• Authors:
    • Schindler, U.
    • Muller, L.
  • Source: AMA-Agricultural Mechanization in Asia, Africa and Latin America
  • Volume: 42
  • Issue: 4
  • Year: 2011
  • Summary: Efficient water use and intelligent water management are essential for sustainable agricultural production. Long-term soil hydrological measurements were used to quantify deep drainage rates and nitrate losses from arable land managed under various farming regimes (integrated, integrated with irrigation, ecologic and low input) and tillage systems (plough and no till) in the Pleistocene region of Northeast Germany from 1994 to 2007. As dependent on the management system, the nitrate concentration varied between 40 and 150 mg l -1. In connection with annual deep drainage rates between 100 mm and 200 mm during the study period, the annual nitrogen loss varied between 14 and 41 kg ha -1. Differences in nitrogen loss observed between the farming systems were low, but yields increased and nitrogen losses decreased as a result of irrigation throughout the variants. No-till treatment resulted in reduced nitrate leaching (18 kg ha -1) as compared with the tillage systems with plough and tooth cultivator (27 kg ha -1).
  • Authors:
    • Ladewig, E.
    • Schulte, M.
    • Schmitz, F.
    • Burcky, K.
    • Buhre, C.
  • Source: Sugar Industry / Zuckerindustrie
  • Volume: 136
  • Issue: 10
  • Year: 2011
  • Summary: Since 1994, data on sugarbeet production in Germany are continuously collected in annual cultivation surveys based on the information from the German sugar factories. Because of the long-term data set, many developments over the last years as well as short-term adaptations could be described. Cereals, particularly winter wheat, are the main pre-crop before sugarbeet (50%), followed by maize. Intercrops have been cultivated on 40% of the sugarbeet area since the beginning of the survey. The use of reduced systems increased in soil cultivation. The soil is covered by intercrops or pre-crop residues on more than 65% of the sugarbeet area. Since 2006, an increase in nitrogen fertilization was observed. Organic fertilizer was applied on 50% of the sugarbeet area. Crop production, from sowing to harvesting is characterized by an increase in technical specialization. The survey is conducted in cooperation with the farmers, or by specialized contractors. The beets are harvested mainly with six-row harvesters and transported increasingly with semi-trailer trucks.
  • Authors:
    • Piepho, H.
    • Hartung, K.
    • Graeff-Honninger, S.
    • Grozinger, H.
    • Knorzer, H.
    • Claupein, W.
  • Source: Field Crops Research
  • Volume: 121
  • Issue: 2
  • Year: 2011
  • Summary: Wheat/maize related multi-cropping systems are the dominant cropping systems in North China. To improve and adjust those systems, and to study competition effects within intercropping, extended field experiments are necessary. As field experiments are time consuming, laborious and expensive, a viable alternative is the use of crop growth models that can quantify the effects of management practices on crop growth and productivity. Field experiments showed that intercropped maize yielded as high as monocropped maize, and grain yield of intercropped wheat increased by up to 32%. Based on a process-oriented modeling approach, this study focuses on analyzing and modeling competitive relationships in a wheat/maize relay intercropping system with regard to yield, solar radiation and microclimate effects. A simple shading algorithm was applied and integrated into the CERES models, which are part of the DSSAT software shell vs. 4.5. The algorithm developed estimates the proportion of shading as affected by neighbouring plant height. The model was tested to investigate the applicability of this shading algorithm within the CERES models in the simulation of grain yield and dry matter yield of wheat and maize. Model error of grain and dry matter yield for both species was below 10%. There was a tendency for grain yield to be simulated adequately but for dry matter yield to be slightly underestimated. Increased top soil temperature in intercropped wheat increased the mineralization of nitrogen and improved N supply. The wheat/maize system was N efficient. Thus, N dynamics were taken into account for simulation as well as CO 2 dynamics based upon modified wind speed. Wheat border rows were exposed to a higher wind speed until mid-June and to reduced wind speed thereafter. As a result, solar radiation, soil temperature and wind speed differed between monocropping and intercropping and could provide a starting point for simulating intercropping. Microclimate effects are often small, subtle or non-existent, while spatial and climate variability and the heterogeneity of plant populations can be considerable. Quantifying microclimatic effects may prove difficult but should not be neglected when simulating intercropping systems.
  • Authors:
    • Gruber, S.
    • Möhring, J.
    • Claupein, W.
  • Source: Soil & Tillage Research
  • Volume: 115
  • Year: 2011
  • Summary: 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: rototiller, NT: no-till, and VAR: alternating SIP or S/CP. Best management practices were used for crop rotation, fertilisation and plant protection. CP, VAR and NT resulted in 18.7-19.0% gravimetric water content in spring. Partially significantly lower water content was observed in spring under S/P and CP with 18.2%; P and S/RTT resulted in 18.5%. Autumn soil moisture ranged from 15.3 to 15.8% and did not significantly differ between the treatments. Interactions between treatment and depth were not significant. There was no clear trend for spring soil moisture. No treatment showed a particular response to dry or wet season. Total SMN ranged between 8 and 49 kg ha(-1) in spring and 5-26 kg ha(-1) in autumn; significant effects of the treatments or interactions of treatment x depth did not occur. The effect of the season was most relevant for the amount of SMN, probably as a result of different conditions for mineralisation. Downward movement of nitrogen in spring was low in all treatments if catch crops were grown in the previous autumn. Overall, different soil tillage methods had little effect on soil moisture and soil SMN under temperate conditions. Seriously adverse effects of any tillage treatment in terms of nitrate leaching or reduced mineralisation seem unlikely. Similarly, the tillage systems did not exhibit obvious advantages or disadvantages in terms of soil water content. An exception may have been the higher water content in autumn in 0-30 cm under high soil disturbance which provided more suitable conditions for germination of the following crop. The decision of whether or not to adopt conservation tillage in temperate climates seems not to be primarily dependent on soil moisture and nitrogen mineralisation or on nitrogen leaching.
  • Authors:
    • Pan, G.
    • Ogle, S.
    • Siebner, C.
    • McConkey, B.
    • Katterer, T.
    • Grace, P. R.
    • Goidts, E.
    • Etchevers, J.
    • Dodd, M.
    • Cerri, C. E. P.
    • Andren, O.
    • Paustian, K.
    • vanWesemael, B.
  • Source: Plant and Soil
  • Volume: 338
  • Issue: 1-2
  • Year: 2011
  • Summary: As regional and continental carbon balances of terrestrial ecosystems become available, it becomes clear that the soils are the largest source of uncertainty. Repeated inventories of soil organic carbon (SOC) organized in soil monitoring networks (SMN) are being implemented in a number of countries. This paper reviews the concepts and design of SMNs in ten countries, and discusses the contribution of such networks to reducing the uncertainty of soil carbon balances. Some SMNs are designed to estimate country-specific land use or management effects on SOC stocks, while others collect soil carbon and ancillary data to provide a nationally consistent assessment of soil carbon condition across the major land-use/soil type combinations. The former use a single sampling campaign of paired sites, while for the latter both systematic (usually grid based) and stratified repeated sampling campaigns (5-10 years interval) are used with densities of one site per 10-1,040 km2. For paired sites, multiple samples at each site are taken in order to allow statistical analysis, while for the single sites, composite samples are taken. In both cases, fixed depth increments together with samples for bulk density and stone content are recommended. Samples should be archived to allow for re-measurement purposes using updated techniques. Information on land management, and where possible, land use history should be systematically recorded for each site. A case study of the agricultural frontier in Brazil is presented in which land use effect factors are calculated in order to quantify the CO2 fluxes from national land use/management conversion matrices. Process-based SOC models can be run for the individual points of the SMN, provided detailed land management records are available. These studies are still rare, as most SMNs have been implemented recently or are in progress. Examples from the USA and Belgium show that uncertainties in SOC change range from 1.6-6.5 Mg C ha-1 for the prediction of SOC stock changes on individual sites to 11.72 Mg C ha-1 or 34% of the median SOC change for soil/land use/climate units. For national SOC monitoring, stratified sampling sites appears to be the most straightforward attribution of SOC values to units with similar soil/land use/climate conditions (i. e. a spatially implicit upscaling approach).
  • Authors:
    • Herppich, W.
    • Schmidt, U.
    • Geyer, M.
    • Giebel, A.
    • Bauriegel, E.
  • Source: Computers and Electronics in Agriculture
  • Volume: 75
  • Issue: 2
  • Year: 2011
  • Summary: Infections of wheat, rye, oat and barley by Fusarium ssp. are serious problems worldwide due to the mycotoxins, potentially produced by the fungi. In 2005, limit values were issued by the EU commission to avoid health risks by mycotoxins, both for humans and animals. This increased the need to develop tools for early detection of infections. Occurrence of Fusarium-caused head blight disease can be detected by spectral analysis (400-1000 nm) before harvest. With this information, farmers could recognize Fusarium contaminations. They could, therefore, harvest the grains separately and supply it to other utilizations, if applicable. In the present study, wheat plants were analyzed using a hyper-spectral imaging system under laboratory conditions. Principal component analysis (PCA) was applied to differentiate spectra of diseased and healthy ear tissues in the wavelength ranges of 500-533 nm, 560-675 nm, 682-733 nm and 927-931 nm, respectively. Head blight could be successfully recognized during the development stages (BBCH-stages) 71-85. However, the best time for disease determination was at the beginning of medium milk stage (BBCH 75). Just after start of flowering (BBCH 65) and, again, in the fully ripe stage (BBCH 89), distinction by spectral analysis is impossible. With the imaging analysis method 'Spectral Angle Mapper' (SAM) the degree of disease was correctly classified (87%) considering an error of visual rating of 10%. However, SAM is time-consuming. It involves both the analysis of all spectral bands and the setup of reference spectra for classification. The application of specific spectral sub-ranges is a very promising alternative. The derived head blight index (HBI), which uses spectral differences in the ranges of 665-675 nm and 550-560 nm, can be a suitable outdoor classification method for the recognition of head blight. In these experiments, mean hit rates were 67% during the whole study period (BBCH 65-89). However, if only the optimal classification time is considered, the accuracy of detection can be largely increased.
  • Authors:
    • Wegener, C.
    • Jurgens, H.
    • Jansen, G.
  • Source: Kraftfutter
  • Volume: 94
  • Issue: 5/6
  • Year: 2011
  • Summary: The potentials of light hybrid rye varieties as a major ingredient in animal feeds was discussed. The nutritive value and chemical composition of hybrid ryes were also presented.
  • Authors:
    • Fomitcheva, V.
    • Rabenstein, F.
  • Source: Journal fur Kulturpflanzen
  • Volume: 63
  • Issue: 3
  • Year: 2011
  • Summary: The production of winter barley in Germany is threatened by a number of insect- and fungus-transmitted viruses. The situation is now worsened by the discovery of a new soil-borne virus. It was isolated from barley varieties possessing resistance to viruses of the barley yellow mosaic disease complex. The new virus has two sizes of rod-shaped virions that measure about 180 nm and 300 nm in length and 20 nm in diameter and can be decorated by immunogold labeling using selected furovirus-specific antibodies. Based on results of serological tests and preliminary molecular analysis, the new barley virus was closely related to isolates of Soil-borne cereal mosaic virus or Soil-borne wheat mosaic virus, two viruses hitherto only isolated in Germany from rye, triticale and winter wheat but never from winter barley. Further investigations will focus on the geographic distribution and relative importance of the new furovirus in Germany and on its identity to similar furoviruses isolated from barley in France and Japan.
  • Authors:
    • Marold, R.
  • Source: Zeitschrift für Arznei- & Gewürzpflanzen Journal of Medicinal & Spice Plants
  • Volume: 16
  • Issue: 3
  • Year: 2011
  • Summary: Medicinal and spice plants are risky crops. In comparison to the agricultural main crops, there is a strong fluctuation of the yields and the expenses are much higher. The risk increases if the crops are organically cultivated due to the restrictions of the use agro-chemicals. The organic farm Marold is located in Thuringia and grows 70 minor crop species on 340 ha of predominantly loess soil. Grass-clover in the crop rotation and well prepared manure with as little as possible weed seeds ensure the nitrogen supply of the plants. Couch grass and thistle require a special strategy of weed control. Seed weeds can be controlled by prophylactic measures in the crop rotation and soil management and by maintenance of boundary ridges. The expense of manual labour can be reduced by minimising the width of the band of the row with the crop plants which can not be covered by the tools of the hoeing machine. The seeds used for drilling crops should not be infested by diseases. Umbel diseases of fennel, coriander and caraway provoke severe yield losses up to 40%. The most important pests are field mice (in biennial caraway), blossom rape beetle (in Brassicaceae) and aphids. Systematic investigations for the development of effective plant protection method for organic cultivation are required.
  • Authors:
    • Windhorst, W.
    • Reiche, E.-W.
    • Middelhoff, U.
  • Source: Ecological Indicators
  • Volume: 11
  • Issue: 4
  • Year: 2011
  • Summary: Potential environmental as well as socio-economic effects of the cultivation of genetically modified (GM) oilseed rape (OSR) may be caused by large-scale dispersal of transgenes. We present an up-scaling approach that was based on scenario assumptions concerning the percentage of GM cultivation and took into account natural and anthropogenic variation of involved dispersal processes. The applied methods include computer modelling and spatial analysis. A simulation model (GeneTraMP) was used to calculate the spatio-temporal pattern of the spread of a neutral transgene (without any specific function) in OSR. Basic scenario calculations were carried out for different spatial configurations covering 1 km(2) each and taking into account information on climate and cultivation systems of the region of the federal state of Schleswig-Holstein, Germany. For the exemplary regional study presented here, we analysed the numbers of flowering plants of GM OSR in different types of locations as predicted by the model. The results confirmed the expectation of a very high variability of GM occurrences at distinguishable intensity levels which were closely related to the proximity of areas of intended GM oilseed rape cultivation and may be described by a combination of management parameters and location type. The up-scaling method included a spatial analysis of the target region. Based on satellite images and digital maps, the structure of the region was analysed resulting in a map of Schleswig-Holstein that represents each single field, also including information on crop rotation, ownership and production systems. Applying GIS queries to this database, we identified the area of relevant location types. Both, the model results and the spatial data were used to predict the total numbers of flowering GM OSR plants for the region of Schleswig-Holstein. As an important feature, the up-scaling of modelling results to a larger scale allows for a comprehensive analysis by also enclosing regional parameters, as, for example the cropping density. The presented methods can support decision making if they are incorporated into the planning of an environmental monitoring of commercial GM crops or into life cycle assessment and cost-benefit analyses of GMO cultivation. (C) 2009 Elsevier Ltd. All rights reserved.