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February 2008 : The Five-Bed Unit


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The 5-Bed Unit: 2006-2007

Notes and Observations | Data Analysis  | DesignGarden  

Notes and Observations

This was a challenging season for our main-season crops, as it was an unusually cool summer.  Our corn and amaranth struggled.  We harvested more calories from 12.5 sq ft of tomatoes than 50 sq ft of corn!

This was a hard year for corn.  The seedlings started out well but we continually found weak plants that needed to be supported.  They grew inconsistently inside and outside the mini-greenhouses.  (This was a garden research crop, experimenting with corn on 12-inch and 15-inch spacing both inside and outside of a mini-greenhouse.)  All the corn was interplanted with pinto beans.  We transplanted some cosmos seedlings at the edge of the bed to help keep the corn worms away.

Our main-season amaranth was planted on 18-inch centers, leaving a lot of soil exposed.  In an effort to provide more cover we broadcasted buckwheat into the amaranth.  This seemed to provide more moisture retention and might be worth repeating.

Sweet potatoes were an interesting endeavor.  We pampered them, keeping the mini-greenhouse (MG) lid on until the sun had warmed the air in the MG and closing the lid earlier in the evening than we might otherwise.  We tried to water with warm water, but that didn’t always happen.  Periodically, we pulled the vines up from the ground to prevent them from sending down roots from stem nodes.  The vines looked great, and we did enjoy eating our meager harvest.

Cayenne was harvested when the peppers were uniformly bright red and hung to dry.  They are waiting to be ground or mashed into powder.  There were some small, green peppers on the plants at the end of the season.  The plants seemed to produce well and could have produced longer with more warmth.

The parsley grew lushly at first, but ran into trouble mid-season, encountering the voracious appetite of gophers.  We did not get a complete harvest; however, it did pass the GROW BIOINTENSIVE intermediate yield level and produced the best yield in the 5-Bed Unit relative to the index!

The leeks were beautiful.  Based on a shift in how much leaf was edible, we seemed to hit peak yield in mid-December.  The leeks were still good as of December 28, but there was less edible weight.  Because this is an income crop, we will need to convince our market to eat the greens!

We planted a catch crop of broadcasted amaranth (after the potatoes were harvested) and took the time to thin it, transplanting some of the seedlings into the gaps to better cover the bed.  This seemed like a good time-investment that provided the benefits of both broadcasting and transplanting. 

We were able to eat from our catch crop beans (planted after the winter grain was harvested), some as dry beans and some as shell beans.  Because we pulled them out of the bed hurriedly before a rain, we didn’t shell the beans immediately and didn’t get any data on how many calories we were able to harvest.  It became clear that getting the catch crop planted in good time is a key to a successful catch crop (in both biomass and caloric terms).

Watching grains we transplanted this fall spread out to cover the bed, we learned that we did not harvest potatoes thoroughly enough.  Potatoes volunteered themselves all over the grain bed.  This is challenging because complete potato removal at this stage seems like a large disturbance for the grains.  Fortunately, the persistent volunteers were removed by the first frost.

As we compiled our data, we realized we need to perfect our record-keeping practices.  For instance, we found many tasks for which we neglected to record the time invested, as well as some tasks grouped together by bed instead of separated by crop (which is more helpful).  We also wanted biomass figures for some of our crops that we did not take dry samples for mid-season.  This first year of record-keeping has given us a lot of insight into how to better organize and record our data.

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Data Analysis

Beds:  Due to the beds selected in the garden, our 5-Bed Unit measures 583 sq ft.  The beds are a little larger than 100 sq ft each.  The design behind the unit is 25.01 beds, using GROW BIOINTENSIVE intermediate yields.

Calories:  Our 5-Bed Unit produced a total of 56,138 calories.  The design provides 2,129 calories per day.  At this rate of calorie-consumption our 5-Bed Unit can feed us for 26 days.  As 23.3% of the full design, it was projected to feed us for 85 days at intermediate yields.

Extrapolating to the full design, 240,825 calories were produced, one-third of the calories planned for in the design (777,232).  With these crops, these growing conditions, and this rate of production, 80.7 beds would be required to meet the calorie goals of this 25-bed design.  This is not surprising to us, as the mini-farm design is based on the intermediate yields in How to Grow More Vegetables, and the challenging soil and climate of the Research Garden inconsistently produce yields at the intermediate level.  We suspect that, had we grown this 5-Bed Unit at our partner site, the Golden Rule, the yields would indicate that the design could be grown in fewer than the planned 25 beds.

Biomass:  Total calculated dry biomass for the unit was 134.86 lb.  (This is a small increase over the 133.9 lb published in the February 2008 Newsletter.  As we crunched more numbers and rechecked our data, we realized we had not included the biomass from the amaranth for income.)  The biomass yield is 23.13 lb per bed, between the beginning and intermediate biomass goals of 15 and 30 lb per bed.  (We did not take dry samples of some of the crops; therefore, we do not have dry biomass figures for all the biomass produced.)  The best yields came from the fava beans.

60/30/10:  To meet the low weight-to-eat goals, the design is heavy in 60% crops and low in 30% crops.  Considering Bed-Crop-Months, the 5-Bed Unit comes to 76/8/16.  (60/30/10 is a design concept unique to GROW BIOINTENSIVE that emphasizes a healthy balance among crops that produce biomass and calories, considering both how area-efficient and weight-efficient crops are for calorie production.  The 60/30/10 ratio is a guideline to minimize the growing area and maximize the sustainability of the process.  See How to Grow More Vegetables and Ecology Action’s Booklet #31: Designing a GROW BIOINTENSIVE Sustainable Mini-Farm for more explanation.)

Time:  We spent 83.4 hours working in our 5-Bed Unit from February through September.  We recorded the time spent on most activities and were able to estimate the times for activities that happened before the unit began or happened so regularly we didn’t record time spent each day.  Examples of the latter are planting the fall 2006 compost crops and regular harvesting and vegetable cleaning. The 83.4 hours do not include watering or building compost.  Watering is a task that is site-specific and will be different for each garden.  However, it would be interesting to follow in our own climate, a project for next season.  Because we did not build compost piles specifically for the 5-Bed Unit, this is a number we will not be able to fill in.

Comparing crops based on hours spent per 100 sq ft shows that the most time-consuming crops were peppers, parsley, and EBOs.  Corn and beans were the least time-consuming.  Note that the income crops are all fairly time-consuming.  Here is a look at a few important diet crops:

Crop

Hours/100 sq ft

Calories/hour

B67 Peppers, Cayenne

29.9

368

B67 Sweet Potatoes

8.4

1,301

B38 Potatoes

7.1

3,238

B26 Pinto Beans

9.7

648

B36 Corn

4.3

534

Cayenne peppers, though very weight-efficient for calories, were not time-efficient this season.  It is a good thing they are only a small part of the diet!  Sweet potatoes and potatoes are in the middle as far as hours they demand, but they are the most productive crops for calories produced per hour.  This makes potatoes important when considering both area- and time-efficiency.  The pinto beans highlight this truth about potatoes, as they required 37% more time per 100 sq ft, but produced only 20% of the calories per hour.  Corn is of note because of the few hours invested per 100 sq ft.  The calorie yield was low due to a poor corn harvest; however, in a good year it seems corn could be notable for time-efficient calorie production.  Of added interest, is the caloric benefit that interplanting corn with pinto beans creates on a per-bed basis.  We interplanted all of the corn with beans, but did not look closely at the combined numbers this season.

Extrapolating 83.4 hours to the complete 25-bed design, it would take 357.9 hours of work (excluding the tasks noted above) to produce.  The numbers are too new and incomplete to permit any statements about how many hours it takes to grow a complete diet.  This is an exciting direction of research that will be valuable to continue.

Income:  We did not market any of the income crops.  These income numbers are completely theoretical.  They are based on the direct-sale figures Margo calculated in 2006 and assume the ability to sell all the produce and seeds (see Form 8).  The seed and plant yields are actual yields.

The total income produced by the 5-Bed Unit could have been $1,383.75.  The chart below presents the income breakdown. 

Crop

Seed or plant yield

2006 Sale Price

Income Potential

B39 Amaranth (seed)

0.22 lb

$2/packet

$1,084 (542 packets)

B39 EBOs

18.98 lb

$1.88/lb

$35.68

B39 Leeks

18.30 lb

$2.19/lb

$40.07

B26 Tomatoes (seed)

0.03 lb

$2/packet

$224 (112 packets)

These calculations assume 11,000 tomato seeds per oz and 35,000 amaranth seeds per oz (mean from HTG).  A tomato seed packet has 47 seeds, and a packet of amaranth seeds has 227.  Each packet will plant a 100-sq-ft bed.

The income crops produced more poorly than the diet and biomass crops.  A theoretical income of $1,383.75 is a production level of $2,050.00 per income bed.  The 25-bed design anticipates $12,170 per income crop bed (this assumes intermediate yields and ability to market all the seeds.)  The unit produced 17% of the design goals.  The income potential cannot be extrapolated to the full 25 beds, because the proportion of income beds in the 5-bed unit is greater than the proportion of income beds in the 25-bed design.  (Margo did not allow for this difference in proportion when writing the article “The Royer-Miller 5-Bed Unit” for the February 2008 print Newsletter.  The listed income goal for the 5-Bed Unit is not adjusted for proportion, hence the difference in percent of goal achieved.)

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Changes to Consider: Design

As the design continues to evolve, we want to consider adding the following crops to the diet:

  • Wheat
  • Fava beans, dry
  • Leeks
  • Kale
  • Parsnips

The fava beans will be advantageous as a carbon-and-calorie crop, maybe allowing the elimination of exclusive pinto bean beds.  The goals of edibility (each crop weight and total weight) and small space will determine if we are able to make these additions.  Complexity is increasing in both the diet and the garden through these changes.

We also need to increase the calories produced, possibly through more raisins, as discussed in the overview.

In this climate, sweet potatoes are a challenging crop to grow.  We would consider eliminating sweet potatoes if this were to be our long-term home.

 

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Changes to Consider: Garden

We want to warm the soil for the sweet potatoes before planting and intentionally water with warm water, as well as keep the MG warm through later opening and earlier closing.  We might want to trellis the sweet potato vines for the purpose of keeping the soil covered and allowing more sunlight to get to more leaves (more photosynthesis, therefore more storage root enlargment).  This will also prevent the vines from rooting at stem nodes.

We made notes of some of our observations and learning during the growing season; however, we could have done more of this.  When we prepared this report, it took some thinking back.  It would be advantageous to record the items we will want to remember for future growing seasons.

We want to establish a procedure for recording our time investments.  This might mean making a column or space on the log sheet, possibly the back, for recording the time of each task.  Our calendar system was OK, but we would often forget to take the extra step of making notes in another location.  Moving this to the standard log sheet will streamline and simply the process.  This efficiency will hopefully lead to more complete data.  In addition, we recognize the need to simply be more dedicated to recording the times and will emphasize this next season.

italics: main points for the reader
underline:  for Dan and Margo, a quick topic reference for our use

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