• The Complex Pathway towards Farm-Level Sustainable Intensification: An Exploratory Network Analysis of Stakeholders’ Knowledge and Perception

      Micha, Evgenia; Fenton, Owen; Daly, Karen M.; Kakonyi, Gabriella; Ezzati, Golnaz; Moloney, Thomas; Thornton, Steven; European Union; 675120 (MDPI AG, 2020-03-25)
      Farm-level sustainable intensification of agriculture (SIA) has become an important concept to ensuring food security while minimising negative externalities. However, progress towards its achievement is often constrained by the different perceptions and goals of various stakeholders that affect farm management decisions. This study examines farm-level SIA as a dynamic system with interactive components that are determined by the interests of the stakeholders involved. A systems thinking approach was used to identify and describe the pathways towards farm-level SIA across the three main pillars of sustainability. An explanatory network analysis of fuzzy cognitive maps (FCMs) that were collectively created by representative groups of farmers, farm advisors and policy makers was performed. The study shows that SIA is a complex dynamic system, affected by cognitive beliefs and particular knowledge within stakeholder groups. The study concludes that, although farm-level SIA is a complex process, common goals can be identified in collective decision making.
    • Ecosystem function enhanced by combining four functional types of plant species in intensively-managed grassland mixtures: a three-year continental-scale field experiment

      Finn, John; Kirwan, Laura; Connolly, John; Sebastia, Maria Teresa; Helgadottir, Aslaug; Baadshaug, Ole; Belanger, Gilles; Black, Alistair D; Brophy, C.; Collins, Rosemary; et al. (Wiley-Blackwell, 22/02/2013)
      1. A co-ordinated continental-scale field experiment across 31 sites was used to compare the biomass yield of monocultures and four-species mixtures associated with intensively managed agricultural grassland systems. To increase complementarity in resource use, each of the four species in the experimental design represented a distinct functional type derived from two levels of each of two functional traits, nitrogen acquisition (N2-fixing legume or non-fixing grass) crossed with temporal development (fast-establishing or temporally persistent). Relative abundances of the four functional types in mixtures were systematically varied at sowing to vary the evenness of the same four species in mixture communities at each site, and sown at two levels of seed density. 2. Across multiple years, the total yield (including weed biomass) of the mixtures exceeded that of the average monoculture in >97% of comparisons. It also exceeded that of the best monoculture (transgressive overyielding) in about 60% of sites, with a mean yield ratio of mixture to best-performing monoculture of 1.07 across all sites. Analyses based on yield of sown species only (excluding weed biomass) demonstrated considerably greater transgressive overyielding (significant at about 70% of sites, ratio of mixture to best-performing monoculture = 1.18). 3. Mixtures maintained a resistance to weed invasion over at least three years. In mixtures, median values indicate <4% of weed biomass in total yield, whereas the median percentage of weeds in monocultures increased from 15% in year 1 to 32% in year 3. 4. Within each year, there was a highly significant relationship (P<0.0001) between sward evenness and the diversity effect (excess of mixture performance over that predicted from the monoculture performances of component species). At lower evenness values, increases in community evenness resulted in an increased diversity effect, but the diversity effect was not significantly different from the maximum diversity effect across a wide range of higher evenness values. The latter indicates the robustness of the diversity effect to changes in species’ relative abundances. 5. Across sites with three complete years of data (24 of the 31 sites), the effect of interactions between the fast-establishing and temporal persistent trait levels of temporal development was highly significant and comparable in magnitude to effects of interactions between N2-fixing and non-fixing trait levels of nitrogen acquisition. 6. Synthesis and applications. The design of grassland mixtures is relevant to farm-level strategies to achieve sustainable intensification. Experimental evidence indicated significant yield benefits of four-species agronomic mixtures which yielded more than the highest-yielding monoculture at most sites. The results are relevant for agricultural practice, and show how grassland mixtures can be designed to improve resource complementarity, increase yields and reduce weed invasion. The yield benefits were robust to considerable changes in the relative proportions of the four species, which is extremely useful for practical management of grassland swards.
    • A Functional Land Management conceptual framework under soil drainage and land use scenarios

      Coyle, Cait; Creamer, Rachel E.; Schulte, Rogier P.O.; O'Sullivan, Lilian; Jordan, Phil; Institute of Technology, Sligo (Elsevier BV, 2015-11-15)
      Agricultural soils offer multiple soil functions, which contribute to a range of ecosystem services, and the demand for the primary production function is expected to increase with a growing world population. Other key functions on agricultural land have been identified as water purification, carbon sequestration, habitat biodiversity and nutrient cycling, which all need to be considered for sustainable intensification. All soils perform all functions simultaneously, but the variation in the capacity of soils to supply these functions is reviewed in terms of defined land use types (arable, bio-energy, broadleaf forest, coniferous forest, managed grassland, other grassland and Natura 2000) and extended to include the influence of soil drainage characteristics (well, moderately/imperfect, poor and peat). This latter consideration is particularly important in the European Atlantic pedo-climatic zone; the spatial scale of this review. This review develops a conceptual framework on the multi-functional capacity of soils, termed Functional Land Management, to facilitate the effective design and assessment of agri-environmental policies. A final functional soil matrix is presented as an approach to show the consequential changes to the capacity of the five soil functions associated with land use change on soils with contrasting drainage characteristics. Where policy prioritises the enhancement of particular functions, the matrix indicates the potential trade-offs for individual functions or the overall impact on the multi-functional capacity of soil. The conceptual framework is also applied by land use area in a case study, using the Republic of Ireland as an example, to show how the principle of multi-functional land use planning can be readily implemented.
    • Gain in Nitrogen Yield from Grass-Legume Mixtures is Robust Over a Wide Range of Legume Proportions and Environmental Conditions

      Suter, Matthias; Finn, John; Connolly, John; Loges, Ralph; Lüscher, Andreas (Elsevier, 2015-12-31)
      Global food security is currently challenged and requires sustainable intensification of agriculture through initiatives that include more efficient use of nitrogen (N) and increased protein self-sufficiency through home-grown crops. Such challenges were addressed in a continental-scale field experiment conducted over three years, in which the amount of total nitrogen yield (Ntot) and the gain in N yield in mixtures as compared to grass monocultures (Ngainmix) was quantified from four-species grass-legume stands with greatly varying legume proportions. Stands consisted of monocultures and mixtures of two N2 fixing legumes and two non-fixing grasses. The amount of Ntot of mixtures was significantly greater (P ≤ 0.05) than that of grass monocultures at the majority of evaluated sites in all three years. Ntot and thus Ngainmix increased with increasing legume proportion up to one third of legumes. With higher percentages of legumes, Ntot and Ngainmix did not further increase. Thus, across sites and years, mixtures with one third proportion of legumes had 57% higher Ntot than grass monocultures and attained ∼95% of the maximum Ntot acquired by any stand. The relative N gain in mixture (Ngainmix/Ntotmix) was most severely impaired by minimum site temperature (R = 0.64, P = 0.010). Nevertheless, Ngainmix/Ntotmix was not correlated to site productivity (P = 0.500), suggesting that, within climatic restrictions, balanced grass-legume mixtures can benefit from comparable relative gains in N yield across largely differing productivity levels. We conclude that higher N output (Ntot or forage protein per unit area) can be achieved with grass-legume mixtures than with pure grass alone for a given amount of N fertilizer applied; conversely, the same N output can be achieved by mixed swards with less input of N. Therefore, the use of grass-legume mixtures can substantially contribute to resource-efficient agricultural grassland systems over a wide range of productivity levels, implying important savings in N fertilizers and greenhouse gas emissions.
    • Gain in Nitrogen Yield from Grass-Legume Mixtures is Robust Over a Wide Range of Legume Proportions and Environmental Conditions

      Suter, Matthias; Finn, John; Connolly, John; Loges, Ralph; Lüscher, Andreas (Elsevier BV, 2015-08-19)
      Global food security is currently challenged and requires sustainable intensification of agriculture through initiatives that include more efficient use of nitrogen (N) and increased protein self-sufficiency through home-grown crops. Such challenges were addressed in a continental-scale field experiment conducted over three years, in which the amount of total nitrogen yield (Ntot) and the gain in N yield in mixtures as compared to grass monocultures (Ngainmix) was quantified from four-species grass-legume stands with greatly varying legume proportions. Stands consisted of monocultures and mixtures of two N2 fixing legumes and two non-fixing grasses. The amount of Ntot of mixtures was significantly greater (P ≤ 0.05) than that of grass monocultures at the majority of evaluated sites in all three years. Ntot and thus Ngainmix increased with increasing legume proportion up to one third of legumes. With higher percentages of legumes, Ntot and Ngainmix did not further increase. Thus, across sites and years, mixtures with one third proportion of legumes had 57% higher Ntot than grass monocultures and attained ∼95% of the maximum Ntot acquired by any stand. The relative N gain in mixture (Ngainmix/Ntotmix) was most severely impaired by minimum site temperature (R = 0.64, P = 0.010). Nevertheless, Ngainmix/Ntotmix was not correlated to site productivity (P = 0.500), suggesting that, within climatic restrictions, balanced grass-legume mixtures can benefit from comparable relative gains in N yield across largely differing productivity levels. We conclude that higher N output (Ntot or forage protein per unit area) can be achieved with grass-legume mixtures than with pure grass alone for a given amount of N fertilizer applied; conversely, the same N output can be achieved by mixed swards with less input of N. Therefore, the use of grass-legume mixtures can substantially contribute to resource-efficient agricultural grassland systems over a wide range of productivity levels, implying important savings in N fertilizers and greenhouse gas emissions.