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Rooftop Aquaponics: Facilitating Growth…
by Ritiksha Lobo and Tim Evans
Tuesday, 09 November 2010 12:07

Jerusalem – Many poor around the world struggle to feed their families in arid climates or during droughts or floods. But what about those families in urban areas who don’t even have land to call their own?

In the Middle East, Nazarenes are attempting to turn rooftops into productive gardens.
On 23 August, Tim Evans, a Nazarene involved in ministry in Jerusalem, went to Jerusalem to research a system for growing fruits and vegetables in water-scarce areas in the Middle East. Kyle Petrie and Chris Somerville, researchers with a background in science, accompanied him. They investigated a technology called aquaponics -- a system that combines raising fish with growing soil-less fruit and vegetable plants. In aquaponics, fish waste is used as natural fertilizer for plants, and plants clean the water for the fish.
The group was inspired to research aquaponics as a possible way to meet the needs of the urban poor and refugee communities of the Palestinian areas. The study, which runs from August 2010 to February 2011, will test various aquaponic system designs for their efficiency, sustainability, cost and community interest.
The aim of this research is to see if a system that is both affordable and sustainable could be designed to produce adequate fruit and vegetable yields on household rooftops in the Middle East, in refugee camps and poor urban areas, as well as other less fertile areas in the world.
Given the reduced access to water and green spaces in over-populated urban areas of the Middle East, an aquaponics system has numerous benefits. It could bolster poorer families’ access to a wider variety of nutritional foods and contribute towards food self-sufficiency. It may also reduce the household expenditures on fresh produce. In addition it conserves water due to recycling, uses land efficiently and reduces the environmental footprint for crop production.
This project is supported by Nazarene Compassionate Ministries (NCM); the Church of the Nazarene in Jerusalem; Tearfund Ireland, an independent relief and development charitable agency; and The Leprosy Mission (TLM) Ireland, a charity that works closely with its partners to deliver holistic community development aid, emergency and disaster relief. TLM Ireland and Tearfund Ireland work in some of the poorest and most marginalised places in the world. The groups are interested in seeing if aquaponic food production is a viable method for poorer families to become more self-sufficient.
Evans said the team will try to develop a system that can withstand the environmental constraints, and at the same time consult with surrounding communities to better understand their need and gauge their interest. Like any good development intervention, this is an endeavour that will very much rely on the innovation of the local people with a passion to make it work. As such, the final shape of such a project is undecided.
Earlier this year, Petrie and Somerville volunteered with an environmental project in the Middle East; Evans was working for a humanitarian organization in Central Asia. When they returned to Ireland in April, they started thinking of a response to people’s limited access to water and the lack of land suitable for farming. Petrie kick-started the process by building a small aquaponics system consisting of four tomato plants and five goldfish.
At the same time, Lindell Browning, field strategy coordinator of the Eastern Mediterranean, asked Evans if he could help lead the local church in Jerusalem while Philip Rhodebush, the church team leader and facilitator, was on deputation. Evans agreed, asking if he could bring Petrie and Somerville to trial aquaponics systems on the roof.
In May, they built three small aquaponics systems in Dublin, Ireland, running a trial where they grew lettuce, tomatoes, peppers, basil, chives, strawberries – to name a few. They then began to consult with TLM, NCM, Tearfund Ireland and the church in Jerusalem to assess the viability of doing comprehensive research in this area.
There are now 16 aquaponics systems on the Jerusalem church roof.
“As a Christian Arab, I have never seen anything like this,” said Jeries, a resident of the Old City in Jerusalem and member of the local Nazarene church. “I was so impressed to have this kind of project in my home country.”
Aquaponics is an existing technology but it has mostly been used on large-scale commercial levels. Their interest is seeing this work in a humanitarian setting, through the reuse of scrap materials.
Browning said his hope is that families with no land or income will be able to use their small rooftops or balconies to grow healthy food for their family.
“The aquaponics project is something very new to me,” he said. “It has taken a lot of dedication and hard work but now seeing the vegetables starting to grow, it is exciting. I see it as testimony of people who care about their neighbours. I hope they will know that the church is supporting this project for their sake and know we care about their daily needs, not only spiritual needs.”
Evans, Petrie and Somerville are now living at the church, helping organize services, leading music and getting involved in congregation life. The church is an English-speaking group consisting of both locals and internationals.
“It has been an interesting process to take a project like this from a garden in south Dublin all the way to the rooftop of a church in the heart of Jerusalem,” said Petrie. “It has come with its challenges and also its rewards. It’s been encouraging to meet local people here so enthusiastic about what we’re doing.”
“This has generated a lot of interest in the wider community, and we are hopeful that this could genuinely help poorer families to improve their daily diet, as well as provide enjoyment and satisfaction in moving toward self-sufficiency,” said Evans. “In a part of the world where the urban poor and refugee communities do not enjoy many freedoms, there is significance in growing your own food and exhibiting more control in day-to-day life. We are very excited about the potential and are grateful for the support of the church and our other partners.”
According to Browning, the project has already created exposure and interest in the church. Since the project is on the church rooftop, merchants from whom supplies have been purchased and people who have heard of the project stop at the church frequently to see it.
“It demonstrates a caring people who want to meet practical needs of people. Other groups have indicated they might want to partner with us to reach larger groups of people,” said Browning.
For more information on the Aquaponics project, please visit their Facebook page: “Aquaponics Research” or contactrooftopaquaponic@gmail.com.

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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…