We have a 600 acre integrated crop and cattle operation. We have practiced some form of management intensive grazing for the past 13 years.
PROJECT DESCRIPTION AND RESULTS
The average pasture turnout date for our beef cow herd is about April 30th. The purpose of this experiment is to compare different strategies for extending the grazing season into mid April there by reducing our winter feed costs.
We compared four different treatments on four different contiguous paddocks; all treatments received 40 pounds per acre of actual nitrogen in early April. The cows were split into four separate groups and were turned into individual paddocks on April 23rd, 1996. The grass averaged about 5 inches at turn out in paddocks 2, 3, and 4 and about 3 or 4 inches in paddock 1. We ended the trial when the grass had been grazed down to about 2 inches.
Paddocks 1 and 4 are predominantly Quack grass and Blue grass with sparse Alfalfa. The western half of paddocks 2 and 3 have the same plant mix as 1 and 4, the eastern half of paddocks 2 and 3 are dominated by Orchard grass and Red Clover and are the most productive parts of the whole test area.
Spinks loamy sand an A and B slopes comprise all of the soil types in paddocks 1 and 4 and western half of paddocks 2 and 3. The eastern half of paddocks 2 and 3 consist of Owosso-Miami sandy loam. The soil type change is very consistent with the vegetable change.
Treatment/Paddock 1: area 3.52 acres. The control plot, we allowed fall grazing through November of 1995. Stocking rate, 3.58 Animal units (A.U.)/acre, or 12 cow-calf pairs and one yearling heifer.
Treatment/Paddock 2: area 7 acres. We ended the grazing period on August 21, 1995, no additional treatments.
Stocking rate 3.60 A.U./acre or 24 cow-calf pairs and 2 yearling heifers.
Treatment/Paddock 3: area 6.35 acres. We ended the grazing period on August 19, 1995. On August 22 we no till seeded annual rye into the existing vegetation. Stocking rate 3.62 A.U. or 23 cow-calf pairs.
Treatment/Paddock 4: area 6.60 acres. We ended the grazing period August 17, 1995. On August 20, 1995 paddock 4 was sprayed with Gramoxone herbicide as a Burndown, on August 22, 1995 we no till seeded annual rye into the burned down grass. Stocking rate 22 cow calf pairs and 2 yearling heifers or 3.51 AU/acre.
Results and Discussion:
August and September 1995 were very dry in Mid Michigan. The combination of lack of rain and soils with very little water holding capacity resulted in fairly poor (est. 50%), germination of the annual rye on the burned down acres and virtually no germination of the rye planted into existing sod.
The ungrazed paddocks that were not sprayed with gramoxone in the fall of 1995 made fairly good growth before winter. The perennial grasses in paddock 4 began to recover from the gramoxone by mid September but made considerably less growth then paddock 2 and 3 before winter. Paddock 1 was grazed twice more after August after weaning. 40 dry cows grazed paddock 1 for a total of 4 days. Our dry lot cost for dry cows is 50 cents per day, (at that time of year). So paddock 1 produced $40.00 worth of feed (20*4*.5=40) in the fall of 1995, or 40/3.52 = 11.36 per acre.
Spring of 1996 was much cooler than normal. On April 25, 1996 Flint, MI was 56 degree days behind (base 42) the same date in 1995. Despite the cool growing conditions we still turned out cow herd out 10 days earlier than normal. The cows were initially turned out in stockpiled grass other than the test area.
We assigned a value of 1$/AUM/day, this is roughly equivalent to our dry lot cost for a cow calf unit. With out the stockpiling we would be dry loting our cows the week of 4/23 – 4/30.
Treatment/Paddock 1: Grazing period 2.5 days. Net Economic Gain or Loss/Acre = 3.52*2.50*1 = 8.80$/acre gain.
Treatment/Paddock 2: Grazing period 4.25 days. Net Economic Gain or Loss/Acre = 3.60*4.25*1 = 15.30/acre
Treatment/Paddock 3: Grazing period 4 days. Net Economic Gain or Loss/Acre = 3.62*4*1 = 14.48/acre – 11.36 – 16 (the cost of no till drill rental + rye seed) = -12.88/acre loss.
Treatment/Paddock 4: Grazing period 3.5 days. Net Economic Gain or Loss/Acre = 3.51*3.5*1 = 12.29 – 11.36 – 16 – 9.50 (6.50/acre chemical cost + 3.acre application cost) = 24.58/acre loss.
Eliminating fall grazing does improve early spring pasture condition. Paddock 2 which was rested in the fall furnished 4.25 days of grazing at approximately the same stocking rate as paddock 1 which was grazed in the fall and only furnished 2.5 days of grazing. Some of that advantage is because paddock 2 is inherently more productive than paddock 1. However the increased springtime carrying capacity of the rested paddocks does not compensate for the value of the feed lost by not fall grazing. Resting some pastures in fall could be the most profitable option if very cheap alternative feed is available such as crop residues.
The options of interseeding cool season annuals into existing perennial pasture does not appear to be feasible. The gramoxone sprayed plot actually had less total forage than the rested paddocks in spite of good early season annual rye growth.
Fred Hinckley, MSUE in Sanilac assisted in data evaluation.
The results of my project will be published in the MASA Land Steward and possibly the haying and grazing newsletter. In September 1995 a group of MSU Extension personnel visited the sight. Our farm is not in a grazing area so we did not attempt a grazing field day. But we are attempting to build interest in grazing through the conservation district. Next year we hope host some area grazers for a pasture walk.