Organically grown grassclover in nature areas to remove soil phosphate for development of specious rich grasslands

Summary

Worldwide the current reserves of phosphate rock are being exhausted. In The Netherlands many former agricultural soils have been enriched by large quantities of phosphorus as a result of fertilization. It is thought that this phosphorus prevents development of target-nature types. Nature organizations currently seek ways to remove it. We tested grassclover, organically managed by local farmers, as a tool to extract excessive soilphosphate from nature areas and reimport it into the mineral cycle agricultural farms. In a small scale experiment we have shown that grassclover with potassium fertilization can remove more than twice the amount of soil phosphate compared to mowing alone. We tested the methodology on 60 ha of grasslands in nature areas and measured large decreases in soil phosphate. We conclude that organically managed grassclover could form an elegant way to solve problems with excessive soil phosphate in nature areas and recycle phosphate.