The soybean crop, one of the key crops to the United States, China and Brazil, demands significant amounts of fertilizers, especially phosphates (SILVA; LODI; OLOVICIN, 2013). Brazil is the fourth-largest consumer of fertilizers in the world, representing around 6.0 % of world consumption, behind only China, India and the United States. In some crops, such as cotton, the cost of fertilizer is 30 % of the total cost of production, leading farmers to adopt practices that increase the efficiency of fertilizers in intensive grain and fiber production systems. Conservationist agriculture is responsible to appropriate physical, biological and chemical agricultural conditions for crops to express their genetic productive potential (ZACANARO; KAPPES, 2014).