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Duckponics鴨耕共生

Duckponics鴨耕共生
Patrick improves our mid-level aquaponics system
When I first came to Windward, Duckponics was a project I was immediately interested in. Coming with a background in irrigation and a long time love of pond works and hobby aquariums, I was excited for this was a chance to explore this area at a level I had only dreamed of. Much was in place already, but much was still left to do, and still more was yet unknown. Before I jumped into Duckponics too deep though, I had an opportunity to work with a smaller system already in place here, Barrelponics.
Patrick adds chicken wire to the cattle panel covers

Barrelponics is a study in theory and mechanics. Many projects here start out this way, small. It's a great way to test an idea, a mock up if you will, before making any larger commitments. With anything you do, especially in the presence of unknowns, there will be mistakes. Mistakes, loss, fails, whatever you want to call them, are not necessarily bad if you choose to look at them in the right light. We learn so much from our mistakes and the process of correcting them. This is why starting small works so well for us, small projects = small mistakes = small loss. Once the problems are worked out at the small level we are ready to move on to the next level. So, after getting my hands dirty with barrelponics making some minor changes and additions I had the understanding necessary to more confidently move over to duckponics.

the combination grow raft and float
As I said above, so much was already there. The duck pond, the flood tank, the two large vegetable grow beds, and the smaller duck weed tanks as well as all the tubing, electrical, and drainage. This spring, during his apprenticeship, Jon played an important role in getting duckponics up and running for the first time. So, when I started working on it in early summer, it functioned well, but I wanted to advance the system to achieve its true operational vision. Initially, I focused on getting the holding tank to trigger a flood properly, a better dispersion of water to the grow beds was wanted, working out an appropriate timing with the automatic pump system both in frequency and duration was needed, and inflow and outflow still had to be worked out.


After all this was done effectively (which was much easier after my experiences with barrelponics), there was a whole new gambit of unforeseen challenges to address. Such as, with this abundance of vegetation right there in the open, it invited many local critters to our hopeful feast: the ever present ground squirrels wanted the cucumbers; the yellow jackets wanted the water; and even our own ducks couldn't wait for us to harvest the duckweed for them and were raiding the tanks prematurely. So, it was obvious that protective covers were a must. We made these out of cattle panels and chicken wire and they have proven pretty effective so far.

October 21:
A few words on water flow challenges

the inlet to the flood tank
Another challenge that presented itself even after the basic water flow mechanisms were in place was the effect of the rate of water flow. We have a submersible pump that pulls water from our duck pond up to our flood tank. The pump delivers water to the tank through a one-inch pipe that connects to a 3/4 inch inlet fitting.
This works fine, however, there is a point when the upper float applies enough pressure to the hatch chain to begin opening the rubber flapper door that releases the water to the various vegetable grow tanks. That door is a two inch hole that is diverted to two different pipelines that have ball valve that allows us to control the rate that water flows from the holding tank into the grow tank. If those ball valves are fully open, enough water escapes through the lower port so that the water level in the flood tank never reaches a level where the upper float completely opens the hatch door for the duration of the flood.
So, after much tinkering, we were able to close the ball valves just enough to hold back the escaping water long enough for the pump to trigger the full open flood while still having the ball valves open enough to deliver enough pressure to power the water delivery tubes for the grow beds. If it isn't one thing it's another!

October 22:
Water distribution

So now that the water is flowing and everything seems to be going fine, we need to look at how the plants receive that water. First of all, it is important to know that in any hydroponic system, it is the water that delivers the nutrients the plants need, not the soil. In most hydroponic systems a lot of money is invested in purchasing additives and nutrients for the water, and even more is spent on purchasing special neutral growing mediums such as Hydroton or Vermiculite. That is why we use water from the duck pond, the ducks fertilize the water for free, and in the process the plants filter the water and return cleaner water for the ducks' enjoyment.
ball valve flow adjuster
Awesome!
Also, we use pea gravel as our growth medium as this is more cost effective, more natural, and supports the nitrifying bacteria needed for the necessary biological process of converting ammonia to nitrite and then to nitrate. Pea gravel also makes a great low grade filter.

While we were getting some of the other parts in place and working properly, we were delivering the water to the grow beds as a direct flood to the edge of the bed, you will probably see this in some of the early photos. But as I've said before, the long term vision was for something more sophisticated than this and through experimenting with the setup, we more fully realized the benefits of a "prettier" delivery. Basically, with the pea gravel acting as some what of a filter, if all the water is dumped on one side of the grow tank the nutrients may be unevenly distributed throughout the tank resulting in uneven plant growth.

watering system in action
So, back to the plan. If you have a circular grow bed, one of, if not the most efficient, method of dividing space is to quarter it off. Instead of dumping the water from a tube at the edge we connected four tubes with a central intersection. We capped the end of the three dead end tubes and cut holes in the side of the tank to hold these tube ends up.

Now came the tricky part. From previous observation, we noticed that with sufficient pressure these holes in these tubes acted like spray nozzles, damaging any small plants that were in their line of delivery. The solution we came up with was to drill the holes on either side of the top of the pipes so the water shoots up at an angle and then adjusted the pressure to make sure none of the water flow was directed outside the tank. By using an upward arc in the water we use gravity to pull the water back down to the plants at the speed of rain which every plant is essentially used to.
October 23:
Protecting our pump
It was stated earlier that at a certain point this summer there was a significant increase to our duck flock and this had some unforeseen effects on the pump for duckponics. It was all those baby feathers that eventually clogged up the turbine in the pump and caused it to burn out. We don't want to get rid of the ducks, so what do we do about the feathers?

Well, we cleaned out the duck pond as best as time would allow since other projects (such as watering the main garden and keeping the thriving cucumbers and mint alive in the grow beds of duckponics) depend on the functioning of the duck pond. However, no matter how often we may endeavor to go through a full scale pond flush, the feathers as well as other debris still come back to haunt us, quickly.

We don't know yet if it is the total solution, but we think it is part of it. The box filter. Basically we took an old plastic milk crate and cut mesh screen pieces from a satellite dish to fit on all six sides. We wired them on, cut a custom hole to receive the pump, and attached the two together before resubmerging the new pump.

I don't know if you've seen the screen mesh that old satellite dishes are covered with but the holes are pretty small. Still large enough for plenty of water to move through but just small enough to keep the feathers from getting to the pump. It still requires some checking in on but we would rather clean off the box filter every couple of weeks than replace the pump just as often.

Also on the drawing board is a possible cyclone settling tank that would allow the silt to settle out before being delivered to the flood tank.

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蔬菜對溫度日照條件的要求

蔬菜對溫度日照條件的要求
全日照  8個小時日照 瓜類、茄果類、豆類、山藥、豆薯(地瓜)。番茄、黃瓜、茄子、辣椒等喜溫中、強光性
蔬菜夏秋季生產,玉米、青椒、西瓜、南瓜、西紅柿、茄子、芝麻、向日葵類。
其次是根莖類,如:馬鈴薯、甜菜、胡蘿蔔、白蘿蔔、甘藷、山藥等等。至少需半日照,才能生長,芋頭雖喜歡全日照,但比其他蔬菜耐蔭。 
需要中等光照大白菜、甘藍、芥菜、蒜、洋蔥。 

長日性蔬菜白菜、甘藍、芥菜、蘿蔔、胡蘿蔔、芹菜、菠菜、萵苣、蠶豆、豌豆、大蔥、洋蔥。

短日性蔬菜豇豆、扁豆、莧菜、空心菜。         

中光性蔬菜黃瓜、番茄、茄子、辣椒、菜豆

菜豆

菜豆喜溫暖,不耐高溫和霜凍。菜豆種子發芽的適溫為20-30℃;在40℃以上的高溫和10℃以下的低溫,種子不易發芽。幼苗生長適宜氣溫為18-25℃。花芽分化的適宜氣溫為20-25℃,過高或過低溫度易出現發育不完全的花蕾、落花。

菜豆對光照強度的要求較高。在適宜溫度條件下,光照充足則植株生長健壯,莖的節間短而分枝多,開花結莢比較多,而且有利於根部對磷肥的吸收。當光照強度減弱時,植株易徒長,莖的節間長,分枝少,葉質薄,而且開花結莢數少,易落花落莢。

菜豆根系強大,能耐一定程度乾旱,但喜中度濕潤土壤條件,要求水分供應適中,不耐澇。生長期適宜土壤濕度為田間最大持水量的60%-70%,空氣相對濕度以80%為宜。開花結莢期對水分最敏感,此期土壤乾旱對開花結莢有不良影響,開花數、結莢數及莢內種子數減少。土壤水分過大時,下部葉片黃化,早脫落。空氣濕度過大會引起徒長、結莢不良。

菜豆具有深根性和根瘤菌,對土壤的要求不甚嚴格,但仍以土層深厚肥沃、排水良好的輕砂壤土或粘質壤土為好。土壤過於粘重、低溫、排水和通氣不良則生長不良,炭疽病重。菜豆喜中性至微酸性土壤,適宜的土壤pH為5-7.0,其中以州6.2-6.8最適宜。菜豆最忌連作,生產中應實行2-3年輪作。

菜豆生育過程中,主要吸收鉀和氮較多,還要吸收一定量的磷和鈣,才能良好發育。結莢期吸收磷鉀量較大。磷鉀肥對菜豆植株的生長發育、根瘤菌的發育、花芽分化、開花結莢和種子的發育等均有影響。缺乏磷肥,菜豆嫩莢和種子的品質和產量就會降低。缺鈣,幼葉葉片捲曲,葉緣失綠和生長點死亡。缺硼,則根係不發達,影響根瘤菌固氮,使花和豆莢發育不良。 耐陰半陰(大概3-4小時日照) 應選擇耐陰的蔬菜種植,如萵…

黑檸檬

黑檸檬
Dried lemons are actually limes and are used heavily in Persian Gulf and also Iranian cuisine where they add a strong bitter flavor in addition to sourness. They are made by boiling ripe limes in salt water, and then sun drying until the insides turn black. The outside color varies from tan to black. They are sold whole or ground.

Black Lime is a spice used in Middle Eastern dishes. It is made by boiling fresh lime in salt water and sun drying until the insides turn black. The outside color varies from tan to black. It is sold whole or ground.

黑檸檬實際上是使用萊姆,並且在波斯灣和伊朗料理中被大量使用,除了酸味外,它們還添加了強烈的苦味。它們是利用鹽水煮成熟萊姆,然後曬乾,直到內部變黑。外部顏色從棕褐色變化到黑色。他們可以整顆或切片販售。
黑檸檬是用於中東菜餚的香料。它是通過在鹽水中煮沸新鮮的檸檬並經天然乾燥,直到內部變黑。外觀從棕褐色變成黑色。
USE Black limes are usually used in legume, seafood or meat dishes. They are pierced, peeled or crushed before adding them to the dish. After cooking they become softer and edible. They can also be powdered and added to rice dishes. Powdered black lime is also used as an ingredient in Gulf-…

為何冰箱冷凍室非得是零下18度?

為何冰箱冷凍室非得是零下18度? 不少家庭的冰箱有led面板,可顯示冷藏室和冷凍室溫度。每次看到那個零下18℃,不少人,包括筆者在內就會禁不住提出一個小疑問:為什麼冷凍室溫度非得是零下18℃?最多零下1℃不就結冰了嗎?搞這麼低溫度實在是浪費電呢。

聰明如很多人是這樣推測的

百思不得其解,於是很多人,包括筆者在內就開始推測後面的機制了。冷凍室的零下18℃其實不費電,相反,它是節約電力的一個好措施。為何?

冰箱隔一段時間,內部溫度升高後,它就要啟動壓縮機,嗡嗡嗡的。頻繁啟動壓縮機不僅耗電,冰箱的壽命也會降低,還有就是很吵人。怎麼辦?簡單,先把冷凍室的溫度搞得低低的,比如零下18℃左右。


然後,冷凍室的冷氣往上走,來到冷藏室,如此,就能長時間保持冷藏室的溫度處於0到8℃以內了。

待冷凍室的冷氣散失過多,溫度升高到零下幾度時,再啟動冰箱的壓縮機把溫度再次降到零下18℃,如此,冰箱的啟動次數就變少了。

實際是這樣嗎?很遺憾,不是。

原因之一:不一樣的水

水到零度以下就結冰了,這是絕大多數人的認識。然而仔細一想,這不適用於冰箱的冷凍室。因為冷凍室存放的不是上百升礦泉水,而是各種各樣的食物。

食物中含有大量水這沒錯,但這些水同時含有大量的鹽、糖等物質。就像每1升海水中大約含有35克鹽,所以平均起來,要到零下1.33℃時海水才會結冰。

因此,要想把食物凍結,並不是溫度只要達到水的冰點就可以,得保證足夠低的溫度,食物中的水才能凍結,這很重要,因為食物中只要有液態水存在,這就等於是為各種細菌的繁殖提供了必備條件。

圖為牛肉薄片在不同溫度和不同時間內測得的牛肉中凍結水量的曲線。

當牛肉薄片的溫度為零下4℃時,只有70%的水分被凍結;溫度下降到零下9℃左右時,也還有3%的水分未凍結;即使牛肉薄片的溫度降低到零下18℃時,也不是100%的水分都被凍結住。

原因之二:嗜冷微生物

根據微生物對不同溫度的適應範圍,可將微生物分為三大類,嗜熱菌、嗜溫菌和嗜冷菌。在食物的冷藏和冷凍過程中,我們面對的「敵人」是嗜溫菌和嗜冷菌。

一般來說,能引起食物腐敗和食物致毒的嗜溫菌,在低於3 ℃情況下不產生毒素,當然,個別菌種例外。

而對於嗜冷菌,一般得在零下10 ℃到零下12 ℃時才會停止生長。

有的黴菌甚至要到零下15~零下18 ℃時才會停止生長。

瞧,我們以為,零下幾攝氏度後微生物就被殺死或停止繁殖了,但…