Two agri-tech projects from Hong Kong are seeking to tackle some of the most pressing challenges facing agriculture, from resource scarcity and labor shortages to rising greenhouse gas emissions, while eyeing the US market for deployment.

The first is a regenerative, solar-powered air-to-fertilizer production platform developed by Amonova, a Hong Kong-based agri-tech startup with manufacturing on the Chinese mainland.

The system uses air, water and light to produce nitrogen fertilizer locally, allowing farms to reduce their dependence on large centralized production plants and long international supply chains.

"Our ambition is to change where fertilizer is made. Today, farmers around the world depend on nitrogen produced in a small number of large plants, often thousands of kilometers away," said Simson Wu, founder and CEO of Amonova.

Amonova is part of a Hong Kong delegation visiting Silicon Valley to showcase technologies and meet potential investors.