b"ROUNDTABLEThe SWAT MAPS truck used by Wes Anderson to do the field surveys to make a SWAT MAP. PHOTO: CROPTIMISTICFor example, this past year in northern Alberta,in a lot of fields would be really the ability to in- even the place that it was in the field, production we were extremely wet. And so, zone one, typicallyterpret and predict better nutrient availability andis going with that as well. It's great to see that the driest zone, rarely the highest yielding, wasmineralization, and therefore nutrient response infarmers are taking this stuff seriously and doing a actually the highest yielding zone in the bulk ofdifferent parts of the field.good job of mitigating it in the future. my clients fields. Whereas zone 10, actually zoneIn this part of the world here, we get these seven through 10 were completely flooded out.high organic matter depressions that can supply aSS: Do you need to get the SWAT MAPS Traditionally, zone seven and eight would actuallylot of nutrients, and in particular nitrogen. They'reof your fields redone every so many be a really high yielding zone. Again, it does reallyjust always mineralizing a lot of nutrients, andyears?depend on the area, depends on the rainfall,we can actually afford to cut back even thoughWA: You shouldn't need to would be my typical depends on the field and depends on the factorsthey still have really good deal potential. You don'tanswer. SWAT MAPS are based on really stable affecting yield. need to really put on a lot of fertilizer in thoseattributes of the soil. Unless there has been a lot places. of drainage ditches done, earthmoving, that sort EM: I think it comes down to not all zone onesof thing, physically changing the landscape, there are created equal. If it's a field that's had aEM: This is just an example of about a one-acreshouldn't really be any need to remap a field. particularly hard time with erosion, even on asection of land here, I think this was bean stubbleCrop Pro Consulting has been utilizing SWAT wet year, and I've seen it on irrigated fields even,actually. This is a photo from a 3D model capturedMAPS for I think well over 10 years in Saskatche-there's differences in those zone ones to the lowerwith a drone. There are about 50 tons of topsoilwan at least. A lot of those fields, we're still using areas. Like the areas that just have that thin layerloss on that one-acre section of land with that rillthe same SWAT MAP today, and it still reflects the of topsoil and not a whole lot of ability to holdand gully erosion, which in the springtime aftersoil variability in the field. on to any nutrients or moisture, they do seem tothe snowmelt here, is not totally uncommon. struggle a little bit more.If there were no erosion going forward, it wouldEM: That's kind of what I expect around here, I think in some cases, we need to considertake nearly 20 years to get that topsoil back, justtoo. Those soil properties aren't changing, so things like that. In some places you already seeto give you an idea how long it does take to getwe wouldn't need to make a new SWAT MAP. The it. Where knolls or high sloped areas that wereit back, and that's probably an optimistic lookstrategy is to have your SWAT MAP done. Then almost scalped of topsoil, they're just not plantedat it. I've heard other views say it takes 100 tonormally around here the process is, if someone anymore. I think there's potential there to look at500 years to grow an inch of topsoil. And then indoes do soil sampling, usually it's in the year doing things like using soil building crops in thoseaddition to that, scientists from the University ofbefore potatoes. So, then you keep doing your areas. Wisconsin saying that fertilizer value in a ton ofsoil sampling, and you can use your SWAT MAP to topsoil is about $13 a tonne.target your prescriptions to be more accurate.SS: How can you use the data SWATWe often think of soil erosion as an environ- For more information on SWAT MAPS visit MAPS provides to improve soil quality? mental issue, but really, it's an economic issueSpudSmart.com and watch our latest webinar WA: The real power and value behind SWAT MAPStoo. And with soil leaving the field or leavingabout it. 60 SPUDSMART.COM WINTER 2021"