Life cycle assessment of Swiss organic farming systems

The impacts of organic and integrated farming systems in Switzerland on the environment have been assessed in a comprehensive study by the life cycle assessment method. This paper reports a comparison of the treatments of the DOC experiment. Organic farming showed clear ecological advantages particularly for eco- and human toxicity, resource use and biodiversity. These ecological advantages only partly apply to nutrient losses and are not always found for single products. Per kg of organic product, higher impacts were often found for global warming potential, ozone formation, eutrophication and acidification compared to integrated production. In the same crop rotation with the same amount of organic fertilisers there were no systematic differences in soil quality of organic compared with integrated production. Further improvement of the environmental performance of organic farming should focus on achieving higher yields of good quality – especially in potatoes and cereals - by using inputs more efficiently and minimising nitrogen losses

Multifunctionality of Sown Grassland Is Enhanced by Combining Four Complementary Species

We investigated species diversity effects and multifunctionality in an intensively managed grassland. A diversity experiment was set up with monocultures and mixtures comprising Lolium perenne, Dactylis glomerata, Trifolium pratense, and Trifolium repens, and was maintained for three years at 150 kg∙N∙ha-1∙ year-1. Ten functions were measured that represented i) forage production (aboveground biomass yield (μ), standard deviation of yield (σ), temporal stability (μ/σ), weed biomass), ii) N cycling (symbiotic-N2-fixation, N efficiency, NO3 in soil solution), and forage quality (crude protein content (CP), organic matter digestibility (OMD), metabolizable energy (ME)). We applied multivariate linear mixed-effects regression to estimate simultaneously species identity and diversity effects on the ten functions, and used the mean log response ratio (MLRR) across all functions to evaluate the diversity-multifunctionality relationship. Across the three years, all functions regarding production and N cycling revealed significant beneficial effects in the four-species equi-proportional mixture (used as a reference) compared to averaged monocultures. The reference mixture had 61% more biomass yield, 8% less variation, 68% higher stability, 81% less weed biomass, 96% and 46% higher symbiotic-N2-fixation and N-efficiency, respectively, and 87% less NO3 (each P ≤ 0.05, except variation). The reference mixture and averaged monocultures did not significantly differ in CP, OMD (g∙kg-1∙yield), and ME (MJ∙kg-1∙yield). This, however, resulted in significant beneficial effects between 52% and 72% in all three forage quality functions on a hectare basis (kg or MJ∙ha-1∙year-1). On average across functions, the four-species reference mixture had 1.8 times the performance of averaged monocultures, indicating enhanced multifunctionality in mixtures. The multivariate framework in combination with the MLRR as a measure of overall multifunctionality proved to be an effective tool for the evaluation of the diversity-multifunctionality relationship. We conclude that sown grass-legume mixtures at moderate N fertilization promote high multifunctionality and are a ‘ready-to-use’ option for sustainable intensification of agriculture

The effects of water regime on phosphorus responses of rainfed lowland rice cultivars

Background and Aims Soil phosphorus (P) solubility declines sharply when a flooded soil drains, and an important component of rice (Oryza sativa) adaptation to rainfed lowland environments is the ability to absorb and utilize P under such conditions. The aim of this study was to test the hypothesis that rice cultivars differ in their P responses between water regimes because P uptake mechanisms differ. Methods Six lowland rice cultivars (three considered tolerant of low P soils, three sensitive) were grown in a factorial experiment with three water regimes (flooded, moist and flooded-then-moist) and four soil P levels, and growth and P uptake were measured. Small volumes of soil were used to maximize inter-root competition and uptake per unit root surface. The results were compared with the predictions of a model allowing for the effects of water regime on P solubility and diffusion. Key Results The plants were P stressed but not water stressed in all the water regimes at all P levels except the higher P additions in the flooded soil. The cultivar rankings scarcely differed between the water regimes and P additions. In all the treatments, the soil P concentrations required to explain the measured uptake were several times the concentration of freely available P in the soil. Conclusions The cultivar rankings were driven more by differences in growth habit than specific P uptake mechanisms, so the hypothesis cannot be corroborated with these data. Evidently all the plants could tap sparingly soluble forms of P by releasing a solubilizing agent or producing a greater root length than measured, or both. However, any cultivar differences in this were not apparent in greater net P uptake, possibly because the restricted rooting volume meant that additional P uptake could not be converted into new root growth to explore new soil volume

Seasonal dynamics and turnover of microbial phosphorusin a permanent grassland

Microbial activity is known to be high under permanent grassland, but consequences for soil phosphorus (P) dynamics and availability are not well understood. Our main objective was to assess the microbial P turnover derived from the seasonal fluctuations in microbial P (measured as hexanol-labile P (Phex) at 13 sampling times during 9months) in a permanent grassland in Switzerland as affected by different P fertilization treatments (P inputs of 0 (NK) or 17kgPha−1year−1 in the form of superphosphate (NPK) or dairy slurry (DS)). Plant P uptake, available inorganic P measured as resin-extractable P (Pres), potential organic P mineralization indicated by acid phosphomonoesterase activity and climatic conditions were also recorded. Despite significant differences in plant P uptake and Pres (NPK > DS > NK), the turnover rate of Phex was similar in all treatments (approximately once per growing season). Thus, the seasonal P flux through Phex was similar to the stock of Phex, which was about 18, 25 and 37kgPha−1 in NK, NPK and DS, respectively, and larger than the corresponding seasonal plant P uptake of 6, 17 and 12kgPha−1. The estimate of Phex turnover based on seasonal dynamics did not confirm previous tracer-based findings of a much faster Phex turnover under low availability of inorganic P, and the magnitude of Phex turnover depended on the number of sampling points taken into account. Fluctuations in Pres and Phex were related to soil moisture and indicated competition between plants and microorganisms for available P

Plant diversity greatly enhances weed suppression in intensively managed grasslands

Weed suppression was investigated in a field experiment across 31 international sites. The study included 15 plant communities at each site, based on two grasses and two legumes, each sown in monoculture and 11 four-species mixtures varying in the relative proportions of the four species. At each site, one grass and one legume species was selected as fast establishing and the other two species were selected for persistence. Average weed biomass in mixtures over the whole experiment was 52% less (95% confidence interval, 30 to 75%) than in the most suppressive monoculture (transgressive suppression). Transgressive suppression of weed biomass persisted over each year for each mixture. Weed biomass was consistently low and relatively similar across all mixtures and years. Average sown species biomass was greater in all mixtures than in any monoculture. The suppressive effect of sown forage species on weeds in mixtures was achieved without any herbicide use. At each site, weed biomass for almost every mixture was lower than the average across the four monocultures. The average proportion of weed biomass in mixtures was less than in the most suppressive monoculture in two thirds of sites. Mixtures outyielded monocultures, and mixture yield comprised far lower weed biomass

Rôles,impacts et services issus des élevages en Europe. Synthèse du rapport d’expertise scientifique collective

L’élevage, secteur majeur pour l’économie de nombreux territoires et structurant beaucoup de paysages ruraux européens, fait l’objet de controverses, depuis au moins une décennie, notamment du fait des dommages environnementaux qu’il engendre. Dans un tel contexte, il est apparu nécessaire d’étayer les débats en faisant le point sur l’état des connaissances scientifiques relatives aux rôles, impacts et services environnementaux, économiques et sociaux issus des élevages européens et leurs produits. Pour ce faire, les ministères français en charge de l’Environnement et de l’Agriculture ainsi que l’Agence de l’environnement et de la maîtrise de l’énergie (Ademe) ont sollicité l’Inra pour réaliser une expertise scientifique collective (ESCo) abordant conjointement les multiples conséquences sur les milieux et le climat, l’emploi et le travail, les marchés et certains enjeux sociaux et culturels, de la production et de la consommation humaine de produits d’origine animale (bovins, ovins, caprins, porcins et avicoles). L’analyse de ces diverses dimensions s’appuie sur les démarches d’évaluation rapportées dans la littérature scientifique internationale. Abordées, dans un premier temps, de manière analytique et globale, les connaissances ont ensuite été mobilisées par « bouquet de services » au sein de territoires contrastés. Les relations entre les différents impacts ou services permettent d’identifier des compromis et des leviers d’action envisageables pour les systèmes d’élevage. Livestock production is a sector of major economic importance that defines many European rural areas. It has become the focus of controversy over the past decade or more, particularly with regard to the environmental impacts it causes. In this context, it seemed useful to support this debate with a critical review of the state of scientific knowledge on the role, impacts, and services – environmental, economic, and social – associated with European livestock production. Accordingly, the French ministries responsible for Agriculture and the Environment, in cooperation with the French Environment and Energy Management Agency (ADEME), requested INRA to undertake a collective scientific assessment addressing the many consequences – for the environment and the climate, for employment and labor, for markets, and for a variety of social and cultural issues – related to the production and human consumption of animal products (cattle, sheep, goats, pigs, and poultry). Analysis of these diverse dimensions was based on assessment methods utilized and described in the international scientific literature. Using a broad, analytical overview as a starting point, the review proceeded by identifying the "service bundles" associated with livestock production in contrasting areas

Sustainable management of foxtail meadows through hay making at seed maturity

Harvesting meadows at early heading of the grasses yields large quantities of high quality forage but might in the long term cause the swards to deteriorate due to the lack of formation of mature seeds. We studied 4 cutting regimes on a foxtail meadow to define which would maintain the foxtail population naturally and is acceptable in terms of forage quality. The 1st cut of the different cutting regimes was done either at early shooting, shooting, early heading or seed maturity of Alopecurus pratensis L.. The 2nd cut of the 3 first treatments was simultaneous to the 1st cut of the 4th treatment and was ground dried to allow the seeds to fall on the soil. When the meadow was harvested regularly at early heading of A. pratensis, its botanical composition deteriorated within 5 years and its yield decreased. With a 1st cut at seed maturity, A. pratensis produced the most seeds and its proportion in the sward increased, but the forage had the lowest quality. In the treatments with the 1st cut at early shooting or at shooting, A. pratensis produced significant quantities of seeds during the 2nd regrowth, maintained its population and forage of intermediate quality was produced. Sustainable production of quality forage on intensive foxtail meadows might be achieved by periodically having the 1st cut at shooting and using the second regrowth at seed maturity for ground dried hay

The effects of water regime on phosphorus responses of rainfed lowland rice cultivars

ISSN:1095-8290ISSN:0305-736