August is the time to begin to plan for the end of the grazing season, especially if you are hoping to do some pasture improvement. If you plan to seed some new ground to expand your system, getting the seeding in by the end of August is recommended to reduce competition from weeds and allow the plants to establish a good root system before winter.
If you're not planning a new seeding, but want to interseed new plants into your pasture, August is also the time to do that. Be sure to graze the pastures a bit tighter than you normally would (think "overgrazing"), to reduce competition from the existing sward, and then a no-till seeding is the best strategy. Broadcasting seed is usually not as effective because there needs to be good seed to soil contact.
Grass seed in particular is a challenge, because the seed is so light it doesn't drop down through the sward, or it blows away. If broadcasting is your only option, put the animals on the area and they will push some of the seed into the soil, especially the seed that wouldn't have made it there otherwise.
If you think you want to stockpile some pasture and extend the grazing season, August is the time to start setting aside paddocks or fields to accumulate dry matter. Keep in mind that many species will decline in quality over time, so this may not be an appropriate strategy for lactating dairy cows. However, beef cattle and sheep do quite well on stockpiled forage, and it can reduce the number of days you need to feed hay through the winter.
Last but not least, clipping the weeds that have grown up along your electric fencelines is something to do in August if you haven't already. By now, most weeds have reached maturity (and unfortunately, many have probably set seed), and they could be adding a load onto the fence. This will reduce the amount of charge on the fence, and reduce the effectiveness of the shock. It's also one less thing to worry about in the spring.
The GLCI Grazette is a monthly e-newsletter by the New York NRCS and Grazing Lands Conservation Initiative. To get a free subscribtion simply send an email to email@example.com.