Adorable ladybugs and grotesque spiders may seem an odd pairing, but in the organic rice paddies of Hualien, both are equally welcome as farmers’ assistants. A greater number of spiders and ladybugs is a sign that the paddies are vibrant and healthy without the use of pesticides and toxins.
Cracking the biodiversity code
Hualien ARES director Hwang Peng has been growing organic rice in the county since 1994. Taiwan’s biggest organic rice sales collective is based in Fuli, and the township is also home to the first Taiwanese organic rice to be sold to Japan. Hwang notes that “the sales are a sign of the safety and quality of the rice.” He goes on to explain that working toward organic rice production is not only about the health factors, but also a desire to do better by the environment.
Rice paddies are among the most biodiverse ecosystems on earth. Some 150,000 hectares of Taiwan is rice paddies, providing not only places to grow rice, but also Taiwan’s largest “manmade wetlands,” conducive to fostering biodiversity by providing a breeding and foraging habitat for waterfowl, frogs, and dragonflies and other insects.
Melinda Fan, deputy director of the Hualien ARES, began investigating the differences in biodiversity between organic and conventional rice paddies three years ago. By studying the invertebrates commonly found in rice paddies, Fan found that in terms of numbers of both individuals and species, organic paddies far exceeded conventional ones. Among 2013’s first rice crop, for example, she found 188 species in organic paddies, in contrast to only 137 in conventional paddies.
Through this research, Fan found the two species of predators most indicative of biodiversity in rice paddies—Tetragnatha maxillosa, a species of Japanese orb-weaver spider, and Micraspis discolor, a ladybug species.
Both spiders and ladybugs are easily observed with the naked eye, and both of these species are quite sensitive to pesticides and environmental disruptions, T. maxillosa in particular. “We have found that just one spraying of a paddy is enough to cause a significant drop in T. maxillosa numbers. Studies done abroad have also found spiders to be easily affected by agrichemicals, causing drops in reproduction rate and impairing the predatory abilities of the next generation.”
Undertaking observations is simple for farmers—all they need to do is conduct regular sweeps of their paddies with nets and count up the number of individuals of each of the two species. As long as they’re maintaining levels of at least 80% of their baseline, then the paddies are biologically rich and healthy.
Organic and green
Seven farmers with a total of 6.5 hectares of Hualien farmland have already taken the lead in going organic, earning the right to use the Tse-Xin Organic Agriculture Foundation’s Green Conservation certification mark.
This mark has the potential to kickstart moves to promote organic certification, an effort that has recently fallen into stagnancy.
It is estimated that of Taiwan’s almost 800,000 hectares of agricultural land, less than 1% is used for certified organic farming.
Tse-Xin CEO Su Muh-rong explains that there hasn’t been much movement on the organic certification front in Taiwan in three or four years now, with reasons including the difficulty of finding suitable land, reductions in subsidies, and difficulty meeting the zero-pesticides requirement for certification. Faced with such challenges, smaller farmers have been unwilling to make the move.
In order to overcome this, five years ago the foundation began working with the Forestry Bureau to promote green labeling, tying certification to the numbers and rarity of species found on the land. Dozens of species have been used for certification, including the mountain scops owl, ring-necked pheasant, crested serpent eagle, crested goshawk, pheasant-tailed jacana, purple crow butterfly, and emerald green tree frog.
This year marks the first time the foundation has included T. maxillosa and M. discolor in their certification guidelines. Su Muh-rong hopes these pioneering farmers will be able to expand ideas of what organic farming means, and thus to reshape how the market views organic produce.
Fighting bugs with bugs
To farmers, this move to organic farming has seen them cast off the backbreaking labor of old pest control methods and embrace some bugs as comrades.
Judy Liang, who runs Hualien’s Yin-Chuan Organic Farms, explains that in the past, bugs and pests would keep farmers up at night trying to come up with strategies to win their fight to the death. Ultimately, though, every strategy would prove futile. “Fortunately the heavens have provided many little soldiers to help us, if we only realize they’re there,” says Liang. But even when farmers used organic pest control methods to chase off bugs, it would always be the more fragile “good” bugs that succumbed first. As these little friends died off, the more harmful bugs would grow to overwhelming numbers. Today, says Liang, we know that if you give these good bugs a good home, they’ll work long and hard to help out in dealing with the pests. “One of those orb-weaver spiders can eat four planthoppers a day.”
Sixty-one-year-old Zou Yitang was one of the first farmers to receive the Green Conservation mark. An organic rice farmer for 17 years, Zou says that while organic rice commands a higher price, yields are also smaller, so the greatest benefit he’s received from going organic is better health. To Zou, the mark represents another step toward freedom. “Before, I had to use biological pest control methods and even weed by hand, but now I don’t have to do any of it—it all deals with itself!” he laughs.
“Fighting bugs with bugs” might sound easy enough, but in reality you can’t just sit back and wait for the good bugs to show up and set up shop. Most rice paddy irrigation systems and embankments have been concreted, and over the years they tend to accumulate pesticides and fertilizers. This has long since wrecked the native biodiversity of the paddies, to the point that even the flowers and grasses that once grew alongside them are gone.
Home among the weeds and flowers
Melinda Fan notes that a diverse range of plants between paddies is a cradle for a wide array of insects and other creatures, and so when trying to revive plant life along paddy ridges, hedging is the first priority.
She further adds that there was a significant drop in the number of organisms present in paddies after the concreting of embankments. The Green Conservation mark requires that embankment habitats not be subject to the use of herbicides or other chemicals; that the embankments house vegetation; and that if concreted, those embankments must either be replanted or have hedges planted in the open space around the paddies.
You Chih-ying, an assistant researcher for the Hualien ARES, adds that the preserved or planted vegetation should also primarily be species that grow natively. Among the more common low-growth plant species are mock strawberries, brittle false pimpernels, Asian kidney weed, centella, and Japanese mazus; among flowering plants that grow to 20–30 centimeters, Jersey cudweed, fishwort, and barbed skullcap are well suited to growing along paddy embankments.
Hedging helps block outside pollution, while also providing predators a place to live. Tropical milkweed, Chinese hibiscus, and golden dewdrop are easily grown and have long flowering periods, serving as an excellent habitat for M. discolor and T. maxillosa during the period after the rice is harvested.
After creating these positive habitats, farmers can then wait for the virtuous cycle to kick in. When the birds, bugs, and beasts begin returning to the rice paddies, a balance between productivity and the environment will finally have been achieved. And it all starts with ladybugs and spiders!
Micraspis discolor ladybugs are welcome hunters of pests around rice paddies.
Rice paddies boast some of the most biodiverse ecosystems on earth. The photo shows an emerald green tree frog. (courtesy of Tse-Xin Organic Agriculture Foundation)
These seven farmers from Fuli, Hualien, were the first to receive Green Conservation certification for their use of new indicators of biodiversity. (courtesy of the Tse-Xin Organic Agriculture Foundation)
After sweeping through the paddies with nets and putting their findings in bags, researchers from the Hualien District Agricultural Research and Extension Station head back to tally the species they’ve found.
When the underlying environment is healthy, bugs, birds, and beasts alike will head back to the rice paddies, with birds even nesting there.
Tetragnatha maxillosa orb-weaver spiders are very sensitive to agrichemicals and environmental disturbance, making them outstanding indicators of a rice paddy’s health.