What's Goin' On at the Farm ( By Tanya)
The Kindergarden and 1st graders (K/1s) and 2nd and 3rd graders (2/3s) studied insects . They hunted for insects in the garden and started our very own Ohlone farm insect collection. We used microscopes to see the tiny pollen catching hairs on bee's legs, the many facets of a beetle's compound eye, the rolled up proboscis of a moth and the delicate wings of a damsel fly.
The 2/3s participated in the Bay Area Ant Survey (see www.antweb.org/bayarea.jsp), a project sponsored by the California Academy of Sciences. The survey involves collecting and identifying ants. So far 34 different species have been identified in the Bay Area including the invasive Argentine ant (out of an estimated 12, 000 species worldwide). The students observed ants in colonies in the garden and classified their behavior. Much is still not known about ants' complex social system.
The 4th and 5th graders (4/5s) continued to study environments. They performed experiments with brine shrimp to test their salinity tolerance. Brine shimp eggs were put into solutions of various salinities to find the optimum environment for hatching. The shrimp preferred the 10% salt solution which is comparable to their natural habitat. In Mono Lake, changes in salinity due to human intervention has affected their population and the entire food web. The classes discussed the delicate balance of nature.
The K/1s and 2/3s finished the year with a butterfly lesson. They tried their hand at catching butterflies on the farm with a new set of nets. Then they observed these butterflies under the microscope and colored pages to learn to identify the local butterflies. It was time to harvest honey so many classes also got to taste honey from our very own Ohlone bee hive.
In preparation for the Colonial Simulation the 4/5s learned about 18th century medicinal herbs that we have growing on the farm. In science class, the students learned to use a modern bacteria test to see if any plant extracts had antibiotic properties. During the simulation, some students participated as apothecaries with their newfound knowledge. To end the year, these classes enjoyed a "feast of the phyla" to get a "taste" for the levels of classification in the animal kingdom. Some students tried eating jellyfish, crickets and sea urchin. The new experience was fun and educational.
I would like to take this opportunity to thank all the parents who have come to the farm classes to volunteer this year. Thanks also goes to everyone who has come out to help on the farm workdays. We could not have a successful program without your dedication! It has been a pleasure to work with all of you, and I will truly miss teaching the Ohlone students.
Dear Ohlone community,
As the seasons change so do our lives. It is bittersweet that I must announce that I will be changing to a new stage in my "life cycle" and leaving Ohlone at the end of this school year. After being an Ohlone student many years ago, an Ohlone parent for the last nine years and an Ohlone science teacher for the last five years, the next phase for me is to move on to a full time job teaching high school Biology.
It has been my biggest pleasure to develop the science program on the Ohlone Farm and to work with the fabulous Ohlone students, the staff, my colleague Marieluise and the wonderful group of Farm Council, Farmer's Market, Farm workday and classroom volunteer parents. What we call the "outdoor living laboratory" would not be what it is today without this amazing "Family" effort. We are exceptionally lucky to have such a rich resource as the Farm.
I want you to know that the science and Farm program are in great form and will continue to flourish. Unquestionably, the science position will not go away, and the process is in place to find a replacement. While I have documented the curriculum and cataloged the materials for a two year plan, I know that a new person will have the opportunity to "grow" the program and add his or her own mark. I have enjoyed "planting the seed" and I encourage you to continue to "cultivate" it by volunteering your time especially during Farm workdays. I will be back to help out on these days and look forward to staying in touch.
The K/1s saw many signs of spring on the Farm using their five senses. They saw budding leaves, blossoming trees and newly emerging flowers from bulbs. They touched soft petals, new grass, sheared wool and lamb's ear plant. They smelled spring flowers and herbs including clematis, lavender, mint and lemon balm. They listened for spring birds and identified bird calls. Finally, they tasted miner's lettuce and looked for other vegetables that will be ready soon such as peas, carrots and artichokes.
The 2/3s finished seeing the seed to seed cycle of the Brassica plants. They replanted the seeds from the first generation. They also made bug "pooters" to catch and identify insects and other invertebrates. They had fun using them after overturning rocks and logs around the Farm.
In keeping with the lessons on ecosystems this year, the 4/5s investigated our Ohlone pond ecosystem. In the new Flex Room, we used microscopes and documented microorganisms such as paramecium and algae in the water! Students also tested the health of the pond by measuring the temperature, pH, nitrate and dissolved oxygen levels. Check out the graph of these factors over time made by the Ohlone guides the next time you are by the pond at the Farm!
The K/1s studied the properties of air. At various stations, they observed how air can move, have resistance, take up space, be pressurized and is made of matter. We launched a hot air balloon model and learned how hot air rises. At the weather station the students measured the wind direction and wind speed with our wind vane and anemometer. They used the Beaufort wind scale with our new wind sock to understand about wind strength.
The 2/3s started a unit on insects. After observing live crickets, they listened to a CD as crickets chirped at different rates depending on the temperature. Then they graphed the results in order to guess the temperature based on a given chirping rate. Another lesson focused on termites and their colony structure. Students watched as termites followed a scented trail. The pheromone (scent) that termites use to communicate is very similar to
a chemical in ball point pens. The students experimented with which brand and which color of pen were the best to attract termites. Some termites even followed a figure eight or a name in cursive!
The 4/5s learned how to conduct a proper experiment. Using the scientific method, they determined the best habitats for darkling beetles and isopods (a.k.a. pill bugs). The groups tested gradients of temperature, roughness of surface, moisture and light. In addition the classes got ready for Ohlone's science night by testing out and learning to teach the kits.
The kindergarten and first grade (K/1) students have been watching the effects of the changing seasons. They looked for signs of winter on the Farm including frost, bare trees, dormant plants and cold soil. We played with thermometers and talked about the difference between the Fahrenheit and Celsius scale. In addition, they learned how to read the various instruments in the weather station. Winter vegetables they learned to recognize growing on the Farm were broccoli, kale, Brussels sprouts, cabbage and bok choy.
The second and third grade (2/3) classes also observed the winter vegetables and learned how many of them are in the same family of plants called Brassica based on their leaf shape, stem arrangement and flower type. They planted a special "fast plant" variety of Brassica in their classrooms to watch the entire life cycle in one month and take notes on the growth.
The fourth and fifth (4/5) graders continued their studies of our local ecosystems and focused on the mammals that make up the food chain in various habitats. Tanya borrowed skulls from the California Academy of Sciences for these mammals. The kids observed the teeth to learn about the diet of the animals and whether they were herbivores, omnivores or carnivores. They also studied the eye structure to determine which animals were predators and which were prey. Using special goggles, they got a feel for increased peripheral vision by having eyes on the side of the head. Even principal Bill got into the action!
Principal Bill and kids using special "goggles" to see how prey see with peripheral vision
The kindergarten and first grade (K/1) classes looked for signs of fall. They learned to use our very own Ohlone Farm weather station (note: you can view it at http://www.ohloneweb.com/215.html or by going to Ohlone's webpage and looking under ‘weather' in the farm menu)to check the temperature, wind speed and rain fall we have had this fall. They also noticed changes to the trees andall the leaf colors. They observed all of the vegetables and fruit that we harvest in the fall and have growing in the garden at this time.
The second and third grade (2/3) classes finished their unit called "pebbles, sand and silt" or lessons about soil. They measured how much water is retained in different soil types by using and a balance and liquid measurement tools (graduated cylinder etc.). They also tested soils around the garden for moisture content using a special meter. After recording their data in their lab journals, they discussed the reason for the differences between soil types.
The fourth and fifth graders (4/5) learned about decomposers in our local ecosystems. They are growing bacteria on petri plates to be able to observe a type of decomposer while learning the proper sterile technique for growing cultures. To culminate a unit on food webs and ecosystems, they built terrariums complete with plants and animals (insects and worms) and decomposers.
A "Locavore" Thanksgiving
I thought I would try an experiment this Thanksgiving and see if I could make the meal out of entirely local products for my table of twelve family members and friends. I wanted everything to be grown, raised and produced locally within a 100 mile radius. I started by ordering a Willie Bird turkey from Piazza's Fine Foods which was raised in Sonoma just inside my limit. I prepared it with olive oil, also from Sonoma, rosemary from my garden, local garlic, Pacific coast salt (noted on the Trader Joe's label which I hoped was close enough) and pepper corns from my neighbors' tree. When using the red peppercorns it is important to pick them from a California Pepper tree and not a Brazilian pepper tree, which are inedible. Black pepper, unfortunately, is not from this area, so I had to skip using it. I made gravy from the turkey drippings and broth from boiling the innards.
I also wanted to make sure that I was not making too many car trips in the process of gathering the ingredients since the point of this exercise was to lessen my carbon emissions. I was able to bike to pick up my weekly CSA (Community Supported Agriculture) box from Mariquita Farms, to get to the downtown Palo Alto Farmer's Market and to stop at Ohlone's Thursday Farmer's Market. All the produce I used was from these places. I roasted Brussels sprouts and carrots tossed in olive oil, garlic and salt. I made mashed yams using a bit of juice from oranges. For a salad, I used red leaf and frieze lettuce, fennel bulb, Satsuma oranges and roasted walnuts and a dressing containing local walnut oil, apple cider vinegar and garden spices. The walnuts came from Full Belly Farms, which are grown about 125 miles from here just stretching my limit. I picked them up from their booth at the downtown Palo Alto Farmer's Market
That left the stuffing which was a bit of a production since I started by making whole wheat bread and corn bread. At Ohlone I had just taught a lesson about grains and showed the students how to grind wheat that we'd grown at Ohlone into flour. I found more whole wheat flour and corn meal at the downtown Palo Alto Farmer's Market again from Full Belly Farms. For the cornbread, the only ingredient I wasn't sure about was the baking powder, though it did say that is was made in the USA. For the wheat bread, the item I wasn't sure about was the yeast. I used Fleichman's which does have a plant in Benicia, California. Otherwise, I had local milk, butter and eggs. After making the breads and cubing them I added chanterelle mushrooms, celery, butter (Clover brand which is local) and broth from the turkey and baked the mixture.
Cranberries are the only traditional Thanksgiving item that does not grow near here. Oregon cranberries are the closest. I tried to substitute our very own Ohlone farm plum jam which can be purchased at the Thursday Ohlone Farmer's market, but was eventually over-ruled by family members that wouldn't be denied this tradition.
For appetizers I served two kinds of goat cheese, a soft one made by an Ohlone parent Julianne Bonnet sold at the Ohlone Farmer's Market and a harder one called Garden Variety Cheese sold at the downtown Palo Alto Farmer's Market. I also had grapes, Fuyu persimmons, dried apricots, local almonds I had roasted, fig preserves I made from my garden and local honey. I like to buy honey from Wayne Pitts at the downtown Palo Alto Farmer's Market as he helps us with our Ohlone Farm bee hives.
For drinks I served locally pressed apple juice from Ratzlaff Ranch and local wines. Believe it or not, Martinelli's Apple Cider originated locally, though it is likely not all of their apples come from near here anymore. After dinner I served mint tea made by pouring boiling water over mint sprigs from the garden.
We finished off the meal with pies that one friend brought. One was apple and the other was a rutabaga pie, made from local produce. I am not sure the homemade crust was made from local ingredients, but the local flour and butter certainly could be used. I made an additional pumpkin pie for the next day with a pumpkin I had cooked and sweetened with honey.
The biggest realization I had is how lucky we are to live here in this area where we have so many fresh locally grown products in every season. The Ohlone kids are very aware of what is in season as they observe what is growing on the Ohlone farm! It was such an easy exercise and no different in variety from other Thanksgiving meals I have prepared. I did have to modify my 100 mile limit slightly, but all in all, it was a fun and successful experiment, not to mention tasty!
What's Goin' On At the Farm
The focus of the science lesson for the kindergarten and first grade (K/1) classes was on grains. We looked at which grains we grow on the Ohlone farm including wheat and corn and which ones we use to feed the animals including oat and alfalfa hay. Straw, which we use for animal bedding, comes from the stalks of wheat. Some grains are in the category of grasses like wheat, oats, and barley. We were able to take the grains or seeds out of the spike heads of the grasses and practice grinding them into flour. The students compared the texture of the different flours (rice, rye, wheat etc.) and sorted products made from grains by type (bread, tortillas, crackers, rice cakes etc.). We talked about the differences between white flour and whole wheat flour in which white flour does not maintain the healthy germ part of the kernel and is sometimes bleached. The lesson concluded with tasting freshly baked bread and planting wheat in the pizza garden for a spring harvest.
The second and third grade (2/3) classes learned about the components of soil: humus, pebbles, sand, silt and clay. Students sifted soil from various local habitats (Redwood Forest, Oak Woodland, Chaparral etc.) to look for amounts of these components. They learned how older soils which have had more weathering and time to break down contain larger amounts of clay. Soils in habitats with more plants and animals have more amounts of humus or compost material coming from dead matter and waste. The soil type can vastly affect the type of organisms that can survive there.
The fourth and fifth grade (4/5) classes observed various examples of symbiosis in our local habitats. Symbiosis is a close interdependent relationship between two species. For example, lichen is not its own organism but rather a complex mutualistic relationship between algae and fungi. The algae make food using its green pigment and sunlight and sharing it with the fungus. The fungus provides a moist platform for the algae to live. We also saw mutualism in bacteria that lives in the gut of termites and the relationship between a sweat bee and a California Poppy flower. Another example of a different type of symbiosis occurs between an oak tree and an insect that bores a gall. The gall does not hurt the tree but provides an egg laying environment for the insect, therefore this relationship is termed commensalism. Parasitism occurs when one organism is harmed by the other as in the non-photosynthetic plant dodder feeding off the pickleweed plant in the baylands.
October was time to harvest honey from the Ohlone bee hive! The K/1 and 2/3 classes were able to participate in the process. Students got to try on child size bee suits and visit the hive. We removed honey comb from the hive and used an extractor to spin out the honey. Everyone got to help and try a taste! Students learned how bees drink the nectar with their proboscis tongue and store it in their stomach to bring back to the hive. The wax comb is secreted from special glands and formed into hexagons with the bees' mouth parts. Then the partially digested nectar is regurgitated into the comb and fanned to become honey. We also talked about the complexities of a bee hive with one egg laying queen, several male drone mating bees and many female workers who guard, gather, nurse and scout. A bee "dance" is used for communication to show the other bees where to find nectar and how to navigate back to the hive.
Meanwhile the 4/5 classes were learning about ecosystems and studying plots of land on the farm set up to represent local habitats of redwood forest, oak woodland, chaparral, grassland and wetland pond. Students looked at the form and function of various plants that make them adapted to their particular environment. All the students learned to name the plants growing in our Ohlone farm native habitat and explain their unique adaptations helping them to survive in the different climate and soil conditions.
The K/1 classes started out the year by learning about recycling and composting. We compost at Ohlone in three ways: a worm bin and a pile compost on the farm and the classroom green bins which are taken off site. It is important for the students to understand what happens to the compost and how it is a good fertilizer for our garden. We did several exercises showing what can be recycled and what products come from recycled materials. We talked about ways that we can reduce the amount of materials we use, particularly packaging.
The 2/3 classes followed the same compost theme. Students built mini- compost bins in bottles to watch the process over time. They learned the necessity of brown compost ingredients (paper, straw, dried leaves etc.) to provide carbon and green compost ingredients (vegetable peels, garden clippings etc.) to provide nitrogen to the soil.
For the 4/5 classes, the lesson was on the physics of the tools we use on the farm. Shovels and rakes are levers. Pulleys and wedges are often used to lift heavy farm objects. A ramp and a wheel are common especially on the frequently used wheel barrows. We even have a gear composter! Students tried each simple machine and explained how each works making the effort less and our jobs much easier.