Comparing conventional and improved organic vegetable rotations, yields and nitrogen husbandry

During 2005 to 2009 three approaches to organic vegetable rotations were compared to a conventional rotation in an interdisciplinary project. The organic rotations differed in their reliance on animal manure vs. cover crops and intercrops, but the rotation of main vegetable and cereal crops were identical in the four rotations. One organic rotation (O1) relied on import of manure for supply of nutrients, in another (O2) cover crops were used to replace most of the manure import, and in (O3) also intercrops were grown to improve natural pest regulation. The yearly import of nitrogen were on average 149, 94, 28, and 28 kg N.ha-1 in C, O1, O2, and O3 respectively. On average the yield in the O1 system was 83% of the yield in the conventional system. In the O2 rotation the yield was the same, though the nutrient import was much lower, whereas the intercrops in O3 reduced the yield to 70% of the conventional fotation. The effect on single crops varied with organic yields ranging from 60% (onion) to almost 100% (carrots, oats) of conventional yields. Crop root growth varied strongly among crops with rooting depths of less than 0.4 m (onions) to more than 2 m (cabbage, rye, fodder radish catch crop). Root growth was unaffected by cropping system, but the inclusion of deep rooted catch crops and green manures in O2 and O3 increased the total root exploitation of the soil strongly. Thus, while the O1 and O2 systems had almost identical yields and N uptake there were large differences in their effects on soil N; e.g. the subsoil (1-2.5 m) N content was on average 18 kg N.ha-1 in the O2 compared 61 and 53 kg N.ha-1 in the C and O1 respectively, indicating strongly reduced N leaching losses in O2

Cauliflower and leeks to have company in the field

Organic vegetables may benefit from the growing of living mulch crops between crop rows. Scientists from four EU countries are looking for potential positive effects

Vegetable quality in a conventional and three organic cropping systems

Differences in nutrient availability and methods of pest management may affect crop growth and product quality. The question is if conventional and organic cropping systems, which differ clearly in strategies for nutrient and pest management, influence the harvest and sensory quality of the products? Lettuce and onion were grown in a conventional and three organic vegetable cropping systems with different levels of external inputs and use of cover- and inter-crops for nutrient re-cycling and natural pest management in the period of 2007-2009 (VegQure project). The crop rotation consisted of 8 fields of vegetables and cereals. Onion was grown after a year of oat and iceberg lettuce after winter rye. There were 3 replicates of each cropping system each year. Sensory analysis of samples of iceberg lettuce was performed as quantitative descriptive analysis by a trained sensory panel of 10 assessors. A sensory profile of 9 attributes was evaluated on a 15-cm non-structured continuous scale. Harvest and sensory quality were not affected by the clear differences in nutrient and pest management between the four cropping systems

Strip-cropping and recycling of waste for biodiverse and resource-efficient intensive vegetable production

Presentation of the SureVeg project

Økologisk kvalitet – fra jord til bord

Hvilke faktorer, i produktionskæden, har væsentlig betydning for kva-liteten af et økologisk produkt, og hvordan videreudvikler vi denne kvalitet

Recirkulering af planteaffald som kompost og samdyrkning af grøntsager

Core organic cofund projekt bevilget i 2018, om udvikling af nye økologiske dyrkningssystemer til produktion af grøntsager. Målet er at forbedre systemernes bæredygtighed og resiliens, recirkulering af næringsstoffer og jordens lagring af kulstof

Samdyrkning er en lovende strategi

Discussion of the intercropping technique for reduction of nitrate leaching in vegetable

Nitrogen management in organic cauliflower

Consumers expect that the production of organic vegetables is less harmful to the environment compared to conventional vegetable cropping. However, vegetables with a high nitrogen demand such as cauliflower may cause intensive leaching of nitrate to natural waters in conventional as well as in organic production. In addition, organic growers face difficulties in providing adequate amounts of organic fertiliser in order to attain high yields due to the scarcity of organic livestock manure. In organic cropping systems, the use of an in-season living mulch may decrease the need for fertiliser and the risk of nitrate leaching. It may also improve nitrogen nutrition for next season’s crop. The aim of this study was to investigate the effect of growing an in-season living mulch of grass-clover on cauliflower yields, nitrate leaching over winter, and soil nitrogen availability the following spring. A field experiment was performed on a sandy loam soil using two varieties of cauliflower and with or without grass-clover as living mulch. The mulch consisted of an overwintering grass-clover that was incorporated in strips before the planting of cauliflower, and two levels of fertilisation (dried chicken manure) were applied. Plant samples were taken for evaluation of marketable and non-marketable yields, and for analysis of dry matter and nitrogen content. Evaluation of inorganic N-content in the soil was done at planting, at harvest, in late autumn and in spring by taking soil samples to a depth of 1.5 m. Results show that high yields of cauliflower can be maintained per meter plant row, whereas no effects on nitrate leaching could be observed in a cropping system with an in-season living mulch of grass-clover

Blomkål og porrer får selskab i marken

Økologiske grønsager kan få gavn af, at der dyrkes ledsagerafgrøder imellem rækkerne. Forskere fra fire EU-lande undersøger de potentielt gavnlige effekter

Strip-cropping and recycling of waste for biodiverse and resource-efficient intensive vegetable production

Core Organic Cofund project funded in 2018 about new agronomic methods to improve biodiversity and soil fertility in the organic production of vegetables