PRODIVA WP2. Crop mixtures for weed suppression. Annual Report 2015

In order to assess the weed suppressive ability of a pea/barley crop mixture and the component crops in sole cropping, a controlled outdoor experiment was performed at the Swedish University of Agricultural Sciences, Uppsala, Sweden, in the summer of 2015. A substitutive completely randomized experimental design was used with seven treatments and six replicates. The weed species planted in the experiment was Elytrigia repens (L.) Desv. ex Nevski. At three occasions leaf area index (LAI) was optically measured using a LAI-2200C Plant Canopy Analyzer. Two destructive harvests were taken in order to assess the biomass of different plant parts from each of the component species. At the first harvest leaf area was measured in order to calibrate the optical LAI data. The results revealed a good correlation between optically obtained LAI and LAI data from the destructive harvest; pea had the highest LAI and the intercrop was intermediate to the component crops in monoculture. Presence of a crop (sole crop or intercrop) significantly diminished the growth of E. repens but there were no differences between sole crops and intercrop. Sole cropped pea and barley showed ability to compete against weeds at the first and the second harvest respectively whereas the intercrop showed an ability to compete at both harvests indicating an advantage of the crop mixture in terms of weed suppression

Presentation av Core Organic projektet PRODIVA vid fältvandring den 8 juni 2016 i Sala

Presentation av Core Organic projektet PRODIVA vid en fältvandring den 8 juni 2016 i Sala, Västmanland, Sverige

Väletablerad gröda och tajmad mekanisk bekämpning - bästa sättet att kontrollera ogräs!

Väletablerade grödor tillsammans med tajmad mekanisk bekämpning ger bra förutsättningar för att kontrollera ogräsen. Vidare är det viktigt att alternera mellan närande och tärande grödor i växtföljden. Det är erfarenheter som Tomas Svensson har fått från att bedriva ekologisk odling på en gård nära Sala i Västmanland, Sverige

PRODIVA WP2. Crop mixtures for weed suppression. Annual Report 2016

The aim of WP2 is to assess the weed suppressive ability of crop mixtures as a function of species and densities, using a functional approach. During 2016, field experiments and controlled experiments with mixtures of barley and pea were conducted in Sweden and Poland. The performance of crop mixtures was compared to the performance of pure crops with regard to their ability to suppress weeds. In the fields, natural weed populations were used while the controlled experiments employed Elytrigia repens or Sinapis alba as a model weed. The purpose was to quantify weed suppressive ability of the crops, the impact of weeds on crop yield, and to identify crop traits responsible for the effects on weeds and crop yield. Preliminary results from the controlled experiment in Sweden showed that the presence of a crop (sole crop or intercrop) significantly diminished the growth of E. repens. The ability to compete (weed suppressive ability) was lower in peas, compared to barley and the intercrop. No significant differences were found in the ability to withstand competition (weed tolerance) between sole cropped pea, sole cropped barley, and the intercrop. In the field experiment, the overall weed pressure was rather high (> 500 g DM plot-1). No significant differences in total dry matter were found for spring barley, sown in different proportions in pea/spring barley mixtures. Total dry matter of peas was related to pea seeding density. Preliminary results from the field experiment in Poland showed that crops significantly suppressed weeds compared with the treatment containing only weeds. In the crop combination containing sole peas and 70% peas + 30% spring barley, the crop was not able to suppress the weeds as efficient as in treatments with a higher proportion of spring barley. No significant differences in seed yield were found between the treatments. In the glass house experiment with E. repens, the rhizome dry weight and rhizome length were significantly lower in treatments with both crop and weeds as compared with pure weeds

Pelleterad organisk gödsel - mylla och placera nära såraden

Forskare vid SLU undersöker i pågående försök hur skörden påverkas av att placera pelleterad organisk gödsel på olika avstånd från såraden och att mylla den till olika djup. Preliminära resultat i havre visar att placering fyra centimeter från raden och fyra centimeters myllningsdjup gav störst skörd

PRODIVA Project: Crop species mixtures for weed suppression�

The aim of this study is to assess the weed suppressive ability of crop mixtures and impact of weeds on crop yield as a function of species and densities by means of field experiments and controlled experiments with mixtures of barley and pea, conducted in Sweden and Poland. The performance of crop mixtures was compared to the performance of pure crops with regard to their ability to suppress weeds. In the fields, natural weed populations were used while the controlled experiments employed Elytrigia repens or Sinapis alba as a model weed. Preliminary results from the controlled experiment in Sweden showed that the presence of a crop (sole crop or intercrop) significantly diminished the growth of E. repens. The ability to compete was lower in peas, compared to barley and the intercrop. No significant differences were found in the ability to withstand competition between sole cropped pea, sole cropped barley, and the intercrop. In the field experiment, the overall weed pressure was rather high (> 750 g DM m-2). No significant differences in total dry matter were found for spring barley, sown in different proportions in pea/spring barley mixtures. Total dry matter of peas was related to pea seeding density. Preliminary results from the field experiment in Poland showed that crops significantly suppressed weeds compared with the treatment containing only weeds. In the crop combination containing sole peas and 70% peas + 30% spring barley, the crop was not able to suppress the weeds as efficient as in treatments with a higher proportion of spring barley. No significant differences in seed yield were found between the treatments. In the glass house experiment with E. repens, the rhizome dry weight and rhizome length were significantly lower in treatments with both crop and weeds as compared with pure weeds

Weed Species Trait Selection as Shaped by Region and Crop Diversity in Organically Managed Spring Cereals

Weeds remain a challenge in organic arable farming, as well as supply ecosystem services. The aim is to control weed densities while hosting a diverse and manageable weed community, preventing domination of few deleterious species. Therefore, we want to understand how specific species are stimulated, and which traits are selected for. This study focuses on crop diversity hypothesizing that (1) regions and (2) crop diversity function as filters for specific weed species traits. We conducted a weed monitoring in spring cereals over 2 years on organic farms in five northern European regions. Management and weed trait variables collected for the occurring species allowed an RLQ fourth-corner analysis. The weed communities were regionally specific, but trait selection was not observed, except in Latvia. Hence, the regional species pool provided different species with similar traits. Crop diversity within the management of spring cereals, such as undersowing and cereal frequency in the rotation, affected weed traits. The number of years under organic production selected no traits, although species numbers are known to increase. Hence, general weed species diversity increased, irrespective of traits. We conclude that organic management may support the agility within the weed community against selection of species and act as a buffer rather than as filter

Crop diversification and weeds in organic cereal production

PRODIVA Project introduction and promotio