Agriculture question about corn and crop rotation.?

Question

If the USA were to use massive acreage for corn production for ethanol, would there be a problem of depleting nutrients from the soil? Is corn a crop known for depleting nutrients? Can crop rotation correct any such problem?

Are there water sources available to irrigate barren land to produce massive amounts of corn for ethanol?

Does anyone know of any books or articles I can use as a source?

Answer 1

Ethanol has not been a very good answer to fuel problems. There are sustainable and low input ways to grow corn or other oil crops but production would never be close to demand. Look at articles about sustainable agriculture related to corn. It is lower on the scale of actual power production per gallon and seems to have a short shelf life for fuel use. One might do a bit better making biodiesel and then possibly using waste from that with other corn product to make some ethanol and then turn that over to make some methane which should exhaust it fairly completely and give a decent compost. That compost could enrich some land and if combined with milk cow dairy production and an overage of manure which has to be carefully spread out to avoid pollution issues (laws enacted in most places determine how much and where) one could, with proper management, keep some decent production levels. It might even be possible to reclaim some low production areas. Problems are that some of the fuel needs to be diverted to irrigation. Pumps take a lot of power. That causes some loss in production. Equipment needs to be powered also and processing has some power requirements. All means some losses right off the top. There is, and I use the contemporary phrase, no way in h**l we could ever produce the amount of fuel we need at the level that we consume it. It is just a feeble attempt to help some. We need to slash our use and work on technology to free us from burning any and all fuel. If I remember correctly, and I may be wrong, but the sun puts out 1000KW/ hours per square foot of this planet. I would think that putting that to work, especially in areas that are not farmable is to our benefit. Even the cheesy technology we have for solar panels is actually HUGE given that they harvest such a small amount of the actual energy that the earth receives. Technology for solar panels is simple enough that any person with basic high school education could easily produce their own panels. As we learn more about conversion of sun to a usable energy, it becomes better and better. That is, in my mind, money and effort well spent. Consider how the environment would improve if we stopped burning things and releasing all that carbon back into the air. We keep that up at the rates we are doing and we won't have clear enough air or a stable enough climate to worry about solar power. For all the great things the couple/ few leading countries have done over the years, and given that we are attemping to fix some of the environmental issues we have been causing, other less fortunate countries are swelling in populations and economies and they have absolutly no reason to give up their fuel and burning ways on their way to that comfotable life many of us take for granted. They will, and have a right to (in their own minds and thats what matters)(to them) burn all the fuel they want to be warm and mobile and happy just as everyone else has all these years. Corn won't help them either and we need to figure out this impass that will loom up ahead. Like here, there isn't enough water resources and energy to move the water we/ they have around to do the work of growing all our foods, let alone fuel. The short answer? We need to replace fuel and do without it, solar is the real answer. All the technology is available in trade patents, and it is free info and free to use as long as one doesn't make profit on it. Be it making fuel or harvesting the sun, it's all there.

Answer 2

Well, let me keep it brief.

Yes corn do deplete nutrients. Only crop rotation may not solve the problem and is needed to adopt few more things like application of compost, soil nutrients etc to maintain soil fertility.

Regarding barren land, I dont think it would be a great idea to cultivate corn for the simple reason of nutrient availability. Initially, for 1-2 years you can get good yield of corn but then it is going to be a difficult task to meet CB ratio. If u really need to do something in barren land for biofuel then I would like to suggest for Jetropha cultivation (I dont know whether it could be grown in US) or other energy crops like sweet sorghum for example.

Answer 3

Most of the time USA has water escaping down many rivers which could be reclaimed for irrigation, and there is the option of storing water from periods of  high flow.

Corn is a very heavy feeder, demanding a lot of plant nutrients. Corn with adequate moisture will even more rapidly deplete the soil. In drought conditions corn will not deplete so much, and will not produce much.

Most farmers add plant nutrients as needed to replace the nutrients removed by the corn.

Crop rotation will not assure that there will be enough of any given nutrient. But some crops will ensure there will not be enough of certain nutrients. Some farmers have used plow down crops of clover to get more nutrients available for corn. This works, even though not enough to avoid applying extra fertilizer if one wants maximum production.

However, in most cases, corn would not be the best crop for ethanol production. We have taken to using corn only because we have had major surpluses of corn and a price support system that made it likely we would continue to have such surplus corn.

Answer 4

Only around 3% of the U.S.'s current field corn crop is being used for ethanol.  I just wanted to point that out first before I get started with the rest of my answer.  Everything gets blown out of proportion when corn and ethanol are mentioned.  In fact, farmers are still being given subsidies for doing nothing with certain acres of their farmland.  Let's not forget that either.  And, most farmers will alternate their corn acres.  One year, they'll grow soybeans, or another nitrogen producing crop, then they'll plant corn the following year.  In the meantime, they're planting corn on the land that their soybeans (or other crop) were on last year.  So they are employing crop rotation.  Agribusiness and agriscience have become huge, so I'm quite sure farmers are doing all they can to produce maximum yield on minimum ground with minimum materials.

There's lots of irrigation methods available for watering corn in the corn belt (the Mississippi and all of its tribuitories).  

As for books, I just recommend going to the library and finding textbooks on straight ethanol production or corn growing.  There have been so many debates about this, that it would be hard to find straight facts in any magazine articles or journals that isn't biased one way or the other.