University of Minnesota
University of Minnesota
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Methods for Experiment 069 -

Animal Sampling Methods

Pocket gophers were trapped out of E069 as soon as they appeared (very seldom).

Fertilization Treatment

The following nutrients are added twice each year, once in early May and once in late June:

Nutrient Amount
P205 50 g/plot
K20 50 g/plot
CaCO3 50 g/plot
MgSO4 50 g/plot
Trace Metals 1/4 teaspoon/plot


Each plot is 4 m2. This will give each plot a total of 25 g/m2 of each chemical per year.

Field Operations: Fencing

A below-ground gopher fence (3 feet deep and 1 foot wide) and an above-ground rodent/deer fence (6 feet tall) was built around the plots in 1989. Aluminum flashing 12" wide (deep) was installed to edge the plots and divide them into 48, 5 feet x 9 feet plots.

Field Operations: Fertilization

Fertilizer was mixed and spread by hand twice a year, once in early May and once in late June. All plots received the same fertilizer, with none of them getting any NH4NO3.

Field Operations: Mammal Trapping

Small mammals were trapped in the fall to discourage overwinter inhabitants. Pocket gophers were trapped out of the experiment as soon as they appear (very infrequently).

Field Operations: Weeding

All plots and aisles were routinely weeded to keep the area free of unwanted plants and future weed seed sources.

Treatment layout : trmte69

Species Treatment: 1 = Agropyron repens monoculture 2 = Schizachyrium scoparium monoculture 3 = Pinus strobus monoculture (R-seed means right side starts with seed, R-seedlings means right starts with seedlings -do the same for the left side). 4 = Quercus ellipsoidalis monoculture 5 = Agropyron repens + Quercus ellipsoidalis on half 6 = Agropyron repens + Pinus strobus on half 7 = Schizachyrium scoparium + Quercus ellipsoidalis on half 8 = Schizachyrium coparium + Pinus strobus on half

Field Letter Experiment Number Plot Number Species Treatment Invasion Treatment
E6914-2
E6928-2
E6933R-seed
E6933L-seedlings
E6947-2
E6951-2
E6965-2
E6971-2
E6983R-seed
E6983L-seedlings
E6997-2
E69108-2
E69114-2
E69128-2
E69132-2
E69141-2
E69158-2
E69162-2
E69174-2
E69183L-seed
E69183R-seedlings
E69197-2
E69202-2
E69216-2
E69223R-seed
E69223L-seedlings
E69234-2
E69246-2
E69257-2
E69268-2
E69277-2
E69282-2
E69295-2
E69304-2
E69312-2
E69325-2
E69334-2
E69343L-seed
E69343R-seedlings
E69357-2
E69361-2
E69376-2
E69383R-seed
E69383L-seedlings
E69396-2
E69406-2
E69412-2
E69425-2
E69435-2
E69448-2
E69456-2
E69465-2
E69471-2
E69481-2
 

Vegetation Sampling for E069

1989: none
1990: none
1991: none
1992: none
1993: One 40cm X 1m area was clipped in each plot receiving a monoculture treatment. This area was located in the lower left part of the plot, 20cm in from the front and left sides, extending to the back. In plots that were divided in half (those with treatments 5-8), 2 40cm X 1m areads were clipped per plot (1 in each half). The position of the clip area in the left half of the plot is in the same position as the one in the monoculture plots. The position of the clip area in the right half of the divided plots is 20cm in from the front and right sides extending to the back.
1996: Each clipped area was 40 cm X 100 cm: Monoculture: 20 cm in from front and right sides. Left: 80 cm in from left, 20 cm in from right Right: 80 cm in from right, 20 cm in from front

For pine plots: we clipped 2 rows per clip strip (pine seedlings were planted in rows). This meant that sometimes we had to move the clip strip 5 cm or so in order not to get 3 rows.

Root Cores: In plots or subplots with tree roots, to avoid under- or oversampling, a 30x30x30 cm hole was dug in the front 30 cm of the clip strip- this was our 0-30 cm sample. 3 regular 30-60 cm root cores were taken from this hole. In grass plots and subplots, no holes were dug-normal 0-30 and 30-60 root coring was done. In grass monocultures, the coring was done in the clip strip, 3 cores per level- one at front, back, and center 80 cm (see picture) in 80 cm subplots with trees, however, the tree roots were being sampled from the grass clipstrips, so root cores for grass subplots were taken from the far side from the trees- not the clipstrip.

Sampling Problems: 1989: none 1990: none 1991: none 1992: none 1993: 1996: For plot 10R, due to an original clipping error, only a 20 cm X 1 m area was clipped, 80 cm from R and 20 cm from front. (Initially it was clipped in 1993 clipping spot.)

Watering Methods

All plots received at least 1.5cm/week of water in April, May and October and 2.5 cm/week in June through September. If the plots received this water from natural rainfall, then no supplemental watering was needed. When watering was needed, it was done using a system of hoses set up in the field. A black irrigation pipe, 3 inches in diameter, was hooked up to the pump. This extended out to the E026 area where the 3-inch hose was divided into two 2-inch hoses. One part went toward the E026 (and E071) plots (the other toward E055, E069, E070). From this hose, several regular garden hoses were connected. Gardena Excellent Oscillating Sprinklers, model 6968, were attached to these hoses. These sprinklers were purchased at Sears and made at Gardena, Inc., 6031 Culligan Way, Minnetonka, MN 55345. Three or four hoses/sprinklers were used at one time. Any more than this reduced the water pressure enough so the sprinklers would not work. The sprinklers were rotated in order to reach all of the plots.