Central Grasslands REC, Streeter

Accessibility


| Share

Long-Term Grazing Intensity Research in the Missouri Coteau of North Dakota - 2011 Annual Report

Bob Patton, Paul Nyren and Anne Nyren: NDSU Central Grasslands Research Extension Center

 

Introduction

In 1989, we initiated an ongoing grazing-intensity research project at Central Grasslands Research Extension Center, northwest of Streeter, North Dakota. The objectives of the project are to determine the effect of grazing intensity on cattle performance, profitability, and the sustainability of forage production. Five treatments are included in the study: no grazing, light, moderate, heavy, and extreme grazing. Each treatment is replicated three times in pastures of about 30 acres each except the no-grazing treatment, which consists of six 0.3-acre exclosures placed on both loamy and loamy overflow ecological sites. Livestock are not rotated between pastures and each pasture receives the same treatment each year. Our goal is to stock the pastures each year so when the cattle are removed in the fall, 65, 50, 35, and 20 percent of the forage produced in an average year remains on the light, moderate, heavy, and extreme treatments, respectively. For these pastures, that means 2107, 1688, 967, and 500 lbs./acre of forage remains on the light, moderate, heavy, and extreme pastures, respectively. Table 1 presents the stocking history of the study and Figure 1 shows how much forage remained at the end of the grazing season each year.

Table 1. Stocking history of the grazing intensity trial for 1989 through 2011 at Central Grasslands Research Extension Center, Streeter, ND.

Year Class of Animal Stocking Date Removal Date Length of Grazing Season (Days)
1989 Steers May 22 August 22 92
1990 Bred Heifers May 30 November 27 181
1991 Bred Heifers May 29 September 25 119
1992 Bred Heifers June 1 August 25 85
1993 Bred Heifers May 29 September 26 120
1994 Open Heifers & Steers May 17 November 10 177
1995 Open Heifers May 18 October 30 165
1996 Open Heifers May 20 September 23 126
1997 Open Heifers May 27

November 5

(Extreme- August 27)1

162 (Extreme- 92)

1998 Open Heifers May 16 October 28 165
1999 Open Heifers May 27 November 4 161
2000 Open Heifers May 18 September 25 130
2001 Open Heifers May 21 September 11 113
2002 Open Heifers May 23 July 17 55
2003 Open Heifers May 23 September 19 119
2004 Open Heifers May 19 September 9 113
2005 Open Heifers May 17 October 27 163
2006 Open Heifers May 11 July 27 77
2007 Open Heifers May 18 October 1 136
2008 Open Heifers May 20 August 25 97
2009 Open Heifers May 21 September 1 103
2010 Open Heifers May 11 September 20 132
2011 Open Heifers May 18 October 17 152

1Due to lack of forage, livestock were removed early in the extreme grazing treatment.

Figure 1

Above ground biomass remaining (lbs/acre) on each treatment at the end of the
grazing season from 1989 to 2011

Treatment

Year Light Moderate Heavy Extreme
1989 2,078 2,074 2,035 1,701
1990 2,634 2,383 2,023 1,985
1991 2,385 1,494 833 641
1992 1,915 1,353 574 406
1993 2,924 2,256 1,290 608
1994 2,017 1,728 1,393 901
1995 2,772 1,906 1,583 504
1996 2,552 1,975 1,064 513
1997 2,550 1,711 689 560
1998 2,674 1,848 686 522
1999 2,269 2,108 806 609
2000 2,387 2,246 1,130 718
2001 1,933 1,883 1,197 617
2002 1,225 1,132 701 329
2003 2,434 2,128 1,205 678
2004 1,801 1,775 1,284 518
2005 2,324 1,994 1,331 357
2006 1,443 1,284 826 378
2007 2,172 2,359 1,239 600
2008 2,002 1,527 1,320 551
2009 1,914 1,425 975 488
2010 2,576 2,305 1,691 784
2011 3,354 3,328 2,271 1,469
Average
forage
remaining
2,275 1,923 1,224 715
Ideal
Remaining
2,107 1,688 967 500

Figure 1

To attain the desired grazing intensities, adjustments in stocking pressure are made each year based on information from previous years. Changes in the vegetation are determined by monitoring permanent plots located on loamy and loamy overflow ecological sites in each pasture and the six exclosures. Table 2 lists the average production on these range sites during each year of the study and the total precipitation for the year.

Table 2. Total crop year precipitation (October 1 to September 30) and peak total above
ground biomass production on loamy overflow and loamy ecological sites on the grazing
intensity study from 1989 to 2011.




Year



Precipitation
(inches)
Above Ground Biomass
(lbs/acre)
Loamy
Overflow
Loamy
1989 18.40 3,863 2,089
1990 16.10 3,847 2,962
1991 12.89 3,142 2,629
1992 15.25 2,758 2,065
1993 26.59 3,999 3,446
1994 16.86 4,201 2,803
1995 22.60 4,773 3,134
1996 20.55 3,837 2,645
1997 18.63 3,351 2,376
1998 18.91 3,334 2,855
1999 26.91 4,338 3,152
2000 15.60 3,950 2,846
2001 18.44 3,569 2,678
2002 16.69 1,850 1,175
2003 15.39 3,128 2,730
2004 21.95 3,676 2,814
2005 15.10 4,390 3,097
2006 16.62 2,450 1,632
2007 22.05 3,948 3,114
2008 14.31 3,126 2,433
2009 19.16 3,285 2,484
2010 28.70 4,241 3,616
2011 25.01 5,366 4,242

23-Year
Average

19.25 3,671 2,740

 

Table of Contents

 

    Creative Commons License
    Feel free to use and share this content, but please do so under the conditions of our Creative Commons license and our Rules for Use. Thanks.