Assessment and Decision Making
Comprehensive Pasture Assessment:
Evaluate Forage Quality: Use drone mapping or the point-step method to assess the proportion of desirable forage. If less than 50% of the pasture comprises productive species, consider renovation.
The point-step method is a straightforward technique used to assess pasture composition. While walking through the field, stop at regular intervals (e.g., every 10 steps) and note the plant species that's under your foot at each stop. This process provides a representative sample of the pasture's plant species distribution, allowing you to estimate the percentage of desirable forage versus weeds or undesirable species.
Drone imagery can accomplish the same thing as representative sampling, but with much less time and labor investment. This is done by creating a map overview of the field and using AI tools to select areas with weeds.
Soil Health Check: Conduct soil tests for pH, macronutrients (N, P, and K), and micronutrients to understand fertility needs.
Lab testing is the most accurate way to determine these, but it can take several weeks.
In-field tests for pH and N are cheap, accurate, and readily available. We like to do both. We do in-field testing (along with estimation based on topography) to build field zones. Then we send samples from those zones to a lab for more detailed testing.
Weed Infestation: Identify weed species and infestation levels. Persistent, invasive weeds may necessitate stronger measures.
Certain weeds will have a significant (up to 62%) impact on cattle grazing behavior, and others are toxic. Identifying those weeds is crucial during pasture rehab.
Dry Matter Assessment: Gauge the pasture's productivity by measuring the dry matter (DM) yield. Clip a known area of pasture to ground level, dry the sample, and weigh. This DM weight per unit area gives you a productivity baseline. Low DM yields indicate poor soil fertility, overgrazing, or other stress factors. This also gives a great baseline to measure improvement and determine the economic impact of your rehabilitation.
Topography: The topography of a field is crucially important. How steeply an area is sloped determines where organic matter and plant nutrients will accumulate.
Pasture History Insight: Reflect on past management practices. Issues like overgrazing, inadequate fertilization, or neglect could be culprits behind the decline.
Grazing Patterns: Observe livestock grazing behavior. Uneven grazing can signal issues with certain areas or plant species.
2. Pasture Rejuvenation
Pasture Rejuvenation: Rejuvenating a pasture involves revitalizing the existing forage without completely reseeding. The goal is to improve the health and productivity of desirable plants while suppressing weeds and undesirable species. Here's how to approach it:
Soil Fertility Management: Begin with a soil test to determine nutrient deficiencies and pH imbalances. Based on the results, apply the necessary lime to adjust pH and fertilizers to replenish deficient nutrients. Proper soil fertility encourages desirable forage growth and can naturally suppress weeds.
pH: desirable plants and undesirable weeds grow best at different pH levels. By applying a quick-acting soil amendment (like liquid calcium chelate), we quickly adjust pH to the level best for forages. This allows them to outcompete weeds and suppress them with less herbicide. Traditional ag-lime takes over 6 months to affect soil pH, which often means that weeds won't be suppressed until the following season.
N: N levels in the soil are crucial for plant growth. We like to use more stable products along with soil surfactants. When applied at the right time (split through the spring and summer based on cutting or grazing schedules), these products result in much better N uptake at lower application rates, less runoff, and far less cost.
Weed Control: Implement an integrated weed management approach. This may involve:
Mechanical Control: Mowing or grazing at specific times to prevent weed seeding and reduce weed competition.
Chemical Control: Applying selective herbicides that target weeds without harming the desirable forage. Always follow the label instructions and consider the timing of application to maximize effectiveness while minimizing impact on forage plants.
Cultural Practices: Enhancing pasture conditions to favor desirable forage. This includes managing grazing to prevent overgrazing, promoting dense forage growth to outcompete weeds, and overseeding to fill in gaps where weeds might establish.
Grazing Management: Implement rotational grazing to allow for pasture rest and recovery. Divide the pasture into smaller paddocks and rotate livestock through them. This method ensures that forage is not overgrazed, which can weaken plants and open space for weeds. Adjust stocking rates to match pasture growth.
Overseeding: In areas where desirable forage is thin, overseed with suitable species. This helps to fill in gaps, increase forage density, and reduce weed encroachment. Ensure good seed-soil contact and consider the best seeding time for the chosen species.
Monitor and Adjust: Continuously monitor the pasture's progress and adjust management practices as needed. Look out for signs of nutrient deficiencies, emerging weed issues, or overgrazing. Timely adjustments can prevent minor issues from becoming major setbacks in pasture productivity.
3. Pasture renovation
Pasture Renovation: Renovation involves a more intensive intervention than rejuvenation, often necessary when a pasture's productivity is severely compromised or the desirable forage base is minimal. This process typically includes eradicating existing vegetation and establishing a new, more productive forage system. Here's a detailed approach:
Soil Testing and Amendment: Conduct a comprehensive soil test to determine nutrient levels and pH. Apply lime to correct soil pH and fertilizers to address nutrient deficiencies.
Vegetation Removal: Remove existing vegetation to reduce competition for the new seedlings. This can be done through:
Chemical Burndown: Use systemic herbicides like glyphosate for effective weed and grass eradication.
Tillage: Plow or disk the field to physically remove existing vegetation. However, consider soil erosion risks and compaction.
Spray-Smother-Spray: This involves an initial herbicide application, followed by planting a smother crop (like sorghum or sudangrass) to suppress weed regrowth, and a final herbicide application before seeding the desired forage.
Spray-Wait-Spray: Apply a burndown herbicide, wait for weed regrowth (which indicates active weed roots for herbicide uptake), and then apply a second herbicide dose for thorough weed eradication.
Seed Selection and Planting:
Selecting Forage Species: Choose forage species and varieties that suit your soil type, climate, and grazing management. Consider a mix of grasses, legumes, and other forages for biodiversity and soil health.
Cool-season grasses, warm-season grasses, legumes, and brachias (like kale or rape) all have different growth curves and temperature tolerances. Planting these at different times throughout the year (i.e., fall legumes and brachias) maximizes forages throughout the year and can reduce the need to buy external feed.
Planting Method: Choose between no-till seeding (to minimize soil disturbance) and conventional seeding (where the soil is prepared through tillage). Ensure accurate seed placement and soil contact for optimal germination.
Fertilization: Apply starter fertilizer to provide seedlings with essential nutrients. Monitor growth and apply additional fertilizer based on soil test recommendations and plant needs.
Splitting up N application through the year and applying after a cutting or heavy grazing can encourage re-growth and maximize yields.
Weed Control: Monitor for weed emergence and manage through targeted herbicide applications. Ensure the herbicides used are safe for the young forage species.
Drone mapping is a wonderful tool for identifying weed growth. These maps can then be used for variable-rate spraying to reduce herbicide usage.
Grazing Management: Avoid grazing the new forage too early. Allow plants to establish well, usually waiting until they've reached a sufficient height (check specific guidelines for your forage species). When grazing begins, ensure it's light and doesn't stress the young plants.
Monitoring and Adjustment:
Regular Evaluation: Monitor the pasture's progress, including forage establishment, weed pressure, and soil nutrient status.
Rapid Testing: Using in-field rapid soil testing measures is a great way to speed up the decision cycle and help resolve problems before they get out of hand.
Adjustment of Practices: Be ready to adjust your management practices, such as fertilization rates, grazing intensity, or weed control methods, based on ongoing observations and soil test results.
Proper seeding is a pivotal step in pasture renovation, setting the foundation for a productive and resilient forage system. Here's how to ensure effective seeding for your renovated pasture:
Understand your needs: Consider your primary goals (e.g., grazing, hay production, soil conservation) and select seed varieties that align with those goals.
Local Adaptation: Choose seeds adapted to your local climate, soil conditions, and management practices. Local extension services can provide valuable guidance.
Diversity: Aim for a mix of grasses, legumes, and forbs. This diversity enhances pasture resilience, improves soil health, and offers balanced nutrition for grazing animals.
Legumes: Incorporate legumes like clovers (red, white) or alfalfa to fix nitrogen in the soil, reducing fertilizer needs and enhancing forage quality.
Grasses: Choose grasses that match your seasonal growth needs and soil conditions. Consider cool-season species (e.g., tall fescue, ryegrass) and warm-season species (e.g., bermudagrass) based on your geographic location.
Preparation: Ensure the seedbed is well prepared, with a firm, weed-free surface. This helps with seed-to-soil contact, a crucial factor for germination.
No-till seeding minimizes soil disturbance, preserves soil structure, and reduces erosion risk. Requires specialized no-till drills for proper seed placement.
Conventional seeding involves tillage to prepare the seedbed. It ensures a clean start but can lead to soil compaction and erosion if not managed carefully.
Seeding Rate: Adhere to the recommended seeding rate for each species. Over-seeding can lead to competition and poor establishment, while under-seeding can invite weeds.
Seeding Depth: Plant seeds at the correct depth. Small seeds (like many grasses and legumes) need shallow placement, while larger seeds can be sown deeper.
Timing: Choose the optimal time for seeding based on the species' growth cycle and your local climate. Generally, early spring or late summer or early fall are suitable times, but specific timing can vary.
Monitoring: Regularly check the field for seedling emergence, signs of pest or disease pressure, and soil moisture status.
Early Fertilization: Apply a light starter fertilizer to provide essential nutrients. Be cautious to avoid burning tender seedlings.
Documentation: Keep detailed records of seed mixtures, seeding rates, dates, and weather conditions. This information is invaluable for monitoring progress and planning future management interventions.
5. Post-Planting Management
After seeding, the focus shifts to establishing a strong stand for the new forage. This phase is critical, as the young plants are vulnerable and require careful management to ensure successful establishment and future productivity. Here’s a more detailed approach to post-planting management:
Early Growth Monitoring:
Emergence: Regularly inspect the field for seedling emergence to assess the success of germination.
Pests and diseases Watch: Keep an eye out for early signs of disease or pest activity. Quick identification and response can save a crop.
Soil Moisture: Ensure that the soil remains moist but not waterlogged to support seedling growth.
Starter Fertilizer: If not applied at planting, a starter fertilizer that's high in phosphorus can promote root development.
Nitrogen Management: Apply nitrogen carefully. While it's essential for growth, too much can harm young seedlings or promote weed competition.
Early Identification: Identify weeds early, when they're easiest to control.
Cultural Control: Use mowing or grazing to control weeds without damaging the young forage.
Herbicide Use: If necessary, apply herbicides that are labeled safe for young forage crops.
Initial Rest: Allow the forage to establish before introducing animals. This usually means waiting until plants have reached a certain height (often 6–8 inches) and have been anchored firmly.
Light Grazing: When plants are mature enough, begin with light grazing to encourage tillering and root development.
Residual Forage: Always leave enough residual plant material after grazing to support rapid regrowth.
Irrigation and Drainage:
Water Management: If irrigation is an option, use it to maintain consistent soil moisture, especially in dry spells.
Drainage: Ensure that the fields have proper drainage to prevent waterlogging, which can kill young plants.
Inoculation for Legumes:
Rhizobia Bacteria: If legumes are included in the seeding, ensure they are inoculated with the correct rhizobia bacteria to establish nitrogen-fixing nodules.
Growth Records: Document growth progress, weather conditions, and any management actions taken. This will help in making future management decisions.
Adjustment and Adaptation:
Flexibility: Be prepared to adapt your management strategy based on how the pasture is responding to current practices.
Seasonal Care: Adjust management practices seasonally. For instance, in the fall, manage grazing to leave enough plant material to protect the soil over winter.
Keep in mind that each of these management steps can be made easier through the use of drone technology. Things like yield estimation can be easily automated through drone mapping, and precise application of inputs like fertilizer and herbicide can be more easily handled with a drone. This also has the added benefit of not damaging your fresh pasture through tire compaction.