Perspectives from Italy (part 2): more promising results for barley-pea intercropping
In 2018 the Consorzio Marche Biologiche (Consortium of organic farmers of the Marche Region - ConMarcheBio) participated to the DIVERSify project and a field trial was carried out at the organic farm “Romiti Giovanni”. ConMarcheBio is mainly involved in the production of organic pasta and it has its own storage, milling and processing facilities. However, they are also interested in crop diversification, and encourage diversified crop rotations amongst their farmers. For this reason, they collect many different products other than durum wheat such as grain legumes for human (chickpea, lentil) and animal (faba bean, pea) consumption, trefoil and alfalfa seed, sunflower and more. As in described in our previous blog, organic beef cattle of the Marchigiana breed are commonly reared in the Marche region, and ConMarcheBio were also interested in trialling barley-pea intercropping for animal feed.
The field trial was sown on March 28th, 2018 at the “Giovanni Romiti” organic farm located at Sterpeti (PU), shown on the map below. The sowing date was very unusual as the weather conditions in January-March 2018 delayed the sowing of the DIVERSify experimental trials due to continuous rain. This trial was the very last one to be sown among the UNIVPM DIVERSify trials in 2018. Below we can see that high levels of rock and gravel that characterised the soil where the experimental trial was carried out. However, despte the “unusual” sowing date and soil characteristics, very interesting information on pea as a sole crop and intercropped with barley were obtained that could complement results of the other field trials involving barley and pea.
The same experimental design as used at the “Fattoria San Martino” farm was applied. The field trial was set as a Completely Randomised Block with 4 replicates, with plots of a large size (50 m length x 2,25 m width). Barley and pea monocrops (Tea and Hardy varieties) were compared to 2 different mix combinations: MIX-A (barley 33% - pea 67%) and MIX-B (barley 25% - pea 75%). The percentages shown for each mix refers to the amount of seed of barley and pea included in the mix as percentage of seed used for the sole crops. At sowing time, barley and pea were totally mixed manually before drilling. The effectiveness of mixed cropping compared to sole crops was once again evaluated by the Land Equivalent Ratio (LER) index.
On June 6th, 2018, we visited the field with ConMarcheBio and had an interesting discussion about the potential of intercropping, from field performance to the final use of the mixed grain product. For animal feeding, the use is easier to realise because the mix does not need to be separated, but if intercropping would involve durum or bread wheat then this would be more challenging. The separation of the cereal grain from legume seed fragments is an important technical aspect that was suggested as further investigation by ConMarcheBio. Furthermore information about the quality of the cereal grain produced by mixed intercropping would be of interested to the Consortium if further trials were to be conducted on a wheat-legume mix. All these and other technical, operational but also strategical aspects of intercropping were discussed with ConMarcheBio during the field visit.
Results on yield levels measured at both subplot and whole plot levels showed LER values between 1.1 and 1.25, confirming the usefulness of mixed intercropping barley and pea. However, the barley suffered because of the delayed sowing date and had a relatively low yield as a mono crop (1.24 t/ha). Whereas pea (variety Hardy) as a mono crop showed an excellent performance (around 3 and 2 t/ha for subplot and whole plot yields, respectively). Moreover, even though wild mustard was present at a very low level, a significant reduction of weeds in the intercrop plots versus the mono crop barley was observed, and these results reflected those of the “Fattoria San Martino” on-farm trial. Overall, barley was found to be a very interesting crop for organic farming systems and intercropping with grain legumes, including barley at low seed density in the mix, could be an effective strategy to reduce weed competition. Finally, it must be noted that wild boars did not “visit” this experimental field as was the case at Monte San Martino and in one field at the UNIVPM experimental station..!
Thank you to the farmers and organisations involved in these on-farm trials, and the other 'participatory farmers' from across the DIVERSify network.