Predicting crop yield is analogous to predicting a winner in a horse race. In both cases, there are a lot of variables to consider and decisions are a mix of art and science. Serious bettors analyze data on past performances and then handicap horses for their chance of winning or placing in a race. Handicapping is very personal and there are as many approaches as there are handicappers. While decisions on which horse will win what race will vary among handicappers, they all start with the same source of information — a racing form.
A racing form provides a wide range of data on a horse’s past performance. It lists the tracks and length of races during the past few years, the jockeys riding the horse, track surface type and conditions, horse gender, age, and weight, quality of the competition, positions at the starting post, during a race, and at the finish line, and percentage of winning. There are also subtle statistics such as speed of last race, class rating, and best speed at distance. Modern racing forms include algorithms, such as “prime power,” which combine a number of handicapping variables into a single rating. The challenge to a bettor is to correctly handicap a set of variables according to their importance in determining a profitable outcome for a race. The chosen set of variables will vary from track to track and race to race. Successful handicappers stress the need for flexibility and creativity when choosing variables.
Like racing, growers need to handicap their data when growing a crop. And like racing, one can imagine a “farming form” for crop production. A farming form like a racing form would vary from grower to grower because each has a different history with fields, crop varieties and yield performances. While their prioritization may change from grower to grower and region to region, one can identify a common set of variables important for production decision-making. Just as important as the order of importance of variables is the availability of data for them.
If a field can be imagined as being analogous to a track, a farming form would likely list the soil texture and fertility as the first two variables for handicapping. Soil is the stage on which a crop performs and its texture and fertility determines the quality of that performance. Just as a race track can be turf, dirt, or synthetic (man-made materials), a soil can have a mixed texture of sand, silt, or clay and varying amounts of macro- and micronutrients. The depth and mixture of textures determines rooting depth, aeration, and water-holding capacity, while fertility impacts crop health.
The third variable on a farming form would probably be weather. In horse racing, surface conditions can vary greatly depending on weather conditions, specifically those due to precipitation. For example, for a dirt surface, a track can be rated as “fast” under dry conditions to “sloppy” under saturated conditions. A horse can under perform due to stress in humid, hot weather. In a manner analogous to a horse, a crop will perform differently under weather conditions, and will be negatively affected by extremes in heat or cold or by prolonged periods of wet or dry.
The importance of soil has been recognized since the earliest days of modern agriculture. Soil probes to determine bulk density and tests to determine fertility have become routine. In-ground moisture, temperature, and salinity sensors have become more popular with high value crops for tracking soil conditions during a growing season. It was not by coincidence that one of the first precision agricultural practices involving a global positioning system (GPS) was for “grid” soil samples. And it is not surprising that many growers either have an on-site weather station or subscribe to a service that provides daily updates and forecasts of weather for areas encompassing their farms. The handicapping of soil and weather data through frequent monitoring of the field environment is key for successful production decisions.
The Fantastic Fourth
The fourth variable on a farming form could be field scouting. In the horse racing analogy, scouting a field is like scouting a horse. Scouting a horse includes reviewing past performance against other horses of a similar age class, how many wins or places the horse had at a similar race track, length of race, and jockey, and whether the horse led from the start of a race or came from behind. In a similar manner, a field scout can determine how a crop performs in competition with pests or when stressed environmentally. Like a racing handicapper, a field scout will review records of pest occurrences in previous seasons and past frequencies of extreme weather events that could result in yield loss. The same scout would have good understanding of how a seed variety would perform in terms of its timing of phenological stages during a season, resistance to pests, tolerance to environmental stresses, and potential yield. Data in the form of past records, field study results, and past experience are necessary before a plan can be put together for an upcoming season’s crop production practices.
A potential fifth variable on a farming form could be the resources necessary to grow a crop. Resources are important to a horse as to a crop. A successful racing horse requires years of training by an expert, proper nutrition, and appropriate riding equipment. A successful crop requires resources in the form of equipment, fuel, seed, fertilizers, pesticides, other amendments, and labor. While all growers have a preseason plan in mind, the specific practices in the plan need to be fine-tuned as a season unfolds. Nearly everyone is familiar with the 4R maxim of “right source, right rate, right time, and right place” that is promoted by the International Plant Nutrition Institute for best management practices. Executing the four “rights” requires data on readiness of equipment, fuel stock, seed stores, fertilizer and pesticide inventories, and availability of personnel. It also requires a tactical coordination of these resources with respect to the stage of the crop and environmental conditions throughout a growing season. The status of resources and the coordination of their application during a season requires logistical data that must be continually updated with each management decision.
Depending on the crop and geography, other variables may be candidates for a farming form. In the end, variables that make the list must have readily available data. PrecisionAg.com and PrecisionAg Magazine focuses a lot on data and their usage among service providers in precision agriculture. As illustrated with the farming analog of a racing form, these data must be analyzed and “handicapped” to ensure a crop ends up with a first place finish at the end of a growing season.