ARDEC South Area Description

2003-2005 Weather and Soil Data

The Colorado State University Horticulture Research Center (HRC) is located northeast of Fort Collins, Colorado at the intersection of Mountain Vista Dr. and Interstate 25. It is an 80 acre research center for the CSU Horticulture and Landscape Architecture Department. The Specialty Crops Program manages 8 acres of the HRC organically for the Rocky Mountain Small Organic Farm Project. The soils are a clay loam. Typically, most rain falls in the early spring and then again later in summer in the form of afternoon thunderstorms. See below for more detailed information about the soils and weather at the HRC.

2003 – 2005 Weather Data

The years 2003 and 2004 were very different from each other in regards to precipitation and temperature. The growing season of 2004 was much cooler and wetter than 2003. On average it was 6 degrees (F) cooler in July and August in 2004 than in 2003. The rains also came later and for a longer period of time in 2004 than in 2003. By the end of September, almost 3 inches more precipitation fell in 2004 than in 2003.

The average temperatures in 2005 fell in-between the more extreme low and high temperatures from 2005 and 2003 respectively. There was also more precipitation in the early spring, making it difficult to get into the field for early plantings.

The average killing frost date for this area is around September 22nd. In 2004, the killing frost date was September 23rd, and in 2005, the killing frost date was October 7th.

2003 Soil Data

The plot that is being used for the Rocky Mountain Small Organic Farm Project was previously in alfalfa hay for four years. In the spring of 2003, a small portion of it was plowed to create a plot for the lettuce bolting experiment and melon and artichoke variety trials. Since phosphorous is depleted under alfalfa production, poultry compost was applied to the area (phosphorous availability is also problematic in general due to the high pH of the soils of this region).

Soil test data is provided below from the fall of 2003 for the lettuce, melon, and artichoke plots – note that the reported data are averages of several soil test locations. On October 22, 2003, we added bone meal to the four beds where the garlic was planted.

Year	Month	pH	EC	Lime Est.	% OM	NO3-N	P	K	Zn	Fe	Mn	Cu
2003	September	7.6	1.3	High	3.0	16.3	3.6	329.0	1.5	7.4	2.6	4.5

2004 Soil Data

In the spring of 2004, the majority of the remaining alfalfa field was plowed under to expand our variety trials and experiments. The November 2003 soil data below reflect pre-plowing soil tests in the alfalfa. On March 1, 2004, we applied 4.8 tons/acre of poultry manure compost to the area in alfalfa (before the spring plowing), which is the equivalent of adding 174 lbs of NO3 and 396 lbs of P2O5 per acre.

Year	Month	pH	EC	Lime Est.	% OM	NO3-N	P	K	Zn	Fe	Mn	Cu
2003	November	7.6	1.5	High	2.6	7.9	2.4	302.0	1.4	8.5	4.0	2.4