Rice yields are generally variable across Sierra Leone and depend on the agro-ecological zone. Yields are highest (>2.5 tons per ha) in mangrove zones, then riverine (about 2.5 tons per ha), then inland valley swamps – IVS (> 1.5 tons per ha but less than 2.0 tons per ha), then boliland and upland (about 1 ton per ha on average). The yield assumptions for the five ecologies in the model are calculated from acreage and production information provided by the Ministry of Agriculture for 2016. It is assumed that there has been no significant change in yields between 2016 and 2018. This is not a restrictive assumption as the impact of the variation in yields on consumption, exports and imports can be simulated.

**Table 7: Sierra Leone, Cultivation, Production and Yield of Rice in All Ecologies (2016)**

|**District**|**Upla**|**nd Rice**|**IVS**|**Rice**|**Bolila**|**nd Rice**|**Rive**|**rain Rice**|**Mang**|**rove Rice**|
|---|---|---|---|---|---|---|---|---|---|---|
||**Area**<br>**(ha)**|**Prod (Mt)**<br>**Paddy**|**Area (ha)**|**Prod (Mt)**<br>**Paddy**|**Area**<br>**(ha)**|**Prod**<br>**(Mt)**<br>**Paddy**|**Area**<br>**(ha)**|**Prod (Mt)**<br>**Paddy**|**Area**<br>**(hHa)**|**Prod**<br>**(Mt)**<br>**Paddy**|
|Bo|78,311|70,871|7,286|13,901|1,098|1,270|4,834|12,061|0|0|
|Bombali|54,654|44,598|16,659|26,388|4,850|3,989|4,212|11,859|0|0|
|Bonthe|7,384|7,923|9,048|15,020|1,421|1,449|4,240|11,908|3,221|10,178|
|Kailahun|73,989|82,646|21,836|37,645|0|0|4,309|11,524|0|0|
|Kambia|32,124|29,008|20,406|45,036|4,671|4,297|3,499|8,956|872|2,486|
|Kenema|96,557|90,570|15,959|26,731|0|0|3,554|9,168|0|0|
|Koinadugu|48,183|51,074|19,148|52,121|3,542|3,797|2,640|8,762|0|0|
|Kono|56,743|59,921|19,422|29,366|0|0|2,168|5,507|0|0|
|Moyamba|68,585|64,401|7,874|13,386|2,330|2,796|3,987|11,164|1,724|4,931|
|Port Loko|53,448|45,645|22,779|33,576|4,742|5,121|4,753|9,506|3,247|9,221|
|Pujehun|31,218|33,122|8,816|12,395|1,261|1,319|3,048|7,803|1,023|2,949|
|Tonkolili|58,954|62,786|20,799|29,930|3,570|3,213|3,028|8,197|0|0|
|W/Area|2,365|2,247|543|992|180|184|1,373|3,165|287|679|
|**National**|**662,515**|**644,812**|**190,575**|**336,487**|**27,665**|**27,435**|**45,645**|**119,580**|**10,374**|**30,444**|
|**Average**<br>**Yield**||**_0.97_**||**_1.77_**||**_0.99_**||**_2.62_**||**_2.93_**|

Source: Ministry of Agriculture, Sierra Leone, 2016 Paddy harvesting activities include reaping, stacking, handling, threshing, cleaning, and hauling, all laborintensive activity in Sierra Leone. Most rice varieties are composed of roughly 20 percent rice hull or husk, 11 percent bran layers, and 69 percent starchy endosperm, also referred to as the total milled rice. Milling is an important step in the post-production of rice, involving the removal of husk and brand layers to produce an edible output of kernels with minimum breakage and free of impurities. The by-products in rice milling process are rice hull, rice germ and bran layers, and fine broken kernel pieces. Milling yield is usually determined according to the procedure of the International Rice Research Institute (2009b) using the formula: Milling yield = [Weight of white rice/ Weight of paddy] x 100.

In Sierra Leone, and average of 60 percent of milled rice is recovered from the paddy. This is the conversion factor that is assumed in the model. Appaiah et al (2011) found that in Ghana the advanced mills demonstrated a conversion factor of 67.3 percent, the inefficient mills were at 50 percent and the locally made mills operated at 47.1 percent conversion. Singha (2013) found conversion factors for India in the range of 64 percent for the modern mills and 58.6 for traditional mills.

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