Outdoor Season Update

This summer's growing has been progressing steadily. I've harvested the basil a few times, and the cucumbers and squash now have fruit beginning. The cukes and squash have had flowers for at least three weeks, but until recently all the flowers were male - that means no fruit. I thought the lettuce might grow well under the shade of other plants, but so far they've just stayed small and dormant. Bell peppers have produced a few fruits but few new flowers. Nitrate levels in the water have remained very high (~80ppm) and I've put some Maxicrop plus Iron in as well. I started up the tank with pure ammonia, so I think there was a lack of some trace nutrients, including iron..

Grow beds on 7-26-2011

Squash (foreground), Lettuce, & Jalapeños (background)

Cucumbers (foreground), Peppers (mid), & Lettuce (background)

Basil (R) with Small Hot Peppers (L)

Tengo Muchos Jalapeños (y Otras Verduras)!

In the month since I took my tomato plants out of the grow bed inside, the jalapeños' growth exploded. They've grown tall and have a profusion of flowers. As I've mentioned before, the I was surprised that the jalapeños flowered, due to the predominately blue light of the metal halide bulb. Such light is best for vegetative growth.

Last week I harvested the first fruit: they are about 3 inches long and very spicy! They made for a piquant corn chowder. I have 16 more that will be ready to harvest soon and at least another 15 buds and flowers.

3" Jalapeños on 7/05/2011

Jalapeños Ready for the Chowder

Meanwhile, the chard has re-grown tremendously...

Growth Spurt!

The tomatoes, chard, and peppers in the basement system are now growing vigorously! The tomatoes especially have surged in height. As you can see below, in just four days each tomato plant gained about five to seven inches!

Left: Grow bed on 5/27/2011 Right: Grow bed four days later on 5/31/2011

I needed to transplant these tomatoes, because I was heading out on vacation, and I worried that they would grow into the light, causing a fire hazard. Originally, I planned to transplant these into my outdoor aquaponic system; however, they had grown so fast that the outdoor system didn't yet have the necessary nitrate levels. Instead, I transplanted them into pots with soil. To make up for these, just before I left, I planted more tomato seeds, in addition to cucumbers and summer squash. By the time I return, I expect they will have sprouted and the outdoor system will have enough nitrate to receive them.  I'm interested to compare the growth and output of the tomatoes that spend their whole life in the aquaponic system, the ones I transplanted to soil, and others that I've had in soil since seedling stage.

I was happy to discover through this indoor tomato experiment that tomatoes could thrive in shallow grow beds. The expanded clay grow bed is only about three or four inches deep, yet the plants grew tremendously. You can see from the photos below that once I washed the clay pebbles out of the roots, they were only a few inches long. Of course this is a direct result of the aquaponic growing method: with nutrient rich water delivered regularly right to the plant, roots do not need to travel far to find sustenance.

Roots of heirloom tomato before transplant 6/1/2011

I reason that the shallow bed worked well because of the cool temperatures in the basement. Outside, such shallow beds would fail because the tomato's shallow roots would get baked in the sun. If I used this for future indoor projects, it means I could reduce the amount of media I need to purchase and the amount of weight the table must support.

Meanwhile, the chard has grown rapidly and the hot peppers have sprouted flowers (much to my surprise because of the dominance of blue light from the metal halide bulb).

Two types of rainbow chard in clay grow bed on 5/31/2011

Buds on hot pepper plants 5/31/2011

Meanwhile, in the Basement....

While the outdoor system is cycling, I’m continuing to grow indoors. I have a few rainbow chard plants that are now growing tremendously. I’ve also started some sweet peppers and heirloom tomato seedlings that I plan to transplant into the outdoor system. So far the tomatoes are growing very well, at about five inches tall. At over a year old, the pepper seeds delayed germination; however, they finally sprouted and now stand at half an inch tall. The system has many fewer plants than it can support currently: nitrate is about 30ppm at least. I plan to put this nitrate rich water into the outdoor system to kick start it for the transplants.



Rainbow Chard 5/17/2011

Rainbow Chard with Tomato and Pepper Seedlings 5/17/2011



Winter Growing Season

The winter growing season was a smash! The lettuce did quite well, and I harvested about eight salads that fed four to six people each from February through April, about two-and-a-half salads per month! The first six of those salads came from the clay pebble bed that had densely planted seeds. The dense planting stimulated quick, vertical growth. It also ensured that plants did not grow woody stems, keeping the growing tip low, just above the surface. I harvested this like mowing a lawn,, cutting at about 2” high straight across. The plants responded well! For the first two months I harvested at a staggered pace, which kept the demand for nutrients relatively constant because some plants were in the high demand regrowth stage as others grew slowly near full size.

Mixed lettuce in clay pebble bed on 2/18/2011 (top) and 3/26/2011 (bottom). 
Gray coloration on bottom is due to grow light being off. Note that the gravel 
grow bed seen in upper right of both pictures has significantly smaller plants.

Meanwhile, the gravel grow bed which had plants spaced about 6” apart, as recommended on the seed packet, grew very slowly, so I did not harvest until late March. The plants did bush out nicely, each producing far more lettuce per plant than the dense plantings of the clay bed. The bushy lettuce led to woody stems and larger leaves, which I found could only get a few harvests per plant before the leaves got too tough or bitter (lots of white sap in them). 



Gravel grow bed on 4/28/2011 before the last harvest.



Conclusion: unless I need pretty heads of lettuce, I should plant the seeds dense and harvest often.

And what about the other plants in the system? Well, the chard...

Water Wheel Prototype

19th century water power is alive and kicking!....er, spinning! My water powered biowheel* prototype is complete. Pumped water powers this overshot-style wheel (I'm not quite ready for the Pelton wheel yet), which turns two attached drums. The drums are wrapped with multiple layers of fiberglass screen to provide surface area for nitrifying bacteria to colonize. As the wheel rotates, the bacteria will get a consistent does of moisture and oxygen, which will hopefully lead to vigourous growth and biological filtration (converting fish waste to plant food). You can see a video of the wheel in action below.

Now my wheel will go into test mode: I will fill the tank with fresh water and see if the wheel can provide enough biological filtration to effectively start up or cycle the tank.**

Friction was literally the biggest obstacle to getting the wheel moving. Specifically the wheel had to be able to overcome the resistance the tank water would put against the paddles. To combat this, I angled the paddles so they retain more water as they spin down and then release water as they start to spin upwards. Additionally, I just barely

Part I - Aquaponics in New England

Part I of Aquaponics in New England discusses how aquaponics can supplement the offerings of traditional farming and fishing where they have limits. A PDF of the entire paper (Parts I-III) can be downloaded here, including a full list of sources referenced by footnotes.

Supplement Traditional Farming & Fishing

 

First, it is important to understand the current state of agricultural affairs in Massachusetts. After a precipitous decline in the 1960s, the number of farms in the state is now on the rise (see Figure 1). As of 2008, the state had more than 7,700 farms (including aquaculture and nurseries).¹ Many of these farms have hit on effective and profitable strategies, such as Community Supported Agriculture, farmers markets, and/or organic certification. The growth is fueled significantly by organic agriculture. Between 1997 and 2008, the number of farms in Massachusetts increased 28% while the number of organic farms increased over 3,000% (from 3 to 103).¹

Traditional Farming

Despite the growth, traditional farming has limits in Massachusetts. Whether organic or not, traditional farms have a limited growing season. Many cold hardy species...

Part II - Aquaponics in New England

Part II of Aquaponics in New England discusses how aquaponics can improve the sustainability of produce and fish production. A PDF of the entire paper (Parts I-III) can be downloaded here, including a full list of sources referenced by footnotes. 

Improve Sustainability of Local Harvest

Water Use

In addition to providing a sustainable source of fish, aquaponics has other sustainability advantages over traditional farming, hydroponics, and aquaculture. First, these techniques use a lot of water. Traditional aquaculture methods use between 0.57 and 33 cubic meters (m³) of water produce 1 kilogram (kg) of fish, depending on method⁸ (See Table 2). Research at the University of Virgin Islands has shown that their aquaponics system uses less than half of the water of the most productive aquaculture systems: 0.25 m³/kg.⁸ On average, aquaponic systems use between 90 and 99% less water than traditional aquaculture systems.⁹

 

Aquaponics also uses less water than hydroponic crop production. Aquaponic systems...

Part III - Aquaponics in New England

Part III of Aquaponics in New England discusses how aquaponics can fuel a significant increase in the region's food production. A PDF of the entire paper (Parts I-III) can be downloaded here, including a full list of sources referenced by footnotes. 

Help Scale Up Local Food Production

Scaling up refers to significantly increasing food production to a level well above the status quo, dramatically altering the ratio of imported to in-state/region produced food

 

Why Scale Up?

Aquaponics offers the potential to scale up local food production for Massachusetts and New England. But first, why is scaling up production important to the region? As discussed previously, locally produced food tends to produce less GHGs. It also provides an opportunity for local employment, helps to reinvest money in the state or local community, and preserves open space and rural character of the region, supporting tourism and real estate values. Local food often tastes better, too, because varieties are cultivated for their flavors. In contrast, most commercial varieties are cultivated for their ability to withstand the assault of freezing, packing, and shipping hundreds or thousands of miles.

In addition to growing demand for local food, climate change presents a major economic argument for increasing local food production. Most of the extremely high risk areas for water stress in the Tetra Tech study are in America’s major agricultural areas: the Great Plains and Southwest, including California.¹³ Globally, climate change will have an overall detrimental effect on agriculture, too.¹⁰ This means prices for imported food will...