a man and his hoe

every day is a good day

Month: April 2014

  • Biodiversity and Insect Pests

    There are many who are concerned with the amount of pesticides farmers apply to the crops we eat. Not only are many concerned with the harm pesticide residues cause when they eat this food, they are also concerned with the effect these pesticides have on the environment. Perhaps you are concerned as well.BiodiversityCover

    According to the EPA, “World pesticide expenditures totaled more than $35.8 billion in 2006 and more than $39.4 billion in 2007. U.S. pesticide expenditures totaled $11.8 billion in 2006 and $12.5 billion in 2007.” This is from the EPA’s Pesticides Industry Sales and Usage – 2006 and 2007 Market Estimates report.

    The USGS (US Geological Survey) has a web page, The Pesticide National Synthesis Project, where you can find maps showing estimated annual usage for more than 460 pesticides; pesticides like Acetochlor, Clothianidin , Dichloropropene, and many more. This is what one of these maps looks like.
    24DUseThis map shows the estimated usage in pounds per square mile of 2,4-D, a chemical used in Agent Orange. The map also show the different crops it is used on. So you can look up a pesticide and see if it is used extensively where you live.

    In Biodiversity and Insect Pests, edited by Geoff M. Gurr, Steve D. Wratten, William E. Snyder, with Donny M. Y. Read, the writers make the case that incorporating biodiversity into farms can reduce and even eliminate the need for pesticides. Agriculture, which now accounts for 40% of the land area on our planet, has greatly diminished the diversity of plants, animals, insects and organisms. As a result, agriculture is responsible for greatly reducing the number of beneficial insects which are needed to keep the pest insects under control. And with agriculture practiced on an industrial scale, ever increasing amounts of pesticides are used to keep pest insects under control, resulting in even greater losses to biodiversity.

    The book explores the ways biodiversity can reduce pests, and be a source of genes for better crops and compounds for botanical insecticides.

    Biodiversity and Insect Pests is a technical book, detailing numerous experiments from around the world. One example I particularly liked was the use of flowering plants, like alyssum, to protect lettuce fields. The way this works is that many predatory insects which kill pest insects do not actually eat the pests. Instead they lay their eggs in the pest insects, and when the eggs hatch, the larvae devour the pest insects. But when you have, for example, a field of lettuce which covers hundreds or thousands of acres, there is nothing for the predatory insects to eat, so they don’t venture far into the lettuce to lay their eggs on the pests.

    However, if farmers plant rows of alyssum along with the lettuce, the predatory insects thrive off the pollen on the alyssum, and will spread through the field, laying their eggs in the pest insects, and keeping them under control. Planting a variety of flowering plants in these strips is also helpful, as different predatory insects feed on different flowers.

    At the same time, the writers point out the importance on relying on more than one predatory insect. They stress the need to have strips of undisturbed rows or land nearby for other predatory creatures, like spiders. Many predatory bugs live in burrows in the ground, and so are totally absent in fields that are plowed and tilled. The way having multiple predators helps, is that some pest insects will drop to the ground or flee when they are attacked by predatory insects. By having healthy populations of ground level predators, the pest insects can be mopped up by these ground level predators.

    The writers point out that the financial benefits of biodiversity are usually not counted in economic studies. And yet, they point out that ecosystems can provide significan economic benefits. They state that “the value of coffee borer control by birds in Jamaica has been estimated to be US$310 per hectare,” and that in the cotton fields ofTexas, the value of insect eating bats is estimated to be US$5 to US$70 per hectare. In 2006, researches Losey and Vaughan estimated that insects provide services, such as pest control, worth US$4.5 billion.

    For example, a key pest of vines in New Zealand is a leafroller caterpillar, Epiphyas postvittana (Walker), which can be managed by planting buckwheat or other nectar plants between vine rows to improve the ecological fitness of its key natural enemy, the parasitoid wasp Dolichogenidea tasmanica (Cameron) at a cost of NZ$2 per ha. There is no loss of productive land and annual variable costs of NZ$250 per ha can be saved (Scarratt, 2005) indicating a cost–benefit ratio of 125:1.

    Biodiversity and Insect Pests is a fascinating book with numerous examples of how to incorporate biodiversity not only into farms, but also into urban gardens, so that you don’t need to use synthetic pesticides to control problem pests. At the same time it is a very technical book written for researchers. Hopefully, the writers will come out with a companion book for the lay person, with easy to read examples of how to incorporate biodiversity into their gardens and vegetable plots to eliminate the need for pesticides.

    The chapters in the book are:

    • Chapter 1 Biodiversity and insect pests
    • Chapter 2 The ecology of biodiversity-biocontrol relationships
    • Chapter 3 The role of the generalist predators in terrestrial good webs: lessons for agricultural pest management
    • Chapter 4 Ecological economics of biodiversity use for pest management
    • Chapter 5 Soil fertility, biodiversity and pest management
    • Chapter 6 Plant diversity as a resource for natural products for insect pest management
    • Chapter 7 The ecology and utility of local and landscape scale effects in pest management
    • Chapter 8 Scale effects in biodiversity and biological control: methods and statistical analysis
    • Chapter 9 Pick and mix: selecting flowering plants to meet the requirements of target biological control insects
    • Chapter 10 The molecular revolution: using polymerase chain reaction based methods to explore the role of predators in terrestrial food webs
    • Chapter 11 Employing chemical ecology to understand and exploit biodiversity for pest management
    • Chapter 12 Using decision theory and sociological tools to facilitate adoption of biodiversity based management strategies
    • Chapter 13 Ecological engineering strategies to manage insects pests in rice
    • Chapter 14 China’s ‘Green Plant Protection’ initiative: coordinated promotion of biodiversity-related technologies
    • Chapter 15 Diversity and defense: plant-herbivore interactions at multiple scales and trophic levels
    • Chapter 16 ‘Push–Pull’ revisited: the process of successful deployment of a chemical ecology based pest management tool
    • Chapter 17 Using native plant species to diversify agriculture
    • Chapter 18 Using biodiversity for pest suppression in urban landscapes
    • Chapter 19 Cover crops and related methods for enhancing agricultural biodiversity and conservation biocontrol: successful case studies
    • Chapter 20 Conclusion: biodiversity as an asset rather than a burden

  • Easter Chicks

    There is a new clutch of hatched chicks today at a man and his hoe®. It looks like there are four or five altogether. The mother is feisty, and we’ll need to wait until it is dark to move her and her chicks into their nursery. This is how chicks should come into the world.

    EasterChicks

  • Rhubarb Sauce – Live a Little

    Rhubarb Sauce is an indispensable condiment around here from April through summer. It’s tart flavor goes with most any dish, even something as simple as toast. For heartier fare like lentils, beans, or a roast, it is superb. Or mix it with some yoghurt to make a salad dressing And it is the easiest thing to make.

    • Step 1 – pick some rhubarb
    • Step 2 – chop it up
    • Step 3 – put the chopped rhubarb and some sugar and a bit of sake or white wine in a pot
    • Step 4 – cook it on a low to medium heat until the rhubarb has melted away – you may stir it once or twice
    • Step 5 – take it off the heat and pour into a glass container

    That’s it. You can even start using it while it’s still warm.

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    For variety you can add spices like allspice, cloves or cinnamon, or what ever comes to mind; play with the amount of sugar, or try making it without any sugar at all. If you want it velvety smooth, blend it with a hand mixer or in a blender. It will keep in the refrigerator for several weeks, but just make enough for a few days, and when you run out, head back out into the garden for more stalks. Making it in small batches will give you an excuse to run outdoors more often to pick fresh rhubarb.

  • Far, Far Away

    These are the train tracks I pedal across nearly every day as I go fetch the mail, deliver eggs, and make other errands. And further down this page is the quiet driveway to a man and his hoe®, the forest floor blanketed with bleeding hearts, and a vegetable bed with fresh greens. Idyllic scenes far, far away from the heavily contaminated farmland of China, or so you would think.

    But everyday, along those steel ribbons of railway, which just a few miles away, wind along the breathtaking Chuckanut Coast with stunning views of Guemes, Cypress, Orcas, and Lummi islands, trains more than a mile long haul coal, carved out of the ground in far away Wyoming. The trains take the coal to Vancouver, British Columbia, where it is loaded onto ships and taken across the Pacific Ocean to China. There it is burned in coal-fired power plants which billow out toxic clouds, which then poison the land which grows the garlic and fruit trees and many other crops which then get shipped to the US to be eaten by many of us.

    And someday, all the CO2 emissions, burning that coal pours into the atmosphere, will warm the earth enough to cause the sea nearby to rise so much that these tracks will be under water. When that happens, there will no longer be any coal trains traveling through this idyllic countryside.

    We know all these terrible things we are doing to the earth. But for some reason we can’t stop destroying the only home we have. We keep saying we can’t afford to stop our polluting ways, but when we read that nearly twenty percent of China’s farmland is now toxic, how can we justify such destruction? There is no economic activity worth destroying a fifth of a country’s farmland.

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  • Contaminated Farmland

    Today there were many articles like this one from NPR: China Admits That One-Fifth Of Its Farmland Is Contaminated. The details of the report by the Chinese government are stunning.

    The report, issued by the ministries of Environmental Protection and Land and Resources, says 16.1 percent of the country’s soil in general and 19.4 percent of its farmland is polluted with toxic heavy metals such as cadmium, nickel and arsenic. It was based on a soil survey of more than 2.4 million square miles of land across China, spanning a period from April 2005 until December 2013. It excluded special administrative regions Hong Kong and Macau.
    In a dire assessment, the report declares: “The overall condition of the Chinese soil allows no optimism.”

    Earlier this year we saw images of large portions of China smothered with heavy smog as in this article by Scientific American.

    SmogOverChina

    When reading reports regarding pollution or global warming, some often comment that the report is being alarmist and imply that we should disregard the report. This report by the Chinese government is more than alarming, it is calamitous. But will things change tomorrow? Will the industries and coal power generators that are causing the Chinese farmland to become toxic stop polluting tomorrow? And so ever increasing amounts of Chinese farmland will become toxic.

    So what does that have to do with me living many thousands of miles away from China? For one, the air pollution in China doesn’t stay there. For one, according to The Smithsonian, some of that air pollution is reaching the west coast of the US where I live. Two, the US imports some four billion dollars of food products from China every year. Here are some numbers from the US Department of Agriculture Economic Research Service, these are a listing of food products whose imports from China exceeded $350 million in 2011:

    Agricultural Product US Dollar Value Imported from China in 2011
    Fish $2,646,757,166
    Fish Fresh Or Prep $1,817,861,314
    Shellfish $804,745,740
    Vegetables & Preps $626,224,026
    Fruit Juices $547,044,940
    Grains & Feeds $527,784,428
    Fruits & Preps $518,397,511
    Apple Juice $504,059,866
    Fruits – Prep Or Pres $499,317,088
    Other Fruits – Prep Or Pres $478,258,430
    Animals & Prods $449,291,071
    Vegetables-Prep/Pres $382,588,727
    Feeds & Fodders, Ex Oilcake $372,015,556

    The US imports a huge amount of agricultural products from China, and if nearly twenty percent of the farmland in China is contaminated, what percentage of the agricultural products imported from China are also contaminated with heavy metals and other toxins?

    Enjoying a beautiful day here at a man and his hoe® it’s easy to think this is a problem that doesn’t affect me, but it affects all of us, not matter how far, far away.