Zeolites: Potential soil amendments for improving nutrient and water use efficiency and agriculture productivityAuthor(s): Vijay Sandeep Jakkula and Suhas P Wani
The fertilizer use in developing countries has shown a steady increase over the last few decades, and the use and manufacture of N fertilizers contributes to about 60% of the total release of reactive N. Higher farm subsidies and lower N fertilizer prices have further increased N inputs. Inappropriate fertilization patterns and excessive use of N fertilizer have resulted in considerable N losses through ammonia NH3 volatilization and NO2 leaching. This has meant that NUE has been as low as ~35%. An efficient crop nutrient management is important practice and thus, new designer or smart N fertilizers technologies are needed to support the increasing demand and avoid the low nitrogen use efficiency (NUE). The ammonia nitrogen volatilization and nitrate leaching can be reduced or prevented by the use of zeolite carrier material applications which have N in their framework and act as slow/controlled release fertilizers. These materials will reduce ammonia volatization and nitrate leaching and at the same time increase crop yield. Zeolites are also known for their water holding capacity and in drylands they are the most suitable fertilizers to prolong moisture levels in severe drought like conditions. In addition to macronutrients, micronutrients can also be introduced into zeolites which can supplement nutrient deficient soils. Thus, zeolites along with increasing yield can also increase the nutrient and water use efficiency of drylands.