The issues of soil quality impact on humans and environmental migration have been highly debated in the scientific community. However, studies previously conducted on these issues have lacked a large-scale program to monitor soil-degradation. Furthermore, no study has examined economic or social concerns about soil quality outside of agriculture. With the intention to correct these oversights, Gray et al (2011). sought to measure how soil quality impacts internal migration from grain-producing households in the East African Highland countries of Uganda and Kenya. The results of the study show that out-migration from these counties declined with soil quality. Soil quality in Kenya was particularly relevant for migration in small farm households. In Uganda, there was an increase in marginal migration with soil quality, which is consistent with the poverty trap of migration where rural population is large and access to agricultural resources is limited. The authors of the study see their work as a necessary consideration for development policy in Kenya and Uganda. –Adriane Holter
Gray, Clark L., 2011. Soil quality and human migration in Uganda and Kenya. Global Environmental Change 21, 421— 430
To implement their study, Gray et al. used a longitudinal survey dataset with information collected through the Research on Poverty, Environment, and Agricultural Technology (REPEAT) project. This dataset contained information on migration and soil properties for 1200 households. From this information, the researchers created a household-level measure of soil quality as well as the rate that single persons undertook either temporary or permanent migration. A model of possible random effects tested the effect that soil quality had on migration with a control for household variables.
In Kenya, soil quality had a negative effect on migration. The likelihood for temporary labor migration was 67% lower and permanent labor migration was 42% less likely to occur when soil quality was high. Researchers found that women or married individuals were the most likely to undertake both temporary and permanent non-labor migration. This result is significant because it highlights how responses to soil degradation have gendered manifestations in society. Multiple attachments to several households as a result of marriage helps explain the increase in migration for married individuals. Additionally, migrants were stratified by age with the largest amount of movement occurring between 25 and 29-years-old except for permanent labor migration, which peaked between 35 and 49-years-old.
Since Uganda had a smaller sample size than Kenya, the results from the study are not as dramatic. Nevertheless, research in the country found that soil quality had a marginally positive effect on migration, especially for permanent non-labor migration. There was no clear gender divide for migration, but like Kenya age was also an issue in Uganda with temporary and permanent labor migration peaking between 30 and 34-years-old. Temporary non-labor migration was not affected by age. Also like Kenya, the likelihood of migration increased for married individuals. Importantly, individuals in both countries were less likely to migrate if they had been educated. This information reveals the socio-economic advantage afforded to the educated in the realm of migration, signaling a class-based element of the issue. Additionally, non-labor migration increased with a large number of inhabitants in a household and when the household owned large parcels of land. These results reflect the interplay of resource holdings with the need for human movement to sustain household livelihoods at a desired level.