Perennial Grasslands in Peril
Grasslands are a globally imperiled biome. Known as steppes, prairies, savannas, and rangelands these perennial grass-dominated landforms cover nearly 30 percent of the land area of the planet. Grasses of the family Poaceae evolved over millions of years where our ancestors hunted endemic grassland wildlife. Gone are the nomadic lifestyles of hunters and herders replaced by agrarian cropping systems. Agriculture began in fertile river valleys where sediment and organic matter deposition by annual flooding resulted in deep soils well suited to cropping. From simple agricultural beginnings we have subsequently industrialized and converted much of the world’s grassland and good soil into crop production.
Soil fertility was derived initially from organic matter decay. With the rise of industrial agriculture, soil fertility has been increasingly provided by petrochemical nitrogen addition. Soils unsuited to cropping due to steepness, rock content or low fertility were left as grazing lands. Perennial grasslands historically grew each year from the same root stock that converted atmospheric carbon dioxide into soil organic matter through photosynthesis, while native plants fixed atmospheric nitrogen for plant growth in a stable cycle where unused biomass decayed and was recycled back to soil organic matter. Decaying soil organic matter resulted in release of organic acids which further aided soil fertility by dissolving trace micronutrients from the mineral soil, further fueling grassland growth. Soil impairment began with losses of organic matter. Nutrient losses followed. Since weeds thrive in nutrient-poor and disturbed soil, the stage was set for explosive growth.
Fast forward to today, formerly healthy rangeland soils and perennial grasslands have lost species richness, have lost soil organic carbon, have lost fertility, have lost infiltration capacity, have lost productivity for grazing and have become invaded by early successional (i.e. weedy) plant species. In parallel with degradation of these formerly rich grasslands, the arid western United States has become fire prone. More than 100 million acres (156,000 square miles) of western rangeland may be affected. Collectively this area of degraded grassland is larger than the State of Montana (147,000 square miles) and declining further in health every year as rangeland fires increase in frequency and intensity. Without intervention to reverse the decline of grasslands our wildlife and watersheds will only be a memory. Ranching will become ever more unprofitable. Endangered species will become even more imperiled. Economic losses will stretch into untold billions, undermining the stability of rural communities.
Replacing Lost Soil Nutrients
Recognizing that healthy grasslands do still exist, what is it about the resiliency of these systems that allow desirable perennial vegetation to thrive? These ‘old growth’ grasslands are unique in their ability to retard invasion by weeds. Healthy soil is their strength. Abundant organic matter is critical. Edaphix’s technologies are built on these observations and employ novel low-nitrogen formulations of plant nutrients designed to mimic the soil chemistry of healthy soil.
In healthy grassland soil organic matter is degraded by microbes leading to the release of dissolved organic carbon and organic acids that fuel biogeochemical edaphic processes. Natural soil-building commonly requires hundreds or even thousands of years to build an inch of organic soil while companion plant community succession requires similarly long periods of time. These late successional plant communities that are dominated by perennial vegetation are dependent on the supporting soil solution chemistry laden with dissolved organic carbon as well as micronutrients dissolved from solid minerals found in the soil.
The robust growth of perennial plant life is made possible by Edaphix treatment to replace lost soil nutrients, particularly micronutrients. Symbiotic rhizosphere interactions of soil fungi and root exudates follow where plants exchange sugars created by photosynthesis in the leaves for plant nutrients mobilized by microorganisms in the roots. The edaphic engine for accumulation of soil organic matter is restarted and plant community characteristics rapidly change to being perennial plant dominated.
What are the Benefits?
Abiotic soil conditions are also improved by increased infiltration, improved soil aggregation, reduced runoff and improved forage quality. Development of deep and long-lived roots by perennial vegetation also capture atmospheric carbon that ultimately decays and becomes the future source of nutrients for subsequent generations of plant life. Micronutrients are taken up by plants resulting in improved forage mineral content as well as improved plant physiological function. Rangeland flammability is reduced because plants stay greener later in the season and because annual grass cover decreases over time as perennial grasses occupy a greater percentage of the plant community composition. Rangeland species diversity is also improved as the near-monoculture of annual grasses is reduced, leaving openings for native forbs and important pollinator species.
There are 100 million acres of unhealthy rangeland affected by annual grasses, 30 million acres of turf grasses invaded by broadleaf weeds, and additional hundreds of millions of acres of pasture and cropland imperiled by invasive plants. The global need for innovation is compelling. New technologies that reduce the use of herbicide, increase the capture of soil carbon, improve soil health and are healthy for the planet are critically needed. Edaphix is committed to developing those innovations that result in nutrient-dense soil where weeds struggle and desirable species thrive. We have a robust start on that journey measured by a family of patented innovations, a breakthrough product release and many on-going research efforts.