• Authors:
    • Kindred, D. R.
    • Wiltshire, J. J. J.
    • Sylvester-Bradley, R.
    • Hatley, D. L. J.
    • Clarke, S.
  • Source: HGCA Project Report
  • Volume: i + 47 pp.
  • Issue: 460
  • Year: 2009
  • Summary: This report describes a second year of research that tested whether soil nitrogen supplies to cereal crops can be detected using canopy sensors; the first season was reported in HGCA Project Report No. 427. Nitrogen fertiliser experiments on cereals were established at four sites in 2006-7. In the following year, commercial cereal crops (wheat, oats or barley) were grown and, at each site, plot positions as used in the previous year were marked out for testing with a reflectance sensor. Reflectance was measured four times during tillering, between December and May (dependant on site), using a Crop Circle instrument (provided by Soilessentials Ltd) which measured reflectance at 880 nm (near-infrared, NIR) and 590 nm (orange). A Normalised Difference Vegetation Index (NDVI) was calculated to give a measure of vegetation cover. Soil mineral N (SMN) data were obtained for the sites. No fertiliser N was applied in 2008 and total N uptake at harvest was taken to represent the 'soil N supply' (SNS). Data were interpreted for relationships between canopy reflectance and soil N. The best level of tillering and ground cover was achieved at High Mowthorpe, which was sown early. Boxworth and Terrington crops were smaller, and the crop at Rosemaund was very small. High levels of N applied in 2007 had large effects on SMN at Boxworth and Terrington, but maximum amounts were smaller at High Mowthorpe or Rosemaund and maximum SMN and SNS levels were small. Use of the sensor successfully detected the differences in SMN residues at Boxworth and Terrington, especially below 120-140 kg/ha, as was found in the previous year's experiments. The relationships improved with later assessment of NDVI. Change in NDVI between assessment dates showed that canopies always grew during the 2007/08 winter but change in NDVI was less useful for predicting SNS than absolute values of NDVI. Merged data from both seasons of the study showed that NDVI signals overwinter could be interpreted according to their differences from the theoretical NDVI of an unlimited crop. It was concluded that young canopies can signal soil N status where SMN is less than 120-140 kg/ha. Effects were more certain as crops grew, so canopy sensing for soil N supplies should prove more useful as the season progresses.
  • Authors:
    • Tobiasz-Salach, R.
    • Bobrecka-Jamro, D.
    • Szpunar-Krok, E.
  • Source: Fragmenta Agronomica
  • Volume: 26
  • Issue: 2
  • Year: 2009
  • Summary: The field experiments was carried out on good wheat soil complex during 2003-2005 in Podkarpacie region (5003′ N, 2206′ E). The 2-species mixtures of naked oats Polar with cultivars of faba bean Akord - its growth pattern undefined, Albus - with low tanine content and self-completing, Titus - self-completing were not distinguishable as regards grain yield as they in most cases gave yields higher than faba bean in pure sowing and even in years with highest rainfall, it gave higher yields than oats in pure sowing. While crude protein yields of mixtures were higher than oats in pure sowing but lower than faba bean, the energy value of yields were however higher in comparison with sole-species cultivations. The content of faba bean grains damaged by Bruchus rufimanus Boh. in mixtures with naked oats did not differ significantly from those in pure sowing. The traditional Akord cultivar was characterized with less stability of yields during the period covered but its grains were infected by Bruchus rufimanus Boh. than self-completing cultivars. Having in mind prevailing conditions of Podkarpacie, it is recommended that Albus cultivar be added to mixtures with naked oats, Polar variety due to very high grain and protein yields as well as energy value of yields.
  • Authors:
    • Bobrecka-Jamro, D.
    • Tobiasz-Salach, R.
  • Source: Annales Universitatis Mariae Curie-Skodowska
  • Volume: 64
  • Issue: 1
  • Year: 2009
  • Summary: The results of field experiments undertaken during 2004-2006 at the research station in Krasne near Rzeszow are presented in the study paper. The study covered the influence of foliar fertilization with compound fertilizers on the yield and chemical composition of grains of husk free oats cultivated on average soils. The obtained results demonstrated that the response of the varieties to foliar fertilization was not uniform. Fertilization with Adob Mn as well as Adob Cu resulted in yield drops by 5.1% in Akt variety. As regards the Polar variety, all applied types of fertilizer resulted in increased yields with the highest of 19%, which was due to Adob Cu application. Both Basfoliar 36 Extra and Adob Mn application resulted in increases in the weight of 1000 grains by 3.5% and 1.18%, respectively. An influence of foliar fertilization on the content of protein, fat, fibre, and volatile non-nitrogen compounds in oats grains was not observed. Increases in ash content of husk free oat grains were due solely to Adob Mn fertilization. All applied fertilizer types led to decreases in protein content while increasing digestible fat content for pigs. Foliar fertilization led to increased outputs of protein, fat as well as energy value of yields from a unit land area.
  • Authors:
    • Davis, A.
    • Tracy, B.
  • Source: Crop Science
  • Volume: 49
  • Issue: 4
  • Year: 2009
  • Summary: Crop and livestock production are rarely integrated together in modern farming systems. Reintegrating crops with livestock production has been shown to produce many agronomic and environmental benefits. The objective of this study was to evaluate how an integrated crop-livestock system would influence weed biomass and weed species composition compared with a conventional, continuous corn ( Zea mays L.) cropping system. The experimental farming system used in this study was established on a 90-ha site near Pana, IL, in 2002. The integrated system included two phases: (i) a corn and oat ( Avena sativa L.) cash crop rotation, grown in summer, and (ii) post-harvest grazing of corn stover with annual cover crops. Over a 4-yr period (2004-2007), weed biomass was approximately 4.5 times higher in the conventional system (8.4 g m -2) compared with the integrated system (1.8 g m -2). Weed species composition was affected by the integrated system and showed a temporal disjunction between the time of year and weed life history. Surprisingly, cattle grazing on cropland had little effect on weed biomass or species composition. The primary drivers that suppress weed biomass and change species composition appear to be use of crop rotation and annual cover crops within the integrated system. Wider adoption of integrated crop-livestock systems, such as the one used in this study, should reduce reliance on herbicides compared with more conventional cropping systems.
  • Authors:
    • Ernani, P.
    • Zanatta, J.
    • Bayer, C.
    • Vieira, F.
  • Source: Australian Journal of Soil Research
  • Volume: 47
  • Issue: 7
  • Year: 2009
  • Summary: Nitrogen-fixing crops and N fertilisation increase soil acidification, but few studies have attempted to evaluate the capacity of soil organic matter to alleviate the Al toxicity in acid no-tilled soils. This study was carried out in a 21-year-old experiment aiming to evaluate the effect of crop systems [fallow/maize ( Zea mays L.), F/M; oat ( Avena strigosa Schreb)/maize, O/M; oat+vetch ( Vigna sativa L.)/maize, O+V/M; lablab ( Dolichos lablab)+maize, L+M; and pigeon pea ( Cajanus cajan L. Millsp.)+maize, P+M] and mineral N fertilisation (0 and 149 kg/ha.year) on chemical attributes and Al speciation in the 0-0.05 and 0.05-0.10 m layers of a no-tilled Paleudult of Southern Brazil. The original soil pH (5.8) decreased in all crop systems, declining 0.37-1.52 units in 21 years without re-liming. This decrease was larger in subsoil layers and, in general, was exacerbated by legume-based crop systems and by N fertilisation. The drop in soil pH increased Al content in solid phase (range 0.07-1.85 cmol c/kg) and in soil solution (range 0.01-0.06 mmol/L), and decreased base saturation on cation exchange capacity (range 12.5-61.2%). However, the Al 3+ activity in the soil solution (1.03*10 -7-9.3*10 -8) was kept below threshold values of toxicity to maize roots, primarily due to the formation of organometallic complexes at low pH, which was estimated as up to 90% of the total Al in solution, but also due to the increased ionic strength in this no-till soil (0.0026-0.0104). Our results highlight that, although legume cover crops and N fertilisation can accelerate soil acidification, Al toxicity is offset by increased organic matter in no-till subtropical soils.
  • Authors:
    • Cui, L.
    • Wu, B.
    • Zhang, Z.
    • Xu, W.
  • Source: Acta Agronomica Sinica
  • Volume: 35
  • Issue: 12
  • Year: 2009
  • Summary: Oat ( Avena L.) is one of the most important cereal crops in the world, ranked at the sixth top place in planting area and yield among all cereal crops, and possesses high values in food and nutrition, health protection and feeding livestock. Naked oat ( A. nuda) is an endemic type in China. However, a few studies on naked oat germplasm at molecular level have been reported. The aim of this study was to evaluate the genetic diversity of core collection of naked oat using AFLP markers. A total of 281 accessions of naked oat were analyzed using 20 AFLP primer combinations. Selective amplification created 1 137 bands, of which 260 were polymorphic, accounting for 22.96% of the total bands. The mean polymorphism information content (PIC) was 0.0326. For different geographic groups, Simpson's index ranged from 1.235 to 1.495, and Shannon's index varied from 0.1558 to 0.4437. The majority (83.45%) of the AFLP variation resided within accessions of each group, and the rest (16.55%) existed among accessions between groups. The sample size of geographic groups was significantly associated with the number of polymorphic loci, proportion of within-group variation, Simpson's index and Shannon's index. Accessions from Inner Mongolia and Shanxi were most diverse, and those from northeastern China were most distinct. Genetic resemblance was found within accessions from western China. Germplasm from East Europe was genetically close to that from Inner Mongolia, China. The genetic diversity of Chinese accessions was significantly higher than that of exotic accessions. Compared with breeding cultivars, landraces presented a higher proportion of within-group variation. Naked oat landraces were suggested to be collected in the regions where are not well represented by the current collections, and collecting activities should be continuous in the diversity-rich areas such as northwestern and southwestern China in order to enrich naked oat gene pool in China.
  • Authors:
    • Hill, J.
    • Jacobs, J. L.
    • Jenkin, T.
  • Source: Animal Production Science
  • Volume: 49
  • Issue: 7
  • Year: 2009
  • Summary: The efficient production and subsequent utilisation of home-grown forage is seen as the cornerstone of profitability of the dairy industry as it leads to lower unit costs of milk production compared with purchased forage or grain supplements. Cereals such as wheat ( Triticum aestivum L.), oats ( Avena sativa L.) and triticale ( Triticum * Triticosecale) all have the potential to produce high forage dry matter (DM) yields. These forages are not widely grown within dryland Australian dairy systems and there is a paucity of information on both the agronomic requirements and subsequent ensiling and feed-out management under these conditions. The experiment reported in this paper examines the DM yield, nutritive and ensiling characteristics of three small-grain cereals (triticale, wheat and oats) cut at various stages of development and ensiled with or without silage additives. We hypothesised that: (1) delaying harvesting until later stages of growth would result in higher DM yields, but negatively impact on both nutritive and fermentation characteristics of subsequent silages; (2) ensiling wilted material at earlier harvests would improve fermentation characteristics compared with direct ensiled material; and (3) the use of silage additives at all harvests would improve fermentation characteristics of resultant silages compared with untreated silages. Apart from winter oats, the estimated metabolisable energy of forages was highest at the boot stage of growth, declined during anthesis and then rose again during milk and soft-dough stage of growth. The crude protein content of forages declined with maturity, with final values at soft dough below 90 g/kg DM. Neutral detergent fibre content was highest at anthesis and then declined, with lowest values observed at soft dough (497-555 g/kg DM). In the majority of cases silages were well preserved, with direct ensiled material having pH values generally below 4.5 and wilted material below 5.0, with limited proteolysis as assessed by ammonia-N contents in the range of 5-15% of total-N. The production of volatile fatty acids and lactic acid was influenced by wilting and the use of additives. Generally, wilted silages fermented less than the corresponding direct ensiled forages, whereas the use of Sil-All 4*4 additive resulted in a lactic acid-dominant fermentation compared with LaSil additive, which resulted in a greater proportion of acetic acid as an end product of fermentation. The findings of the present study highlight the potential of forage cereals to produce high DM yields for whole crop cereal silage. The timing of harvest directly influences nutritive characteristics of forages for ensiling. The use of silage additives can assist in controlling fermentation pathways during ensilage, ensuring the production of silages with fermentation attributes more likely to lead to higher intakes when fed to animals.
  • Authors:
    • NASS
    • USDA
  • Year: 2009
  • Authors:
    • Jones, R.
    • Hatfield, J. L.
    • Kerr, B. J.
    • Singer, J. W.
    • Moorman, T. B.
    • Kaspar, T. C.
    • Chan, A. S. K.
    • Parkin, T. B.
    • Jarecki, M. K.
  • Source: Agriculture, Ecosystems & Environment
  • Volume: 134
  • Issue: 1-2
  • Year: 2009
  • Summary: Agriculture contributes 40-60% of the total annual N2O emissions to the atmosphere. Development of management practices to reduce these emissions would have a significant impact on greenhouse gas levels. Non-leguminous cover crops are efficient scavengers of residual soil NO3, thereby reducing leaching losses. However, the effect of a grass cover crop on N2O emissions from soil receiving liquid swine manure has not been evaluated. This study investigated: (i) the temporal patterns of N2O emissions following addition of swine manure slurry in a laboratory setting under fluctuating soil moisture regimes; (ii) assessed the potential of a rye (Secale cereale L.) cover crop to decrease N2O emissions under these conditions: and (iii) quantified field N2O emissions in response to either spring applied urea ammonium nitrate (UAN) or different rates of fall-applied liquid swine manure, in the presence or absence of a rye/oat winter cover crop. Laboratory experiments investigating cover crop effects N2O emissions were performed in a controlled environment chamber programmed fora 14 h light period, 18 degrees C day temperature, and 15 degrees C night temperature. Treatments with or without a living rye cover crop were treated with either: (i) no manure: (ii) a phosphorus-based manure application rate (low manure): or (iii) a nitrogen-based manure application rate (high manure). We observed a significant reduction in N2O emissions in the presence of the rye cover crop. Field experiments were performed on a fine-loamy soil in Central Iowa from October 12, 2005 to October 2, 2006. We observed no significant effect of the cover crop on cumulative N2O emissions in the field. The primary factor influencing N2O emission was N application rate, regardless of form or timing. The response of N2O emission to N additions was non-linear, with progressively more N2O emitted with increasing N application. These results indicate that while cover crops have the potential to reduce N2O emissions, N application rate may be the overriding factor.
  • Authors:
    • Lal, R.
  • Source: Soil & Tillage Research
  • Volume: 102
  • Issue: 2
  • Year: 2009
  • Summary: Global energy demand of 424 EJ year-1 in 2000 is increasing at the rate of 2.2% year-1. There is a strong need to increase biofuel production because of the rising energy costs and the risks of global warming caused by fossil fuel combustion. Biofuels, being C-neutral and renewable energy sources, are an important alternative to fossil fuels. Therefore, identification of viable sources of biofuel feedstock is a high priority. Harvesting lignocellulosic crop residues, especially of cereal crops, is being considered by industry as one of the sources of biofuel feedstocks. Annual production of lignocellulosic residues of cereals is estimated at 367 million Mg year-1 (75% of the total) for the U.S., and 2800 million Mg year-1 (74.6% of the total) for the world. The energy value of the residue is 16 × 106 BTU Mg-1. However, harvesting crop residues would have strong adverse impact on soil quality. Returning crop residues to soil as amendments is essential to: (a) recycling plant nutrients (20-60 kg of N, P, K, Ca per Mg of crop residues) amounting to 118 million Mg of N, P, K in residues produced annually in the world (83.5% of world's fertilizer consumption), (b) sequestering soil C at the rate of 100-1000 kg C ha-1 year-1 depending on soil type and climate with a total potential of 0.6-1.2 Pg C year-1 in world soils, (c) improving soil structure, water retention and transmission properties, (d) enhancing activity and species diversity of soil fauna, (e) improving water infiltration rate, (f) controlling water runoff and minimizing risks of erosion by water and wind, (g) conserving water in the root zone, and (h) sustaining agronomic productivity by decreasing losses and increasing use efficiency of inputs. Thus, harvesting crop residues as biofuel feedstock would jeopardize soil and water resources which are already under great stress. Biofuel feedstock must be produced through biofuel plantations established on specifically identified soils which do not compete with those dedicated to food crop production. Biofuel plantations, comprising of warm season grasses (e.g., switch grass), short rotation woody perennials (e.g., poplar) and herbaceous species (e.g., miscanthus) must be established on agriculturally surplus/marginal soils or degraded/desertified soils. Plantations established on such soils would restore degraded ecosystems, enhance soil/terrestrial C pool, improve water resources and produce biofuel feedstocks.