SIMBIO-VEG: an interdisciplinary project for improvement of organic systems and meth-ods in arable and vegetable cropping

SIMBIO-VEG is the first large interdisciplinary research project on organic farming ever being funded in Italy. The project partnership is composed of eight Working Units including Universities as well as public and private research centres and associa-tions, with a high degree of interaction among them. SIMBIO-VEG aims to acquire knowledge on the func-tioning of organic arable and vegetable cropping systems, as to (1) optimise systems management and the cultural practices (methods) therein, and improve the understanding of how organic systems and meth-ods influence produce quality and environmental impact. SIMBIO-VEG activities are structured in four strongly integrated research lines. Line 1 aims to understand the functioning of organically-managed agroecosystems and evaluate the technical and agro-nomic feasibility of crop production methods applied therein. Line 2 aims to evaluate the effects of organic systems and methods on overall produce quality, including both standard and innovative methods. Line 3 aims to evaluate the sustainability of organic sys-tems and methods through assessment of parameters and indicators related to soil quality, environmental impact, and economic viability. Lastly, line 4 is aimed to favour diffusion of results and innovation transfer through a comprehensive set of activities

Long term effects of cover crops on weeds in Mediterranean low input arable management systems

The introduction of cover crops (CC) in crop rotations is a key tool to control weed and ameliorate soil conditions in low input arable systems. In 1992 a long term experiment (LTE) was set up at Centre for Agri-environmental Research “E. Avanzi (CIRAA), University of Pisa to determine the combined effect of tillage intensity, nitrogen fertilization levels and CC types on soil quality, crop yield and weed communities. The LTE is based on 4-year crop rotation (maize, durum wheat, sunflower, durum wheat) with cover crops grown twice, in between wheat and summer crops. Two tillage systems were compared: i) a conventional system (CS), with annual ploughing (30 cm depth); ii) a low input system (LIS), with chiseling (30 cm depth) for summer crops and no till for wheat. In both systems cover types were: control; Brassica juncea L.;Trifolium squarrosum L.; and Vicia villosa Roth.). Four Nitrogen levels (from 0 to a maximum rate, varying across crop type) were applied. The experiment was replicated in 4 blocks for a total of 128 plots (21 x 11 m). Weed and CC above-ground biomass were assessed at CC termination, while weed species cover and total biomass were assessed at harvest. Data collected in CC (2011, 2014), sunflower (2012), durum wheat (2012) were used to calculate species richness, weed community diversity indices (Shannon’s H’ and inverse Simpson index) and Pielou equitability. Weed biomass and cover were analyzed by split-split plot ANOVA. Weed community composition was analyzed by a permutational multivariate analysis of variance based on Bray Curtis dissimilarity and Non-metric Multidimensional Scaling

ORGANIC FARMERS IN EUROPE: MOTIVATIONS AND PROBLEMS FOR USING CONSERVATION AGRICULTURE PRACTICES. "TILMAN-ORG Session"

As conservation agriculture and organic farming are currently considered as environmentally friendly options for producing food, this study explores the motivations and problems of organic European farmers that apply at least two of the following techniques: (i) no-tillage, (ii) reduced tillage and/or (iii) green manures conservation practices. We carried out a survey about motivations and problems of 159 farmers located in 10 European countries with a questionnaire with closed-ended questions. Data were analysis with a principal component analysis followed by clustering to identify groups of farmers that share the same type of motivations and problems. The most important motivations are related to soil preservation concerns and problems are mainly linked to agronomic conditions and crop management. There are three groups of farmers that share the same type of attitude: “atypical farmers”, “soil conservationists” and “agro-technically challenged farmers”. According to this study, research may address in priority agronomic problems, such as weed infestation, caused by adoption of conservation agriculture in organic agriculture

REDUCED TILLAGE AND COVER CROPS IN ORGANIC ARABLE SYSTEMS PRESERVES WEED DIVERSITY WITHOUT JEOPARDISING CROP YIELD

One of the objectives of the TILMAN-ORG Project is to improve weed management under conservation agriculture (reduced tillage and/or cover crops) in organic arable systems. The shift from ploughing to conservation agriculture should not only maintain crop yield but possibly improve weed community diversity. This paper summarises the results on (1) weed abundance, (2) weed diversity and (3) crop yield obtained in the first year of the project (2012) in 13 trials scattered across Europe

Efficiency of incomplete split-plot designs – a compromise between traditional split-plot designs and randomised complete block design

The paper shows, how incomplete split-plot designs can be constructed from -designs and how they can be analysed. The incomplete split-plot design can be regarded as both a practical and statistical compromise between traditional split-plot design and randomised complete block design. The efficiency of the design is compared to traditional split-plot design and randomised complete block design using data from 5 trials carried out using incomplete split-plot designs in Denmark through 2004-2007. The comparisons showed that the incomplete split-plot design were superior to traditional split-plot design in most cases – and in all cases when comparing differences among treatments in the whole-plot factor. The incomplete split-plot design was in many cases also better than the randomised complete block design

COMPARISON BETWEEN DIGITAL ANALYSIS METHODS FOR THE ESTIMATION OF VEGETATION COVER IN WEED RESEARCH

Vegetation cover is a widely used parameter in weed research and several methods are used to asses it through digital images, ranging from simple methods (visual estimate) to more complex ones based on image analysis processing. By using photographs of a wheat experiment we first compared three simple subjective methods for the estimate of vegetation cover through digital image analysis (visual estimate, point quadrate and supervised classification) to understand which of them gave results which were less dependent on operator's subjective value assignment. We did not find a significant difference between operators in case of visual estimate (P=0.784). We then tested the relative performance of two completely automated image analysis techniques based on image transformations (IV 1 V 2 and Principal Components) frequently found in the scientific literature. IV 1 V 2 gave a better performance with respect to Principal Components. There was a highly significant correlation (p=0.947) between IV1V2 and visual estimate, i.e. the two methods of the respective categories which gave the best results. Although being very simple and potentially influenced by operator's skills,visual estimate always performed better in terms of repeatability. We conclude that visual estimate carried out by experienced observers could be regarded as a standard tool in weed research