Grazing Management (full course)

Grazing Management 101 for Native Grasses

Introduction to Native Grass Management

• The course aims to equip participants with tools for managing native grass pastures, emphasizing that principles are similar to other pasture types.

• Key differences in managing native grasses include their tall growth and unique physiological adaptations affecting energy storage and grazing response.

Principles of Grazing Management

• Effective management focuses on maintaining vigorous canopies; avoiding both overly short and excessively tall canopies is crucial.

• Understanding plant biology is essential, particularly how different grasses store energy and their vulnerability to grazing.

Energy Storage in Grasses

• Bermudagrass has low-growing structures that withstand close grazing, while taller species like tall fescue store energy higher up, making them more vulnerable.

• Persistent close defoliation of tall grasses reduces leaf surface area, negatively impacting root development and overall plant health.

Impact of Grazing on Root Mass

• A study showed clipped big bluestem plants had only 5% of the root mass compared to unclipped ones, highlighting the detrimental effects of over-grazing.

• Historical studies from 1933 confirm that excessive grazing leads to significant loss of root biomass in native grasses.

Growing Points and Plant Recovery

• The growing point in tall grasses is located higher up, making it susceptible to removal through close grazing. This impacts regrowth as plants must draw from root reserves.

• Research indicates that removing the growing point significantly decreases carbohydrate reserves, delaying forage production recovery.

Managing Canopy Height

• Maintaining appropriate canopy height prevents reproductive growth which diminishes forage quality; light grazing pressure can lead to stemmy plants with seed heads.

• Healthy big bluestem plants consist of numerous tillers; fewer tillers indicate reduced vigor and productivity.

Optimal Grazing Heights

• Ideal maintenance height for big bluestem is around 15 inches; this allows continued photosynthesis and growth by preserving leaf surface area.

• Consistent over-grazing leads to weakened plants with minimal leaf area, increasing vulnerability to weeds and reducing overall stand vigor.

Effects of Over-Grazing

• Over-grazed areas show a vicious cycle where weakened plants become more susceptible to weed invasion due to lack of ground cover.

Plant Vigor Assessment

• Observations reveal that consistently grazed plants exhibit less vigor compared to those managed properly; this affects overall pasture productivity.

Switchgrass Growth Patterns

• Studies demonstrate how consistent management influences switchgrass vigor; aggressive early season grazing promotes better growth outcomes later in the season.

Seasonal Growth Curves

• Understanding seasonal growth curves helps manage forage production effectively across different grass types based on nitrogen application during trials.

Switchgrass vs. Eastern Gamagrass Growth Curves

• Switchgrass shows high carrying capacity with a surge in late spring/early summer followed by a decline as it shifts towards reproduction.

• Eastern gamagrass exhibits a more level growth curve but responds well when nitrogen is applied.

Big Bluestem / Indiangrass Blend

• This blend has lower carrying capacity but maintains steady production levels throughout the growing season compared to switchgrass.

Mid-Summer Growth Shift

• All three grass types experience a shift towards reproductive growth mid-summer which necessitates careful management strategies during this period.

Practical Applications for Grazing Management

• Maintaining vigorous canopies remains central; various stocking methods (continuous or rotational grazing), can be employed flexibly based on conditions.

Continuous vs Rotational Stocking

• Successful continuous stocking observed without adjustments throughout summer demonstrates effective pasture management under certain conditions.

Heavy Early Stocking Strategy

• Implementing heavy early stocking aligns animal numbers with grass growth patterns leading into slower periods later in the season.

Importance of Proper Stock Density

• Rotational grazing requires precise stock density management; too low density results in selective grazing leading some plants under stress while others thrive.

Patch-Burn Grazing Technique

• Patch-burn grazing involves dividing pastures into sections burned annually which encourages cattle focus on fresh regrowth while allowing other patches time for recovery.

The Benefits of Patch-Burn Grazing

Nutritional Advantages Post-Burn

• After a burn, grasses quickly regrow, offering highly nutritious and palatable forage for cattle. Cattle tend to graze these areas preferentially over unburned patches due to their higher quality.

Observations from Pasture Management

• In a pasture treated with patch-burn grazing, the burned section shows significantly heavier grazing pressure compared to the unburned area. This indicates that cattle are attracted to the regrowth in burned sections.

Factors Influencing Grazing Pressure

• The difference in grazing selectivity between pastures is influenced by two main factors:

1. Timing of stocking after burning.

2. Intensity of stocking (light vs heavy).

These factors determine how much cattle focus on recently burned areas.

Managing Grazing Pressure and Rest Periods

Impact of Forage Quality on Grazing Patterns

• Even with high grazing pressure on newly burned areas, patch-burn systems can shift cattle grazing away from heavily grazed patches over time, allowing for recovery and maintaining pasture quality without degradation.

Key Targets for Canopy Height

• Maintaining a vigorous canopy is crucial; ideal heights range from about 13 to 32 inches depending on species being grazed. Keeping forage within this range ensures healthy growth and minimizes weed encroachment risks.

Considerations for Continuous vs Rotational Grazing

Adjustments Based on Grazing Systems

• In continuous grazing systems, taller residual foliage is necessary since there’s no built-in rest cycle as seen in rotational systems; thus, more foliage must be left behind during cuts or harvests.

Importance of Residual Height During Harvest

• When harvesting native grass hay, it’s essential to leave at least an eighth-inch stubble to promote regrowth and maintain plant health post-harvest. An alternative method includes mob grazing with high stock density but may lead to increased trampling loss if not managed properly.

The Role of Rest in Pasture Management

Strategies for Effective Rest Periods

• Implementing rest periods during the growing season can help recover heavily grazed pastures; options include resting pastures for short durations between rotations or having a full season of rest after intense use. This practice supports long-term pasture health and productivity.

Recovery Examples from Over-Grazed Areas

• A previously over-grazed big bluestem/indiangrass pasture showed significant recovery simply through resting it for one growing season without additional interventions like fertilization or reseeding after three years of heavy use leading to weed encroachment issues.

Understanding Plant Health Through Rest

Effects of Leaf Surface Area Retention

• Studies indicate that retaining at least half the leaf surface area on plants has minimal impact on root health, allowing them to withstand longer periods without rest under certain conditions while still recovering effectively when given adequate time off from grazing pressures.

Flexibility in Forage Management Through Rest Scheduling

• Strategic scheduling of rest periods allows managers flexibility in forage availability throughout different seasons; varying lengths of rest before frost can enhance late summer forage production significantly based on previous summer growth rates and conditions experienced by the grasses during that period.

Seasonal Considerations for Native Grasses

Importance of Fall Rest Before Dormancy

• Ensuring native grasses have sufficient time to recharge root reserves before winter dormancy is critical as they remain alive through winter months requiring energy reserves for spring growth initiation following dormancy periods; timing is key here especially leading into fall months where preparation becomes vital for future vigor post-winter dormancy phases ahead!

Spring Management Practices

Optimal Timing for Early Spring Grazing

• It’s crucial not to graze native grasses too early in spring when they are just emerging (around 2–4 inches tall), as this can deplete their energy reserves needed for robust growth later in the season; waiting until they reach around 12–15 inches ensures better sustainability under grazing pressures moving forward!

Stocking Levels Influence Initial Grazing Decisions

• Depending upon intended stocking levels (heavy vs light), initial entry times into paddocks may vary accordingly—heavier stocking necessitates waiting longer before entering while lighter stocking allows earlier access ensuring optimal management practices align with grass growth dynamics observed throughout seasonal cycles!

Transition Between Cool-season and Warm-season Grasses

Prioritizing Warm-season Grasses During Growth Surges

• When both cool-season and warm-season grasses are available simultaneously during springtime surges—prioritize grazing warm-season varieties first due their superior nutritional value compared against cool-seasons which could otherwise diminish overall herd performance if neglected at peak readiness stages!

Harvest Options Post-Grazing Cool-season Grass

• If cool-season grasses remain productive post-grazing transitions—harvesting them as hay provides an effective solution since cutting reduces toxic compounds present within those plants making them safer feed alternatives down-the-line while also improving overall quality metrics associated with harvested materials produced thereafter!

Key Takeaways from Native Grass Pasture Management

Essential Principles Recap

• Maintain appropriate canopy height ranges throughout various management strategies employed whether intensive rotational or continuous approaches taken—this helps prevent weakening grass stands encouraging weed invasions ultimately prolong stand life expectancy across diverse environmental contexts encountered regularly within eastern US regions specifically targeted here today!