Final report for the Core Organic third call funded project: DIVERSILIENCE - Diversifying organic crop production to increase resilience

Summary

In DIVERSILIENCE we have selected novel resilient lines or populations of several crops, such as lucerne with good survival in Nordic climate, wheat with resistance to common bunt, common bean with drought tolerance and resistance to diseases, white lupin with frost tolerance, as well as buckwheat, white lupin and maize for organic agriculture. Molecular tools for selection of common bunt resistance in wheat have been developed and are now in use by breeders. We have evaluated germplasm collections of cowpea and soybean for tolerance to key stresses (especially drought) and to identify contrasting plant types used for intercropping research, producing indications on elite genetic resources and cultivars of special interest for organic farming. Selection for intercropping (with pea) has also been performed in buckwheat. These results were summarized in the Deliverable report D1.1 and D2.3.
We have provided direct and indirect evidence for the high agronomic value of heterogeneous material (evolutionary populations, composite populations, or cultivar mixtures) in terms of yielding ability in low-input systems, yield stability, stress tolerance and/or farmers’ acceptability (Deliverable report D2.1):
(a) In Norway, wheat populations displayed similar grain yield and protein content and higher yield stability relative to pure line varieties.
(b) In Romania, a six-component wheat cultivar mixture was the only material combining moderate tolerance to a set of abiotic or biotic stresses and good yielding ability.
(c) In Italy, two white lupin populations showed grain yield, protein content and farmers’ appreciation comparable with those of a pure line variety and an elite breeding line.
(d) In Romania, a four-component cultivar mixture of soybean displayed higher grain yield than any pure line cultivar, along with no grain quality disadvantage.
Indirect evidence arose from the following results:
(a) In Denmark, wheat mixtures composed of lines with up to six different resistance genes displayed an increase of tolerance to common bunt.
(b) In Slovenia, common bean composite populations, and particularly a commercial one, showed high allelic variation for functional markers associated with several agronomically important traits.
Deliverable D2.2 discussed challenges and opportunities to make the seed of heterogeneous material available to organic farmers as a function of the type of material (population or cultivar mixture), the extent of morphophysiological heterogeneity, the ownership of the material, and the potential market size of the species and the cultivar.
On the whole, our results justify a greater emphasis on the breeding and the cultivation of genetically heterogeneous cultivars of inbred crops. Our results also provide evidence for the high agronomic value of species mixtures in organic cropping systems (Deliverable report D3.1 and D3.2):
(a) In Denmark and Finland mixtures generally increased yield stability and weed competition, especially in relation to pea and camelina.
(b) In Slovenia and Northern Italy intercropping cowpea and soybean with sorghum was a successful technique to sustain crop yield and field biodiversity.
(c) In Romania mixtures of triticale and peas, wheat and peas contributed to improving soil fertility, reducing the use of chemical fertilizers, and increasing biodiversity.
(d) In Romania forage mixtures produced a higher volume of quality forage compared to single-species mixtures and possibly providing supply of grazed forage throughout the year and increasing stability.
In Norway, however, none of the mixtures outperformed the pure stand of red clover in terms of yield in the establishment year and first harvesting year. Plots including forage legumes had 30-80% higher yields of barley sown as the following crop, but the grain protein content was not significantly affected.