New Agriculture in Oregon, US
A Onion growers in eastern Oregon are adopting a system that saves water and keeps topsoil in place while producing the highest quality “super-colossal” onions. Pear growers in southern Oregon have reduced their use of some of the most toxic pesticides by up to two-thirds, and are still producing top-quality pear. Range managers throughout the state have controlled the poisonous weed tansy ragwort with insect predators and saved the Oregon livestock industry up to $4.8 million a year.
B These are some of the results Oregon growers have achieved in collaboration with Oregon State University (OSU) researchers as they test new farming methods including integrated pest management (IPM). Nationwide, however, IPM has not delivered results comparable to those in Oregon. A recent U.S General Accounting Office (GAO) report indicates that while integrated pest management can result in dramatically reduced pesticide use, the federal government has been lacking in effectively promoting that goal and implementing IPM. Farmers also blame the government for not making the new options of pest management attractive. “Wholesale changes in the way that farmers control the pests on their farms is an expensive business.” Tony Brown, of the National Farmers Association, says. “If the farmers are given tax breaks to offset the expenditure, then they would willingly accept the new practices.” The report goes on to note that even though the use of the riskiest pesticides has declined nationwide, they still make up more than 40 percent of all pesticides used today; and national pesticide use has risen by 40 million kilograms since 1992. “Our food supply remains the safest and highest quality on Earth but we continue to overdose our farmland with powerful and toxic pesticides and to under-use the safe and effective alternatives,” charged Patrick Leahy, who commissioned the report. Green action groups disagree about the safety issue. “There is no way that habitual consumption of foodstuffs grown using toxic chemical of the nature found on today’s farms can be healthy for consumers,” noted Bill Bowler, spokesman for Green Action, one of many lobbyists interested in this issue.
C The GAO report singles out Oregon’s apple and pear producers who have used the new IPM techniques with growing success. Although Oregon is clearly ahead of the nation, scientists at OSU are taking the Government Accounting Office criticisms seriously. “We must continue to develop effective alternative practices that will reduce environmental hazards and produce high-quality products,” said Paul Jepson, a professor of entomology at OSU and new director of
D OSU’s Integrated Plant Protection Centre (IPPC). The IPPC brings together scientists from OSU’s Agricultural Experiment Station, OSU Extension service, the U.S. Department of Agriculture and Oregon farmers to help develop agricultural systems that will save water and soil, and reduce pesticides. In response to the GAO report, the Centre is putting even more emphasis on integrating research and farming practices to improve Oregon agriculture environmentally and economically.
E “The GAO report criticizes agencies for not clearly communicating the goals of IPM,” said Jepson. “Our challenge is to greatly improve the communication to and from growers, to learn what works and what doesn’t. the work coming from OSU researchers must be adopted in the field and not simply languish in scientific journals.”
F In Oregon, growers and scientists are working together to instigate new practices. For example, a few years ago scientists at OSU’s Malheur Experiment Station began testing a new drip irrigation system to replace old ditches that wasted water and washed soil and fertilizer into streams. The new system cut water and fertilizer use by half kept topsoil in place and protected water quality.
G In addition, the new system produced crops of very large onions, rated “super-colossal” and highly valued by the restaurant industry and food processors. Art Pimms, one of the researchers at Malheur comments: “Growers are finding that when they adopt more environmentally benign practices, they can have excellent results. The new practices benefit the environment and give the growers their success.”
H OSU researcher in Malheur next tested straw mulch and found that it successfully held soil in place and kept the ground moist with less irrigation. In addition, and unexpectedly, the scientists found that the mulched soil created a home for beneficial beetles and spiders that prey on onion thrips – a notorious pest in commercial onion fields – a discovery that could reduce the need for pesticides. “I would never have believed that we could replace the artificial pest controls that we had before and still keep our good results,” commented Steve Black, a commercial onion farmer in Oregon, “but instead we have actually surpassed expectations.”
I OSU researchers throughout the state have been working to reduce dependence on broad-spectrum chemical spays that are toxic to many kinds of organisms, including humans. “Consumers are rightly putting more and more pressure on the industry to change its reliance on chemical pesticides, but they still want a picture-perfect product,” said Rick Hilton, an entomologist at OSU’s Southern Oregon Research and Extension Centre, where researches help pear growers reduce the need for highly toxic pesticides. Picture perfect pears are an important product in Oregon and traditionally they have required lots of chemicals. In recent years, the industry has faced stiff competition from overseas producers, so any new methods that growers adopt must make sense economically as well as environmentally. Hilton is testing a growth regulator that interferes with the molting of codling moth larvae. Another study used pheromone dispensers to disrupt codling moth mating. These and other methods of integrated pest management have allowed pear growers to reduce their use of organophosphates by two-thirds and reduce all other synthetic pesticides by even more and still produce top-quality pears. These and other studies around the state are part of the effort of the IPPC to find alternative farming practices that benefit both the economy and the environment.
The evolutional mystery: Crocodile survives
14
Crocodiles have been around for 200 million years, but they’re certainly not primitive. The early forms of crocodiles are known as Crocodilian. Since they spent most of their life beneath water, accordingly their body adapted to aquatic lifestyle. Due to the changes formed within their body shape and tendency to adapt according to the climate they were able to survive when most of the reptiles of their period are just a part of history. In their tenure on Earth, they’ve endured the impacts of meteors, planetary refrigeration, extreme upheavals of the Earth’s tectonic surface and profound climate change. They were around for the rise and fall of the dinosaurs, and even 65 million years of supposed mammalian dominance has failed to loosen their grip on the environments they inhabit. Today’s crocodiles and alligators are little changed from their prehistoric ancestors, a telling clue that these reptiles were (and remain) extremely well adapted to their environment.
15
The first crocodile-like ancestors appeared about 230 million years ago, with many of the features that make crocs such successful stealth hunters already in place: streamlined body, long tail, protective armour and long jaws. They have long head and a long tail that helps them to change their direction in water while moving. They have four legs which are short and are webbed. Never underestimate their ability to move on ground. When they move they can move at such a speed that won’t give you a second chance to make a mistake by going close to them especially when hungry. They can lift their whole body within seconds from ground. The fastest way by which most species can move is a sort of “belly run”, where the body moves like a snake, members huddled to the side paddling away frenetically while the tail whips back and forth. When “belly running” Crocodiles can reach speeds up to 10 or 11 km/h (about 7mph), and often faster if they are sliding down muddy banks. Other form of movement is their “high walk”, where the body is elevated above the ground.
16
Crocodilians have no lips. When submerged in their classic ‘sit and wait’ position, their mouths fill with water. The nostrils on the tip of the elongated snout lead into canals that run through bone to open behind the valve – allowing the crocodilian to breathe through its nostrils even though its mouth is under water. When the animal is totally submerged, another valve seals the nostrils, so the crocodilian can open its mouth to catch prey with no fear of drowning. The thin skin on the crocodilian head and face is covered with tiny, pigmented domes, forming a network of neural pressure receptors that can detect barely perceptible vibrations in the water. This enables a crocodile lying in silent darkness to suddenly throw its head sideways and grasp with deadly accuracy small prey moving close by.
17
Like other reptiles, crocodiles are endothermic animals (cold-blooded, or whose body temperature varies with the temperature of the surrounding environment) and, therefore, need to sunbathe, to raise the temperature of the body. On the contrary, if it is too hot, they prefer being in water or in the shade. Being a cold-blooded species, the crocodilian heart is unique in having an actively controlled valve that can redirect, at will, blood flow away from the lungs and recirculate it around the body, taking oxygen to where it’s needed most. In addition, their metabolism is a very slow one, so, they can survive for long periods without feeding. Crocodiles are capable of slowing their metabolism even further allowing them to survive for a full year without feeding. Compared to mammals and birds, crocodilians have slow metabolisms that burn much less fuel, and are ideally suited to relatively unstable environments that would defeat mammals with their high food demands.
18
Crocodiles use a very effective technique to catch the prey. The prey remains almost unaware of the fact that there can be any crocodile beneath water. It is due to the fact that when the crocodile sees its prey it moves under water without making any noise and significant movement. It keeps only its eyes above water surface. When it feels it has reached sufficiently close to the target it whistles out of water with wide open jaws. 80 percent of their attempts are successful. They have very powerful jaws. Once the prey trapped in its jaws they swallow it. Their power can be judged from the fact they can kill the wild zebras which come to watery areas in search of water. They do not chew their food. They normally feed on small animals, big fish, birds and even human flesh. As like some water creatures that interact by making sounds crocodiles also use many sounds to communicate with other crocodiles. They exist where conditions have remained the same and they are free of human interference. The crocodile is successful because it switches its feeding methods. It hunts fish, grabs birds at the surface, hides among the water edge vegetation to wait for a gazelle to come by, and when there is a chance for an ambush, the crocodile lunges forward, knocks the animal with its powerful tail and then drags it to water where it quickly drowns. Another way is to wait motionless for an animal to come to the water’s edge and grabs it by its nose where it is held to drown.
19
In many places inhabited by crocodilians, the hot season brings drought that dries up their hunting grounds and takes away the means to regulate their body temperature. They allowed reptiles to dominate the terrestrial environment. Furthermore, many crocs protect themselves from this by digging burrows and entombing themselves in mud, waiting for months without access to food or water, until the rains arrive. To do this, they sink into a quiescent state called aestivation.
20
Most of (At least nine species of) crocodilian are thought to aestivate during dry periods. Kennett and Christian’s six-year study of Australian freshwater crocodiles – Crocodylus johnstoni (the King Crocodiles). The crocodiles spent almost four months a year underground without access to water. Doubly labeled water was used to measure field metabolic rates and water flux, and plasma (and cloacal fluid samples were taken at approximately monthly intervals during some years to monitor the effects of aestivation with respect to the accumulation of nitrogenous wastes and electrolyte concentrations. Double found that the crocodiles’ metabolic engines tick over, producing waste and using up water and fat reserves. Waste products are stored in the urine, which gets increasingly concentrated as the months pass. However, the concentration of waste products in the blood changes very little, allowing the crocodiles to function normally. Furthermore, though the animals lost water and body mass (just over one-tenth of their initial mass) while underground, the losses were proportional: on emergence, the aestivating crocodiles were not dehydrated and exhibited no other detrimental effects such as a decreased growth rate. Kennett and Christian believe this ability of individuals to sit out the bad times and endure long periods of enforced starvation must surely be key to the survival of the crocodilian line through time.
Learning lessons from the past
A Many past societies collapsed or vanished, leaving behind monumental ruins such as those that the poet Shelley imagined in his sonnet, Ozymandias. By collapse, I mean a drastic decrease in human population size and/or political/economic/social complexity, over a considerable, for an extended time. By those standards, most people would consider the following past societies to have been famous victims of full-fledged collapses rather than of just minor declines: the Anasazi and Cahokia within the boundaries of the modem US, the Maya cities in Central American, Moche and Tiwanaku societies in South America, Norse Greenland, Mycenean Greece and Minoan Crete in Europe, Great Zimbabwe in Africa, Angkor Wat and the Harappan Indus Valley cities in Asia, and Easter Island in the Pacific Ocean.
B The monumental ruins left behind by those past societies hold a fascination for all of us. We marvel at them when as children we first learn of them through pictures. When we grow up, many of us plan vacations in order to experience them at first hand. We feel drawn to their often spectacular and haunting beauty, and also to the mysteries that they pose. The scales of the ruins testify to the former wealth and power of their builders. Yet these builders vanished, abandoning the great structures that they had created at such effort. How could a society that was once so mighty end up collapsing?
C It has long been suspected that many of those mysterious abandonments were at least partly triggered by ecological problems: people inadvertently destroying the environmental resources on which their societies depended. This suspicion of unintended ecological suicide (ecocide) has been confirmed by discoveries made in recent decades by archaeologists, climatologists, historians, palaeontologists, and palynologists (pollen scientists). The processes through which past societies have undermined themselves by damaging their environments fall into eight categories, whose relative importance differs from case to case: deforestation and habitat destruction, soil problems, water management problems, overhunting, overfishing, effects of introduced species on native species, human population growth, and increased impact of people.
D Those past collapses tended to follow somewhat similar courses constituting variations on a theme. Writers find it tempting to draw analogies between the course of human societies and the course of individual human lives – to talk of a society’s birth, growth, peak, old age and eventual death. But that metaphor proves erroneous for many past societies: they declined rapidly after reaching peak numbers and power, and those rapid declines must have come as a surprise and shock to their citizens. Obviously, too, this trajectory is not one that all past societies followed unvaryingly to completion: different societies collapsed to different degrees and in somewhat different ways, while many societies did not collapse at all.
E Today many people feel that environmental problems overshadow all the other threats to global civilisation. These environmental problems include the same eight that undermined past societies, plus four new ones: human-caused climate change, the build-up of toxic chemicals in the environment, energy shortages, and full human utilisation of the Earth’s photosynthetic capacity. But the seriousness of these current environmental problems is vigorously debated. Are the risks greatly exaggerated, or conversely are they underestimated? Will modem technology solve our problems, or is it creating new problems faster than it solves old ones? When we deplete one resource (eg wood, oil, or ocean fish), can we count on being able to substitute some new resource (eg plastics, wind and solar energy, or farmed fish)? Isn’t the rate of human population growth declining, such that we’re already on course for the world’s population to level off at home manageable number of people?
F Questions like this illustrate why those famous collapses of past civilisations have taken on more meaning than just that of a romantic mystery. Perhaps there are some practical lessons that we could learn from all those past collapses. But there are also differences between the modem world and its problems, and those past societies and their problems. We shouldn’t be so naive as to think that the study of the past will yield simple solutions, directly transferable to our societies today. We differ from past societies in some respects that put us at lower risk than them; some of those respects often mentioned include our powerful technology (ie its beneficial effects), globalisation, modem medicine, and greater knowledge of past societies and of distant modem societies. We also differ from past societies in some respects that put us at greater risk than them: again, our potent technology (ie its unintended destructive effects), globalisation (such that now a problem in one part of the world affects all the rest), the dependence of millions of us on modern medicine for our survival, and our much larger human population. Perhaps we can still learn from the past, but only if we think carefully about its lessons.
