• Authors:
    • Flower, K. C.
    • Crabtree, W. L.
  • Source: Field Crops Research
  • Volume: 121
  • Issue: 1
  • Year: 2011
  • Summary: On acid soils, no-tillage farmers are often advised to apply lime to the soil surface without incorporation by tillage. As such, it can take a number of years before the subsoil acidity is decreased. However, no-tillage seeders vary in the level of soil disturbance caused during seed placement. The consequence of such variations in soil disturbance for the effectiveness of lime in no-tillage cropping has not been explored. Our objectives were (i) to determine if the liming effect could be accelerated by increasing the rate of lime and level of soil disturbance during no-tillage seeding, and (ii) evaluate the effect of no-tillage seeding method, rate of lime and soil pH on yield of wheat, barley, canola and lupins. Three trials, each with a factorial design consisting of four seeding methods and four lime rates, were established in 1999 and continued until 2005. The soil had a texture contrast with about 15-20 cm of sand over yellow sandy clay loam and the initial pH (CaCl 2) at both 0-10 and 10-20 cm was between 4.5 and 4.7. The four seeding treatments were: low disturbance zero-till disc openers (ZT), higher disturbance no-tillage tines with narrow knife-points (NT), higher disturbance full cut seeding with sweeps (FC) for the first three years followed by ZT from then on, and FC for the first year followed by NT thereafter. The four lime rates were 0, 1, 2 and 4 t ha -1. The liming effect was more rapid with the higher disturbance seeding of NT, FCZT and FCNT, compared with ZT; the seeding effect on soil pH diminished with time and was not detected in the subsoil after four years. Higher rates of lime increased this effect and there was no interaction between seeding method and lime rate. This indicated that soil pH under the different seeding methods responded in a similar manner to increased lime. Nonetheless, significant positive linear regressions were found between yield and soil pH for wheat and barley and a negative relationship for lupins. Canola showed no response to soil pH, possibly because establishment was affected by seeding method, and soil pH was not low enough to elicit a response. The ZT seeding method gave lower yields than the other methods for canola and lupins in some years, but had no effect on wheat and barley yields. Higher disturbance at the time of no-till seeding can, therefore, accelerate the liming effect, making earlier economic gains possible.
  • 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:
    • Avval, S. H. M.
    • Rafiee, S.
    • Jafari, A.
    • Mohammadi, A.
  • Source: Journal of Agricultural Technology
  • Volume: 7
  • Issue: 3
  • Year: 2011
  • Summary: The energy consumption in different operations of soybean, canola and sunflower productions in Golestan province of Iran was investigated. This study also focused sketches the environmental footprints of energy use in oilseed production. For these purpose Inquiries on 319 oilseed farms were conducted in 2009/10 production period. The results revealed that soybean gave the highest operational energy input (22235 MJ ha -1); while, total operational energy for canola and sunflower was relatively low as 8317 and 6013 MJ ha -1, respectively. Irrigation operation consumed the highest share of total operational energy in soybean and sunflower productions; it was mainly in the form of electricity energy; however, in canola production, the tillage operation was the most intensive energy consumer, followed by harvesting practice. From this study it was found that increasing energy use efficiency of water pumping systems by good repair and maintenance and employing improved tillage and harvesting practices, such as low till agriculture, could be the pathways to make oilseed productions more environmental friendly and thus reduce their environmental footprints.
  • Authors:
    • Lehane, K.
    • Orange, D.
    • Holmes, C.
    • King, A.
    • Weston, E.
    • Dalal, R.
    • Thomas, G.
  • Source: Journal of Sustainable Agriculture
  • Volume: 35
  • Issue: 1
  • Year: 2011
  • Summary: Rainfed grain production in semi-arid, subtropical south-west Queensland in north-east Australia is marginal, because of low and variable rainfall and low soil fertility. Current cropping systems are based around winter cereals, with a summer fallow period essential for storing soil water to reduce risk. Increasing the soil water storage and the efficiency of water and nitrogen use is essential for sustainable crop production in this region. The effects on crop production and economic returns of various crop rotations involving winter crops - wheat ( Triticum aestivum), chickpea ( Cicer arietinum), faba bean ( Vicia faba) and canola ( Brassica napus); summer crops - grain sorghum ( Sorghum bicolor) and mung bean ( Phaseolus mungo); and fertilizer N application to wheat, canola and grain sorghum were studied from 1996 to 2005 on a grey Vertisol. Annual rainfall was above the long-term average in 6 of these 10 years and below average in 4 years. Crops were either not sown or failed due to drought in 3 years during this period. Under the seasonal conditions and grain prices that occurred during this experiment, mean annual gross margin was $100/ha greater for a 2-year chickpea-wheat rotation, $20/ha greater for a faba bean-canola-wheat rotation and $45/ha greater for an alternate cereal-grain legume rotation involving grain sorghum, mung bean, wheat and chickpea than for continuous wheat ($40/ha), where no nitrogen fertilizer was applied to wheat, canola or grain sorghum. Where nitrogen fertilizer was applied to target prime hard grain protein in wheat and maximize yield in canola and grain sorghum, chickpea-wheat ($170/ha) was the only rotation to result in greater gross margin than continuous wheat ($110/ha). Chickpea generally yielded well and resulted in a mean yield increase of 22% in the following wheat crop compared with continuous wheat, where no nitrogen fertilizer was applied in wheat and of 11% where N fertilizer was applied in wheat to target prime hard grain protein. On average, the grain legumes, chickpea and faba bean, provided soil nitrogen benefits of 20 and 40 kg N/ha, respectively, thereby reducing nitrogen fertilizer requirements for following cereal crops and canola. Therefore, the profitability and sustainability of crop production in this semi-arid, subtropical environment can be improved, compared with continuous winter cereal cropping, by appropriate crop rotations and nutrient management.
  • Authors:
    • Bueckert, R.
    • Gan. Y.T.
    • Liu, L. P.
    • Rees, K. van
  • Source: Field Crops Research
  • Volume: 122
  • Issue: 3
  • Year: 2011
  • Summary: Oilseed and pulse crops have been increasingly used to diversify cereal-based cropping systems in semiarid environments, but little is known about the root characteristics of these broadleaf crops. This study was to characterize the temporal growth patterns of the roots of selected oilseed and pulse crops, and determine the response of root growth patterns to water availability in semiarid environments. Canola ( Brassica napus L.), flax ( Linum usitatissimum L.), mustard ( Brassica juncea L.), chickpea ( Cicer arietinum L.), field pea ( Pisum sativum L.), lentil ( Lens culinaris), and spring wheat ( Triticum aestivum L.) were tested under high- (rainfall+irrigation) and low- (rainfall only) water availability conditions in southwest Saskatchewan, in 2006 and 2007. Crops were hand-planted in lysimeters of 15 cm in diameter and 100 cm in length that were installed in the field prior to seeding. Roots were sampled at the crop stages of seedling, early-flower, late-flower, late-pod, and physiological maturity. On average, root length density, surface area, diameter, and the number of tips at the seedling stage were, respectively, 41, 25, 14, and 110% greater in the drier 2007 than the corresponding values in 2006. Root growth in all crops progressed rapidly from seedling, reached a maximum at late-flower or late-pod stages, and then declined to maturity; this pattern was consistent under both high- and low-water conditions. At the late-flower stage, root growth was most sensitive to water availability, and the magnitude of the response differed between crop species. Increased water availability increased canola root length density by 70%, root surface area by 67%, and root tips by 79% compared with canola grown under low-water conditions. Water availability had a marginal influence on the root growth of flax and mustard, and had no effect on pulse crops. Wheat and two Brassica oilseeds had greater root length density, surface area and root tips throughout the entire growth period than flax and three pulses, while pulse crops had thicker roots with larger diameters than the other species. Sampling roots at the late-flower stage will allow researchers to capture best information on root morphology in oilseed and pulse crops. The different root morphological characteristics of oilseeds, pulses, and wheat may serve as a science basis upon which diversified cropping systems are developed for semiarid environments.
  • Authors:
    • Bueckert, R.
    • Gan, Y. T.
    • Liu, L. P.
    • Rees, K. van
  • Source: Field Crops Research
  • Volume: 122
  • Issue: 3
  • Year: 2011
  • Summary: Root distribution patterns in the soil profile are the important determinant of the ability of a crop to acquire water and nutrients for growth. This study was to determine the root distribution patterns of selected oilseeds and pulses that are widely adapted in semiarid northern Great Plains. We hypothesized that root distribution patterns differed between oilseed, pulse, and cereal crops, and that the magnitude of the difference was influenced by water availability. A field experiment was conducted in 2006 and 2007 near Swift Current (50°15′N, 107°44′W), Saskatchewan, Canada. Three oilseeds [canola ( Brassica napus L.), flax ( Linum usitatissimum L.), mustard ( Brassica juncea L.)], three pulses [chickpea ( Cicer arietinum L.), field pea ( Pisum sativum L.), lentil ( Lens culinaris)], and spring wheat ( Triticum aestivum L.) were hand-planted in lysimeters of 15 cm in diameter and 100 cm in length which were pushed into soil with a hydraulic system. Crops were evaluated under low- (natural rainfall) and high- (rainfall+irrigation) water conditions. Vertical distribution of root systems was determined at the late-flowering stage. A large portion (>90%) of crop roots was mainly distributed in the 0-60 cm soil profile and the largest amount of crop rooting took place in the top 20 cm soil increment. Pulses had larger diameter roots across the entire soil profile than oilseeds and wheat. Canola had 28% greater root length and 110% more root tips in the top 10 cm soil and 101% larger root surface area in the 40 cm soil under high-water than under low-water conditions. In 2007, drier weather stimulated greater root growth for oilseeds in the 20-40 cm soil and for wheat in the 0-20 cm soil, but reduced root growth of pulses in the 0-50 cm soil profile. In semiarid environments, water availability did not affect the vertical distribution patterns of crop roots with a few exceptions. Pulses are excellent "digging" crops with a strong "tillage" function to the soil due to their larger diameter roots, whereas canola is more suitable to the environment with high availability of soil water that promotes canola root development.
  • Authors:
    • Middleton, A. B.
    • Bremer, E.
    • McKenzie, R. H.
    • Pfiffner, P. G.
    • Woods, S. A.
  • Source: Canadian Journal of Plant Science
  • Volume: 91
  • Issue: 2
  • Year: 2011
  • Summary: High crop productivity is essential for irrigated crops and may be strongly affected by decisions of seeding date and rate. An irrigated field experiment was conducted at two locations in southern Alberta for 4 yr to compare the impact of seeding date and rate on productivity and quality of nine cereal crops and two oilseed crops. Seeding rate was only evaluated on one date in late April or early May, when maximum yields were expected. Delayed seeding reduced crop yields by 0.6 to 1.7% per day after the end of April: flax ( Linum usitatissimum L.) ≤ CWRS wheat ( Triticum aestivum L.), feed triticale (* Triticosecale W.) ≤ CPS or SWS wheat ≤ triticale or barley ( Hordeum vulgare L.) silage ≤ durum ( T. turgidum L.), feed or malt barley
  • 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.
  • Authors:
    • Nelson, S. O.
    • Trabelsi, S.
  • Source: Transactions of the American Society of Agricultural and Biological Engineers
  • Volume: 54
  • Issue: 2
  • Year: 2011
  • Summary: Based on microwave dielectric properties of wheat, corn, barley, oats, grain sorghum, soybeans, canola, shelled peanuts and pod peanuts measured over ranges of frequency and moisture content, models for predicting the dielectric constant and loss factor of these commodities are described. Nearly linear relationships between dielectric properties and log of frequency or frequency and moisture content permitted multiple linear regression models to be developed for predicting dielectric constants and loss factors for each type of grain and seed at 23degreesC. Models predicted dielectric constants with s.e. of 1 to 2% with some up to approx. 4% for grain and seed at frequencies in the range 5 to 15 GHz over given moisture ranges. Loss factors are predicted with s.e. of a few percent, but much larger errors can naturally result when loss factors are very small.
  • Authors:
    • Jauhiainen, L.
    • Peltonen-Sainio, P.
    • Hakala, K.
  • Source: The Journal of Agricultural Science
  • Volume: 149
  • Year: 2011
  • Summary: Global warming has accelerated in recent decades and the years 1995-2006 were the warmest ever recorded. Also, in Finland, the last decade has been exceptionally warm. Hence, this study examines how current field crop cultivars, adapted to northern long-day conditions and short growing seasons, have responded to the elevated temperatures, especially with regard to determination of yield potential and quality. These comparisons were carried out with spring and winter wheat (Triticum aestivum L.), oats (Avena sativa L.), barley (Hordeum vulgare L.), winter rye (Secale cereale L.), pea (Pisum sativum L.) and rapeseed (turnip rape, Brassica rapa L. and oilseed rape, B. napus L.). Long-term data sets of MTT Official Variety Trials and the Finnish Meteorological Institute were used to study crop responses to precipitation and elevated temperatures at different growth phases. The MTT data sets were also grouped into experiments that could be considered typical of the temperature conditions in the period 1971-2000 seasons (termed '1985' conditions) or typical of the period 2010-39 (termed '2025'). At elevated temperatures, yields generally declined in these relatively cool growing conditions of northern Europe, except for pea. Elevated temperatures tended to have negative effects both in the pre- and post-anthesis phases, but the response depended on species. The response was probably associated with reduced water availability, which limited yield determination, especially in early growth phases. For example, in spring cereals a decrease in early summer precipitation by 10 mm decreased yields by 45-75 kg/ha. As warmer conditions also typically hastened development and growth in such generally cool growing conditions of Finland, it is essential that breeding programmes produce cultivars that are less sensitive to elevated temperatures, which are likely to become more frequent in future.