全球范围内不同作物的无机肥（简称化肥）使用量（112个国家）

Ludemann, C.I., Gruere, A., Heffer, P. et al. Global data on fertilizer use by crop and by country. Sci Data 9, 501 (2022).
https://doi.org/10.1038/s41597-022-01592-z

Ludemann, Cameron; Gruere, Armelle; Heffer, Patrick; Dobermann, Achim (2022), Global data on fertilizer use by crop and by country, Dryad,
Dataset, https://doi.org/10.5061/dryad.2rbnzs7qh

var LSIB = ee.FeatureCollection("USDOS/LSIB/2017"),
    fertilizer_use_ct = ee.FeatureCollection("projects/sat-io/open-datasets/global_fertilizer_use_centroid");
//Create a filter
var Filter = ee.Filter.equals({
  leftField: 'COUNTRY_NA',
  rightField: 'COUNTRY_NA'
});

var country_join = ee.Join.inner();
var country_join = country_join.apply(LSIB,fertilizer_use_ct,Filter);
function cleanJoin(feature){
  return ee.Feature(feature.get('primary')).copyProperties(feature.get('secondary'));
}

var joined = country_join.map(cleanJoin)
print('Sample fertilizer application', joined.first())

//Break down by year of publication
print('Year of publication',joined.aggregate_histogram('Year_FUBC_publication'))

//Export individual country usage to CSV
var selected = fertilizer_use_ct.filter(ee.Filter.eq('COUNTRY_NA','Canada'))
print('Total features for Country',selected.size())

Export.table.toDrive({
  collection: ee.FeatureCollection(selected),
  description:'fertilizer_country_canada',
  fileFormat: 'CSV'
});