3.2.5 Farm Size
Farm size is relevant to the efficiency of resource use in crop production, but with controversial conclusions. Many studies suggested that smaller farms are more sustainable in their uses of some resources (D’Souza and Ikerd 1996, Altieri 2009). However, some studies found that smaller farms tend to use more fertilizer and have lower nutrient use efficiency (Ju et al. 2016, Wu et al. 2018).
Analysis both on the national and global scales suggests a generally positive relationship between adjusted average farm size and PUE (Table 4). Twenty-three countries show a significant positive relationship with PUE, more than those with a significant negative relationship (16 countries). These 23 countries accounted for 14% of the global harvested area, 14% of P in harvested crops, and 13% of P fertilizer input in 2010. Note that these results do not necessarily mean that large farms are “better” than small farms, as there are other socio-economic reasons behind the relationship. Besides, increasing farm size may bring into other problems, such as decreased food diversity (Herrero et al. 2017).
3.3 Projected Phosphorus Budget and Challenges in 2050