Farming from space   (Page 1 of 2)

How GPS and satellites are taking over farmers’ toolsheds

By Don Gayton with photography by Tim Smith

The Indian Head Research Farm “checkerboard” as seen from above (Photo: Tim Smith)

We enter the Indian Head Research Farm headquarters, a small, well-organized village of buildings, Quonset huts and grain bins arranged around a main yard. The complex is surrounded by a dense grove of shelterbelt trees. Beyond the treeline, grain fields stretch to the horizon. The farm, located 75 kilometres east of Regina, is busy this April day, as people and machinery come and go. Spring has arrived late to Saskatchewan; a ferocious blizzard halted everything for a few days, but now seeding is in full swing.

Guy Lafond leads me over to a large Quonset where a tractor and seeding drill are parked. An intense and engaging agriculture scientist, Lafond is one of the veterans of Indian Head who has made his mark during his 25-year career. While Lafond chats with a colleague, I take a look at the business end of the seeding drill. I recognize the furrow openers that cut a path in the soil. Just behind them are separate seed and fertilizer delivery tubes and, behind those, hydraulically controlled packer wheels. The top of the machine is a complex maze of bins, delivery tubes, air compressors and electronic sending units.

There’s something else that’s out of the ordinary: a Global Positioning System (GPS) monitor, similar to what you’d find in a passenger vehicle, is mounted in the cab, and the tractor features hydraulic steering cylinders that I’ve never seen before. If I didn’t know better, I’d think that someone did a “Pimp My Ride” job on this dusty farm vehicle. Lafond picks up on my curiosity. “That tractor you’re looking at is a good example of precision-farming technology,” he says with a smile. “It’s equipped with auto-steering.”

A tractor that drives itself is GPS wizardry not normally associated with farming. But as I am about to learn during my visit to Indian Head, this is only one application in the constellation of space-age farming tricks with far-reaching potential. “Precision agriculture” is helping farmers change how they work and learn things about their land they never thought possible. GPS and Earth-observation satellites are offering both navigational know-how to farm machinery and a treasure trove of data on soil and crop health, down to a few square metres, to farmers. With this new knowledge and tool kit, farmers can tailor their practices to the varying conditions of the land, which means lighter applications of fertilizer, higher crop yield and more effective soilconservation practices. Indian Head, it turns out, has a lot to say about the future of Canadian farming.

How Earth-observation satellites work (Source: Canadian Atlas Online)

Prairie agriculture is not generally thought of as a high-tech endeavour, but it is. Since the 1880s here in Saskatchewan, grain farmers and researchers have continuously pushed the innovation envelope. Isolated and faced with wildly unpredictable weather, they learned early on to adapt and invent farm implements and cropping techniques to suit the demands of Canadian prairie conditions. Between 1905 and 1975, an impressive 1,000 agricultural patents were issued to Saskatchewan farmer-inventors. New designs and successful modifications were made to every conceivable implement — swathers, seeders, diskers, rod weeders. Early adopters of new technology abound within that dry triangle once declared unsuitable for anything but ranching by Irish explorer Captain John Palliser.

Indian Head Research Farm, operated by Agriculture and Agri-Food Canada, was born in 1886 and grew in tandem with prairie agriculture. The sense of history is palpable as Lafond and I walk from the Quonset over to the elegant brick office building. This is where summerfallowing was first practised, where Marquis wheat — a famed hardy and quick-growing variety — was first field-tested and distributed and where no-till farming was researched before it was widely adopted elsewhere.

Lafond has had a hand in numerous agricultural innovations. He started his research career in the 1980s, during the early stages of the no-till farming revolution, and has closely tracked it ever since. Summerfallowing, a traditional grainfarming practice, was done to control weeds and store up soil moisture and nutrients for the next crop, but leaving the land black for an entire year exposed it to the ravages of wind and water erosion. With no-till, the subsequent crop is planted directly into the stubble of the previous crop. Land cultivation is virtually eliminated, and weed control is achieved with a chemical herbicide. No-till allows for the gradual rebuilding of critical soil organic matter, which breaks down every time the soil is tilled. Over the years, it has been shown to improve the long-term productivity of prairie soils.

Much of Lafond’s voluminous research work revolves around crop nutrition, weed control and soil conservation. “For me, good agricultural research is about understanding problems and setting priorities,” he says from the comfort of his office, with Indian Head’s official mouser purring loudly under a chair. This makes his present focus on the hardware and software side of agronomy — implements and monitoring systems — all the more curious.

Lafond smiles and offers a two-word explanation. “Precision farming,” he says, with a faint francophone lilt betraying his family roots in St. Jean Baptiste, Man. “Maximizing yield and sustainability by applying crop inputs like seed, fertilizer and pesticides in just the right amounts, at just the right time and in just the right place.”

That explains the unusual hydraulics and computer monitor I was puzzling over minutes ago. Lafond explains that on-board GPS navigation systems are being developed to analyze complex farm fields, taking into account irregular borders, permanent obstacles and the width of the farm implement used, and to compute an “optimum path” that minimizes the number of overlaps the tractor drivers have to make as they traverse the field.

“When you’re pulling a 75-foot seeder or a 120-foot sprayer behind you,” says Lafond, “it’s very difficult to line up the edge of the implement right at the edge of your last pass, to avoid skips or overlaps. Auto-steering uses GPS technology to align and steer the tractor precisely relative to the last pass down the field. That means a big saving, since you are not wasting expensive seed or fertilizer or spray by overlapping. It also reduces driver fatigue.”

Most of all, precision agriculture means more productive farms, he says. Small changes in topography, soil type, fertility and moisture levels within these fields can translate into big changes in crop yield. “The technology we’re working on,” says Lafond, “attempts to provide farmers with the ability to respond to those in-field variations by applying different amounts of crop inputs — in this case, nitrogen fertilizer. So one of my pet definitions for precision farming is the management of variability.”

GPS-based farm applications, such as auto-guided tractors and harvesters, use ground-based receivers that capture radio-wave signals from overhead satellites; these signals carry precise navigational coordinates. The same technology can be used to tag soil samples or harvested crops from multiple areas, a handy management tool for farmers. Yield maps, for example, can be generated from data collected by high-tech combines that measure the moisture and protein content of grain as it is harvested, as well as the yield. If the system includes a GPS receiver, the resulting information shows the precise position where the grain was harvested.

Earth-observation satellites make possible a different set of precision-farming tools. These satellites, such as Canada’s RADARSAT, transmit and receive microwave data that can be processed into information-rich, high-resolution maps revealing soil conditions and crop health and providing clues on how best to manage drought and floods (see sidebar, Growing by satellite).

Data from Earth-observation satellites are at the heart of Lafond’s research with the Normalized Difference Vegetation Index (NDVI). These satellites measure the amount of light reflected by crop canopies from two specific light bands: green leaves strongly absorb visible light and reflect nearinfrared light, whereas bare ground does just the opposite. The resulting data are built into the NDVI map. When linked to GPS coordinates, NDVI can give a picture of productivity: on a given plot of land, the higher the NDVI index, the more crop biomass there is.

Up to now, NDVI has been used primarily for large and even global-scale vegetation assessments, but Lafond has been able to narrow its scope to the farm level to assess crop variability. “We assume that NDVI values equate to plant biomass, which equates to final crop yield,” he says. “So we get an NDVI image of a particular field and divide it into areas of high, medium and low crop productivity. We have compared our NDVI classifications against the actual yield literally hundreds of times now, and we know we’ve got a very strong relationship.”