Tuesday, January 28, 2014

A Discussion about Soil Compaction, Brought to Us by RICl Attorney at the ICC



Below is another excerpt from the ICC testimonies regarding to the Rock Island Clean Line.  Dr. Paul Marshall gives testimony as an attorney questions him about modern farming practices and soil management practices. In reading this cross examination, it’s difficult to tell if this attorney is RICL’s lawyer or a lawyer for the opposition.  It’s actually RICL’s attorney, but he actually did a great job assisting Dr. Marshall explain the problems of soil compaction and the economic feasibility of some natural and passive options. 




Q.  What crops do you typically grow on your Serena Township property?
A. It's a very complicated rotation system. Half of the farm is corn, the other half is soybeans.

Q. But -- all right. So corn and soybeans. And do you sell your crops to a particular buyer, like Carpal or ADM?
A. That's part of the marketing plan, we go where the best prices are. And yes, we have sold grain to both of those. GrainCo Farmers Supply in Serena is another close-by outlet for our grain.

LATER

Q. All right. Now you state in the first part of the response to A, let me read this: "The length of time that soil compaction can affect crop growth will depend on a number of factors, including the depth of the initial compaction, soil types, soil moisture content, the effectiveness of mitigation efforts, farm tillage practices, types of vegetation, and depth of frost. In so far as the request pertains to the instances in prior written testimony, the effects could last less than one year, or greater than a decade." Correct?
A. Correct.

Q. You also go on to state in this response, quote: "Plants with deep fibrous root systems such as alfalfa will penetrate compacted soils to some extend, and will ameliorate compaction issues faster than the root systems of more shallow rooted species, such as corn. However, it may not be economically feasible to plant deeply rooted plant species in compacted areas." Is that correct?
A. Correct.

Q. Can you explain what you mean by, or what you meant in this response by: "It may not be economically feasible to plant deeply rooted species in compacted areas?"
A. There's a growing trend to using cover crops between major production, major crops, and this could be in the form of dry grass or hydro branches or other things that would add organic matter to the soil and penetrate deeply, but those are, are tilled under and not harvested, they have no economic value other than helping the soil. We don't make any money, we spend a little money on that to do that.  Soybeans are somewhat deeply rooted, but we can't continually grow just soybeans, we use a year-to-year crop rotation. I'm trying to think of the deeply rooted species that would do what, what we need done to break up deep compaction that would actually be worth a lot in an agricultural market, and other than, other than possibly wheat, or I mentioned alfalfa before, neither one of them would, would work particularly well in our particular farm situation.

Q. You used the term "cover crops." Can you explain for the record what a cover crop is?
A. We planted corn in, in late April, harvested in October. We may follow that with a, a cover crop of some species that will hold the soil in place to prevent wind and water erosion, add organic matter and put roots down deeply to break up compaction. They grow through the fall, tilled under in the spring, we start the cycle over, production, production of crop.

Q. Is a cover crop a crop in lieu of or instead of or during a time period when you would otherwise be planting a more profitable crop --
A. No.

Q. -- like corn and soybeans?
A. No, it's planted in between crop seasons, mostly, as I say, to hold the soil in place and to sink down deep roots.

Q. And can you explain again why it would not be economically feasible to plant these cover crops, given that as I understand your last answer, they're planted at a time when marketable crops would not, would not be planted?
A. If, if we had a strong need for a cover crop -- we don't use cover crops on our, on our farm. We haven't identified a need for them yet to justify spending money to make more passes over the ground and to plant these. We don't get the benefit back from making the economic expenditure, so on my farm in particular and what I was concerned about here, it doesn't provide any revenue, and the benefits that we get would not be worth the cost. So it's uneconomical.

Q. And why are you concerned about reducing the number of passes over your land?
A. Well, every, every point of pressure on the soil results in some compaction. Walking across the ground does surface compaction. Driving a 70,000 pound fully loaded concrete truck would provide a lot of compaction.

Q. And driving some of the large farm equipment that's used on your property also potentially causes compaction.
A. It certainly does, and that's one of the reasons that things like cover crops are becoming somewhat popular, because farm equipment has gotten to a size that compaction is a significant issue.

Q. Do you consider the use of cover crops a good farming practice?
A. Where needed, yes.

Q. Do you consider it a good soil conservation practice?
A. When -- when they do what they're supposed to do, yes, it would be.

Q. You also indicated in the response to Staff Data Request RJZ 1.3 that: "Freezing and thawing cycles will also work to alleviate soil compaction, but again, these cycles are moderated by winter temperature, depth of snow cover, and other factors which change annually." Is that correct?
A. Correct.

Q. And can you explain for us how freezing and thawing cycles work to alleviate soil compaction?
A. Well, it's expansion and contraction.  Freezing actually causes the soil, frozen soil to expand. Thawing shrinks it back down. And that movement of the soil, freezing and thawing, actually does put pour space back into the soil. But it's limited by the depth of the frost, it's varied in temperatures, and the timing.

No comments:

Post a Comment