Organic forage production systems for organic dairies in the Southern region

Project Overview

OS11-057
Project Type: On-Farm Research
Funds awarded in 2011: $14,993.00
Projected End Date: 12/31/2013
Region: Southern
State: Tennessee
Principal Investigator:
Dr. David Butler
University of Tennessee

Annual Reports

Commodities

  • Agronomic: general hay and forage crops, grass (misc. perennial), hay

Practices

  • Animal Production: grazing management, pasture fertility, range improvement, stocking rate, winter forage, feed/forage
  • Crop Production: nutrient cycling, organic fertilizers, tissue analysis
  • Education and Training: demonstration, extension, farmer to farmer, on-farm/ranch research, participatory research
  • Farm Business Management: budgets/cost and returns, agricultural finance
  • Production Systems: organic agriculture
  • Soil Management: organic matter, soil analysis, nutrient mineralization, soil chemistry, soil quality/health
  • Sustainable Communities: sustainability measures

    Abstract:

    In late spring 2011, we began establishment of an on-farm experiment with an organic dairy near Philadelphia, TN. Three forage systems [a) annual system, b) perennial system, and c) a cool-season perennial legume overseeded with a warm-season annual grass] were established in 1-acre plots and replicated. Estimated total herbage yields were similar among treatments, however, percentage of nonsown species differed significantly, with the highest observed in the perennial legume-annual grass system and the lowest observed in the annual system. Results suggest that all systems examined have utility for organic grazing livestock producers, depending on producer objectives and management capabilities.

    Introduction

    Organic milk production continues to be one of the strongest sectors of the organic food industry. However, in the U.S., organic dairy production has been concentrated in the upper Midwest and the Northeast. While there is increasing interest in the Southeast in organic dairy production as a way to increase the viability of family farms, there is limited research and extension information from this region to help conventional dairy farmers transition to organic or to help beginning dairy farmers establish their operations. This is especially true in the area of forage management for organic farms, an important issue considering that the USDA National Organic Program specifies that 30% of a dairy cow’s dry matter intake must be supplied through grazing, and that dairy cattle must graze throughout the length of the grazing season. The issue is also of great economic importance to producers given the high cost of organic feed grains.

    Research and extension information relating to the production of organic forages for organic dairy production is extremely limited. Further, available information typically relates to forage production systems in cool, continental climates such as northern Europe, the northern U.S., and Canada. Information relating to forage species selection and management from these regions is of limited value to organic forage production in the humid southeastern U.S. where climatic conditions and soil properties differ markedly. While these climatic conditions can provide for a lengthened grazing season, it can be difficult to produce forages of sufficient quality during the hot summer months. Additionally, given that soils in the Southeast are typically low in organic matter, forage productivity without conventional fertilizers can be limited without proper selection of forage species mixtures and appropriate nutrient management.

    Selection of forage species mixtures will be a key part of a successful organic forage production program. Forage species vary widely in their yield, chemical composition, and nutrient digestibility (Staples, 1992). Additionally, organic forage production can be constrained by the lack of conventional nutrient and pest management inputs, particularly herbicides for weed control. As such, it is important to investigate forage species and mixtures that have been shown to be aggressive in establishment and growth, as well as forage legumes which will decrease the dependence on nitrogen application.

    A second important aspect of forage production for grazing dairies, especially in the Southeastern U.S., is seasonal availability of forage. Forage rotations and mixtures containing both cool and warm-season species will be an important solution to this problem. Annual grass/legume mixtures are an obvious choice, since these forages generally establish relatively quickly, and conventional planting methods allow for the mechanical destruction of weed competition prior to planting. However, the use of only cool and warm-season annuals in rotation creates a difficulty in that twice during the year, there is an establishment period with limited forage production. Additionally, the tillage operations limit accumulation of soil organic matter and increases risk of erosion, which reduces the sustainability of the system. Incorporating perennial forages into the system can help minimize the problem created during annual forage crop establishment transitions.

    Forage legumes should increase sustainability of the overall forage program, regardless of the grass species used. Legumes offer an advantage in two areas. First, adequate forage quality to support milk production is often limited for several months of the year and forage nutrient quality can frequently decrease to the point where supplementation is needed (James and Collins, 1992). Legumes are generally higher in protein and energy content than grasses, which will improve the nutrient availability to grazing dairy cattle. Second is the advantage of biological nitrogen fixation. Research has shown that including a legume in a grass mixture can provide an equivalent yield to a grass sward fertilized with 60 to 100 lbs nitrogen per acre (Miller and Heichel, 1995).

    Project objectives:

    The objectives of this study were to (1) examine the performance (yield, forage quality, soil quality, grazing days, botanical composition, and economics) of three organic forage systems for the Southern region (an annual mixture, a cool-season perennial and warm-season annual mixture, and a perennial mixture) and (2) disseminate results to producers and other professionals via a producer field day, extension programming, conferences, and scientific journal publications.

    Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture or SARE.