Search

The intensity of pastoral management in areas of High Nature Value farming is declining in some regions of Europe but increasing in others. This affects open habitats of conservation concern, such as the British uplands, where bird species that benefit from low‐intensity grazing may be most sensitive to such polarization. While experimental manipulations of livestock grazing intensities have improved our understanding of upland breeding bird responses in the short term, none have examined the long‐term impacts of altered management on reproductive success.Using a replicated landscape‐scale experiment that started in 2003, we investigated the effects of four grazing treatments (intensive sheep; low‐intensity sheep; low‐intensity mixed sheep and cattle; and no grazing) on the breeding productivity of meadow pipits Anthus pratensis, the most common upland passerine. Surveys were carried out systematically during early (2003 and 2004) and late (2015 and 2016) sampling periods of the experiment to compare the short‐ and long‐term effects of grazing treatments on breeding density and productivity of pipits specifically, but also on the overall bird community.Pipit breeding density was lowest under low‐intensity sheep grazing while the highest egg‐stage nest survival was observed in the same treatment, although no significant treatment effects were detected on overall nest survival or fledgling output. There were no significant differences in treatment effects between the sampling periods on any breeding variable, but overall nest survival was lower in the later sampling period across all treatments.Breeding bird species richness differed between treatments in the later sampling period, with highest species richness in the ungrazed treatment.Synthesis and applications. Livestock grazing management can have different outcomes for different upland birds. Our results showed that, with time, meadow pipit breeding productivity tended to be higher when sheep grazing intensity was reduced and/or mixed with cattle, and lower when livestock were removed, but not significantly so. Removal of grazing, however, can significantly increase bird species richness. The long‐term experiment showed an overall decline in fledglings regardless of grazing treatments, potentially a result of increased predator numbers harboured by nearby developing woodland, highlighting the importance of considering wider landscape processes in grazing management decisions. [ABSTRACT FROM AUTHOR]

The intercropping of two or more crop species on the same piece of land at a given time has been hypothesized to enhance crop yield stability. To address this hypothesis, we assessed the grain yield stability of various barley-pea and wheat-faba bean mixtures grown in seven experimental field trials (locations) across Europe during two years with contrasting weather (2017 and 2018). Three different yield stability measures were used, all based on the expected yield variability of the mixture components grown as sole crops, and the corresponding observed yield variability of the same components grown in 50:50 mixtures in a replacement design. Stability indices were calculated as ratios between the expected and observed variabilities, with values > 1 indicating greater stability of the intercrops. Mean grain yields tended to be higher in intercrops than sole crops. However, in contrast to our hypothesis, the observed (intercrop) yield stability was similar or lower than the expected (sole crop) stability in most locations except one. Furthermore, yield stability significantly increased with increasing mean yields when assessed across differentially productive locations. The results are relevant for the designing of intercropping systems as a means to increase yield stability and the resilience of cropping systems. [ABSTRACT FROM AUTHOR]

• APSIM was calibrated and validated for pure cultures of wheat and faba bean. • APSIM was evaluated for wheat-faba bean pure cultures and intercrops in Europe. • APSIM reproduced pure culture aboveground dry matters and, for wheat, yields. • APSIM overestimates faba bean performance relative to wheat in intercrops. • APSIM must incorporate an alternative approach to simulate height growth. Cereal-legume intercropping can increase yields, reduce fertilizer input and improve soil quality compared with pure culture. Designing intercropping systems requires the integration of plant species trait selection with choice of crop configuration and management. Crop growth models can facilitate the understanding and prediction of the interactions between plant traits, crop configuration and management. However, currently no existing crop growth model has been calibrated and tested for cereal-legume intercrops throughout Europea. We calibrated the Agricultural Production Systems sIMulator (APSIM) for pure cultures of wheat and faba bean using data from Dutch field trials, and determined the phenological parameters to simulate pure cultures and intercrops from seven field experiments across Europe. APSIM successfully reproduced aboveground dry matters and, for wheat only, grain yields in pure cultures. In intercrops, APSIM systematically overestimated the aboveground dry matter and grain yield of faba bean and underestimated those of wheat. APSIM was reasonably capable of simulating plant heights in pure cultures, but respectively overestimated and underestimated the height of faba bean and wheat in intercrops. In order to simulate wheat-faba bean intercrops better, APSIM should be improved regarding the calculation of biomass partitioning to grains in faba bean and of height growth in both species. [ABSTRACT FROM AUTHOR]