Rates and Residual Effects of Potassium Fertilization in a Brazilian Soil

IPNI-2010-BRA-56

06 Sep 2010

Project Description


The requirement for worldwide abundant food, feed, fiber, and more recently biofuel, leads to higher amounts of fertilizer utilized in agriculture in diverse parts of the globe. Potassium (K) is, most generally, the second nutrient in terms of plant demand (after nitrogen, N). Potassium is highly mobile in most soils and relatively mobile in the plants. This nutrient is responsible for several vital mechanisms for plant development and high yields (enzyme activation, translocation and stock of compounds, osmotic regulation, water maintenance, etc). Potassium fertilizers are very commonly a must in terms of plant nutrition in acid soils of the tropics, including Brazil. In many areas farmers are cutting back on fertilizer expenses, which could compromise good yields, profit and food safety in the future. Farmers expect that the soil supply will be sufficient to provide the ideal conditions for plant development and yield, even with lower or no supply of K fertilizers. Studying the impacts of K fertilizer cut back on Brazilian soils is absolutely essential as to demonstrate the effects in the medium to long run. The main objective of the study will be to verify the effects of cutting back K fertilizer rates in some Brazilian soils. Also, it will be possible to study other important factors which affect the K fertilizer effectiveness in tropical soils.