A student developed a smart irrigation system to help farmers optimize water usage on their crops. With water scarcity becoming a major issue globally, especially for agriculture, the student designed a low-cost automated irrigation system controlled by soil moisture sensors and a mobile app. The system monitors soil moisture levels in different areas of the field and only waters sections that need it, cutting water usage by up to 30% compared to traditional irrigation methods. It also allows farmers to control the system remotely via their smartphone. The student conducted field tests on a local farm over a growing season to collect data on water and cost savings. They presented the results to the farming community and several expressed interest in adopting the system. Some have since implemented it on their farms with positive results.

Another project focused on sustainable aquaculture and developed a recirculating aquaculture system (RAS) for growing fish. RAS aims to minimize water use and waste by recirculating the same water through a series of biological and mechanical filters that keep the water clean. The student designed and built a small-scale RAS to grow tilapia as a proof of concept. They incorporated several filtration stages including mechanical filtration to remove solid wastes, biological filtration using nitrifying bacteria to break down ammonia, and disinfection using UV light. Oxygenation was also added to keep dissolved oxygen levels high for the fish. Over a 12-week period, the student monitored water quality parameters and fish growth rates, finding the system was effective at maintaining water quality within acceptable levels for the tilapia with minimal water changes needed. They determined the system could be scaled up for commercial aquaculture use. The local aquaculture department was impressed with the project results and discussion has begun on potentially incorporating RAS technology in future farm expansion plans.

Another successful capstone involved developing a low-cost mobile grain drying system that could help smallholder farmers in developing nations properly dry and store harvests to avoid spoilage. After harvest, grains like maize, rice and wheat need to be dried before long-term storage to reduce moisture levels and prevent mold growth and food losses. The cost of stationary dryers is often prohibitive for small farms. The student designed a solar-powered mobile dryer mounted on a trailer that could be transported between fields. It used solar thermal collectors and a small fan and vents to slowly circulate heated air through perforated trays of grain over 3-5 days. A microcontroller automatically regulated the drying process. After testing prototypes on-farm, results showed the system could dry a ton of grain for around $500, significantly lower than other options. Partnering with a local NGO, the student helped set up a grain drying cooperative where farmers could share access to the mobile dryer, lowering individual costs further. By preventing spoilage, the dryer helped improve food security and farmer incomes. The NGO has since scaled up use of these dryers across multiple regions.

Those represent some examples of in-depth capstone projects focused in different areas of agriculture that addressed real industry challenges and had tangible, positive impacts. Sustainable agriculture projects also commonly center around topics like improving soil health, reducing agricultural runoff pollution, increasing productivity through technologies like precision agriculture, developing new varieties of drought-tolerant or pest-resistant crops, and diversifying farm revenue through expanded direct marketing or agritourism initiatives. No matter the specific topic, impactful projects demonstrate thorough research, careful planning and implementation of prototype systems or pilot programs, collection of meaningful data, and presentation of clear results and recommendations that can contribute new knowledge or solutions for the agriculture sector. Effective communication and partnerships with local farmers, businesses and organizations also help ensure projects have reach and potential for further application beyond the academic setting.