Sporobolus indicus mitigation in Texas pastures

This is not a scientific study.  This is an observation of what happened during a 1.5 year timeframe on my pasture when compared with that of my neighbors across the road.

Like our neighbor's pasture, our pastures were overrun with small smutgrass with some bahaia and weeds mixed in.  Suggestions were made to mitigate the smutgrass with poison and mechanical removal.  Both options were not attractive.  I had pretty much decided that I would use animals and heavy rotational grazing in an attempt to reduce the selective feeding habits in a continuous grazing system, thereby giving the other grasses in the pasture a fair shake.

Various circumstances, some out of our control, prevented us from following through with the rotational grazing plans.

Half of 2010 and most of 2011 brought drought to the Texas landscape.  Basically, nothing green grew in the middle of Summer 2011.  Some referred to it as a second winter due to the lack of forage even though temperatures soared above 100 degF for weeks in a row.  Ponds that had never run dry dried out.  People were feeding hay in the middle of summer cut from the previous year just to keep their animals alive.  Cows were skinny.  Wildfires were consuming much of the parched landscape.  Things were bleak.

We did not renew the lease for grazing in November, and the few cows that were trying to scratch out an existence on our pasture were moved off.  By the time we moved the cows off, they had basically eaten everything in the pasture but the dirt, including the smutgrass which they normally won't touch. For some dumb reason I decided to plant some oak trees (still alive today) in the middle of this drought. I fenced them well to protect them from the cows, and they still managed to strip every leaf off of them because they were so hungry (starving). Cows normally don't eat oak tree leaves because of the tannins in them.

During the winter of 2011 we started to get some rain.  My family decided to put 1 ton per acre of lime out on the pastures as prescribed by the soil lab following some sampling that I had done earlier in the year.  At the time we put the lime out the pH in our pastures was ~5 to 5.5 - very acid.  This is great for growing blueberries, but we wanted to grow clover, and for that the pH needs to be closer to the 6.5 to 7 range.  We waited for more rain.

Fortunately through the winter and into spring we got more rain, and the drought was lifted.  Nothing was planted.  We got a very heavy crop of wild winter ryegrass over a good-size portion of the front pasture, and weeds and wildflowers over the rest.  No cows allowed the forage to come in full and go to seed.

Spring came and went.  Our pastures are now covered with bahaia, and no smutgrass.  Our neighbors pasture is covered in smutgrass and no bahaia.

The 2 pastures (ours and neighbors) were subject to the same weather conditions over a 2 year period.  The only differentiating factors were:

- heavy grazing load on our pastures from the beginning of drought until November 2011 (neighbor only had a few horses and a donkey)
- no animals from November 2011 on our pastures (neighbor continued to keep a few horses and a donkey on his)
- we put lime out, 1-ton per acre which should have raised the pH to ~6 to 6.5 (we haven't tested), neighbor did not

I'll leave it for you to make your own conclusions as to why there isn't any smutgrass on our pasture.