字幕列表 影片播放 列印英文字幕 (Dr. Jaradat) We live in a world of salt, but we do not recognize it. (Dr. Cihacek) Once it's salinated, you got a problem. (Dr. Hopkins) One of the points that many, many farmers have said is that they're seeing salts in places that they'd never witnessed problems before. (Harold Steppuhn) If I'm a producer and on my ground, I've got a problem with it-- it's not overblown-- that's my livelihood off that land. Funding for "Salt of the Earth" is made possible by an EPA Section 319 grant administered by the North Dakota Department of Health. the Eastern North Dakota Resource Conservation and Development Councils, with support provided by the... ...helping people help the land, and by the members of Prairie Public. It's a waste of fertilizer, seed, and your time and effort on it. It went from, I would say 5% to 10% of the farm acres being affected by salinity to up to 40% to 50%. Salinity isn't a new problem, it's a worldwide problem (Matt Olien, narrator) If you've driven by farm fields in the Upper Great Plains, you've no doubt noticed patches of white, chalky soil, usually near roads and ditches, that just doesn't seem to belong, and doesn't seem to go away. Farmers wish it would. It's soil salinity, too much salt in the soil, and it can prove nearly impossible to grow a productive crop in those areas. Overall reduced soil health, so compaction issues, reduced biological activity. You don't have as good of soil to till. It's harder to work the soil. A lot of that depends on your strategies you're using for management-- if you're using conventional tillage or no till or strip till. But it really depends on the producer and what they're willing to try. In my area I would say over 95% of my fields have salinity, and 80% of them have visible white spots that are well in excess of this. All of my producers are very concerned about it and are actively looking for answers and trying new things and trying to seed some cover crops, trying some crop rotations, trying some limited drainage when they can get the permission. So the producer is going to try to pick the crop that gives him the best option and economic return. (narrator) Excess Salinity is caused generally by too wet of conditions resulting in a high water table. Most agree the problem in the Upper Great Plains got worse around 1993 when the dry cycle converted to a wet cycle and has never left. But the problem has been around for centuries. (Dr. Jaradat) The land in Mesopotamia is very flat, and irrigating that land created problems in addition to the high temperature and high evaporation from the irrigated water. Salts became concentrated, and the irrigation water coming from the twin rivers, the Tigris and Euphrates, enriched that salt in the Mesopotamia plain, and in less than 1500 years, the problems started showing up to the point that most fertile parts of lower Mesopotamia turned into white crusts. People went hungry, and cities and the empires themselves crumbled because of the loss of their wealth. (Dr. Cihacek) This is a geologic process so it's been going on for a long period of time. We've got relatively young glacial soil. A lot of our soils were pushed in here by the glaciers, spread out on the landscape. So as these salts weather-- they're young materials; there's a lot of things to weather in there. They dissolve and go into the water. Then wherever the water goes, they carry these salt minerals. (Dr. Abdullah) Although it is a problem here, but it's no comparison to the salinity problem in other parts of the world. Just to give you an example-- California, the Joaquin Valley and the Salton Sea. The problems there are much bigger. The world is losing approximately a million hectares a year to salinity, and there are 200 million hectares of saline land which is not producing up to its productive capacity. There are issues in the Nile Delta especially after the construction of the Aswan Dam. After the construction of the dam, this kind of natural remedy, so to speak, of soil fertility and handling salinity stopped abruptly. Based on that, in fact, major health problems were created. (narrator) In our region, the topography of the land has lent itself to salinity problems, forcing many farmers to move this land to the Conservation Reserve Program. When the glaciers came through here, they ground up to pure shale, and most of the salinity that is in our soil originated from the pure shale formation in Eastern North Dakota at least. We were just looking in our training yesterday at a soil survey that was completed in Stutsman County back in the '80's before the wet cycle really started. There was only, I think, about 10 acres of a whole quarter section that was mapped saline. I believe that there's no question but that some of the salinity that we're seeing and the degree and the nature of the salinity, it's a function of what we're doing with water. It's linked to the Red River Valley floods. It's linked to overland flow. So consequently what that means is, is that there's simply more water on the landscape. More water either runs off the landscape. More water resides within the landscape, and there's less water that is moved back up through evapotranspiration. It's roughly 10.8 deciSiemens per meter. And in this type of sampling, it'll show less salts 'cause we have a higher concentration of water with this soil, but that would easily equate to 25 deciSiemens on the other methods, and that is restrictive to almost all plant growth. (narrator) Salinity can be invisible or visible. Either way, it is affecting the bottom line and livelihood of producers all over the Upper Great Plains. Joleen Hadrich with North Dakota State University has researched the economic impact of salinity. What we know is that their yield is going to decrease, and that, of course, is going to relate into lower revenues and a lower profit level. Slightly saline would result in about a 15% yield loss. The moderate would be 50% yield loss. When I applied the average crop prices that we're receiving right now in those yield decreases, it resulted in $150 million decrease in revenue. (Bill Schuh) I think it's first and foremost a crop problem and secondly an economic problem. The loss of crop yields from salinization of the soil is a very, very major economic loss for our state. (Joe Breker) I did a recent poll with our group, our corn growers group, and it was fairly common to have producers from all over the state that are in the corn growers that had from 10% to 15% of their farms severely impacted by salinity. In terms of an overall problem, we could say that the agricultural land in Canada, about 1/3 includes salt-affected soils. If I'm a producer, I will try to minimize that-- any kind of problems that relate to salinity-- primarily because my assessed lands, the assessments, will decrease if my lands are identified as salinized. When we get to an EC of about 8 which is moderately saline, we have at least 50% reduction in yields on wheat. You can have 75% yield loss on corn, and soybeans, you might as well forget it because we're down to maybe 10% or not even worth harvesting. Basically it's an osmotic problem. If you get too much salt on the outside, you have too much osmotic suction on the outside, it competes with the electrolyte in the plant, and the plant reaches a point where it can't imbibe water properly, and you start getting yield reductions. (narrator) Another fear is what has happened in other parts of the world.-- health issues, food supply issues and water quality issues. We constantly review the best available science from EPA and their contractors that they work with--universities that develop the best toxicological information that's available to date, and we incorporate those. If it's something immediate, we do it right away in our water quality standard. (Bill Schuh) I don't think that on the basis of current EPA and CDC documents we can conclude that sulphate is particularly damaging to water quality. As far as drinking water quality is concerned, people drink water that have a lot of salts in them. There's a very wide range of qualities in the waters that people drink and are capable of drinking. Right here in this area of the field--this is one of the more obvious places that you'll see salt. The obvious effects of the salt is this white crusting. I see too many guys trying to manage their salinity. They put some into CRP, but they don't go far enough, and then that salinity just continues to move out, and then they're mad because they don't have an impact, and it's just making it worse and worse. (narrator) And as you'll see next, the solutions farmers come up with can mean the difference between lost revenue and successful yields. Good management practices for salinity would include definitely CRP, understanding that, the variable rate and site specific technologies is the biggest one that I'm involved with. (David Burkland) Actually in Grand Forks County here, the level of salinity is one of the higher levels in the Red River Valley so we've tried a lot of different things. We have put some land into CRP, but we've done other things too to try to overcome the saline conditions--just crop choice is a big factor, picking the right crops. Picking crops that are tolerant to saline conditions is real important. (Shawn Kasprick) On the precision ag side of things, we got different site-specific products and services that we can provide that will give the growers a handle on where their salinity is, what impact it has on their crop, and how far out that impact really is effecting their crop. That all will wrap up eventually into a variable rate application for fertility and eventually the grower's bottom line. (Joe Michels) It takes a little while to get established. It did the job for me. We have had salinity issues. There's one hayfield we got from a fella that got sick. He told the landlord that he wanted to rent it to my dad back in the early 70's. We took it over; the ground was white. It would grow foxtail, kochia, and not too good at that. Then the garrison seemed to help. It took a long time to establish, but it is very thick. We got a good root structure where Dad could drive across there with a swather in the water and not get stuck. (Dr. Cihacek) Cover crops, especially deep-rooted cover crops, can have an effect on lowering the water table in an area. My favorite crop to lower water tables is alfalfa which is a perennial, permanent cover type crop. Alfalfa is very, very deep-rooted. (Hal Weiser) Out in Montana, they've really had a lot of success in addressing saline seeps and addressing how to correct those situations. One thing that's happened- there's been a shift in the western part of the state to no till so they've gotten a lot more efficient at water. A couple of years ago in 2008, we did a special initiative through the Equip Program which allowed us to provide cost share to producers that were having issues with salinity, and that was specifically on saline seeps. What they wanna see is which direction the groundwater is flowing when they start testing this, and then they wanna see the levels of the water.