Pastoral Systems

Best Management Practices for the Remediation of Former Sugarcane and Pineapple Land for Sustainable Livestock Production in Hawai‘i

Between 1992 and 2002 over 128,000 acres of land was taken out of sugarcane and pineapple production in Hawai‘i. Much of this former sugarcane and pineapple land was converted into nonagricultural uses or remains fallow today. The conversion of this land for sustainable agricultural enterprises is important to the state’s conomy. Indeed, agriculture contributed $536 million to Hawai‘i’s economy in 2002. This number could be sizably larger with the return of the former sugarcane and pineapple land to sustainable agricultural production. The alternative for these areas, urban development, is less attractive from an ecological and environmental standpoint.

Unfortunately, despite its availability, the former sugarcane and pineapple land is not being converted into sustainable agricultural production systems. In part, this is the result of the relatively low soil fertility levels and the assumed expense needed to bring the land back into production. Consequently, the trend for this land to be converted into non-agricultural uses will continue unless a feasible method for remediation is developed to efficiently convert it for sustainable and productive agricultural enterprise. Beef cattle production is an efficient and low-intensity agricultural production system that is perfectly suited to utilizing former sugarcane and pineapple land. However, for the efficient remediation and conversion of such areas into sustainable grazing systems, there is an immediate need to develop a series of “best management practices” (BMPs). Current soil remediation recommendations (addition of fertilizer and lime) are based on maximizing crop production and are therefore not economical for livestock producers. Moreover, the recommended application levels, based on maximizing crop production, are typically greater than what is needed for sustainable forage production and livestock grazing systems. Thus, these BMPs would include appropriate and economical lime and fertilizer application levels and incorporating forage legumes in combination with rotational grazing to facilitate the remediation of this land for sustainable livestock production.

Objectives

• Determine the most economical and efficient combination of treatments, including applications of lime and fertilizer, inter-seeding of legumes, and grazing management, that allows for the efficient conversion of former sugarcane and pineapple lands on the islands of Hawai‘i, Kaua‘i, and Maui into sustainable forage production systems.
• Determine the long-term effects and interactions among treatments on soil fertility, forage production, and animal production standards as they relate to sustainable forage production.
• Determine the long-term effects of the different treatments on the ecology of improved pasture ecosystems.
• Develop a series of recommendations or best management practices for livestock producers, county extension agents, and federal land-management personnel to efficiently remediate and convert former sugarcane and pineapple lands into sustainable forage production systems.

Work on this research project started in August 2005 and will terminate in August 2008. This project is funded through the USDA–CSREES Tropical and Subtropical Agriculture Research Grant Program in the amount of $262,013.

Hawai‘i Animal Nutrition and Forage Production Profiling Project

Forage-based beef cattle production is an important factor in Hawai‘i’s economy and environment, with more than 1 million acres of grazing land dedicated to livestock production. Grazing lands are characterized as those lands capable of growing grasses and other forages. Forage quantity and quality are major limiting factors for the sustainable production of grazing animals. The quantity and quality of grazed forages is primarily a function of the species composition of the pasture, soil quality, and climatic conditions including amount and timing of precipitation, growing degree days, amount of photosynthetically active radiation (PAR), and relative humidity. In addition, past and current grazing impacts greatly affect forage quality and quantity. For the Beef Industry to remain sustainable in Hawai‘i, a better understanding of these soil-plant-animal interactions is needed. The primary goal of this project is to correlate various animal nutrition and performance indicators with key forage-production values. These associated indicators, or profiles, will help producers make proactive
decisions about their management practices, allowing them to make changes rapidly without
affecting animal performance.

Objectives

• Determine the relationship between animal performance indicators (BCS, rate of gain, hair coat
  length) with tropical forage quality and quantity measures.
• Determine the effects of season and intensity of solar radiation on the photosynthetic rate of
  tropical forage grasses.
• Quantify and characterize the changes in forage quality with changes in growing season, solar
  intensity, and age of regrowth.

The results of this project will provide needed information that will assist Hawai‘i beef cattle producers to adopt sustainable grazing management practices. Specifically, it will provide information on grazing management strategies that will help producers maintain high levels of forage quality and quantity throughout the production year for tropical pasture systems, information that is currently very limited. The results of this project will also be broadly applicable across the diversity of cattle operations in Hawai‘i including not only cow-calf producers but stocker-finisher and seed-stock operations as well. Additionally, the information gained from this project will be compiled into Extension outreach publications, research technical notes, and peer-reviewed publications and presented in workshops and field days. Funding for this project, $17,110, is provided by the USDA Natural Resources Conservation Service through the Grazing Lands Conservation Initiative. Work on this project began in June 2005 and will terminate in May 2007. Project directors are Dr. Mark S. Thorne, Dr. James R. Carpenter, Joe May, NRCS State Range Conservationist, Hawai‘i, and Arnold Norman, NRCS Central Region Rangelands Specialist.

Maui Ranchers Take Action in Organizing the New Feed Source Task Force

Imported roughage (hay) and concentrate (grain and supplements) costs represent the highest operating
cost for confined livestock operations. Pastoral systems can greatly reduce these costs except during weather patterns of severe drought, as experienced in the late 1990s. In a proactive decision by the Maui Cattlemen’s Association, a New Feed Source Task Force was organized for cattle producers to work together with current and potential feed producers and the county, state, and federal government agencies to find and develop new, sustainable, and affordable sources of feed for beef cattle.

The purpose of the task force is to (1) provide roughage for Maui farmers and ranchers to feed to their cattle on pasture during times of drought, and (2) investigate alternative feedstuffs to replace the diminishing supply of pineapple waste used also by the farmers and ranchers for cattle feeding. The source of roughage that the task force is currently looking at is the sugarcane leaves that are deposited on the ground when the seed cane harvester goes through the field gathering “pula pula,” or cane stalks, for re-planting the cane fields. This project is a joint venture with HC&S Plantation. The ranchers can feed the green leaves. and the plantation can burn the older, drier leaves. It is hoped that this venture will be a win-win situation for both industries. Grant money awarded to assist the group includes Tri Isle RC&D, $63,000, and County of Maui, $50,000. These funds will be used mainly to purchase machinery to get the leaves from the sugarcane fields to the cattle in one form or another. To date no machinery has been purchased, but a small hay baler, owned by CTAHR, University of Hawai‘i at Ma¯noa, and coordinated by the CTAHR Beef Initiative Program, will be tried in the near future. The task force is represented by beef ranchers, the Maui Cattlemen’s Association, Tri Isle Resource Conservation and Development Council, Inc., County of Maui Office of Economic Development, UH-CTAHR Cooperative Extension Service, and Hawaiian Commercial and Sugar Company.

Follow-Up: Tufted Beard Grass, Kaua‘i’s Dominant Invasive Pasture Weed

Tufted beard grass, Schizachrium condensatum (Kunth) Nees, continues to be a noxious grass on Kaua‘i. Tufted beard grass is largely ungrazed by domestic livestock including cattle, goats, and sheep. It was first observed in higher-elevation conservation lands and has since expanded to midelevation pastures. Wind is seen as the primary factor in spreading it. There appear to be two strains of tufted beard grass. One has a much thicker clump, finer leaf blades, and a taller seed stalk without leaves, while the other does not form a dense clump, has fewer leaf blades, and has a shorter seed stalk with leaves.

Much of Kaua‘i’s newer pasture development is on recovered sugarcane lands with guineagrass establishment. Communication with producers including personal observation of marginal perimeter lands have shown increased expansion and establishment of tufted beard grass into guineagrass stands, apparently due to selective grazing of guineagrass by livestock. While exact control measures have not been established, it appears that management efforts should include timed mowing, even grazing pressure, and soil amendments to increase soil fertility. As a short-term relief, guinea-grass has been observed to outgrow tufted beard grass under timed mowing, especially during fall under adequate rainfall.

A previous pasture amendment trial comparing six treatments of lime and urea (46% N) applications with mowing and non-mowing comparisons were inconclusive. The cooperator’s inability to mow selective plots, including continuous grazing pressure on the existing guineagrass by livestock, resulted in the dominance of tufted beard grass over the trial.

Glyphosate, a postemergence herbicide, has been shown to kill tufted beard grass. Unfortunately it will also kill all other desirable forage species. Glyphosate should be applied to new growths of tufted beard grass as soon as it is observed. Once established, it is extremely difficult to eradicate and will dominate any given pasture.

Future: No-Till Pasture Seed Drill Arrives

Through the CTAHR Beef Initiative program, a no-till pasture seed drill was purchased and will be used for pasture improvement demonstration projects at the Mealani Research Station and for use (rental charges and freight costs) by the livestock industry involved in cooperative pastoral improvement projects. We hope that the industry can benefit from the use of this new tool to enhance productivity of pastures in Hawai‘i. Please contact Glen Fukumoto or Milton Yamasaki for more information.