Traditional and Contemporary methods

Traditional 3 Sisters Garden
Corn grows tall to provide poles for the beans to climb
Bean roots fix nitrogen to make fertilizer to feed the corn
Squash has big leaves that shade the soil and reduce weed growth
     2024 version organized by Barb Williams
Commercial Agriculture in Lake Elmo
Field Corn
Soybeans  (Crop Rotation in different years)
Vegetable Gardening for Farmers’ Market
Hay, Sod, Christmas Trees, Beekeeping
     2024 version organized by Tony Manzara
The historical problem of sustainable agriculture is maintaining the level of the nitrogen compounds required for plant growth in the soil. Otherwise the land is depleted and farmers must move to new lands after a few years. After many years, nitrogen compounds produced by lightning re-fertilize the land and it can be farmed again temporarily. Various technologies have been developed over the years to resolve this issue. Traditional ways of adding nitrogen compounds include spreading animal (including bird and human) manure, growing legumes such as alfalfa or beans that replace the nitrogen compounds, or utilizing scarce mined nitrates.  Then “Crop rotation” was shown to be an effective way to maintain nitrogen compound levels. When the chemical industry developed cost- effective processes to make ammonia, nitrate, and urea, these began to be used as fertilizers on a large scale (1910-1920). 
Our Three Sisters Garden demonstrates a traditional “companion planting” system. In our garden, ten corn kernels are planted in each of the four hills, and once the corn is well-started (about 10 days)  pole beans are planted near each corn plant. The corn stalks act as a support for the beans, and certain bacteria living in nodules in the bean roots “fix” nitrogen from the air. The resulting nitrogen compounds provide fertilizer for the corn plants.   

Squash is planted between the corn hills, and its large leaves, held near the ground, provide shade that discourages weed growth, and reduces sun-driven evaporation that dries the soil too much. This year we are using yellow Summer squash because they form compact plants

The garden is protected from voracious rabbits and deer by a seven-foot high black mesh deer fence on eight-foot T-posts. Four hundred years ago an elder would have sat near the garden with a bow and arrows, and the rabbits would have been trapped, and the family would have had venison / rabbit / vegetable stew. But that is not an option today.

It has been found that many modern beans have reduced capability for fixing nitrogen, because that trait was not emphasized in their development. Heritage varieties have been shown to fix much more nitrogen than modern varieties. For more information visit
Contemporary Commercial Agriculture in our area: We have planted commercial varieties of corn and soybeans to show visitors the main crops grown in Lake Elmo. A few seeds of locally-bred “Big Blue” winter squash cultivar developed by Ed Heit of River Falls WI were planted to represent vegetable gardening in Lake Elmo.
The main commercial crops by acreage in Washington County are listed by the amount of acreage in each crop (2022)
Corn for grain                    12,821
Soybeans for beans          11,080
Forage (hay/haylage), all    5,600
Oats for grain                        997
Vegetables harvested, all       92
Sales value of crops  54,703                           ($1,000s)                                                                  
Grains, oilseeds, dry beans, dry peas                20,842 
Vegetables, melons, potatoes, sweet potatoes    8,545 
Fruits, tree nuts, berries                                       6,734 
Nursery, greenhouse, floriculture, sod               17,066 
Cultivated Christmas trees, etc                               665
Other crops and hay                                               852
Sales value Livestock, poultry, and products       6,007
In contemporary agriculture, the conservation of nitrogen is accomplished by crop rotation. Soybean roots have nodules that host nitrogen fixing bacteria, which increase the soil fertility. The next year when corn is planted, the nitrogen compounds are depleted. To control weeds, 93% of field corn and 96% of soybeans grown in Minnesota use biotechnology (genetic engineering, GE) to make the plants resistant to glyphosate, which kills many weeds. 
How is Minnesota corn used? 42% is exported to other countries, 37% is processed into things like ethanol, 14% is used for animal feed, 7% is used in other ways..
How are soybeans used? Soybeans are an oil seed crop.  More than half this crop is exported, much of this to China as animal feed. When soybeans are crushed for oil, 20% of the weight is oil. The other 80% is soybean meal, which is a great source of protein and essential amino acids
reading for fun and education: about the top ten plants that changed Minnesota
(apple, alfalfa, American elm, corn,  purple loosestrife, soybeans,  wheat, white pine and wild rice)
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