Estimating the global distribution of field size using crowdsourcing

There is an increasing evidence that smallholder farms contribute substantially tofood production globally, yet spatially explicit data on agricultural field sizes are cur-rently lacking. Automated field size delineation using remote sensing or the estima-tion of average farm size at subnational level using census data are two approachesthat have been used. However, both have limitations, for example, automatic field size delineation using remote sensing has not yet been implemented at a globalscale while the spatial resolution is very coarse when using census data. This paperdemonstrates a unique approach to quantifying and mapping agricultural field sizeglobally using crowdsourcing. A campaign was run in June 2017, where participantswere asked to visually interpret very high resolution satellite imagery from GoogleMaps and Bing using the Geo‐Wiki application. During the campaign, participantscollected field size data for 130 K unique locations around the globe. Using thissample, we have produced the most accurate global field size map to date and esti-mated the percentage of different field sizes, ranging from very small to very large,in agricultural areas at global, continental, and national levels. The results show thatsmallholder farms occupy up to 40% of agricultural areas globally, which means that,potentially, there are many more smallholder farms in comparison with the two dif-ferent current global estimates of 12% and 24%. The global field size map and thecrowdsourced data set are openly available and can be used for integrated assess-ment modeling, comparative studies of agricultural dynamics across different con-texts, for training and validation of remote sensing field size delineation, andpotential contributions to the Sustainable Development Goal of Ending hunger,achieve food security and improved nutrition and promote sustainable agriculturre.

LESIV Myroslava;  LASO BAYAS Juan Carlos;  SEE Linda;  DUERAUER Martina;  DAHLIA Domian;  DURANDO Neal;  HAZARIKA Rubul;  SAHARIAH Parag Kumar;  VAKOLYUK Mar'Yana;  BLYSHCHYK Volodymyr;  BILOUS Andrii;  PEREZ HOYOS Ana;  GENGLER Sarah;  PRESTELE Reinhard;  BILOUS Svitlana;  AKHTAR Ibrar Ul Hassan;  SINGHA Kuleswar;  CHOUDHURY Sochin Boro;  CHETRI Tilok;  MALEK Ziga;  BUNGNAMEI Khansembou;  SAIKIA Anup;  SAHARIAH Dhrubajyoti;  NARZARY William;  DANYLO Ohla;  STURN Tobias;  KARNER Mathias;  MCCALLUM Ian;  SCHEPASCHENKO Dmitry;  MOLTCHANOVA Elena;  FRAISL Dilek;  MOORTHY Inian;  FRITZ Steffen; 

2018-12-10

WILEY-BLACKWELL

JRC114269

1354-1013 (online),   

https://onlinelibrary.wiley.com/doi/full/10.1111/gcb.14492,    https://publications.jrc.ec.europa.eu/repository/handle/JRC114269,   

10.1111/gcb.14492 (online),