Tag Archives: agriculture

The innocent pyrethroids, perspectives from the bottom of the ag drainage canal

17 Jan
English: Pumping station A drainage channel le...

. (Photo credit: Wikipedia)

Hello, gentle readers,

I am writing to announce that I have actually started working in my field, or more precisely, in the canals at the end of the irrigation ditches at the downhill side of my field, and I am thrilled. My job is to sample water to help California growers comply with state and federal regulations regarding nutrient and pesticide loads in their tailwater. I have no skill getting my waders un-stuck from the mud, so I only hope one day to go pro, but this is my big chance, I think.

From a debriefing session at the company headquarters I learned that there are exceedences for two organophosphate pesticides, a family of pesticides effective against many insect pests and very soluble in water. Instead, to protect waterways from further contamination, farmers are switching to more frequent use of pyrethroids, a family of pesticides extracted from the marigold family of plants and effective against a narrower range of pest insects, namely the butterfly and moth family. Pyrethroids were considered safe because they bind to soil well and they break down fairly quickly, but if they do wash down into waterways on sediment particles, they are deadly to aquatic invertebrates, and they need to be used more frequently than their organophosphate predecessors. Is switching to pyrethroids really an improvement? I have my doubts.

Am I glad to be doing something about my passion for public access to environmental quality data? You betcha!

From the ditch,

Your faithful correspondent.

How much Aflatoxin can our beef and poultry handle in these stormy times? Senator weighs in.

1 Dec

The laws of supply and demand dictate that scarcity drives prices up. Corn and other feed grains are moldier than usual due to unusually stormy weather, making quality corn more scarce on the market, thereby driving corn prices up. The price of corn is also rising because of the increasing demand for corn ethanol fuel, a renewable, cleaner burning gasoline additive,., and because of a severe recent drought in the US midwest. Meat animals no longer bring in enough money to pay for their traditional, corn-based feed, so farmers and ranchers are reportedly sacrificing their herds to make ends meet.
Senator Roberts has a solution to this problem. Why not ease up on the regulations about feed grain quality? Why not  feed livestock a mix of moldy grain and quality grain, a mix that is designed to reach, but not exceed, the Food and Drug Administration’s maximum Aflatoxin concentration? After all, we have plenty of moldy grain this year, and plenty of hungry livestock. He understands that dairy cows should be given less aflatoxin than other types of livestock, and this should be considered when giving out aflatoxin waivers. More feed means lower feed prices and possibly more ranchers able to stay in business this year.

What are the risks to poultry, beef cattle, dairy cattle and consumers of overexposure to Aflatoxin? For poultry, aflatoxin reduces weight gain. For dairy cattle, aflatoxin has minimal effects on the cows but goes directly into the milk supply, putting human consumers at risk.


How much is too much aflatoxin in feed grain, according to the FDA? No harm comes to animals consuming 20 parts per billion of aflatoxin, but it is legal to use feed with up to 300 parts per billion of aflatoxin. The difference is due to the fact that resulting meat or poultry meets FDA standards for aflatoxin levels in consumer products. The compliance policy guidelines can be found here.

What about other types of fungal toxins? Why did Senator Roberts not mention Fumonisin, a more potent fungal toxin on corn and other feed grains? The FDA compliance policy guidelines on food and feed levels for this toxin are available here.

Since more aflatoxin-contaminated feed  will be on the market instead of being tilled under, will this result in increased risks of direct human consumption?

If Senator Roberts’ idea is adopted, for how long will the mixed grain waivers be available?  What if this decision were made permanent? Would long-term low-level exposure to these fungal toxins decrease our animal product yield and increase our long-term exposure to these dangerous fungal toxins?

You can email Senator Roberts, or write your own senator, if you have an opinion about his proposed solution to this critical feed shortage.


Roundup Ready Ragweed!

25 Oct

A great video on BBC shows the consequences of overuse of Roundup on Roundup Ready corn.

Ploughshares into spray nozzles–the California Tour

6 Sep
English: Wild elephants in Munnar, Kerala

English: Wild elephants in Munnar, Kerala (Photo credit: Wikipedia)

How will farmers feed 9 billion people by the close of this century? That is the question posed to six renowned leaders in the field of conservation farming during the Conservation Ag Systems Innovation conference tour (CASI)
On August 28th, 29th and 30th,
Jeff Mitchell, University of California Cooperative Extension Specialist,  gathered together some of the world’s great visionaries to sell conservation farming practices to California farmers, students, and agency staffpeople. Conservation farming, a term used to refer to no-till, minimum tillage and controlled traffic farming practices, is popular in the midwestern US because it saves water and cuts fuel costs while preserving soil organic matter, which has many benefits to soil fertility. No-till is also popular in South America, particularly in Brazil, while controlled traffic farming (with conventional tillage) is practiced in Tasmania, an island off the coast of Australia, for the purpose of reducing soil compaction on the cropped rows while improving traction on the trafficked rows.

Don Reicosky from Morris, MN, a retired USDA ARS employee, explained the nuts and bolts of tillage and likened it to natural disasters for soil microorganisms. The best tillage is no-till, he explained.
Rolf Derpsch from Paraguay, who has worked in Brasil, Argentina, Somalia and Germany, explained why conservation tillage not only saves water but also reduces the need for fertilizer because soil microbes and organic matter act as a slow release fertilizer, protecting ground and surface water from contamination. He said that early adoption of no-till in South America was easier to support than here in the US because there was no initial attachment to what we call conventional tillage, and the yield increases with less gas and less fertilizer inspired the spread of conservation farming there.

Clay Mitchell from Geneseo, IA grows corn and soybeans alternating in a north-south direction to maximize profitability based on market prices for those two commodities, but that is not all. This farmer has combined controlled traffic farming with satellite GPS (Global Positioning System) technology, and an awe inspiring data collection protocol which allows him to micromanage the fertilizer application based on things like prior yield in a particluar square foot of field. Tillage has long been considered the primary way to get rid of weeds and make the fertilizer applications and rooting depth more uniform. With no-till, surface application of soil ammendments like lime (calcium or calcium-magnesium carbonates) could be inconsistent and will only reach a depth of a few centimeters during a growing season, so Mr. C. Mitchell advises crop rotations rather than tillage to incorporate surface applied lime at depth, and he relies on satellites to position his fertilizers exactly where they are most needed rather than tilling for greater uniformity. This is a real engineering problem solving strategy, but weed control

Jerry Hatfield spoke about what the EPA and the California Air Quality Control Board want from soil, and how much more food we will need to produce on the same land. These two ideas do not conflict–by keeping more carbon on the ground, soil water holding capacity goes up, meaning that less irrigation water is needed and droughts are less severe. Water use efficiency increases as does productivity per unit fertilizer, giving us some hope for the future, when worldwide land area will decrease while demand will be as high in the next 10 years as in the previous 100 years.

John McPhee of Burney, Tasmania explained how GPS technology can aid in controlled traffic farming which reduces erosion and compaction, improving drainage and allowing cultivation and planting sooner after rain events. He said that tillage was an integral part of his operation and it was not popular to consider no-till systems in Tasmania. He likened the soil microbes to an elephant per acre, and the residue left in the field as food for the elephant -FEED the Elephant!

I would like to suggest that there was another elephant in that room. Herbicides. There is no such thing as organic no-till. Tillage is a wonderful alternative to herbicides and with all the hype about overuse of Roundup and other easily available potent herbicides, which results in herbicide resistance in common weed species such as Palmer Amaranth. Mr. Clay Mitchell of Iowa explained that he rotated his herbicides by rotating his GMO corn and soybeans from Roundup Ready varieties to Liberty Link varieties (the first can tolerate lots of the herbicide Roundup, or Glyphosate, and the second can handle a lot of Glufosinate, an herbicide with a different mode of action. Rotating modes of action is smart to prevent resistance in weed species, but mechanical control is the only option for organic growers, so if we stop plowing, we protect the environemnt from carbon dioxide and particulate matter but this system depends on constant innovation of herbicide chemistries to keep up with herbicide resistance, and constant new developments in the world of GMO’s to allow excessive herbicide applications. The herbicide question looms large in my mind, particularly for the developing world, where transportation infrastructure increases the cost of everything from fertilizer to herbicide to parts for fancy GPS directed no-till equipment. So feed the soil microbial elephant, and give that herbicide elephant a few peanuts too, while you’re at it–the future of humanity and food security depend on it!

Pest management for your sweetie: Cacao Pesticide Public Relations poster–Thoughts?

22 Mar
A Russell Stovers box of milk chocolates.

A Russell Stovers box of milk chocolates. (Photo credit: Wikipedia)


An industry poster (above) shows a picture of a heart-shaped box of chocolates with all but one of the chocolates missing, a vivid depiction of the impact of pests, particularly a fungus commonly known as black pod disease, has on this tropical crop where no pest control is applied. The poster advocates for “modern agricultural approaches”, implying that the chemical industry should be thanked for the rest of the box of chocolates in the image, the chocolate harvest to which we have become accustomed (example at right).

I researched the pest management options available to cacao growers and found that black pod disease is one of the primary pests in cacao, resistant varieties of the crop are not resistant enough to ward off the disease, beneficial fungi such as Trichoderma give about 50% control of the pest, but fungicides like Kocide give almost complete control of the pest.

1. What is this fungicide, Kocide? Copper Hydroxide.

2. Who makes it and what kinds of precautions should be taken when using this material? This is a basic salt of copper and it is most hazardous if you inhale it, causing lung and kidney problems. It is also very hazardous to inhale as a gas if it were exposed to fire. Handlers should wear long sleeves and protection against breathing the wettable powder or the spray.

3. Does it harm nontarget species? How long does it stick around? Copper hydroxide is very toxic to aquatic invertebrates like daphnia, the classic ‘canary in the coal mine’ of water bugs. This substance should not get into waterways, and empty containers need to be disposed of as hazardous waste because it is a heavy metal and is regulated as hazardous waste. Copper binds tightly to the soil and may reside there for a long time in a not-very available form, but repeated use of this pesticide might result in buildup of this naturally occurring metal in the soil.

OP-ED: What are the implications for chocolate growers around the world?
Deberdt’s article mentions that most farmers in Cameroon, a cacao growing country, cannot afford the chemical fungicide and may experience up to 100% loss of their crop, validating the poster’s depiction of the losses that the untreated disease can cause. Copper hydroxide is a real option for improving yields and livelihoods of these farmers and they probably would use it if they could afford it. Biological controls like beneficial fungi might be a good compromise because they have some carry-over effects to the following year, so farmers can buy them every few years and get some relief from the black pod disease. I actually do agree with this industry poster and feel that this particular fungicide, if used away from waterways and if care is taken to prevent inhaling this product, can make a big difference in the lives of growers and I will still eat cacao!

How much sewage sludge can you apply to land (federal register volume 58 #32 part 503 USEPA 1993)

19 Jan

USEPA 1993 part 503 “Standards for use or disposal of sewage sludge