b Watching the grass grow

Notes from Windward: #71



 

Watching the grass grow



Andrew:

     I agree with Lindsay's post of a few days ago that, as summer hits a peak, there seems very little time for sitting down and writing for the notes. The days are so long and there's so much to do! Now that things have settled down a bit, I am here to revisit the last few months of summer.

     One thing which is constantly on my mind is the grass. Watching how the sheep eat it. How it responds and recovers. Observing the life cycle of each species. Seeing what time of year each tends to go to seed. How and when it dies back. What species persist and come back the next year.

     Understanding the answers (and more) to these questions for our land is an essential step forward in deriving the greatest benefits from a grazing system.

     Last year I seeded some newly cleared and fenced in areas with various types of native grass and purchased legumes. It has been encouraging to see what worked and what did not. what species have germinated and survived, and where they did so. Much of my seeding met with little success, but those plants which survived give me a clue into how I should proceed.

a legume I seeded in a summer pasture. It looks like yellow clover, but I did not seed clover!
  

     I also attended a forestry field day for timberland and rangeland owners a few months ago. I spent a good deal of my time picking the brain of an WSU extension officer for rangeland management and livestock. He has many years more practical experience in the kinds of conditions which I am trying to establish pasture.

     As his insights melded with my observations of my plantings from last year, it became clearer as to how to proceed this coming year. The biggest and newest challenge in creating pasture on our land is that, it is primarily forested. Establishing grass in a hilly forest is not as simple as doing it on a relatively flat open area. There are a few technical details to consider.

     Some of the biggest points that I feel bear explicit documentation for the notes include:

1.      The addition of 1% of biomass doubles soils water holding capacity.

     One pound of biomass can hold four pounds of water. Soil is base of everything. The better the soil the more productive a pasture can be. Luckily there are varieties of perennial grass which can get established in hash conditions and build soil cover and biomass over the course of grazing. Healthy soil is living soil, and building some degree of it is a necessary first step to success.

mostly invasive grasses growing in our "courtyard" area this spring. the good quality soil allows for a stupendous amount of growth even for these short lived annual plants
  

2.      Native perennial grass species should be the backbone of grazing.

      These species provide a variety of benefits to pasture, and if managed properly can allow us to extend our grazing season well into the winter. Perennial grasses generally invest more energy in there roots. Many have roots that reach 10 feet in appropriate conditions. This ensures they have access to subsurface water into the dry season.

     These massive root structures are also "pruned" in the course of grazing, charging the soil with biomass and providing food for soil biota. Some Perennial species also retain a high level of nutritional value in their foliage as they go dormant. This means that dormant pasture can be grazed into the winter time, with little to no affect on the health of the plant. Once established, many perennials also have the capacity to produce a great deal of seed each year which will tend to stay on the ends of the stalk through the winter, providing energy and protein to supplement the dormant foliage.

tall fescue is a perennial grass. these mature plants have grown to over 3 feet this season
  

3.      Healthy natural prairies are a mixture (in order of percent composition) of perennial bunch grass, perennial/annual sod-forming grass, legumes, forbs (mostly Asters).

     In terms of nutrition, grass comprises the basis for energy. Bunch grasses tend to grow tall and make use of vertical space, making them more productive than short grasses. Sod forming grasses may not get as tall, and their roots do not penetrate as deep, but the fill in the spaces between the bunch grasses and hold soil in place. Legumes provide protein and additional soil nitrogen, while broad leafed herbs accumulate trace minerals from the soil. All of these components work together in a natural prairie to provide a well rounded diet for ungulates.

a native legume, Nevada Birds-foot Trefoil
  

4.      Poor productivity is most commonly caused by a lack of management.

     Continuous open grazing on an area will very quickly kill perennial species. Leaving ever more poorly performing species that can resist the grazing pressure. This include most of the stubby, short lived grasses we have growing throughout our main living space. This is the area sheep have been allowed access through the spring and early summer. Without back-fencing animals out of a recently grazed area, they will tend to continue to graze the new growth of the grazed plants. This will readily kill all but the hardiest or unpalatable plants.

5.      Grazing a high density of animals for a short period of time is more natural (and healthier for prairie) than continuous grazing.

     This means, the plants are adapted to being grazed intensively for a short period of time, and then having adequate time (3-4 weeks) to recover.

6.      The more light that comes through the tree canopy, the more energy the plants will have.

     While more canopy cover can increase water rentenion, and provide an annual layer of mulch to build and shade soil. Finding the appropriate balance is important for maintaining a high level of productivity. This is particularly true for us because much of our potential grazing areas are forested to some degree.

dense canopy cover, with very little understory growth
  

7.      Grass and legumes require contact with bare mineral soil to germinate and take root. In a forest setting with a dense layer of leaf mulch, this means scraping the litter aside when planting, and covering the seeds with a light mulch to keep them moist. After the grass is taller than the mulch, it can be moved back into place to preserve soil moisture.

     With these things in mind, I move into the grass seed harvesting season in search of the best species which I have been observing throughout the year.





Notes From Windward - Index - Vol. 71