Ievina Sturite
Research Scientist
(+47) 934 99 484
Ievina.Sturite@nibio.no
Place
Steinkjer
Visiting address
Ogndalsveien 2, 7713 Steinkjer
Abstract
Me fornyar enga for at avlinga skal verta større og ha betre kvalitet. Omlaupslengden er ein balanse mellom meir avling/kvalitet og kostnadar ved fornying.
Authors
Thiago Inagaki Frederik Bøe Ievina Sturite Meike S. Bärmann Franziska Bucka Alice Budai Anders Aas Daniel RasseAbstract
In high-latitude arable systems (63.9°N), short growing seasons and cold climates often constrain regenerative practices. This study investigates how cover crop (CC) diversity influences the synergy among root development, carbon (C) persistence, and nutrient (N and P) dynamics within a barley (Hordeum vulgare L.)-oat (Avena sativa) rotation. Over three years, we evaluated a gradient of CC intercropping complexity using a randomized complete block design. Treatments were: (1) Control (barley/oat without NPK), (2) Biochar-Fertilizer (barley/oat + NPK + 1.8 Mg ha-1 year-1 biochar), (3) Monocrop (barley/oat), (4) Ryegrass (barley + ryegrass), (5) Clover (barley + ryegrass + white/red clover), and (6) Chicory (barley + ryegrass + red clover + chicory + bird’s-foot trefoil). We quantified root biomass, soil organic matter (SOM) fractions, specifically Mineral-Associated Organic Matter (MAOM) and Particulate Organic Matter (POM), aggregate stability, nutrient stocks, and microbial abundance via qPCR. The CCs sown shortly after barley were successfully established, with an average biomass of 1525 kg/ha, without compromising cereal yields, thereby confirming their viability in Nordic climates. A central finding was that root development served as the primary driver of organo-mineral associations. Ryegrass- and Clover-based systems produced significantly higher root biomass, which correlated strongly (p < 0.01) with MAOM stocks and total P acquisition. These systems stored 12 Mg/ha more MAOM-C and 1.1 Mg/ha more MAOM-N than the control at 0-20 cm depth. The inclusion of diverse functional traits in the complex five-species mixture significantly improved soil physical structure, yielding higher aggregate stability and lower bulk density. While CCs accumulated approximately 7 kg P/ha, the diverse mix optimized nutrient availability, whereas simpler mixtures showed higher C:P ratios, suggesting potential microbial P immobilization. Microbial abundance was consistently higher in multi-species treatments, indicating a more active biological environment. Ongoing analysis integrates cereal physiological data, focusing on the photosynthetic efficiency of oats in response to cultivation? regimes. Our findings bridge the gap between root morphology, plant physiology, and long-term SOM persistence, providing a strategic framework for using functional crop traits to enhance soil resilience and nutrient efficiency in cold-climate regions.
Abstract
The decline of soil organic carbon (SOC) content is a major concern in agricultural soils, and reduction of tillage frequency is proposed as a measure to counteract this tendency. Here, we assessed the effect of tillage and renewal frequency on grassland SOC content based on a long–term experiment at Fureneset, Western Norway. The objective was to compare permanent and unrenewed grassland treatments with treatments ploughed and renewed 6 to 15 times from 1974 to 2016. Mean SOC content of the permanent grassland was 64 ± 9 g kg−1 (one standard deviation) at 0 to 40 cm depth and soil contained 210 Mg C ha−1, compared to 60 ± 6 g kg−1 and 190 Mg C ha−1 for grassland renewed with ploughing. Higher SOC contents were associated with reduced forage dry matter yields (DMY) of the permanent grassland, but not in frequently renewed grasslands. High SOC contents correlate with high porosity and water content, as soil properties approach those of organic soils. This may cause a wetter soil and reduced plant growth and increase soil compaction. In areas with generally high SOC contents in agricultural soils, increased carbon content due to no tillage may thus make the soils more agronomically challenging to manage
