13 December 2007
Today's Garden Column is about the impact of global climate change on gardening in Oklahoma Plan ahead for possibly earlier spring next year
Scientists around the world have looked at the evidence and have decided that climate change is real. Carbon dioxide and other greenhouse gasses are trapping more heat from the sun and are contributing to rising global temperatures.For Oklahoma, climate change is likely to lead to earlier springs, later falls, shorter winters, more damaging late spring freezes, and longer dry, drought spells. Local impacts will vary and there will still be the natural cycle of drier and wetter years. These are the Oklahoma impacts summed up in the Oklahoma Climatological Survey's statement on Climate Change and its Implications for Oklahoma.
Climate change will bring new challenges to Oklahoma gardeners and farmers, but there are ways to meet these challenges. And new approaches can turn these climate challenges into new opportunities. Using water more effectively and minimizing warm temperature impact are nothing new to Oklahomans. To make the most of their water, gardeners have moved away from using sprinklers to drip irrigation systems.
Using garden mulches is a standard Oklahoma gardening practice that lowers soil temperatures and reduces water loss from bare soil.
Albert Sutherland, the agriculture coordinator for Mesonet, a joint project of Oklahoma State University and the University of Oklahoma, in a recent conversation, talked about a number of ways gardeners and farmers are adopting new methods to deal with climate changes.
In agriculture, fuel prices are having a big impact on farming methods. One example of new technology is using no-till farming instead of plowing. While no-till methods require bigger tractors to cut through the crop debris, in the long run, the fewer trips across the ground result in lower fuel costs.
Irrigation methods that preserve water are being implemented on a large scale in agriculture. The worst offenders are of course, sprinklers that throw water into the air where wind and high air temperature can evaporate 30 percent or more of it.
LEPA, Low Energy Precision Application, is a method that uses existing irrigation equipment by adapting it to emit larger droplets of water close to the ground.
On a smaller scale, gardening practices that help preserve resources and reduce human impact on the global climate include: using natural mulches and drip or weeping soaker hoses to irrigate.
"Climate change brings with it warmer temperatures and mulch lowers the soil temperature. Plants do not like their roots above 90 degrees F. Studies show that natural mulches keep the soil temperature 85 degrees F and under," Sutherland said.
Sutherland's tips for gardeners:• Mulch the garden: Use grass clippings to mulch vegetable gardens; make compost to improve water retention of soil and mulch garden; use cottonseed hulls, straw and alfalfa baled hay for mulch. • For shrub beds: Pecan shells stay put better than most. Tree bark products, such as cypress and oak, float and can be harder to work with if you want to change the use of a particular bed and have to dig through the wood chunks. • Mulch around trees: Tree bark mulch works well. Pine needles: Austrian pine needles and cones can be sources of disease and infection. Loblolly pine needles present fewer problems with tip and needle blight.Mulches also minimize soil surface moisture evaporation so more water that is applied to the plants, goes into the plants.
"Watering in the morning is best," Sutherland said. "Mornings not only are cooler, but often have little wind. Cooler temperatures and low wind means less evaporation water loss."If you use a sprinkler, choose ones that keep the water closer to the ground and don't produce small droplets. Newer, turbine, rotary sprinklers fit both of these criteria and rotate without spraying water sideways, like older technology impact sprinklers. Another impact of climate change of interest to foresters, farmers and gardeners is that diseases and insects can move to new, warmer locations.
The good news about climate change is that a longer spring and warm fall will allow gardeners to grow more of their own food due to the longer season. For example, longer spring and fall seasons will allow us to start planting outdoors earlier in the spring and later in the fall. Oklahoma is already working to meet the challenges of climate change.
"The state is undergoing a water planning project," Sutherland said. "The Oklahoma Comprehensive Water Plan will consider the current water availability of water and the future needs of communities from 2010-60."
Oklahoma Mesonet, a world-class network of environmental monitoring stations, was designed and implemented by scientists from the University of Oklahoma and Oklahoma State University. It is operated as part of Oklahoma Climatological Survey. The Mesonet Web site, http://agweather.mesonet.org, is a wealth of information for gardeners, farmers and weather watchers.
"Oklahomans can track current weather, wind shifts, air temperature, freeze lines, soil temperatures and link to radar for storm watching," Sutherland said. "Oklahoma Mesonet climate trend data goes back to 1994 and Oklahoma Climatological Survey data goes back to 1895. Annual average temperatures and rainfall can be viewed as a graph to illustrate that wetter years are cooler years and hotter years have less rainfall."
Another new Oklahoma Mesonet Web site is the Simple Irrigation Plan, SIP for short, that allows landscapers and gardeners to know exactly how long to water their turf. Using SIP tells you how much water grass needs to thrive. Sutherland pointed out that all of us will need to find ways to reduce carbon dioxide emissions. We will need to learn how to live in ways that use less energy and make the most of the energy we do use.
"Individuals can make fewer trips in the car, consider closer vacation spots, re-use or repair what they own instead of throwing it away, replace appliances with more energy efficient ones, use florescent light bulbs where lights are left on for longer periods and make other choices that will help," Sutherland said.