As plants grow, they absorb and deplete (or mine) nutrients from the soil. Farmers harvest those same nutrients when they harvest crops. Fertilizers, whether mineral or organic, nourish the soil by returning essential mineral nutrients.
It is a biological fact that plants require 1.0 kilogram (kg) of nitrogen to produce 10 to 15 kg of grain. Our atmosphere is about 80 percent nitrogen. Most tropical soils fix, or draw from the atmosphere, enough nitrogen to produce about 1 metric ton (mt) of grain per hectare. To produce more grain, the plants must have more nitrogen, whether from organic or mineral fertilizer sources. Plants must also have phosphorus, potassium and trace minerals. If a soil lacks or has insufficient amounts of these minerals, they must be added as fertilizers or production will stagnate or cease.
