Publications
NIBIOs employees contribute to several hundred scientific articles and research reports every year. You can browse or search in our collection which contains references and links to these publications as well as other research and dissemination activities. The collection is continously updated with new and historical material.
2024
Sammendrag
The effectiveness of mechanical subsoiling for alleviating subsoil compaction is controversially discussed, particularly due to the sensitivity of mechanically loosened soils towards re-compaction. In order to improve the alleviation potential by subsoiling it was hypothesized that the loss of soil stability by mechanical subsoiling of compacted soils can be reduced by top and subsoil liming. The primary objective was to evaluate whether (a) mechanical subsoiling (to a depth of 35 cm with a subsoiler or a plough with a pan-breaker) could alleviate compaction in a clayey Stagnosol and (b) whether liming could stabilize soil structure to minimize re-compaction. Undisturbed soil samples were collected to assess physical properties in both "compacted", "subsoiled", and "limed", as well as in untreated plots. The Compaction Verification Tool (CVT) identified potentially harmful soil compaction in the subsoil. The results showed that wheeling increased the extent of harmful subsoil compaction (from 8% to 33%) in the first year, which was accompanied with a reduction in crop yields. Subsoiling with a pan-breaker combined with high liming intensity improved soil physical properties and yields and may have mitigated re-compaction in the loosened subsoil. Nevertheless, it is expected to be not economically viable on the studied clay soil.
Sammendrag
To facilitate nutrient management and the use of manure as a feedstock for biogas production, manure is often separated into a solid and a liquid fraction. The former fraction is usually high in P and low in N, so when incorporated in the soil as fertilizer, it needs to be supplemented by N from, e.g., mineral fertilizers or nitrogen-fixing species. To explore strategies to manage N with solid-separated manure, we examined how the amount of digestate and the N:P ratio of pig digestate, i.e., manure that had partially undergone anaerobic digestion, affected the productivity of Westerwolds ryegrass and red clover in a pot experiment with one soil which was rich and another which was poor in plant nutrients. The soil and plant species treatments were combined with four doses of digestate, which gave plant available phosphorus (P) concentrations of 2, 4, 8, or 16 mg P100 g−1 soil. Ammonium nitrate was dosed to obtain factorial combinations of digestate amount and N:P ratios of 1.8, 4, 8, and 16. Clover was harvested once at the beginning of flowering (15 weeks after seeding), while Westerwolds ryegrass was allowed to regrow three times after being cut at the shooting stage (in total, 4 cuts, 6, 9, 12, and 15 weeks after seeding). Ryegrass yield increased by up to 2.9 times with digestate dosage. Interactions with the N:P ratio and soil type were weak. Hence, the effect of increasing the N:P ratio was additive across digestate dosages. Red clover biomass also increased by up to 39% with digestate dosage. Residual nutrients in the soil after red clover cultivation were affected by the initial differences in soil characteristics but not by digestate treatment or biomass of harvested red clover. A targeted N management is required to benefit from the P-rich digestate in grass cultivation, while the long-term effects of red clover culture on N input need further investigation.
Forfattere
Narta ElshaniSammendrag
No abstract has been registered
Forfattere
Nicole AndersonSammendrag
No abstract has been registered
Forfattere
Nicole AndersonSammendrag
No abstract has been registered
Forfattere
Nicole AndersonSammendrag
No abstract has been registered
Forfattere
Nicole AndersonSammendrag
No abstract has been registered
Forfattere
Nicole AndersonSammendrag
No abstract has been registered
Sammendrag
Strong creeping red fescue (Festuca rubra L. spp. rubra Gaudin) is a cool-season perennial turfgrass widely used in temperate and subalpine regions around the globe. Although creeping red fescue turf is tolerant of shade, low fertility acidic soils, and drought conditions, creeping red fescue seed crops grown in optimal growing environments can lodge, ultimately reducing yield in regions where this important turfgrass is grown for seed. To address this issue, we investigated the effects of two plant growth regulators (PGRs), chlormequat chloride (CCC) and trinexapac-ethyl (TE), on plant height, lodging, and seed yield of strong creeping red fescue over 9 site-years in the Peace River region of western Canada. The study encompassed 6 site-years with first-year stands and 3 site-years with second-year stands. The PGRs were applied alone and in a TE + CCC mixture at the two-node (BBCH 32–33, where BBCH is Biologische Bundesanstalt, Bundessortenamt and Chemische Industrie) and early head emergence (BBCH 51–52) growth stages in first- and second-year stands, respectively. The application of TE, CCC, and their mixture resulted in a differential decrease in lodging and an increase in seed yield in first-year stands. However, PGRs applied at BBCH 51–52 on second-year stands had no effect on seed yield but reduced plant height and lodging. This study found a negative correlation between seed yield and lodging. Among the PGR treatments, the CCC + TE mixture was the most effective in reducing lodging and increasing seed yield of strong creeping red fescue.
Sammendrag
Orchardgrass (Dactylis glomerata L.) is an important forage seed crop, but unlike other cool-season grasses, seed yields have not increased over time. Seed yield increases in orchardgrass may be possible with plant growth regulators (PGRs) such as trinexapac-ethyl (TE) and chlormequat chloride (CCC). Field trials were conducted at Hyslop Experimental Farm near Corvallis, Oregon, over three crop years (2017–2019) to examine the effects of spring nitrogen (N) and PGRs on seed production characteristics in orchardgrass. Spring N treatments included 0, 112, 157, and 202 kg N ha−1 and PGR applications were timed using the BBCH (Biologische Bundesanstalt, Bundessortenamt und Chemische Industrie) scale. Four PGR treatments included an untreated control, 210 g TE ha−1 at BBCH 32, 210 g TE ha−1 at BBCH 51, and 105 g TE ha−1 + 1500 g CCC ha−1 at BBCH 32. An interaction of spring N and PGR increased seed yields in 2 years, while spring N and PGR increased seed yield independently in the other year. The combination of TE and CCC PGRs did not increase seed yield over TE alone. Seed yield increases from spring N were due to an increase in seed number m−2, while increases in seed yield attributable to PGRs were the result of increased seed number m−2 and harvest index. This study suggests that the combination of 112 kg ha−1 spring N and 210 g ha−1 TE PGR is the best practice to maximize seed yield in orchardgrass.