Environmentally friendly agronomically superior alternatives to chemically processed phosphate fertilizers: Phosphate rock/sulfur/Acidithiobacillus sp. combinations

Phosphate fertilizers are produced from phosphate rock (PR), an indispensable and finite resource. To extend its life span, the mined PR needs to be processed into P fertilizers with minimum waste. The fertilizers need to supply P to plants at optimal levels and maximum efficacy. It is also imperative that the production of P fertilizers and their usage should not have a significant negative impact on the environment. Production and usage of currently manufactured and widely used phosphate fertilizers such as triple superphosphate and ammonium phosphates have stark limitations in all these respects. PR premixed with elemental sulfur (So) and Acidithiobacillus sp. bacterial culture (PR/So/Cult) or without the culture (PR/So) are environmentally friendly phosphate fertilizers. In this Chapter, using meta-analyses results from multiple trials conducted across countries we quantified the agronomic effectiveness of PR/So/Cult and PR/So on permanent pastures and seasonal crops. Strong evidence emerges that PR/So/Cult is agronomically a better alternative to chemically processed fertilizers for application to permanent pastures and short-term crops in a wide range of soil and climatic conditions. Considering the simplicity of the method, the fertilizer can be manufactured at remarkably low capital and operating costs. The conclusions support the need for a major change in phosphate fertilizer production moving towards biotechnology and away from chemical processing. A recently innovated biotechnology has the potential for large-scale production of PR/So/Cult.