Imported phosphate for fertiliser is expensive – could this homegrown alternative be a solution?
Research shows a phosphorus-rich compound found in wastewater raises uptake by plants and reduces discharge to waterways.
Since the conclusion of World War II, phosphorus supplementation in soil through mineral fertilisers has been vital to sustaining and expanding worldwide agricultural output, primarily in response to population booms. However, plants typically only absorb 20-50% of the phosphorus present in fertiliser applications. The surplus phosphorus is largely fixed in soil via chemical reactions, generating "legacy soil phosphorus" that elevates the danger of water pollution. In New Zealand, phosphorus for fertilisers is solely produced from imported phosphate rock.
An alternative to this conventional method is struvite, a phosphorus-enriched compound recoverable from wastewater treatment procedures. Our research indicates that struvite can heighten plant phosphorus absorption and potentially diminish phosphorus transfer into water bodies, potentially replacing conventional phosphorus fertilisers at least partially.
After a field trial, it was discovered that applying struvite instead of single superphosphate increased perennial ryegrass absorption by more than 30%, resulting in achieving a similar plant yield with a third less phosphorus added to the soil. This research, corroborated by data from a three-month glasshouse experiment, demonstrates that struvite could be a feasible and sustainable substitute for conventional phosphorus fertilisers in New Zealand's primary sectors.
Further research is required to determine how various soil types, plants, and environmental factors affect the efficacy of struvite phosphorus and its commercial viability.
Written by urgent.news from The Conversation AU's reporting — not their text. Machine-written — may contain errors; check the original before relying on it.
