An agronomist's advice for Patrícia's onions farm in São Paulo

I farm 3 hectares of onions in São Paulo. This season I'm dealing with yields that have halved for two seasons. I've tried what the local suppliers recommended, but results aren't improving. I'm looking for an agronomist or experienced grower who can look at photos, soil-test results and my planting plan, and advise on what to change. A 30-minute call or exchange of messages would be fantastic. I'm happy to share photos and a soil test. I'm using only what I can afford, so low-cost suggestions are best. I'll share how it goes - and what worked - to help others in the community. You're what makes this possible, and I'll never forget it.