Database: Biomass yield, yield stability and soil carbon and nitrogen content with various cropping systems targeting future biorefineries

Ideally, climate-smart and robust agriculture could increase biomass yield and yield stability, while protecting soil carbon (C) and nitrogen (N) content. However, few studies have rigorously explored the effects of various cropping systems on biomass yield, yield stability and soil C and N content in the same experimental platform. In this study in Denmark, 10 different cropping systems are simultaneously investigated for their biomass yield, yield stability and changes in soil C and N content over 5 years. Those 10 various cropping systems can be divided into: (1) two continuous monocultures, (2) optimized crop rotations for longer growing season and higher radiation use efficiency, (3) five intensively fertilized perennial grasses, and (4) two grass-legume mixtures without N fertilization. Our results showed that biomass yield and yield stability highly differed across various cropping systems, highlighting the species-specific characteristics. Across those 10 cropping systems, tall fescue significantly increased top layer soil C and N content, while sustaining relatively higher biomass yield and yield stability. There was generally no clear relationship among biomass yield, yield stability, and changes in soil C and N content across the five years (with the only exception for biomass yield and changes in top layer soil N content). These results suggest that we could potentially increase biomass yield and yield stability without weakening soil C and N content through optimizing cropping systems or cropping managements. Our results highlight the importance of species-specific documentation of biomass yield, yield stability and changes in soil C and N content in the same experimental platform, whereas long-term continuous observations are still required to clarify the relations among them.