Friday, 2 September 2011

Fun with Hydroponics Farming & Butterflies

By Amy Tsang and Gloria Seow, Education Group Chairperson
Photos by Lena Chow and KC Tsang

Our affable guide Adrian with his rapt audience.

We had an unlikely combination of a butterfly and hydroponics adventure in our NSS Kids’ outing on 18 June 2011, to Oh Chin Huat Hydroponics Farm located near Yishun. The laid back vibe of the place was a natural balm to our frazzled city souls.

We started the day in an outdoor classroom where Oh’s Farm guide Adrian conducted a fascinating show and tell session on butterflies. He took us through the butterfly’s life cycle, from miniscule eggs deposited on host plants, to the caterpillars' metamorphism through various 'costume' or instar changes, their pupation and finally their eclosure as beautiful butterflies. A few brave kids even allowed the prickly-looking Mime and Autumn Leaf caterpillars to crawl all over their arms. However, mostly ‘spiky’ caterpillars have skin irritants and should not be handled.

Some girls have no fear of caterpillars, allowing them to crawl all over their arms.

Kids had an exciting time exploring the Butterfly Enclosure. Here, beauties such as Autumn Leaf, Lime, Plain Tiger, Tawny Coster and Jacinta Eggfly flit freely amongst their host and nectar plants. Some of us even caught the rare sight of an Autumn Leaf caterpillar transforming into a pupa, by doing a writhing ‘belly’ dance. A butterfly quiz had kids vying for plant prizes including some butterfly host plants. KC and Amy Tsang were great at promoting butterfly watching. They handed out information sheets, recommended various field guides, as well as sold copies of the pocket-sized “NSS Field Guide to the Butterflies of Singapore”.

We even saw a Tawny Coster Butterfly eclosing from its pupa case.

The adults particularly enjoyed the hydroponics tour. We learnt that Oh’s Farm grows six types of vegetables including Kang Kong, Chye Sim and Xiao Baicai, as well as 10 types of herbs such as Italian Basil, Sweet Basil and Stevia. We were astounded that the farm sells about 1,000 kg of produce daily, to supermarkets such as NTUC where it is marketed under the ‘Pasar’ brand. Our guide shared with us that the soil-free nutrient solution comprises 16 minerals. Minerals essential for vegetable growth, such as calcium, potassium, magnesium and phosphorous, are present in high concentrations. These are mixed together with trace elements such as copper, molybdenum, iron and manganese.

Vegetables are grown from seeds sown into sponges. These are placed in a dark, moist and warm Germination Room for two to three days, where 95% of them will sprout leaves. The seedlings are then transferred to a nursery where they are kept until they develop four leaves. These plantlets are then transplanted into greenhouses where cultivation occurs for another three to four weeks.

Lush, pesticide-free hydroponics vegetables grown right here in Singapore.

Vegetables and herbs are grown using the DRF (Dynamic Root Floating) hydroponics technique whereby a nutrient solution is circulated under the culture boards. This induces the plants to develop an air root system (numerous fine roots) in the humid space between the underside of the culture board and the surface of the nutrient solution. The plants are protected by black netting that covers the greenhouse, which negates the need for pesticides, lowers the amount of sunlight, as well as reduces the buildup of heat. These modified conditions are necessary as most vegetables and herbs consumed in Singapore originate from cooler climes such as South China. It takes about 28 days for Kang Kong to mature, which is a full week shorter than if it were grown in a regular farm. However, detractors claim that hydroponics-grown Kang Kong tastes more ‘watery’, less fibrous, and even less ‘delicious’ than the soil-grown variety. We sampled the Sweet Basil with relish.

We had fun sampling some of these produce. The Italian Basil had a numbing effect on our tongues, where purportedly only the healthy can detect. We enjoyed the taste of Stevia, a herb that is 250 times sweeter than cane sugar. It is sometimes used by diabetics as a sugar substitute. We were even allowed into the Cold Room (4°C to 8°C), which is essentially a walk-in misty refrigerator. Here, harvested vegetables are left for a day to rehydrate, so that their leaves do not tear as easily. Participants snapped up vegetable seeds, plantlets and fresh greens at the farm shop. Kids were encouraged to experiment with hydroponics at home, using a cut-up water bottle and some seeds. The tour aptly rounded off with each of us getting two free packets of leafy Xiao Baicai.

Fun at Chek Jawa

By Gloria Seow, Education Group Chairperson

Chek Jawa’s coastal boardwalk enabled us to admire marine life such as Purple Climber Crabs and Rock Oysters.

There was a major stampede to see the splendid marine life of Chek Jawa on Pulau Ubin when it was first ‘discovered’, which ironically killed off a good portion of the ‘discovery’. In order to protect this fragile inter-tidal treasure from further damage, NParks implemented restricted access. It built an elevated coastal and mangrove boardwalk as compensation. The Education Group visited the area during the spring low tide of 10 April 2011, guided by Tan Hang Chong, Edzra Iskandar, Boon Peiya, Timothy Pwee and myself.

As chief guide, Uncle Hang Chong was superb with the kids. He peppered our walk with lots of stimulating edutainment. Kids learnt that the giant Orb Web Spider that we usually see is actually the female. The males are the tiny ‘babies’ that hang around the periphery of the web, essentially leeching off the female’s catches. They have to be careful not to get chomped on by their ‘wife’ after mating, which unfortunately happens sometimes. Auntie Gloria then spotted a Water Monitor Lizard climbing up a coconut tree, an arresting sight to say the least.

At the start of the coastal boardwalk, we came across the inedible Sea Nutmeg and Sea Mangosteen. We then spied several Carpet Anemones with tentacles swaying in the incoming tide. Purple Climber Crabs scrambled on sea boulders, which themselves were plastered with huge Rock Oysters. A stately Great-billed Heron, Singapore’s largest bird, was seen striding the distant mudflats, accompanied by a Little Heron and Whimbrel. Fiddler Crabs went about their daily business eating the coating of detritus on sand grains. Males cheerily waved their enlarged bright orange pincers in the hope of attracting the ladies.
As chief guide, Uncle Hang Chong even brought along a stash of ‘attap chee’, which comes from the Nipah Palm found also at Chek Jawa.

Kids found out that mangrove trees can thrive in poorly-oxygenated mudflats because they have aerial (air breathing) as well as buried roots. Depending on the species, the aerial roots can be pencil shaped or prop like. We were introduced to the Nipah Palm, source of the Ice Kachang must-have ‘attap chee’. Uncle Hang Chong even brought along a stash of these sugared treats, which were eagerly gobbled up. We rounded off the tour with a stop at the NSS Green Hub @ Ubin. Everybody was wowed by the surprisingly bright lighting system that uses diffused daylight. A big tube punched through the roof channels sunlight through a diffuser which also functions to remove the sun’s heat.

Fun in the Forest

By Gloria Seow, Education Group Chairperson
Photos by Timothy Pwee

How would you describe a forest? Dark, mysterious or fun? Led by veteran nature guide Goh Si Guim, a chirpy group of kids and their caregivers chose the last adjective of 'fun' to describe their forest foray on 19 February 2011.

Uncle Si Guim briefing kids and their caregivers at the work-in-progress submerged boardwalk.

Circumventing MacRitchie Reservoir’s work-in-progress submerged boardwalk, we proceeded towards the Lornie Trail. Here, hundreds of joggers and trekkers zipped pass, quite unaware of the intriguing life forms that co-existed in the trees and undergrowth.

Near the trailhead, we visited our favourite patch of Slender Pitcher Plants. This carnivorous climber lures unwary insects with sweetened droplets, invariably leading them to a watery deathtrap. Digestive juices reduce the drowned insects into a nitrogen-rich supplement for the pitchers. As a result, pitchers typically flourish in nitrogen-poor soils where most plants cannot grow.

Uncle Si Guim pointed out the contrast between the hot and unsheltered landscaped garden that we had passed, with the cool and canopied forest that we had entered. Waving his hands animatedly, he explained in simple terms the role of plants in the ecosystem and the amazing biodiversity that it supported. Then we started poking around the undergrowth.

The cool and canopied forest revealed life forms that go unnoticed by most.

Kids grew increasingly fascinated with the micro organisms that Uncle Si Guim uncovered. They learnt that Jumping and Wolf Spiders did not build webs, but prowled the forest floor to hunt for insect prey. They saw a ‘ladder’ of bracket fungi, forming a ‘stairway’ up a dead tree that had possibly been zapped by lightning. Peering closely with torch and magnifying glass at the uneven bark of a Pulai tree, we found a well-camouflaged Whip Scorpion and several pinkish Forest Silverfish. Different species of Forest Cockroach (adults and nymphs) scampered amongst the leaf litter, quite unlike their American Cockroach cousins that live in our houses.

An entomophagous (insect-eating) fungus slowly snuffed out the life of this fly.

Next, Uncle Si Guim stumbled upon the ultimate find in the insect world. On closer examination of an innocuous-looking dead fly resting on a twig, he was ecstatic to witness for the first time, an entomophagous (insect-eating) fungus growing out of its head and body. A spore of this fungus had landed on the unfortunate fly. Its deadly mycelia had spread inside the fly, slowly drawing the nutrients and life out of its unsuspecting host. We could only see the fruiting bodies (“mushrooms”) of the fungus that had sprouted on the fly’s desiccated exoskeleton. These “mushrooms” were laden with spores that could infect the next victim. Kids learnt from Auntie Gloria that Cordyceps is a famous example of a medicinal entomophagous fungus.On the way out, some of us found a Kendall 's Rock Gecko resting in the branched crevice of a huge Callophyllum inophyllum tree near the exercise corner. In all, this trip cultivated an appreciation for the seemingly insignificant world of insects - a microcosm that can turn out to be terribly intriguing too.