**2. Literature Review**

#### *2.1. Farm Production Diversity in Smallholder Agriculture*

Smallholder farming systems particularly in Sub-Saharan Africa are characterized by a considerable amount of diversity, owing to heterogeneous biophysical and socio-economic environments [19]. Consequently, smallholders are confronted with multiple constraints and opportunities in their environments, which ultimately shape the diversity of their strategies [19,20]. As argued by Barrett [20], diversification of assets, activities or incomes by farm households may be due to "push factors" such as land or liquidity constraints and high transaction costs or "pull factors" where new opportunities may provide higher returns and thus enable improvement of livelihoods. Farm production diversity constitutes part of smallholder diversification strategies. Fundamentally, farm production diversity, which falls within the broader concept of agro-biodiversity, entails not only maintaining a variety of species for both plants and domestic animals but also genetic diversity within each species [12].

The level of farm diversity maintained by smallholders depends on households' socio-demographic characteristics (such as age, gender and education) and assets such as land and

labor [21,22]. Households' productive assets can be, in particular, important in enhancing the capacity of households to exploit the advantages of production diversity such as through crop-livestock integration. Equally important, agro-ecological characteristics, access to markets and available infrastructure are also instrumental in influencing the level of farm production diversity [22,23]. Corral and Radchenko [24], for example, note that in Nigeria, decisions by households regarding diversification are driven by factors in the local environmental such as constraints in infrastructure and weather shocks. Depending on existing agro-ecological characteristics, smallholders may be inclined to maintain a high diversity in their production due to presence of climatic and other agricultural risks. Similarly, smallholders may substantially rely on self-provision of food in less accessible villages due to high costs of accessing markets, thereby maintaining a higher diversity at the farm. Following on the "push factors" argument, farm production diversity can be used as a way of mitigating risks by smallholders, especially in presence of output market imperfections and harsh agro-ecological environments [8,25].

#### *2.2. Linking Production Diversity to Consumption Diversity*

The wider benefits of maintaining diversity of various species—both plants and animals—by smallholders are well argued in the literature. The contribution of this diversity includes enhancing resilience of food production, provision of important nutritional benefits and supporting the overall sustainability of food systems [12]. However, despite these unarguably important benefits, promotion of farm production diversity for improved nutrition has confronted several challenges. An example is the existence of agricultural and food security policies in many developing countries which promote a few cereal staples. This follows decades of implementation of Green Revolution policies, which focused primarily on cereal-based systems—involving mainly maize, rice and wheat—to enhance calorie availability [12]. In addition, Hunter and Fanzo [26] argue that there is a general lack of empirical evidence that links biodiversity and improved nutrition outcomes such as dietary diversity.

In recent empirical literature, several studies show a positive influence of farm production diversity on household food consumption diversity. For example, in a wide study involving eight developing countries, Pellegrini and Tasciotti [8] assessed the role of crop diversification and found a positive correlation between the number of crops cultivated and indicators of dietary diversity. Similarly, Oyarzun et al. [27] observed that on-farm species diversity is positively correlated with household-level dietary diversity in the Ecuadorian rural highlands. Also using a nationally representative sample of farming households in Malawi, Jones et al. [3] found that farm production diversity is positively associated with dietary diversity. However, these results may be context driven and thus promoting farm production diversity cannot be viewed as a blanket policy to enhance dietary diversity of most rural smallholders. In addition, this literature acknowledges that the relationship may be complex given influences of household characteristics, market orientation and the nature of farm diversity. In Tanzania, Herforth [18] offers first insights into the relationship between farm production diversity and food consumption diversity at the household. Using household data from northern Tanzania and central Kenya, the study found that crop diversity was positively associated with household dietary diversity. However, it does not offer insights on diverse contexts as it was based on areas with largely similar agro-ecological and market access characteristics. Also, farm diversity was limited to crop diversity (i.e., the number of crops grown by a household).

Conversely, mixed results have also been documented. KC et al. [11] observed in three agro-ecological regions of Nepal that crop diversity was more beneficial in enhancing food self-sufficiency for households in low agricultural potential areas and with poor market access compared to those in agro-ecological zones with higher agricultural potential and market access. Also, Sibhatu et al. [9] conducted a study using household-level data from Malawi, Kenya, Ethiopia and Indonesia. They observed that on-farm production diversity was not positively associated with dietary diversity in all cases and that this relationship depended on the level of production diversity and the nature of market access. In addition, the relationship between farm production diversity and

food consumption diversity was insignificant, and even negative, at higher levels of diversification, implying foregone income from specialization. With this, specialization and market access could also be argued to play an even stronger role in enhancing food consumption diversity. However, context still matters. Radchenko and Corral [24], for example, in a study looking at agricultural commercialization and food security in Malawi, found that higher agricultural incomes from cash cropping did not translate to higher food expenditures and better diets. The transmission from agricultural income to higher nutrition-related expenditures was rather weak. Other studies find no significant associations between farm diversity and dietary diversity. For instance, Ng'endo et al. [28] found no strong association between on-farm diversity and dietary diversity among smallholders in western Kenya. Instead, socioeconomic factors such as household wealth and education played a stronger role in influencing dietary diversity.

Accordingly, in assessing the links between the nature of farm production diversity and food consumption diversity, an emerging realization is the significant role of opportunities and constraints provided for by household socio-economic factors and the existing market characteristics and agro-ecological environment. The theorized links are summarized in the conceptual framework presented in Figure 1. Food security outcomes (such as food consumption diversity) are assumed to be influenced by the level of agro-biodiversity (represented here by farm production diversity). In addition, farm production diversity and food consumption diversity are also influenced by household socio-economic factors together with the existing agro-ecological and market access characteristics.

**Figure 1.** Conceptual framework (Authors' construction based on KC et al. [11]).
