Precision farming or precision agriculture is an agricultural concept relying on the existence of in-field variability. It requires the use of new technologies, such as global positioning (GPS), sensors, satellites or aerial images, and information management tools (GIS) to assess and understand variations. Collected information may be used to more precisely evaluate optimum sowing density, estimate fertilizers and other inputs needs, and to more accurately predict crop yields. Application of precision farming concepts is usually considered related to sustainable agriculture. It seeks to avoid applying same practices to a crop, regardless of local soil/climate conditions and may help to better assess local situations of disease or lodging. Over fifty GPS satellites such as this NAVSTAR have been launched since 1978. ... To meet Wikipedias quality standards, this article or section may require cleanup. ... A satellite is any object that orbits another object (which is known as its primary). ... A geographic information system or geographical information system (GIS) is a system for creating and managing spatial data and associated attributes. ... Sustainable agriculture integrates three main goals: environmental stewardship, farm profitability, and prosperous farming communities. ...

In the Midwest it is not associated with sustainable agriculture but with mainstream farmers who are trying to maximize profits by spending money only in areas that need fertilizer. This practice allows the farmer to vary the rate of fertilizer across the field according to the need identified by GPS guided Grid Sampling. Fertilizer that would have been spread in areas that don't need it can be placed in areas that do, thereby optimizing its use.

Precision farming may be used to improve a field or a farm management from several perspectives :

• agronomical perspective : adjustment of cultural practices to take into account the real needs of the crop (e.g., better fertilization management)
• technical perspective : better time management at the farm level (e.g. planification of agricultural activity)
• environmental perspective : reduction of agricultural impacts (better estimation of crop nitrogen needs implying limitation of nitrogen run-off)
• economical perspective : increase of the output and/or reduction of the input, increase of efficiency (e.g., lower cost of nitrogen fertilization practice)

Other benefits for the farmer may be to help him set an history of his/her farm practices and results, to help him in his decision making and traceability requirements (as increasingly required in developed countries).

See also integrated farming, sustainable agriculture, organic farming, pest management, fertilization management, soil sampling, spatial variability, geostatistics Integrated farming (or integrated agriculture) is a system of agricultural techniques developed in France in 1993 by FARRE (Forum de lAgriculture Raisonnée Respecteuse lEnvironnement). ... Sustainable agriculture integrates three main goals: environmental stewardship, farm profitability, and prosperous farming communities. ... Organic cultivation of mixed vegetables in Capay, California. ... Spatial variability is characterized by different values for an observed attribute or property that are measured at different geographic locations in an area. ... Geostatistics applies the theories of stochastic processes and statistical inference to geographic phenomena. ...

External links

• PrecisionTalk discusion list
• Precision Farming Updates
• Australian Centre for Precision Agriculture
• Centre for Precision Farming Cranfield University at Silsoe (United Kingdom)
• Purdue Site-Specific Management Center
• Kansas State Precision Agriculture
• Association Research Project pre agro