about this simple, NOP-compliant method can inactivate the virus and reduce bacterial pathogens without the need for pasteurization. To learn how to implement this low-cost strategy on your farm, read my full article here: A New Organic Tool Against H5N1 in Calves: Citric Acid in Waste Milk.

Resources & References

  1. The impact of highly pathogenic avian influenza H5N1 virus infection on dairy cows, Peña‑Mosca et al., Nature Communications, 2025 ↩︎
  2. Avian flu has major economic costs for dairy industry. (2025, July 15). Phys.org. Retrieved July 17, 2025, from Phys.org agriculture news section ↩︎

Using Google Earth and Web Soil Survey to Understand Your Fields

Modern agriculture is becoming more data-driven—and one of the most powerful, yet underutilized, tools available to producers is the combination of Google Earth and the Web Soil Survey (WSS). By combining satellite imagery with accurate USDA soil maps, we can get a clearer picture of what’s happening below the surface—and make better decisions above ground.

In this post, I’ll show how I use Google Earth to not only view an alfalfa field visually but also overlay the soil types, interpret their characteristics, and use that data to plan irrigation, understand yield variability, and improve management.

Step 1: Start With a Clear Aerial View of the Field

Here I opened Google Earth and zoomed in on our irrigated pivot field that we are studying. This field is part of an irrigation experiment we are conducting to determine alfalfa response to varying irrigation rates. Numbers 1-6 pins on the map represent the sensors buried in the soil and those sensors measure soil moisture to 3 feet deep. You will also notice a jagged yellow line through the field which represents where two soil types are in this field. The east side is a May soil type, and the west side is a Chaney soil type. Google Earth does not typically show soil types – so how did I get these soil types added?

Step 2: Adding a SoilWeb Earth KMZ file

If you will open your browser and go to https://casoilresource.lawr.ucdavis.edu/soilweb-apps you will see the screenshot I have demonstrated in the picture above. For this to work you need to have Google Earth on your computer already but hopefully you have done that by now. Next click on the picture under SoilWeb Earth and your computer will ask you to save a file called SoilWeb KMZ. Save it where you can find it on your computer.

Next open Google Earth and at the top left click on File and then open so you can choose the location of your recently saved KMZ file. When you open this file in Google Earth it will now show all the soil types for any piece of property in the United States. It may take a minute to open all the features. If you scroll down the left menu under Places, you will see the SoilWeb item, and you can check or uncheck to turn it on or off. It will probably be under the temporary file section and you just need to move it up to get it to stay open when you open Google Earth.

Step 3: Investigate the Features

When turned on you will see all the yellow lines that represent differing soil types. If you click inside of a soil type outlined with the yellow lines, you are inside that type.

When you click anywhere in that soil area you will see the picture below pop up. This is the pop up when I clicked in that “soils” area in the picture and this shows the soil types represented in this area of the pivot. This area is predominantly a Chaney soil type with a small percentage of the others in this area as well.

Now if you click on the blue words loamy sand under the title “Chaney” it will pop up the description in the picture below.

When I get this popup, it is displayed in Google Earth, but you can just click on the upper right to get it to appear in your web browser too. On the left of this picture, you see a menu full of information on this Loamy Sand soil type. Play around with it and learn about your soil.

Now lets go back to Google Earth by clicking the button at the top left that says, “Back to Google Earth.” When you do let’s once again click inside the soil type we are interested in and you will see this popup graphic again.

Click inside the colored soil column and you will get a different page pop up.

The picture below is a description of the Chaney soil series, and it is very detailed. At the top are different tabs you can click on like lab data, water balance, and more or just scroll down through it! You will spend a lot of time just looking at this one series and your farm could have many different series across your different fields. As you zoom out in Google Earth you will find lots of soil types and experiment by clicking on several and then clicking again in the popup menu of soils in that series. It is interesting and it will help you learn how to get the information you need. Do not be afraid to “click” on something!

In our irrigation study we are interested in the water holding capacity of the soils and you can get that under “water balance.” This graphic below will show the water storage in this soil series based on the month and we quickly see we will run a pretty hefty deficit in July, August and September but an abundance in winter. This corresponds to when the typical vegetation in summer is using the water.

Why do I like this soil series feature?

I am constantly using Google Earth in my work. If I have a call from a producer about crops, soils, irrigation or just about anything else on a producer’s farmland I will pull up the fields in Google Earth. When I do this special feature is automatically available and so I can look at the fields and I can evaluate the soils. I can tell how deep they are for crop growth, what the estimated pH is, soil water holding capacity, organic matter, and even estimated yields on dryland crops. This doesn’t mean that things won’t vary somewhat from the data in Google Earth, but that variation will not be too far off from this excellent information! And it is certainly a great starting place for figuring out any problems in any field before we start.

Turning Oilfield Wastewater into Agricultural Opportunity

As farmers in the Texas know all too well, water is the lifeblood of our land—and it’s in short supply. But what if one of the most abundant waste streams in our region could be cleaned up and used to grow crops? That’s the question being tested right now in several pilot projects across Texas, where treated oilfield wastewater, called produced water, is being evaluated for agricultural use.

WaterTectonics at a site in Midland treating Produced Water for reuse in a fracking operation. Similar to what might be done in agriculture. Picture from https://www.watertectonics.com/project/texas-produced-water-reuse-treatment/

What is Produced Water?

Produced water is the salty, chemical-laden byproduct that comes up with oil and gas during drilling operations. The Permian Basin alone generates around 24 million barrels of this water every day—that’s equivalent to roughly 1 billion gallons, about 37,196 acre-inches, or over 3,100 acre-feet daily. Historically, this water has been disposed of underground, but with growing water needs and improving treatment technologies, many are asking: can we make this water safe and useful for agriculture??

New Pilot Projects in Texas Agriculture

Thanks to recent legislation (notably SB 1145, effective Sept. 1, 2025), Texas is laying the groundwork for farmers to eventually use treated produced water. But for now, only pilot projects are permitted—and here are some of the most important ones:

OrganizationPilot ScopeLocationCrops or Focus
Texas Pacific Water Resources (TPWR)Treating water with reverse osmosis; testing 400+ contaminantsMidland and Pecos River areaAlfalfa, native grasses (greenhouse & outdoor)
Deep Blue OperatingIrrigation pilot using up to 27,300 gal/dayMidland CountyCotton, bermuda grass, alfalfa, wheat
Texas Produced Water ConsortiumResearch coordination, data analysisMultiple West Texas sitesSupports 5 pilot sites with varying treatment systems
TETRA & EOG ResourcesDesalination pilot with high recovery ratesPermian BasinRangeland grasses (greenhouse testing)
Aris Water Solutions & GarverMembrane & thermal treatment systemsPermian BasinSystem design; seeking TCEQ irrigation permits
General Land Office & EOG Resources1-acre soil/crop health trialReeves CountyMonitoring nutrient uptake and plant health

These pilot projects are being carefully watched—not only by state regulators but by farmers, environmental scientists, and rural water managers. If successful, they could help shift produced water from being a liability to a resource.

Opportunities for High-Value Ag

For Texas (particularly West Texas) growers, the implications are huge. While piping treated produced water to distant farms is one possible use, its greatest potential may lie right at the source—near oilfields. These areas often have access to electricity, trucking infrastructure, and available land. That makes them ideal for developing high-value production systems where water and logistics are already in place. In this context, treated produced water could potentially support:

  • Alfalfa for hay export or dairy feed
  • Hydroponic cotton in controlled environments—growing cotton without soil in greenhouses using treated produced water. This approach, pioneered in Spain by Magtech and now being explored by researchers in Texas, can increase cotton yield up to 60 times per plant while reducing water use by as much as 70%. With greenhouse infrastructure, electricity, and logistics already in place at oilfield sites, hydroponic cotton may offer a promising high-value use for treated produced water.
  • Small grains for forage or cover crop use—including some hydroponic or germinated forage systems grown in controlled buildings, which allow rapid biomass production using minimal land and continuous water supply
  • New specialty crops on reclaimed or marginal land—such as tomatoes, cut flowers, ornamentals, and guayule—offering high-value returns in controlled or niche markets
  • Controlled Environment Agriculture (CEA) in Containers/Buildings — Treating produced water and using it in hydroponic or aeroponic systems within shipping containers or retrofitted buildings.

However, it’s not without concern. Produced water contains salts, heavy metals, even traces of radioactive materials and PFAS (so-called “forever chemicals”). These pilot projects are focused on whether new treatment technologies can remove or neutralize those contaminants. No broad use is permitted yet—only tightly monitored experiments.

What Happens Next?

Texas regulators (RRC and TCEQ) are developing rules for future land application. Meanwhile, the Texas Produced Water Consortium at Texas Tech is coordinating research and setting potential standards. Full-scale use in agriculture will depend on:

  • Successful pilot results
  • Clear treatment and monitoring rules
  • Economic viability for farmers
  • Long-term environmental and crop safety

Bottom Line for Farmers

This is not ready for prime time—but it’s getting closer. If you’re farming in Texas near where there is Produced Water and facing water stress, this is an idea worth watching. You may soon have access to a new, local water source that was once just oilfield waste.

A New Organic Tool Against H5N1 in Calves: Citric Acid in Waste Milk

As organic dairy producers, you do a lot with less—less antibiotics, less synthetic inputs, and often less infrastructure than our conventional neighbors. But you are no less committed to calf health and biosecurity. And now, with the emergence of the H5N1 avian influenza strain in dairy cattle, we all are facing a new challenge that demands creative, organic-compliant solutions.

I read about a possible treatment for organic dairy producers in an article written by Maureen Hanson in the May/June Bovine Veterinarian1. A very practical tool we have at our disposal is citric acid powder—an affordable, National Organic Program (NOP)-allowed substance that can be used to acidify waste milk and protect our calves from pathogens, including the H5N1 virus.

The Problem: Infected Milk Transmits H5N1

USDA researchers have confirmed that H5N1 is shed in the milk of infected cows—even up to two weeks before those cows show any signs of illness. In a controlled study, Holstein calves fed raw milk from infected cows contracted the virus within days. Although symptoms were mild—fever, nasal discharge, lethargy—the virus was confirmed in lung, lymph, and tonsil tissue. All calves had to be euthanized for analysis.

What does this mean for organic dairy farmers? If we’re feeding raw, unpasteurized waste milk—especially from cows not yet showing symptoms—we may be unknowingly exposing our calves to a highly contagious virus.

The Challenge: Most Organic Farms Don’t Pasteurize Waste Milk

Pasteurizers are expensive, and many small to mid-sized organic dairies don’t have them. In fact, even fewer than 50% of large-scale dairies pasteurize their waste milk. So what’s the alternative?

The Solution: Citric Acid Powder – Affordable, Organic, and Proven

Researchers at UC Davis have confirmed that acidifying waste milk with citric acid to a pH of 4.1–4.2 completely inactivated the H5N1 virus—and it did so within six hours in controlled lab trials2. This method worked not just on typical waste milk, but also on colostrum and milk from treated cows—broadening its relevance for real-world dairy operations.

For organic producers without access to pasteurization equipment, this presents an ideal alternative:

  • Application Rate: 6 grams of food-grade citric acid per liter of milk (be sure to test milk pH after adding)
  • Target pH: 4.1
  • Effectiveness: Deactivates H5N1 and reduces other pathogens (see below)
  • Cost: ~10 cents per liter (this depends on the rate and cost to purchase)
  • Time Required: Six hours contact time before feeding

Citric acid is approved under the USDA National Organic Program and is easy to source, store, and apply. It requires no heat, no specialized equipment, and is safe for both calves and farm workers.

Citric acid powder sometimes called “lemon salt”

UC Davis researchers concluded that acidification is a practical, sustainable, and accessible tool to prevent the spread of H5N1 and other harmful microbes in preweaned calves. Compared to more complex systems like lactoperoxidase activation, citric acid stood out as the most straightforward and consistently effective method. UC Davis researchers are planning to conduct more tests but so far this treatment looks to be a way to prevent future infections.

Why This Works for Organic Producers

Citric acid is permitted under the USDA National Organic Program for this kind of use. It’s also widely available, easy to store, and can be scaled up or down depending on how much milk you’re feeding.

In organic systems, where animal health starts with prevention and careful management, this method offers a simple and economically viable tool for protecting calf health and stopping the spread of disease without compromising organic integrity. Be sure to source “feed grade” or “food grade” with the organic seal to ensure it is the right product and can be used in organic feeds.

Beyond H5N1: Broader Pathogen Control

Acidifying milk doesn’t just stop H5N1. It helps reduce bacterial loads in general—particularly Salmonella, E. coli, and Mycoplasma—which can all challenge young calves. In other words, citric acid is a broad-spectrum line of defense, not just a response to a single threat for waste milk fed to calves.

Final Thought: Protecting Calves in Beef-on-Dairy Programs

In today’s dairy world—organic or not—many producers are using sexed semen to retain replacement heifers and breeding the rest of the herd to beef sires. The resulting calves often leave the dairy within a few days as part of beef-on-dairy programs, where they are raised off-site for beef markets.

That means the responsibility for disease prevention starts on the dairy, even if the calf doesn’t stay there long. If calves receive waste milk contaminated with H5N1 in those first critical days, they could carry the virus into the next phase of production—putting entire systems at risk.

By acidifying your waste milk with citric acid, you can cost-effectively reduce that risk from day one. It’s a low-cost, NOP-compliant biosecurity step that protects animal health, supports the beef-on-dairy market, and upholds the integrity of your organic operation.

As always, I need to remind certified organic producers to check with their certifiers before making any changes to their Organic System Plan and check with your veterinarian who develops your herd health plan.

We have the tools. Let’s use them wisely.

  1. Inspired by: “Calf Milk Poses H5N1 Risk, Too” by Maureen Hanson – Bovine Veterinarian, May/June 2025
    https://www.bovinevetonline.com ↩︎
  2. Crossley, B.M., Pereira, R.V., Rejmanek, D., Miramontes, C., & Gallardo, R.A. (2025). Acidification of raw waste milk with citric acid inactivates highly pathogenic avian influenza virus (H5N1): An alternative to pasteurization for dairy calves. Journal of Dairy Science, 108(5), 3456–3465. doi:10.3168/jds.2025-00051 https://www.ucdavis.edu/news/killing-h5n1-waste-milk-alternative-pasteurization ↩︎