b'ROUNDTABLEOne concern growers have voiced about potato yield monitors is the accuracy of the data, particu-larly in heavy or wet soils. On sandy soils potatoes can be very clean when harvested. In heavy soils, wet conditions, or when a field has many rocks or clods, the potato stream is not as clean. Menkveld says in his experience growers harvesting in heavy or wet soils, or fields with rocks or clods, still want yield maps, as they provide them with data they would not otherwise have. The point of a yield monitor is not only to measure weight pound for pound, but to measure relative differences and variabilities across a field, he says. Even without post-season adjustments to account for debris, those results are useful. He also points out harvesters today have greater separation capacity. Paget agrees. I am not going for the actual weights Im putting into storage. Im looking for variabilities in the field, and the yield monitor will tell me that, he says. If its off five per cent, its offLoad cells, sometimes called strain gauges, look like five per cent in the high [productivity] areas and itsrectangular steel bars with mounting holes and are easy off five per cent in the low [productivity] areas. It stillto install on a harvesters conveyor frame. They are usually gives you those ups and downs. positioned toward the back of the conveyor frame where potatoes are cleanest, and they support a section of the belt.Currently, Paget is collecting yield map data for his fields. Hes breaking his fields into five zones and soil testing in those zones, which is saving him timeprovide insights growers can use to drive increasedAdditionally, the newest planters offer variable and money. productivity and revenue through precision manage- rate adjustment of population density to spread the Were on a 2.5-acre grid sample now, so thats ament of crops. distance of the seed in the row. A map can be loaded lot of soil sampling. Im hoping by doing this, it will cutPaget says Riverview Farms is moving in thatto a planter so that the planter automatically chang-my soil sampling down by a quarterso itll be a lotdirection, using variable rate fertilizer application toes its seeding rate as it moves across a field.quicker. Ill have the data back as soon as I finish thebetter manage fertility in his fields.In addition to using variable rate fertilizer and field. Ill have the soil samples back within a week.Were getting to the point where we can applylime applications, Paget says hes just getting into By identifying major yield variability, growers candifferent rates of fertilizers for different areas of thevariable rate seeding at his operation. He says hell develop practically-sized management zones thatfield, as well as lime recommendations. Were tryingtry prescription seeding with his corn crops first and can be managed individually, says Menkveld. He alsoto bring those poor [yielding] areas back up. then move into potatoes. He has high hopes prescrip-agrees that a yield monitor is far more convenientTheres no need to put fertilizer in a place wheretion farming will increase his yields.than carrying out test digs by hand at different loca- your yield potential is low, agrees Menkveld. Also, if aCombining yield data gathered by the monitor tions in the field. In fact, in general, yield monitoringpivot doesnt put water in the corners of a field, donton his combine with that collected from his potato has become far more important than it used to beput down a lot of fertilizer there because yield willharvester, Paget has multiple years of yield data from due to larger field sizes, increased use of leased land,still be low, he adds.different crops, and sometimes they overlap, he says. the use of bigger and more expensive machinery,You cannot begin to start that kind of manage- If you look at the averages, if its a high-producing increased input costs and land values, he says. ment until you have the information, and you dontarea, its usually a high-producing area in every crop.Profit margins are shrinking and the only wayhave the information if you dont have the technology.There are many ways of collecting information you can do better is by reducing your costs andIt all goes hand in hand, says Menkveld.from a crop, says Menkveld. However, it all comes increasing your revenues. While there are many waysGrowers are also using variable rate irrigationtogether at harvest. With yield monitoring, farmers of doing that, really understanding and getting aon their farmssoil sensors tell an irrigation pivotcan examine the data and determine what was good handle on whats happening in the field is veryhow much water to apply in certain areas. Moreaccomplished with their crop management efforts. important, says Menkveld. growers are putting down liquid fertilizer with irriga- Did the changes they made make a difference? tion water, which can also be mapped in-season andCan they measure that difference? What can they do PRECISION MANAGEMENT followed up with a yield map at harvest. with the differences theyre seeing? Does something Yield maps when combined with others, such asYou can see if what you did to improve manage- need to be done differently in the future? Have they soil, elevation, application, planting and populationment of irrigation sites actually resulted in bettermaximized what they can do? Should they consider maps, as well as NDVI data and drone images,yields or margins, says Menkveld. different varieties or plant spacing? These are just 58 SPUDSMART.COM FALL 2019'