With a plentiful supply of livestock manure, compost and cover crops, the Northeast states may provide prime organic crop production land. That's because nitrogen is one of the most limiting factors of organic crop production, suggests a study by McGill University of Montreal, Canada and the University of Minnesota.
The study, published recently in Nature journal found that organic crop yields average 25% less than conventional crops. It compiled results from 66 studies across 34 crop species.
But results varied by crop. Organic fruit, perennials and legumes like soybeans, for example, nearly matched conventional crop yields in rain-watered applications. But organic cereal crops yielded 26% less and organic vegetables were 33% lower. The differences were even greater on irrigated acres. Part of the reason is that those cereal crops and vegetables require more plant nutrients – nitrogen, phosphorus and potassium.
The biggest challenge for organic production is getting enough nitrogen to the crops that need it, says Verena Seufert, the lead researcher at McGill University. Organic crops rely on manure, compost or cover crops – in plentiful supply in the Northeast. Another challenge is controlling weeds and pests in organic fields.
An even bigger question in all of this is: Can we produce enough food to feed an estimated 9.5 billion people by 2050? While some contend conventional agriculture is not sustainable, organic agriculture cannot produce enough food.
The answer may lie somewhere in between, what Seufert describes as a "hybrid system" utilizing management practices from both systems. That's what many would call "sustainable farming".