Sabine Gruber

University of Hohenheim · Institute of Crop Science

For decades, conservation tillage has been promoted as a measure to increase carbon stocks in arable soils. Since organic farming improves soil quality and soil carbon storage, reduced tillage under organic farming conditions may further enhance this potential. Therefore, we assessed soil organic carbon (SOC) stocks of reduced tillage compared with...

The framework conditions for chemical weed control in oilseed rape (OSR) are becoming increasingly unfavorable in Central Europe. On the one hand, weed resistance is spreading and, on the other, there is a growing social desire to reduce or eliminate the use of chemical crop protection products. In a field experiment, hoeing, as a weed control meas...

Oilseed rape production is under pressure due to a limited availability of herbicides. Therefore, the performance in terms of management intensity (MI) and herbicide strategy (HS) and the involved yield formation was evaluated in a two-year Clearfield® oilseed rape field experiment. Furthermore, weed density and weed composition were also investiga...

Cultivation of lentils had ended by mid-20th century in Germany, but a revival was initiated in the first decade of this millennium in Southwest Germany. However, knowledge of lentil cultivation was almost lost, and today’s yields are still low. To gain an overview of current farm practices and of factors that can help lentil cultivation thrive, 25...

The cultivation area of soybean (Glycine max (L.) Merr) is increasing in Germany as a way to ensure self-sufficiency through its use as feed and food. However, climatic conditions needed for soybean cultivation are not appropriate in all parts of the country. The objective of this study was to determine the influence of solar radiation, temperature...

Soybean (Glycine max L. Merrill) is one of the most important crops worldwide. In several European countries such as Germany, soybean cultivation is not traditional and as such remains to be optimized. One option to increase soybean production is to adapt and improve the seeding system. To investigate the effects of different seeding systems on see...

Intensive agriculture and meat-based westernized diets have brought a heavy environmental burden to the planet. Legumes, or pulses, are members of the large Fabaceae (Leguminosae) family, which comprise about 5% of all plant species. They are ancient crops whose popularity both for farmers and consumers has gone through several stages of acceptance...

Biological and vegetarian raw food products, in particular based on legume sprouts, are an increasing food trend, due to their improved nutritional value when compared to seeds. Herein, protein and mineral profiles were studied in 12 lentil varieties, with varieties Du Puy, Kleine Schwarze, Rosana, Flora, Große Rote and Kleine Späths II demonstrati...

The term ‘Permaculture’ (PC) refers to a theory about diversified farming systems, based on an ethical attitude (worldview) and a practical design process, guided by 12 principles and flanked by a holistic sustainability concept. Invented in the wake of Australia’s socio-political ‘back-to-the-land’ aspirations of the 1970s, PC has since developed...

To find out exactly how sowing density and sowing pattern affect soybean grain yield, quality and its components in non-traditional soybean growing regions, such as Germany, two field trials have been conducted at two locations in Bavaria in 2016 and 2017. The experiments were carried out with four sowing densities (30, 50, 70, 90 seeds/m<sup>2</su...

Natural fibre based composites are being used more frequently in the automotive industry because of their positive characteristics. Fibres currently used and mostly imported to Europe do not sufficiently meet all the demands for natural fibres. As a new fibre plant velvetleaf (Abutilon theophrasti) has been taken into consideration. However, there...

A list of the knowledge exchange and communication activities (with internet links to some of the resources) from the second year of the TRUE project.

As a requirement of multi-actor approach, we provide here 'Practice Abstracts' that describe innovative knowledge resulting from the first 2 years of project activities. The Practice Abstract present knowledge in simple easy-to-use terms. Nineteen Practice Abstracts here, and from 13 different project partners. They span all sectors of the supply c...

Dormant seeds of oilseed rape (OSR) can persist in the soil and cause OSR volunteers in subsequent crops. Several approaches were tested in the laboratory and in the field to determine whether dormancy induction and seed persistence can be reduced by using dormancy‐breaking exogenous compounds. In a laboratory experiment, OSR seeds were coated with...

Natural fibres are environmentally friendly and therefore often used in the automotive industry as an alternative to glass or mineral fibres. In order to meet the demands of natural fibres for the European automotive market, mainly flax and hemp are cultivated in Europe, but the import of other fibres, like kenaf, is also necessary. To increase the...

A joint assessment of two separate approaches investigated the occurrence of volunteer oilseed rape (Brassica napus L.; OSR) as affected by cultivar, field history and environment. Approach I comprised surveys for volunteers on >100 farmers’ fields in Germany in the years 2009 and 2010. Volunteers were assigned to the cultivars grown in previous ye...

Appropriate timing of post-harvest tillage to oilseed rape (OSR, Brassica napus L.) is crucial for the creation of a soil seed bank and unwanted OSR volunteers. Existing recommendations, however, can contrast with needs for early post-harvest tillage e.g. for pest control. To specify and to systematically further improve preventive volunteer manage...

Core Ideas Woodchip mulching significantly suppressed weeds under field conditions. Sixteen‐year woodchip mulching had no impact on grain yield of cereals or faba bean. There was a continuous decreasing trend of the relative yield with woodchip mulching. There was no impact of woodchip mulching on the weed seed bank after 16 yr. To test the possib...

This study investigated the induction and loss of dormancy in oilseed rape ( Brassica napus ). Twenty genotypes were preliminary screened; from these, two genotypes, RGS003 and Hayola 308, which possess high potential for dormancy induction (HSD) and medium potential to induce secondary dormancy (MSD), were selected. The stratification of seeds at...

The conversion from ploughing to reduced tillage is discussed in the context of increased humus accumulation as an opportunity to mitigate climate change. To date, little attention has been paid to the question whether reduced tillage systems in organic farming result in increased nitrous oxide (N2O) emissions. Thus, as part of FiBL’s long-term til...

Core Ideas A long‐term field trial of important perennial and annual energy crops was conducted. Maize is most high yielding of biomass with high N inputs. Miscanthus is most high yielding of biomass without or with moderate N inputs. In crop rotations, no‐till practice with less input does not reduce the productivity. Nitrogen input is more import...

Only 34% of all German farms apply reduced tillage (RT), while approximately 1% of the arable land is under no-tillage (NT). Statistics for organic farming are not available, but the percentages are probably even lower. The development of German organic RT and NT has been strongly driven by pioneer farmers for 40 years, and supported by field trials...

The effect of cultivation methods on plant development, yield, secoiridoid glycoside content, and physical and microbiological contamination of centaury (Centaurium erythraea) were investigated. Plants were cultivated in uncovered soil, soil covered with mulch film, or in pots. There was no difference in dry matter yield of plants grown on a mulch...

Linseed contains substantial amounts of desired ingredients, such as omega-3 fatty acids (α-linolenic acid) and antioxidants, as well as undesired ingredients such as cyanogenic glycosides and cadmium. This paper presents and discusses the abiotic factors which influence quality and yield of linseed seeds in organic cropping systems. In temperate c...

Seed dormancy is a critical factor in determining seed persistence in the soil and can create oilseed rape ( Brassica napus L.) volunteer problems in subsequent years. A 3-year field trial in south-west Germany investigated the effects of seed maturity on primary dormancy and disposition to secondary dormancy of ten oilseed rape varieties (lines) i...

A two-factorial field experiment should reveal the performance of Clearfield® oilseed rape under different cropping intensities. The experiment was conducted at the experimental station Ihinger Hof in 2014, with cropping intensity as factor 1 and herbicide strategy as factor 2, all treatments sown with variety PT228CL. Treatments of cropping intens...

The introduction of imidazolinone-tolerant oilseed rape (Brassica napus; Clearfield®, CL OSR) meets with skepticism on volunteer control. This study examined the disposition to secondary seed dormancy of 15 CL OSR geno­types at two locations in south-west Germany in 2012/2013 (trial 1) between sown seed (F1) and harvested seed (F2), and effects of...

Mineral nitrogen (N) fertilization in cereals is commonly split into three or four applications. In order to simplify N fertilization, a single N application either broadcast or placed on the soil surface was compared to conventionally split fertilization for winter wheat (Triticum aestivum L.). The 4-year experiment (2007–2010) was performed using...

Field grown vegetables with wide row spacing would likely benefit from the conservation tillage practice, strip-tillage, with regards to minimizing soil erosion or increasing soil moisture contents, but there are only few studies for strip-tilled vegetables at present. For this reason, a 2-year field experiment was performed in South West Germany t...

Row crops and field grown vegetables, such as white cabbage (Brassica oleracea convar. capitata var. alba), are affected by soil erosion caused by rainfall energy. Conservation tillage, such as strip-tillage, is the most effective way to reduce soil erosion. Hence, the objectives of this study were to develop and modify the strip-tillage system for...

Volunteer oilseed rape (OSR, Brassica napus L.) causes various agronomic problems in crop rotations and can contribute to gene dispersal by pollen and by seed admixture. A 4-year field experiment (2008–2011) was set up in south-west Germany to investigate the performance of volunteers derived from two OSR cultivars with different levels of seed dor...

Row covers are usually used to protect plants from insects and cold temperatures, and to accelerate plant growth. But they could also serve as an erosion control strategy. For this reason, fleece (FC) and net covers (NC) in white cabbage (Brassica oleracea convar. capitata (L.) Alef. var. capitata L. f. alba) cultivation were tested in a two-year f...

The study should reveal the effects of soil texture and of seed characteristics of oilseed rape (Brassica napus L.) on seed survival in the soil by a burial experiment. Seeds of 58 conventional and new trait accessions (genetically modified and/or with altered seed ingredients) were buried for six months in sandy loam (SL), clay (C) or silty clay l...

Mineral nitrogen (N) fertilization in cereals is commonly split into three or four applications. In order to simplify N fertilization, a single N application either broadcast or placed on the soil surface was compared to conventionally split fertilization for winter wheat (Triticum aestivum L.). The 4-year experiment (2007–2010) was performed using...

The introduction of imidazolinone-tolerant oilseed rape (Clearfield® system, CL; OSR) meets with scepticism in Germany. Frequently mentioned as a major drawback for growing CL-OSR in Germany is the possible occurrence of herbicide resistant CL-volunteers which could run out of control. A monitoring was started by BASF in the seasons 2011/2012/2013...

Spring wheat (Triticum aestivum) and spring barley (Hordeum vulgare) were mixed cropped with lentils (Lens culinaris) in five seeding ratios (100:0, 75:25, 50:50, 25:75, 0:100) at the Experimental Station for Organic Farming Kleinhohenheim, SW Germany in the years 2009 and 2010. Aim of the study was to test the effect of different mixing ratios on...

Um die Entwicklung der Symbiose zwischen Soja und Bradyrhizobium japonicum zu garantieren, wird das Saatgut vor der Aussaat hierzulande üblicherweise inokuliert. Die in Deutschland erhältlichen Impfmittel führen nach Einschätzungen aus der Praxis jedoch oft zu unterschiedlich guten Symbioseleistungen und somit Ertragsschwankungen, und letztendlich...

The present study examined variation in sowing date on lentils (Lens culinaris) in a standard lentil–barley (Hordeum vulgare) mixed cropping system in the temperate climate of central Europe to determine the effect on crop yield and weed control. A 2-year (2009/10) field experiment was carried out at the organic research station Kleinhohenheim (KH)...

Linseed (Linum usitatissimum L.) has multi-purpose role for human nutrition, animal feed and also for industrial purposes mainly as a source of drying oil and fiber. It is an im-portant oil crop in Ethiopia because of its high nutritive value, though little is known about the quality of traditional genotypes grown by farmers. A total of 120 linseed...

A field experiment was performed in Southwest Germany to examine the effects of long-term reduced tillage (2000-2012). Tillage treatments were deep moldboard plow: DP, 25 cm; double-layer plow; DLP, 15 + 10 cm, shallow moldboard plow: SP, 15 cm and chisel plow: CP, 15 cm, each of them with or without preceding stubble tillage. The mean yields of a...

The potential of oilseed rape seeds from harvest losses to persist in the soil and to emerge later as volunteers in following crops is mainly driven by the ability of the seeds to go into dormancy under certain soil conditions. Using low-dormant oilseed rape cultivars could reduce volunteer problems considerably, but up to now there are unanswered...

Power based on biomass, in particular biogas, is increasing, with a concomitant increase in the need for energy crop production. The objective of this study was to determine the profitability of biogas substrate production on a marginal site in southwestern Germany. The effects of crop rotation and nitrogen fertilization level were evaluated in a t...

Introduction Pathways of Gene Flow in Oilseed Rape Managing Gene Flow in Oilseed Rape Combining Biological Measures Package for Gene Containment Conclusion Acknowledgments References

Mixed cropping of lentil (Lens culinaris) with five spring-sown companion crops: naked barley (Hordeum vulgare), wheat (Triticum aestivum), oats (Avena sativa), linseed (Linum usitatissimum) and buckwheat (Fagopyrum esculentum) was compared with monocropping at the organic research station Kleinhohenheim, University of Hohenheim, Germany, in 2009 a...

The study provides information to more reliably estimate the value of conservation tillage in a temperate climate. Tillage effects on yield and weeds were evaluated in field experiments at two sites in SW Germany between 1999 and 2010. Tillage varied at site Ihinger Hof from mouldboard plough (P), chisel plough (CP), rototiller (RTT), varying P and...

Wang L, Gruber S & Claupein W (2012). Effects of woodchip mulch and barley intercropping on weeds in lentil crops. Weed Research 52, 161–168. The effect of woodchip mulch on weed infestation and crop yield of lentil (Lens culinaris) was tested in a 2-year field experiment at the organic research station Kleinhohenheim, University of Hohenheim, Germ...

Canola (Brassica napus) varieties containing inherent restrictions on gene flow may address problems of seed- and pollenmediated gene flow. The aim of this study was to explore the effectiveness of 1) low-dormancy varieties in avoiding GM soil seedbanks and volunteers, and 2) cleistogamous (clg) genotypes to avoid outcrossing. GM and non-GM varieti...

The cultivation of lentils (Lens culinaris) is currently a niche production in Germany, because agronomic knowledge about weed control has been lost during the last decades, and because the traditional knowledge was not adapted to modern cropping conditions. A compilation of strategies for weed control from Central European history and from studies...

Ten years of a long-term field experiment using different strategies of conventional and conservation tillage in SW Germany were evaluated for soil mineral nitrogen (SMN) and soil moisture content. Treatments analysed were combinations of stubble tillage (S) or no stubble tillage with primary tillage P: mouldboard plough, CP: chisel plough, RTT: ro...

After commercial cropping of lentils (Lens culinaris) expired in Germany 50 years ago, a re-of lentil cropping systems to make lentils a more popular crop in German organic farming. One of the trials was set up to identify suitable companion crops and cropping ratios for len-) were combinations with barley (Hordeum vulgare), wheat (Triticum aestivu...

The cultivation of Jerusalem artichoke (Helianthus tuberosus L.) for bioenergy is not yet realised, although the potential is quite promising. About 1/3 of the tubers remain in the soil after harvesting which can sprout next year, and result in highly competitive volunteer plants in the following crops. Two different methods of tuber harvesting wer...

Conventional tillage systems with high soil disturbance are being steadily replaced by tillage systems with low or no soil disturbance. An approach using three methodological steps (greenhouse, deliberate seed burial and field) revealed the long-term vertical distribution and losses of a soil seed bank as effects of different tillage operations. Se...

Oilseed rape (OSR) genotypes having low predisposition to secondary dormancy can reduce agronomic problems arising with volunteers from persistent seeds, and contribute to gene containment if genetically modified cultivars are grown. This study introduces a standardized laboratory method (HSDT; 35 days) for testing the predisposition of OSR to seco...

Conservation tillage is not yet widely accepted by organic farmers because inversion tillage is considered to be necessary for weed control. Three long-term experiments were established with combinations of reduced and conventional plough tillage and stubble tillage to determine weed infestation levels in organic farming, i.e. herbicide application...

Secondary dormancy is the major reason for seed persistence of canola (Brassica napus L.) in the soil. Volunteers emerging from the soil seed bank can lead to unwanted gene dispersal. More than 40 B. napus canola cultivars were tested for secondary dormancy under laboratory conditions. All cultivars were classified into groups of low, medium, and h...

Data about gene escape by seeds and volunteers were compiled for the first time in one study for several crops, i.e. wheat (Triticum aestivum), sugar beet (Beta vulgaris), oilseed rape/canola (Brassica napus) and maize (Zea mays). These species represent important genetically modified (GM) crops with herbicide tolerance (HT) or insect resistance (B...

Gene flow in oilseed rape is a process occurring over the years and large distances and has been the object of several models for evaluating the co-existence of GM and non-GM crops. Oilseed rape volunteers play a major role and the survival, dormancy and emergence of the volunteer seeds left after oilseed rape crops are key processes for gene flow....

The effect of wood chips mulch on weeds and yield was tested in a long-term experiment within a crop rotation in Organic Farming. The wood chips originated from hedge-rows and trees of the Experimental Station Kleinhohenheim of the University of Hohenheim. The material consisted for 25% of bark and had a CN ratio of 47. After annual mulching of cro...

Volunteer oilseed rape (Brassica napus L.) can contribute to gene dispersal by pollen flow or by seed admixtures. The study should analyse the competition capacity of different crops towards oilseed rape volunteers. A field with a large soil seed bank of oilseed rape was planted with three winter crops (winter turnip rape (replacing oilseed rape, s...

Data about gene escape by seeds and volunteers were compiled for the first time in one study for several crops, i.e. wheat (Triticum aestivum), sugar beet (Beta vulgaris), oilseed rape/canola (Brassica napus) and maize (Zea mays). These species represent important genetically modified (GM) crops with herbicide tolerance (HT) or insect resistance (B...

The study aimed at strategies for managing the soil seed bank of oilseed rape and minimizing gene dispersal by transgenic volunteers. Three-year results and well-combined approaches were evaluated in one overall approach. Varieties differed in dormancy from 8-46 % in the laboratory. Corresponding field experiments showed that low-dormancy genotypes...

Comparison of 84 data sets provided by partners in the SIGMEA project from France, Germany and the UK, that recorded seed rain at harvest of winter rape crops, concluded that mean seed loss from non-transgenic crops was 4102 seeds m-2 and from GM crops 6039 seeds m-2. Evaluation of 63 data sets on seed persistence indicated a decline rate of 80% in...

Oilseed rape volunteers were able to flower and to set seed in winter wheat and winter barley. The flowering period of the volunteers coincided with the flowering of related wild species which are potential crossing partners, but there was only a short period of synchrony with the flowering period of the sown oilseed rape. Consequently, cross-polli...

Lupines are used as protein-rich feeding stuff with high quality for the organic farming. Therefore important quality parameters are estimated in different cultivars and breeding lines of blue lupins in relation to location. Protein content, amino acid composition, fat and fatty acid composition, as well as antinutritive substances (raffinose oligo...

Tillage operations with different intensities following the input of oilseed rape seeds and an inert reference material (plastic pellets) resulted in seed banks which varied in size and vertical distribution. The size of the rapeseed bank has mainly to be attributed to seed losses in or on the soil, since seed bank and seed losses correlated with 0...

The study examined the effect of tillage (intensive vs. zero tillage) on potential gene flow during the life cycle of oilseed rape volunteers between July 2002 and August 2003. After growing oilseed rape, 4–29% of the seeds lost during harvest entered the soil seedbank when stubble tillage was performed immediately after the seed input. The seedban...

Volunteer plants of oilseed rape (Brassica napus L.) from persistent seeds in soil can affect subsequent crops. Apart from the agricultural disadvantages, the environment and the marketing of the seeds may also be affected, particularly if plants with special ingredients or genetically modified (gm) plants are grown. In order to investigate the inf...

Seeds of oilseed rape (Brassica napus L.) can persist in the soil over several years by becoming secondarily dormant and can then germinate to create volunteer plants in following crops. As well as agricultural impacts caused by volunteers, gene dispersal in time – particularly from genetically modified cultivars – can be another undesirable conseq...

The outcome of four winter rape seed cultivars from harvest losses of 3,000 to 3,500 seeds M was observed over the following year. Immediately after harvest in July stubble tillage was performed at 8 cm, and followed by ploughing at 20 cm in October shortly before seeding the following winter wheat. 15 up to 25 % of all seeds emerged in autumn befo...

A long-term experiment at the Experimental Station for Organic Farming Kleinhohenheim should determine effects of stubble tillage on weed density and weed communities. The treatments were stubble tillage by a chisel plough (10 cm), a modified skimmer plough (7 cm), a rotary hoe (5 cm) and a control, previous to primary tillage by a mouldboard ploug...

Safflower (Carthamus tinctorius) varieties and genotypes often showed low emergence rates in previous experiments. Since no apparent seed damage was observed which could have reduced the germinability, dormancy was supposed to be the reason for the low germination. Aim of the current study was to determine innate seed dormancy of several safflower...

Hohe Ausfallverluste bei der Rapsernte und die Ausbildung sekundärer Dormanz in den Samen können zum Aufbau eines langjährigen Bodensamenvorrats führen. Aus diesem Samenvorrat auflaufender Durchwuchsraps ist in Folgekulturen oft nur eingeschränkt chemisch oder mechanisch zu kontrollieren, besonders in einem späteren, erneuten Rapsbestand. Neben pfl...