Using Irrigated Forage Pastures to Enhance Livestock Production Sustainability

ABSTRACT

This project focused on producer success in establishing and managing irrigated cool-season grass pastures in Northeastern Colorado. Four cooperating producers shared production and expense information related to their irrigated pastures. We gathered forage production and quality data from clipping demonstrations on three sites designed to show the effects of clipping frequency and intensity on plant productivity and persistence.

OBJECTIVES

1) Gather historical cost estimates for establishment and maintenance of livestock production.
2) Record the harvested hay yields and animal unit grazing days per acre by pasture age and forage species.
3) Sample forages from grazing enclosures to simulate rotational grazing to analyze forage quality and yields.
4) Take cattle performance measures on farms such as number of calves/yearlings produced, pounds of beef sold, yearling weight gains, calf weaning weights and health statistics.
5) Conduct a standardized performance analysis on each farmer’s irrigated pasture enterprise.
6) Catalog each producer’s recommendations regarding the advantages and management challenges from integrating irrigated pastures into their beef farm enterprise.

TOURS

Two tours were held in 2004 with 80 people attending. We sent out 44 evaluations after the tours, with 22 returned. The results are as follows:

1) Approximately 1,650 acres of irrigated pasture were planned for 2005.
2) More information is needed on livestock fence and water systems, grazing management and forage selection, economics and stocking rates, and fertilizer and water management.
3) Producers indicated the most important things they learned were:
-- tax savings on converting cropland to pasture,
-- need fewer acres to run more cattle,
-- adding alfalfa to pasture is possible,
-- fertilizer pays,
-- species selection,
-- clipping/grazing height is important,
-- irrigated pasture is another tool for producers to use.
4) A respondent said the tour helped him get a feed cost savings of $0.25 per head per day.
5) Producers indicated they liked spending time with and listening to other livestock producers discussing their irrigated pastures.
6) Other producers mentioned they received many positive comments from event attendees.

CLIPPING DEMONSTRATIONS

Observations indicated that frequent, short clipping heights (or grazing heights) will rapidly decrease plant vigor and lead to reduced plant density. This increases the amount of bare ground allowing for more rapid weed encroachment and results in potentially much less yield in later years.

Simply put, yields in a single year may be greater for short, frequently grazed pastures, but those yields are not sustainable due to reduced plant vigor and density, increased bare ground and potential increased weed encroachment. This increase in bare ground is also a concern for irrigated pastures located on sandy soil, which has an increased potential for erosion and blowouts. Producers should evaluate their livestock forage needs and market conditions against the long-term potential for erosion and weed infestations when considering grazing beyond their forage productivity capacity.

PRODUCER SUMMARY

Three farms were closely evaluated: Amen Angus farm, Christensen Brothers Inc. and the Kitzmiller Grazing Association. The three business managers differed significantly from each other in how they used their grass pastures.

At the Kitzmiller Grazing Association, continuous grazing is the norm. This operation has used the same grazing system for over 25 years. The pastures have some of the improved grass species but a lot of the stand is low productivity Kentucky bluegrass. Reestablishing the pastures to a high proportion of more productive cool season grasses as well as including alfalfa coupled with rotational, deferred grazing should result in increased beef productivity. However, using this strategy would increase management demands.

The Amen Angus Farm raises and sells registered Angus seed stock. Its primary use for grazed pastures is for cow/calf development. It uses rotational pasture grazing through six irrigated grass pastures and dryland native rangeland.

Ken Amen’s father planted the first grass pastures in the 1950s including tall fescue, which has become a dominant species. Ken values this pasture for its winter-feed quality. He contends that kochia becomes abundant when the pastures are grazed heavily, and Canada thistle comes on under light grazing pressure; both are suppressed with herbicides.

Ken values his irrigated pasture off-season when supplies are short and expensive. He observed that steers gain better when grazing on dry range than irrigated grass but that irrigated pastures allow greater livestock grazing flexibility and irrigation flexibility under short water supply situations. In addition, grass is more forgiving on high pH and saline soils and fields with shallow depth than row crops. Cattle production on irrigated pastures has lower inputs and risks are more profitable for his farm than raising cash grain crops.

The Christensen Brothers cattle operation consists of cow/calf pairs as well as feeding yearlings. Grass was seeded in the fall of 2004 on a 150-acre pivot and two intermittently flood irrigated fields. In addition, this farm has 1,800 acres of dry rangeland. Grass tillage was harvested in June yielding 2.27 tons wet weight. Cow/calf pairs were brought into the field on July 13 and removed on October 2, 2004. In addition, 143 yearling steers from the farm’s feedlot were put on the field on July 15 and were removed on September 10. The yearlings gained 1.62 pounds of weight per day on the pasture. The change from the feedlot may explain this low gain. Cattle were rotated through four cells on the pivot during the grazing season.

The Christensens are enthusiastic about their switch because they have a better return on investment than with silage. The system adds flexibility with their dry rangelands and flexibility in purchasing calves when markets are favorable.

CONCLUSION

All three of these farm operations use grazed irrigated pastures differently, making comparisons difficult. However, this livestock/crop production system is very flexible and can be both profitable and sustainable for differing farm operations. The inherent ecological advantages from a perennial grass system and the better net profitability and lower risk make irrigated pasture grazing a sustainable agricultural system.

FUTURE PLANS

Bruce Bosley, extension agent and ag advisor, continues this work through CSU’s Sustainable and Profitable Agriculture as the chair for its Forages Work Team. He will collaborate with producers on pasture grazing systems education and in studies on seasonally interrupted irrigation of alfalfa and perennial grasses.