Precision farming

precision agriculture is a type of information management whose objective is to improve agricultural productivity. "Precision agriculture" is used as an agronomic expression that defines the management of agricultural plots on the basis of observation, measurement and action against inter- and intra-crop variability.^{[citation required ]} Requires a suite of technologies consisting of the global navigation satellite system (GNSS), sensors and both satellite and airborne imaging, along with geographic information systems (GIS), and machine learning to estimate, evaluate and understand such variations. The information collected can be used to more accurately assess optimal planting density, estimate the appropriate amount of fertilizers or other inputs needed, and more accurately predict crop yields and production. This information is also used by Variable Application Technologies (VRT) to optimize the distribution of seeds, fertilizers and phytosanitary products.

Definitions

The International Society for Precision Agriculture, a non-profit professional and scientific organization, defines precision agriculture as:

a management strategy that collects, processes and analyzes temporary, spatial and individual data and combines them with other information to support management decisions according to the estimated variability, and thus improve efficiency in resource use, productivity, quality, profitability and sustainability of agricultural production.

Importance of precision agriculture

Precision agriculture aims to optimize the management of a plot from the point of view

• Agronomics: adjustment of cultivation practices to plant needs (e.g.: meeting nitrogen requirements).
• Environment: reduced impact linked to agricultural activity (e.g., nitrogen dispersion limitations).
• Economics: increased competitiveness through greater effectiveness of practices (e.g., improved management of the cost of nitrogenated manure).

In addition, precision agriculture makes available to the farmer a lot of information that can:

• Make a real memory of the field.
• Helping make decisions.
• Go in the direction of traceability needs.
• Improve the intrinsic quality of agricultural products (e.g., protein index in the case of panifying wheat).

Stages and instruments

Four stages can be distinguished in the implementation of precision agriculture techniques that take spatial heterogeneity into account:

Geolocation of information

The geolocation of the plot allows the available information to be superimposed on the latter: soil analysis, analysis of nitrogenous remains, previous crops, soil resistivity. Geolocation is done in two ways:

• physical delimitation with the help of a GPS on board, which requires the operator's displacement to the plot;
• mapping based on an air or satellite image. To ensure the accuracy of geolocation, these background images must be adapted in terms of resolution and geometric quality.

Characterization of heterogeneity

The origins of the variability are diverse: the climate (hail, drought, rain, etc.), the soil (texture, depth, nitrogen, phosphorus and potassium content), cultivation practices (sowing without tillage), weeds, diseases.

Several permanent indicators (mainly related to the soil) allow the farmer to keep informed about the main constants of the environment.

Other specific indicators keep you informed about the current state of the crop (development of diseases, water stress, nitrogen stress, lodging, damage caused by frost, etc.).

The information can come from meteorological stations, from sensors (electrical resistivity of the soil, detection with the naked eye, satellite images, etc.).

The measurement of resistivity, completed by pedological analysis, leads to precise agropedological maps that allow taking into account the environment.

Decision making: two strategies that can be adopted in the face of this heterogeneity

From the agropedological maps, the decision on the modulation of the inputs in the plot is made based on two strategies:

• preventive approach: it is based on an analysis of static indicators during the campaign (the soil, resistivity, the history of the plot, etc.),
• the management approach: the preventive approach is updated through regular measurements during the campaign. These measurements are performed:
  • by physical samples: weight of biomass, chlorophyll content of leaves, weight of fruits, etc.,
  • by proxy-detection: sensors aboard the machines to measure the state of the foliage but that require the total agrimensity of the plot,
  • by air remote sensing or satellite: multispectral images are acquired and are treated so that maps that represent different biophysical parameters of crops can be developed.

The decision can be based on decision support systems (agronomic simulation models of crops and recommendation models, for example DSSAT), but it depends above all on the farmer, depending on the economic interest and the impact on the environment.

Implementation of practices to compensate for these variabilities

Information and communication technologies (ICT) allow the modulation of cultivation operations within the same plot to be more operational and facilitate the use by the farmer.

The technical application of modulation decisions requires the availability of adequate agricultural material. In this case, we speak of VRT or variable rate technology (example of modulation: sowing with variable density, application of nitrogen, application of phytosanitary products).

The implementation of precision agriculture is easier thanks to the equipment installed on the tractors:

• Global positioning system (e.g. GPS receivers using satellite transmissions to determine an exact position on the Earth globe).
• Geographic Information System (GIS): programs that help manipulate all available data.
• Agricultural material that can practice the technology of variable indices (seeder, fertilizer).

Precision agriculture around the world

The concept of precision agriculture, in its current form, appeared in the United States at the beginning of the 1980s. In 1985, researchers from the University of Minnesota varied the contributions of calcium fertilizers in agricultural plots. It was at this time that the practice of grid-sampling (collection of samples on a fixed network of one point per hectare) appeared. Towards the end of the 80s and thanks to the extractions carried out by means of samples, the first recommendation maps appeared for the modulated contributions of fertilized elements and for the pH corrections. The evolution of technologies allowed the development of performance sensors and their use, together with the appearance of GPS, has not stopped growing until it currently reaches several million hectares covered by these systems.

Across the world, precision agriculture is developing at different rates depending on the country. Among the pioneering countries we find, of course, the United States, Canada and Australia. The Latin American country most involved with this crop management methodology, both in terms of adoption rate and in the development of highly complex agro-components, is without a doubt the Argentine Republic, a country that thanks to the efforts of the private sector and of official dependency research institutions, today has a large amount of area planted under this modality and a significant number of highly trained professionals for this new paradigm of modern agriculture. In 1995, technological innovation was applied for the first time in grain production at the EEA Manfredi of the National Institute of Agricultural Technology INTA, who made an Argentine yield map of a grain harvest. Another Latin American country that is emerging as a great demand for this type of technology is Brazil. The current scenario of agriculture in Brazil is moving towards efficient production while protecting the environment, therefore, Embrapa established the Brazilian Network for Research in Precision Agriculture, with the objective of generating knowledge, tools and technologies for agriculture of precision applied to soybean, corn, wheat, rice, cotton, pasture, eucalyptus, pine, grape, peach, orange and sugar cane crops.

In Europe, the forerunners were the English, closely followed by the French. In France, precision agriculture appeared in 1997-1998. The development of GPS and modular spreading techniques helped to entrench these practices. Currently, less than 10% of the French farming population is equipped with modulation tools of this type. GPS is more widespread. But this does not prevent them from using services, which provide recommendation maps by plots, considering their heterogeneity.

Economic and environmental impact

The reduction in the amounts of nitrogen supplied is significant, which tends to generate better performance. Therefore, the return on investment is achieved at various levels: savings in the purchase of phytosanitary products and fertilizers, and better harvest recovery.

The second positive effect, on a larger scale, of these directed contributions, geographically, temporally and quantitatively, refers to the environment. Indeed, providing the correct dose in the right place and at the optimal time can only benefit the crop, the soil and the water tables, and thus the entire agricultural cycle.

Therefore, precision agriculture has become one of the pillars of sustainable agriculture, since it is respectful of crops, land and farmers. Sustainable agriculture is understood as an agricultural production device that aims to guarantee a perennial food production, respecting the ecological, economic and social limits that guarantee the maintenance over time of this production.

Therefore, precision agriculture does nothing more than put high technology at the service of this respectable and praiseworthy ambition.

Emerging Technologies

Precision agriculture is a field of application of new digital technologies:

• Robots
• Autonomous vehicles
• Satellite and drone images
• Internet of Things (IoT, Internet of Things)
• Mobile applications
• Machine Learning
• Precision Nax Agriculture
• Bioo 100% Sostebible Sensor: No batteries of any kind, since it has plants that operate as a biological switch. They generate a bacterium from organic substances found on the ground, which then gives energy to that device.

Lectures

• InfoAg Conference
• European conference on Precision Agriculture (ECPA) (biennial, in years none)
• International Conference on Precision Agriculture (ICPA) (well, in even years) I am Diego