Bumper crop yields begin in the spring, with careful attention to seeding. And variable-rate seeding is showing real value in edging those yields upward.

Current research points to the biggest benefits in a few specific agronomic conditions. For example, poor-yielding areas, such as wet spots or eroded hilltops, may reach maximum economic yields with lower seed populations than in other parts of the field. Perennially compacted soils, on the other hand, may benefit most from increased seeding rates. Research at the University of Minnesota showed that stand reductions of 20 to 25% are typical in compacted soils, which may indicate the need to boost populations.

Whatever your field conditions, variable-rate seeding holds the promise of more efficiently matching seed to soil. These new planter monitors some designed for a GPS system and some for the non-GPS farm can closely guard your planter functions to ensure more precise seeding.

GPS ready

Several GPS-ready monitors are part of a larger GPS system, and others are stand-alone models designed to work with most GPS-based yield monitors and software.

Fieldstar Precision Planting System. AGCO's Fieldstar system is part of the broader Fieldstar Precision Agriculture system, which includes a communication unit (the brains of the in-cab system), a display that can be transferred from tractor to combine, a GPS/DGPS receiver and antenna, and software. The additional planting system, which includes the Fieldstar Planter Controller, wiring harness, brackets and radar, uses DGPS and an application map to automatically control the planting rate of the White planter. The application map can be generated by a yield map, soil map or satellite photo or from a map created by the Fieldstar Office software package. That information is then transferred to the tractor via data cards.

The display's 10-in. touch screen allows you to use preprogrammed seeding rates or to override them using DGPS to match specific field situations. Information such as ground speed, local time and GPS status can be displayed digitally and/or as a bar chart. Seed spacing can even be preprogrammed to appear in both formats for easy tracking on the go. The system records all planting information on a data card, which stores up to 2 mb (30 hrs.) of information and allows you to transfer the data to your office PC.

The actual planter monitor unit is a sealed electronic control box that is mounted on the planter frame. Required high-speed or Seed Smart seed drive and seed tube sensors report information to the planter control unit, which processes it and communicates it to the unit in the tractor for display and to automatically adjust seeding rates on up to 36 rows to match the prescribed seeding map.

White planters that are adaptable to the Fieldstar system include all the hydraulically driven models, as well as models 6184, 6512, 6515, 6523, 6524, 6531, 6806 and 6808. Technical product support is available by phone five days a week. Price for the Fieldstar Planting system, plus communication unit and display, starts at $4,000. Contact AGCO Corp., Dept. FIN, 4205 River Green Pkwy., Duluth, GA 30096, 800/922-2426, www.agcocorp.com or circle 211.

AFS system. The AFS planters from Case IH are equipped to monitor and provide variable-rate control of seed, liquid fertilizer and granular chemicals from a touch-screen pad. All monitoring functions have been consolidated into one unit mounted in the tractor cab. The system's seed sensors verify seeding rate changes immediately and can be controlled in sections. A single electronic connection point between the tractor and the implement makes the monitor display easy to move from one tractor to another.

The Case IH system offers a choice of two AFS universal displays. A 5 1/2-in. touch-screen model offers one-touch, variable-rate control; field, season and lifetime area recording; individual low-bin warning; average seed population; bar graph showing the population of every row; meter rate feedback; and automated calibration. The 9 1/2-in. display has the added functions of map-based application control of inputs; immediate site-specific application rate recording; field marker to mark and map specific field observations; and a display of current prescription map and tractor position. This display comes with Agri-Logic desktop software for prescription generation and application mapping.

AFS planters are available in four configurations: 12-, 16- or 24-row narrow front fold, and 12/23 SRC front fold. The AFS system is sold only on new Case IH planters and is not available as an aftermarket system. Contact Case Corp., Dept. FIN, 700 State St., Racine, WI 53404, www.caseih.com or circle 212.

SeedStar. Deere's SeedStar planter monitor is part of the company's GreenStar precision farming system. This spring, for the first time, it will be available on a limited basis with GPS capabilities. The GreenStar system is built around portable components designed to work together. For instance, you can move the GreenStar display from combine to tractor and connect it to your planter or air seeder to manually vary seed populations.

The brains of the GreenStar system is an 8-megabit mobile processor dedicated to each machine. It accepts Flash PC data cards, which hold up to 400 hrs. of data and allow you to transfer information from the field to your office computer.

The SeedStar is a frame-mounted population processor that lets you select from up to six planting rates on the go. Along with tracking basic planting stats, the monitor's key features include an automatic system diagnostic check on start-up, in-cab vacuum level readout for vacuum system adjustment from the cab, pressure monitoring of liquid fertilizer systems, and a preprogrammed information section to provide a quick reference for population charts, seed disc selection, vacuum settings and more.

The SeedStar monitor can be used on other planter brands but requires Deere wiring harness. Price for the monitor (without display) ranges from $1,800 for a four-row unit up to $3,800 for 24-row monitoring capabilities. Contact John Deere North American Agricultural Mrktg. Center, Dept. FIN, 11145 Thompson Ave., Lenexa, KS 66219, 913/310-8324, www.deere.com or circle 213.

Adust-A-Rate II. Orthman recently updated its Adjust-A-Rate II hydraulically driven planter drive system to be compatible with most GPS controllers and software. When combined with a GPS/GIS system, it allows you to vary population rates on the go. It can also be used without GPS, by either manually adjusting seeding rates or by switching to preprogrammed rates.

The unit's digital display and rotary switch allow you to display ground speed, field area, total area and target rates. A proportional valve provides instantaneous response to rate adjustment. A self-diagnosing feature will flash one of several error messages if a problem occurs, such as loss of hydraulic flow or low voltage.

According to the company, the system is easy to mount on nearly any planter configuration, because it has a narrow mounting width and the top half of the drive can be adjusted into three positions. It's available in single-, dual- and triple-drive configurations and is compatible with several brands of planters. Price ranges from $3,700 to $6,600, depending on planter size. Contact Orthman Mfg. Inc., Dept. FIN, Box B, Lexington, NE 68850, 800/658-3270, www.orthman.com or circle 214.

Seed Manager. The Dickey-john Seed Manager is the latest addition to the company's Benchmark series. This GPS-compatible monitor is capable of monitoring up to 36 rows. The unit's bar graph display shows up to 12 rows at a time, tracking population, seed spacing and singulation, and sounding a warning when seed populations get too high or too low.

Simplified circuitry with the company's Seed Smart sensors reduces harnessing needs and allows for easier system installation. Dickey-john claims that the new sensors also provide greater accuracy with small grains and specialty crops. A nonvolatile memory retains settings even when disconnected from the battery.

Base price of the Seed Manager is $1,300. Contact Dickey-john, Dept. FIN, 5200 Dickey-john Rd., Auburn, IL 62615, 800/637-2950, www.dickey-john.com or circle 215.

Accu-Rate. Compatibility is a key feature of the new Accu-Rate planter monitor from Rawson Control Systems, which introduced its first monitor in 1984. The company claims that its new GPS-based monitor works with any planter, drill or air seeder on the market.

The unit's 32-position rate knob lets you change seeding rate by population or pounds, and its multifunction processor enables application of two products at once using GIS. A hydraulic drive with internal drain line can be used with hydraulic blowers on vacuum and pressure-type planters.

The company provides support via its Web site and over the phone. Prices range from $3,825 for a single-drive unit to $8,800 for a three-drive model. Contact Rawson Control Systems, Dept. FIN, 116 2nd St. S.E., Oelwein, IA 50662, 319/283-2225, www.rawsoncontrol.com or circle 216.

Non-GPS

If you don't want to invest the time or money in a GPS system, check out the many conventional planter monitor options. Some are more sophisticated and feature-loaded than others. But one thing most new models seem to have in common is a more consolidated wiring system for easier installation and an overall neater look no more mess of wires in your cab.

Agri-Tronix M3. If you prefer a dial control to a touch pad, the M3 is worth considering. You enter data and make selections by turning and pressing the knob, and the control is menu-driven for easy programming.

The unit can monitor up to 16 rows using conventional sensors of almost any make and calibrates them once the tractor has driven 400 ft. in a straight line. The M3 also allows you to calibrate your seed sensors for different planters. It tracks and displays average and row populations, field area and total area covered, speed, sensor condition, row status, planting activity, and acres per hour, and allows you to display any two of those functions at the same time.

The M3 works with a speed sensor but can be programmed to continue operating accurately, even if your speed sensor fails. It comes with a five-year limited warranty. Base price is $599 for the monitor and $100/row for sensors. Contact Agri-Tronix Corp., Dept. FIN, 2001 N. U.S. 31, Franklin, IN 46131, 800/445-5058, www.agritronix.com or circle 217.

KPM I and II. The KPM I and KPM II from Kinze offer you the choice of a basic or full-featured monitor, both programmable up to 36 rows. The company's Smart Sensors, with self-calibrating, self-diagnosing optical components, count up to 120 seeds/sec. and process seed flow information before sending it to the monitor for instantaneous field feedback. Simplified wire harnessing eliminates the need for dedicated lead wires to each row unit, making installation easy.

The KPM I console features a backlit LCD display with a segmented bar graph showing the relative planting rate for each row, and a four-button, color-coded keypad. A scrolling message informs the operator of failed rows, dirty sensors or system errors.

The 10-button KPM II console can also display speed, row spacing, seed population by row, average seed population, seed spacing by row and average seed spacing, field area and total area covered. Two speed sensor options magnetic or radar-based are available on the higher-end unit.

Both models have a nonvolatile memory to keep data secure if power is lost and are fully upgradable to accept software updates. Prices start at $1,213 for the KPM I on a four-row planter and range up to $6,577 for the KPM II on a 36-row planter. Contact Kinze Mfg. Inc., Dept. FIN, Box 806, Williamsburg, IA 52361, 319/668-1300, www.kinzemfg.com or circle 218.

Deluxe Early Riser. Case IH calls this a combination diagnostic and management monitor. It tracks measurements on up to 24 rows, including total acres planted during a season or in a particular field, average seed spacing, and average seed population for the entire planter or for each row. A bar graph displays rows with the lowest and highest population compared with the average of all rows. It also monitors seed flow, hopper level, ground speed and hopper air pressure, and sounds a warning when any problems occur.

The company also offers a basic monitor called the Seed Flow II, which tracks seed flow in each row and hopper level on up to 16-row planters.

Both monitors can be used on either an Early Riser Cyclo Air or a plate-type planter. Base price ranges from $2,284 for a six-row planter to $5,355 for a 24-row planter. Contact Case Corp., Dept. FIN, 700 State St., Racine, WI 53404, www.caseih.com or circle 219.

Seed Check. The newest monitor from Dickey-john, the Seed Check, monitors up to 12 planter rows or six drill rows and three hopper level inputs. Using one switch, you can step the unit through population, speed and two separate areas to track important data. A low-flow alarm can be set to indicate when seed flow to an individual row drops below the planter average.

The Seed Check uses either radar or magnetic sensor for ground speed and allows you to manually enter ground speed, thus eliminating the need for a speed sensor. Base price of the system is $875.

The company calls its PM3000 model its workhorse monitor. Designed for easy use and durability, it monitors up to 32 rows for speed, area, population, seed spacing and area per hour. A scan feature allows the console to cycle through all the rows and display either an individual row population or seed spacing and then the planter average for either of those.

The unit works with radar or universal magnet speed sensors, or a gear pickup on the planter itself. It also doubles as a speed and area monitor when you're not planting. Base price is $1,300. Contact Dickey-john, Dept. FIN, 5200 Dickey-john Rd., Auburn, IL 62615, 800/637-2950, www.dickey-john.com or circle 220.