Auteur: Ros G.H., Bussink D.W. and Reijneveld J.A.
Jaar van uitgifte: 2015
The ability of soils to meet nitrogen (N) requirements of grass via mineralization of organic matter is of economic and environmental importance to farmers and society. Soil N mineralization is controlled by soil organic matter dynamics and regulated by water availability and temperature. In the Netherlands, the soil N supply in grasslands is estimated by a statistical model relating N supply to the total amount of N present in soil. We showed that a single N index is insufficient to predict the contribution of N mineralization at field scale, limiting the farmer’s possibilities to optimize yields and N-use efficiency. Based on experimental data, we integrated routine soil and climatic parameters in simple empirical models explaining more than 50% of the variation in annual N supply. Combining this information with recent organic manure applications, national fertilizer regulations and optimum N dose-response relationships we showed that the net N efficiency of farming systems can be improved, both on field and farm scale. The developed algorithms are implemented in Dutch advisory systems and will boost the efficiency of N fertilizers.