Page 280 - Niên giám

Current area of perennial crops only recorded for the area of crops
that are still alive at the time of observation, including the area of
concentrated cultivation and the area converted from area of scattered trees
having products to the concentrated area.

Production of agricultural crops is the total volume of the main
product of a certain agricultural crop or group of agricultural crops
obtained in a cropping season or in a year of an agricultural production
unit or a region/ geographical area.
Production of each type of agricultural crops is determined by the
form of the product. For products such as rice, maize, green beans,

soybeans, etc. are recorded in the form of dry grain; sweet potatoes,
potatoes, cassava are recorded in form of fresh bulbs; tea in form of fresh
buds, coffee in form of dry kernel, rubber in form of dried latex, fruits in
form of fresh fruits, etc.
Yield of agricultural crops refers to the main product per one area

unit of a certain agricultural crop or group of agricultural crops actually
harvested in a production season or in a year on average planted area.
 For annual crops:

Planted yield Harvested production (season, year)
(season, year) = Planted area (season, year)

Harvested yield = Harvested production (season, year)
(season, year) Harvested area (season, year)

 For perennial crops:

Harvested yield = Harvested production (season, year)
(season, year) Productive area (season, year)

Harvested area: An indicator refers to the total cultivated/planted
area of a certain crop or group of crops in a year, from which the crop
production is reached at least 30% of yield of the ordinary year. For annual
crops, harvested area is equal the cultivated area minus complete loss area;
for perennial crops, it is equal productive area minus complete loss area.

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