Linking soil microbial nutrient limitation to fertilizer regime and sugar beet yield (2019.0)

Lemanski K., Armbruster M., Bonkowski M.

Plant and Soil, 441 (1-2), 253-259

doi:10.1007/s11104-019-04114-w

Abstract

Aim

Depending on the availability and stoichiometry of nutrients in soil, microbes and plants can compete for the same resources. In this study we aimed to test how microbial nutrient limitation in agricultural systems can be linked to fertilizer regimes and sugar beet yield.

Methods

We measured the dynamics of microbial growth responses by monitoring soil respiration after the application of carbon (C), C and nitrogen (N), C and phosphorus (P) and C, N and P to soils of an agricultural long-term fertilization experiment in Speyer (Germany). Samples were taken in February and June before harvest and in November after harvest.

Results

CN limitation in June was the best predictor for sugar beet yield, with increasing CN limitation there was a decreasing yield. Mineral N fertilization in May alleviated microbial N limitation in June. Over the course of the sampling, microbial nutrient limitations were highest after harvest in November.

Conclusions

Together, our results indicate that plants and microbes compete for the same nutrients, and that plants are more competitive at acquiring them. Measurements of microbial nutrient limitation four months before harvest successfully predicted sugar beet yield and could therefore be used as a diagnostic indicator.