Ecological Data Associated With a Doubled Stocking Rate
Posted on: Dec 13, 2013
In a recent post (found here), we described a Wyoming ranch that had increased its stocking rate by 95%. Such an increase in stocking rate represents a major increase in revenue with minimal changes in cost structure. This ranch has increased both ecological and financial value, as well as an internal rate of return much higher than what its owners anticipated.
Managers of this ranch greatly altered their grazing strategy to produce this improvement. Several tactics were followed, including the following:
- Grazing durations were shortened. In the growing season, cattle are rarely left in a pasture for longer than 10 days.
- Stock densities were increased. Stock densities are two to four times as high (depending on the pasture) than they were historically.
- Recovery periods between grazings were lengthened. In the growing season, forage plants are often allowed a lengthy recovery period between grazing events.
- Timing of grazings was altered. The time of year in which cattle are placed in a pasture is carefully planned and altered year over year.
Such a grazing strategy allowed the strong improvement in rangeland health that led to a near doubling of the stocking rate. What changes were seen on the land in the process?
One of the first changes observed was a reduction in bare ground and a corresponding increase in live plant cover. Simply put, pastures had fewer bare spots on the land that were producing nothing, and those bare spots were filled in with grass. This means the productive capacity of the soil increased. Data from one pasture may be seen below:
This table shows the relationship among bare ground, litter cover (old plant material lying on the soil surface) and live plant cover. In arid western rangelands, bare ground can be highly undesirable, for nothing grows there, and erosion is possible. As can be seen in the data table, this ranch slowly reduced the amount of bare ground since 2003, with the major exception being the dry year of 2006. Simultaneously, the percent live cover (that portion of the soil surface covered by living plants) climbed greatly. These data display strong improvements in rangeland health.
Further, plant production in the pasture also greatly increased. With new plants growing on the soil surface, more production was expected. The data table below shows the strong improvement in production.
As may be seen in this data set, production, as measured in pounds per acre, more than tripled since the site was first visited in 2003 (2006 was a dry year). Such an increase in production has strong implications for rangeland health, wildlife habitat, and revenue. This is what allowed the large increase in stocking rate to occur.
But room for improvement still exists here. Species composition appears to be shifting favorably toward higher-producing perennial grasses. This suggests that additional gains in live plant cover and production are possible on this ranch. In time, stocking rate and its associated revenue may increase on this ranch further with continued positive changes.