On average, yield increases that come from applying extra nitrogen do not offset the cost of the fertilizer. In corn and soybeans, fertilizer can easily account for 25 to 30 percent of a grower's cost. Economically, it is a critical component. If it is not actually needed, then it is a waste not only of money but also of time and labor. Poultry litter is put out before a crop is planted.
Farmers have to stop about every eight acres to refill hoppers with fertilizer.
If a grower only has to put out seed, he can go for about 20 acres without stopping. I cut my P and K down dramatically. I didn't think that was possible. Historically my land has had high P and K indexes, and I wanted to maintain those levels, but Ben showed me that wasn't environmentally sound. Excess fertilizer nutrients, especially nitrogen and phosphorus, have the potential to pollute groundwater and waterways.