School of Sustainability Graduate Culminating Experiences
Student capstone and applied projects from ASU's School of Sustainability.
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- Creators: Beye, Alioune
- Creators: Brelsford, Christa
Description
In Senegal, West Africa, soils are a vital resource for livelihoods and food security in smallholder farming communities. Low nitrogen (N) soils pose obvious challenges for crop production but may also, counterintuitively, promote the abundance of agricultural pests like the Senegalese locust, Oedaleus senegalensis. In this study I investigated how the abundance of locusts and grasshoppers are impacted by soil fertility through plant nutrients and how these variables change across land use types. We worked in two rural farming villages in the Kaffrine region of Senegal. Overall, there was little variation in soil properties and an agricultural landscape low in soil organic matter (SOM) and inorganic soil nitrogen. I corroborated that SOM is a significant driver of soil inorganic N, which had a positive relationship to plant N content. Of the management practices we surveyed, fallowing fields was important for soil nutrient restoration and years spent fallow was significantly correlated to inorganic soil N and SOM. O. senegalensis was least abundant in groundnut areas where plant N was highest. Additionally, I found a significant negative correlation between O. senegalensis abundance and plant N, suggesting that plant nutrients are an important driver of their populations. Grasshoppers, excluding O. senegalensis, were more numerous in grazing areas and fallow areas, perhaps due to a higher diversity of ecological niches and host plants. These results connect land use, soil, and vegetation to herbivores and suggest that improving soil fertility could be used as an alternative to pesticides to keep locusts at bay and improve crop yields.
ContributorsWord, Mira (Author) / Hall, Sharon (Contributor) / Robinson, Brian (Contributor) / Manneh, Balanding (Contributor) / Beye, Alioune (Contributor) / Cease, Arianne (Contributor)
Created2018-04-10
Description
As arid cities’ water scarcity concerns grow, so does the importance of residential water conservation. Understanding the drivers of participation in water conservation programs can aid policymakers in designing programs that achieve conservation and enrollment targets while achieving cost-effectiveness and distributional goals. In this study I identify and analyze the characteristics that drive participation in the Southern Nevada Water Authority’s Water Smart Landscaping rebate program – a program that pays homeowners to replace their grass lawns with xeric landscaping – and how those characteristics change over time as rebate values and water prices vary.
In order to determine what characteristics influence participation in this program I gathered data from multiple sources. I use a panel dataset of household water consumption that spans 12 years of approximately 300,000 homes. I merged this dataset with home structural characteristics, geographical, and demographic context. I then use these characteristics in a linear probability model, with school enrollment zone fixed effects to determine their influence on a household’s probability of participation. School zones are used to control for unobserved characteristics, such as demographics, which are not at a household level. I then utilize these school zone fixed effects in a 2nd stage regression to decompose these elements and analyze their effect on participation.
I find that a household’s water costs, as reflected in the marginal price faced in the summer and the differential between summer and winter water bills, as well as yard size are primary factors that influence participation. I also show that changes in rebate value and water rates can affect different types of households. There is also evidence to support that neighborhood characteristics affect a household’s likelihood of participating.
In order to determine what characteristics influence participation in this program I gathered data from multiple sources. I use a panel dataset of household water consumption that spans 12 years of approximately 300,000 homes. I merged this dataset with home structural characteristics, geographical, and demographic context. I then use these characteristics in a linear probability model, with school enrollment zone fixed effects to determine their influence on a household’s probability of participation. School zones are used to control for unobserved characteristics, such as demographics, which are not at a household level. I then utilize these school zone fixed effects in a 2nd stage regression to decompose these elements and analyze their effect on participation.
I find that a household’s water costs, as reflected in the marginal price faced in the summer and the differential between summer and winter water bills, as well as yard size are primary factors that influence participation. I also show that changes in rebate value and water rates can affect different types of households. There is also evidence to support that neighborhood characteristics affect a household’s likelihood of participating.
ContributorsRusso, Jonathan (Author) / Abbott, Joshua (Contributor) / Brelsford, Christa (Contributor) / Larson, Kelli (Contributor)
Created2018-04-21