Core Organic 2

Project objectives
The project aims at verifying if the introduction and proper management of living mulch in vegetable production systems allows comparable yields and produce quality in comparison to the sole cropping systems, reducing the use of auxiliary, off-farm, inputs (i.e. plant protections products and fertilizers) and non-renewable energy consumption (i.e. fossil fuel for mechanical weeding). The cover crops – vegetables intercropped farming systems should then perform better in terms of environmental impact and profitability due to production costs reduction.

This hypothesis is tested in a range of European areas where open field organic vegetable production are a relevant activity. Field experiments will be carried out in four CORE Countries (IT, DK, DE and SLO), in sites having different soil characteristics and climatic conditions.

Two yielding crops have been identified, one common for all and one for each of the study areas, according to the following criteria: (i) economic relevance, (ii) season of the cropping cycle and (iii) representativeness as “model” crop of a larger crops group with similar characteristic and to which, the project outcomes can be extended. A range of cover crop families and species are intercropped with the yielding species in function of the typology of “service” they provide and in relation to the agro-ecosystems characteristics in which they are introduced.

Cover crops sowing period, root pruning as well as spacing or yielding crop and cover crop density are the relevant experimental factors that will be investigated in order to optimize the performance of the living mulched agro-ecosystems in comparison to the sole crop systems. The living mulched and the sole crop systems will be compared in terms of yield quality and stability, impact of weed and pests as well as nutrient availability and losses in relation to reduction in the use of off-farm inputs and energy, cost effectiveness and environmental impact. Involving 7 partners of 4 CORE countries, project activities are organized in 6 work packages.

Expected results and their impact
The main expected result is the development of cropping practices based on intercropping/living mulch tailored for each of the crop/system studied in the different countries. These ready-to-use cropping model will be then disseminated. Organic vegetable producers will benefit from the project outcome as it will supply knowledge on systems to produce organic vegetables with lower use of external inputs (fertilizers, plant protection products, water, energy etc.). It will result in improved farm profitability and more resilient farming systems that grants long-term productivity and produce quality. The organic sector will also benefit from the higher credibility to consumers of the intercropping production methods based on lower external inputs and higher biodiversity.

Rural communities will benefit from the project outcome in terms of improved environmental profile of organic vegetable farms and this will reduce the negative environmental impacts on soil and water. Furthermore, the increase of plant diversity in the field will benefit the biodiversity of natural fauna and microorganisms in the agro-ecosystems.

Consumers will benefit from the project as they will have the chance to choose, among organic production, vegetable with lower environmental impact. Policy makers and standard setters can use the project outcomes for feeding the standards improvement process (as for organic vegetable production EU Regulation is still simplistic) and for the definition of rural development plans and premium schemes.
Overall, the project will increase the body of knowledge about the effect of introduction of the intercropping/living mulch technique in organic vegetable productions on yield and produces quality, environmental impact and off-farm external energy and inputs use reduction for weeds, fertility and pests management. Accordingly, It is expected that the project outcomes will give a contribution in the debate about of the risk of the so called “conventionalization” of organic farming.

Main outcomes at this stage? The first field experiments were carried out on cauliflower, leek and artichoke, either on research farms or pilot (private) farms. The main, preliminary outcomes available are:

The introduction of early sown LM (i.e. at crop transplanting) in cauliflower cropping systems reduced the yield and the quality. Conversely, in the late sowed LM (i.e. 2 to 4 weeks after cauliflower transplanting, according to local conditions) no significant differences in yield and yield quality were observed. Permanent LM strips could represent a feasible option to design and manage vegetable intercropped systems.
In the Northern EU countries, where vegetables are mainly cultivated in summer, the continued presence of the living mulch in the field over winter may reduce the soil mineral N content during the leaching season in comparison to the bare soil (after the sole crop). Consequently, it may contribute to lower the nitrate leaching risk from the systems. The LM substitutive design (reduction of crop plant density to leave room to LM) tended to increase leaching. This may be due to a lower N uptake ability of the living mulch compared to the cauliflower that was replaced. Whereas the addition design, where the living mulch was introduced in-between the rows of cauliflower (same crop plant density), tended to reduce leaching. However, since these outcomes are strongly depended by the climatic conditions, we need to verify these preliminary evidences in the light of the next year results. CORE organic II
Living mulch sowing time and the choice of the cultivar had a key role in the competitive success of the cash crop against both weeds and living mulch. Preliminary outcomes showed that late sowing of the LM ensured an unfavourable environment for weeds avoiding crop suppression. Moreover, our findings indicated similarities in competitiveness between hybrid and open pollinated/local adapted cultivars.
Preliminary results obtained in the Italian cauliflower â€˜scenarioâ€™ showed that LM introduction did not affect the infestation of P. brassicae, showing no detrimental effect of this technique on pest dynamics. In LM treatments, the P. brassicae parasitisation by the braconid Cotesia sp. was higher than the no LM treatment (88 % and 63 %, respectively). LM also showed to increase the spider and rove beetle populations, while the carabid activity density was slightly higher in the no living mulch.

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