This thesis conducted an evaluation of the performance and return on investment of a 2 x 6m, simple design greenhouse, as a climate control technology. Specifically, differences in internal microclimate conditions between a greenhouse treatment plot, and sun and shaded control plots were assessed and related to observed differences in crop yields across these plots. Growing conditions and productivity of two crops, tomato and swiss chard, which were grown over summer and winter growing seasons, respectively, were compared. It was found that the greenhouse was associated with improved growth conditions (as measured by the R-Index) for both crops but resulted in higher productivity only for tomatoes. Return on investment and food security impacts from the scaling of greenhouse agriculture were also explored.

Urea is an added value chemical with wide applications in the industry and agriculture. The release of urea waste to the environment affects ecosystem health despite its low toxicity. Online monitoring of urea for industrial applications and environmental health is an unaddressed challenge. Electroanalytical techniques can be a smart integrated solution for online monitoring if sensors can overcome the major barrier associated with long-term stability. Mixed metal oxides have shown excellent stability in environmental conditions with long lasting operational lives. However, these materials have been barely explored for sensing applications. This work presents a proof of concept that demonstrates the applicability of an indirect electroanalytical quantification method of urea. The use of Ti/RuO2-TiO2-SnO2 dimensional stable anode (DSA®) can provide accurate and sensitive quantification of urea in aqueous samples exploiting the excellent catalytic properties of DSA® on the electrogeneration of active chlorine species. The cathodic reduction of accumulated HClO/ClO− from anodic electrogeneration presented a direct relationship with urea concentration. This novel method can allow urea quantification with a competitive LOD of 1.83 × 10−6 mol L−1 within a linear range of 6.66 × 10−6 to 3.33 × 10−4 mol L−1 of urea concentration.