Agriculture is under heavy pressure to innovate due to the needs of feeding a rapidly growing global population while agricultural productivity has largely plateaued in recent decades. It is estimated that the world population will reach 9.1 billion by 2050 and the yearly demand for cereals, for instance, will increase by 43%, from 2.1 to 3 billion tonnes. Optimizing crop productivity and addressing current process inefficiencies are critical to meeting the increased demand without creating excessive energy and materials resource demands. Pesticide application, for example, is a highly inefficient process and it is estimated 2.45 billion kg of pesticides are wasted every year because of current application practices. That corresponds to 90% of the total pesticide applied, which end up contaminating the soil, water bodies, and impacting a range of living organisms, including humans. Nanotechnology is viewed as a promising technology to improve pesticide application. Nanocarriers, a class of nanomaterials, can be used as delivery agents for pesticides to provide slow and targeted release in the plant, and protect them against premature degradation and uptake in plants. Therefore, the use encapsulated pesticides within nanocarriers, have the potential to reduce wastage during application. The objective of the thesis is to explore the feasibility and efficacy of deploying silica nanoparticles as pesticide nanocarriers for agriculture. The scope includes the synthesis, characterization, and application of silica nanocarriers and assessing their mobility in the subsurface. The first objective was to develop a reproducible method to synthesize porous hollow silica nanoparticles (PHSN) through soft templating. In summary, when combined in the right ratio, two surfactants, cetyltrimethylammonium bromide and Pluronic P123, self-assemble forming the template onto which the SiO2 precursor can anchor to grow the SiO 2 shell. The resulting PHSN population was monodisperse with diameter of 258 nm, specific surface area of 287 m 2 g-1 and pore size ranging from 1.5 to 2 nm. The characterization was performed using a suite of techniques, including solid-state nuclear magnetic resonance, Fourier-transform infrared spectroscopy, transmission electronic microscopy and light scattering. It was also the first imaging demonstration of nanoencapsulation where iron (Fe) and borohydride ions diffused in the pores to reach the hollow cavity and reacted forming entrapped Fe nanoparticles. The second objective was to investigate the impacts of particle architecture and surface properties on transport in saturated porous media. Solid SiO 2 nanoparticles and PHSN were tested under varying experimental conditions of pH and ionic strength. Retention of PHSN was significantly higher across the board, which was not captured by modeling. This suggests that particle architecture and surface properties play a role in the transport profile. The third objective was to investigate the impacts of nanoencapsulated azoxystrobin added to soils on plant growth and soil microbial community and how these compare with non-encapsulated formulations. Not only did the nanocarriers mitigate the toxicity of the pesticide, they also did not interfere with the soil and plant health. The fourth objective was to explore the uptake and translocation of the nanoencapsulated azoxystrobin in tomato plants following foliar application. It was demonstrated that both the nanocarrier and the pesticide were taken up and distributed throughout the plant, even though the particle size exceeded the size excluding limits discussed in the literature