• Authors:
    • Suyker, A. E.
    • Verma, S. B.
  • Source: Agricultural and Forest Meteorology
  • Volume: 148
  • Issue: 3
  • Year: 2008
  • Summary: In this paper, we present results from 4 years (May 2001-May 2005) of water and energy flux measurements made in a no-till, irrigated maize-soybean rotation system in eastern Nebraska, USA. The peak green leaf area index (LAI) reached 6.0 and 5.5 in maize (2001 and 2003, respectively) and 5.7 and 4.4 in soybean (2002 and 2004, respectively). The dependence of evapotranspiration (ET) on leaf area was consistent with previous studies. There was a nearly linear relationship between the daily ET/ET o (where ET o is the reference evapotranspiration over a grass reference crop) and LAI until a threshold LAI (between 3 and 4). Above this threshold LAI, the ET/ET o was virtually independent of LAI. The cumulative growing season (planting to harvest) evapotranspiration was 544 and 578 mm for maize, and 474 and 430 mm for soybean. The interannual variability in the growing season ET totals correlated very well with the number of days when the LAI was greater than 3. The non-growing season period (harvest to subsequent planting) contributed between 20 and 25% of the annual ET totals for both crops. The maximum canopy surface conductance ( Gsmax) was 29 mm s -1 for maize in both years, 41 mm s -1 for soybean in 2002 (peak LAI=5.7) and 36 mm s -1 for soybean in 2004 (peak LAI=4.4). The variability in Gsmax was largely explained by the leaf nitrogen concentration, consistent with the literature.
  • Authors:
    • Xia, J.
    • Wu, D.
    • Yu, Q.
    • Wang, E.
  • Source: International Journal of Climatology
  • Volume: 28
  • Issue: 14
  • Year: 2008
  • Summary: The North China Plain (NCP) is the largest agricultural production area in China. The extensive use of groundwater for irrigation agriculture under variable climatic conditions has resulted in the rapid decline of the groundwater table especially in areas north of the Yellow River, leading to hydrological imbalance and unsustainable agricultural production. This article analyses the sustainable level of vegetation/crop water use under the NCP climate by mimicking the evapotranspiration of a natural forest ecosystem. Such a system would have a mean annual evapotranspiration ranging from 470 mm/year in the northern to 910 mm/year in the southern part of the plain, leading to a mean annual water excess (rainfall minus evapotranspiration) ranging from 21 to 124 mm/year. The natural forest ecosystem would use less water than the current wheat/maize double cropping system. To mimic the water use of the natural system, dryland farming has to be practiced, and wheat and maize crops would have a water deficit of 90-435 and 0-257 mm/year, respectively. Under average conditions, this would mean that all the areas north of the 36 degrees N line have to abandon winter wheat production. Stopping irrigation will lead to significantly lower wheat yields (average yield 0.8 t/ha in the north to 5.2 t/ha in the south) and increased variability in wheat and maize yield both interannually and spatially. Better management practices, such as opportunity cropping (what and when to crop depending on climate and soil conditions rather than a set annual cycle), better use of climate forecast information to direct decision making, are required in order to achieve maximum return in good years while minimizing cost in bad years. Analysis on rainfall and potential evapotranspiration (PET) from 1961 to 2000 shows that there has been an increasing trend in crop water deficit in the northern part, but a decreasing trend in the southern part of the plain. It remains to be further studied whether this reflects long-term climate change or only a part of the climate variability.
  • Authors:
    • Egbert, S. L.
    • Wardlow, B. D.
  • Source: Remote Sensing of Environment
  • Volume: 112
  • Issue: 3
  • Year: 2008
  • Summary: Improved and up-to-date land use/land cover (LULC) data sets that classify specific crop types and associated land use practices are needed over intensively cropped regions such as the U.S. Central Great Plains, to support science and policy applications focused on understanding the role and response of the agricultural sector to environmental change issues. The Moderate Resolution Imaging Spectroradiometer (MODIS) holds considerable promise for detailed, large-area crop-related LULC mapping in this region given its global coverage, unique combination of spatial, spectral, and temporal resolutions, and the cost-free status of its data. The objective of this research was to evaluate the applicability of time-series MODIS 250 m normalized difference vegetation index (NDVI) data for large-area crop-related LULC mapping over the U.S. Central Great Plains. A hierarchical crop mapping protocol, which applied a decision tree classifier to multi-temporal NDVI data collected over the growing season, was tested for the state of Kansas. The hierarchical classification approach produced a series of four crop-related LULC maps that progressively classified: (1) crop/non-crop, (2) general crop types (alfalfa, summer crops, winter wheat, and fallow), (3) specific summer crop types (corn, sorghum, and soybeans), and (4) irrigated/non-irrigated crops. A series of quantitative and qualitative assessments were made at the state and sub-state levels to evaluate the overall map quality and highlight areas of misclassification for each map. The series of MODIS NDVI-derived crop maps generally had classification accuracies greater than 80%. Overall accuracies ranged from 94% for the general crop map to 84% for the summer crop map. The state-level crop patterns classified in the maps were consistent with the general cropping patterns across Kansas. The classified crop areas were usually within 1-5% of the USDA reported crop area for most classes. Sub-state comparisons found the areal discrepancies for most classes to be relatively minor throughout the state. In eastern Kansas, some small cropland areas could not be resolved at MODIS' 250 m resolution and led to an underclassification of cropland in the crop/non-crop map, which was propagated to the subsequent crop classifications. Notable regional areal differences in crop area were also found for a few selected crop classes and locations that were related to climate factors (i.e., omission of marginal, dryland cropped areas and the underclassification of irrigated crops in western Kansas), localized precipitation patterns (overclassification of irrigated crops in northeast Kansas), and specific cropping practices (double cropping in southeast Kansas).
  • Authors:
    • Zhang, J.
    • Liu, E.
    • Huang, X.
    • Chi, B.
    • Zhang, D.
  • Source: Transactions of the Chinese Society of Agricultural Engineering
  • Volume: 24
  • Issue: 4
  • Year: 2008
  • Summary: Field experiments were conducted in China to analyse the reasons for maize yield decrease under plastic film mulching condition. The results showed that plastic film mulching significantly increased soil temperature, promoted maize growth and significantly sped up phenostages of maize. However, maize encountered a serious summer drought at the heading stage. The normal pollination of maize was affected seriously, which resulted in the decrease of maize yield. Maize yields with plastic film mulching were 73.6 and 12.9% lower than that of open-ground planting for 2 consecutive years. The frequency of serious summer drought was 15.9% at the maize heading stage in the experiment area, which resulted in maize yield decrease. These facts should not be ignored and need investigating. So plastic film mulching should be rationally chosen and applied in semi-arid areas according to concrete conditions.
  • Authors:
    • [Anonymous]
  • Source: Muhle + Mischfutter
  • Volume: 145
  • Issue: 18
  • Year: 2008
  • Summary: The article describes harvest and yield details of the German cereals season 2008. All federal states of Germany are covered and all cereals including milling, feed, industrial and grain maize, but excluding silage and corn-cob-mix maize. In 2008, the total tonnage increased from 23% to 49 million tonnes. The highest yield increases, compared to the poor year 2007, were reported from the northern states, Mecklenburg-Vorpommern, Niedersachsen, Schleswig-Holstein and Nordrhein-Westfalen. Average winter wheat yields were 8.1 t/ha, winter barley 6.6 t/ha and triticale 6.0 t/ha. Spring barley was 4.9 t/ha and oats only 4.6 t/ha. Because of the large quantities, enough good quality milling wheat will be available. An outlook on the EU cereal harvest, the global and USA harvests in 2008 are given at the end of the paper.
  • Authors:
    • Giacomini, S.
    • Aita, C.
  • Source: Revista Brasileira de Ciencia do Solo
  • Volume: 32
  • Issue: 5
  • Year: 2008
  • Summary: This study was conducted to evaluate the accumulation and displacement of N-NO 3- in the soil after pig slurry application in no-tillage maize in southern Brazil. The doses of 0, 40 and 80 m 3/ha pig slurry were applied annually, for three years, on the mulch of cover crop of black oats [ Avena nuda] and of winter spontaneous vegetation, preceding maize sowing. The N-NO 3- concentration was evaluated in different soil layers to a depth of 60 cm and on six dates, from the slurry application until maize tasseling. The amount of N-NO 3- increased quickly in the soil surface layer with the pig slurry application, evidencing the high nitrification rates of ammoniacal N in the slurry. N-NO 3- produced in the surface layers moved down quickly in the soil profile. At a dose of 80 m 3/ha slurry the amounts of N-NO 3- in the 30-60 cm soil layer on the 30th day of the first year, 29th day in the second and 36th day in the third year were higher than the average of the treatments without slurry in 9, 21 and 32 kg N-NO 3-/ha, respectively. In the first two years the amount of soil N-NO 3- in the surface layer did not differ with slurry application on mulch of oats or spontaneous vegetation, indicating the low potential of grass mulch in promoting microbial N immobilization. The high rate of nitrification of ammoniacal N in the slurry and the fast displacement of N-NO 3- in the soil profile when maize N demand was still small indicate a greater susceptibility of N-NO 3- losses by leaching with slurry application, especially at a dose of 80 m 3/ha, where the average amount of total applied N in the three years was 244 kg/ha per year.
  • Authors:
    • Bello, F.
    • Arendt, E.
  • Source: Technology of functional cereal products
  • Year: 2008
  • Summary: This chapter focuses on the association between the ingestion of gluten and an immune-mediated enteropathy known as coeliac disease. Other topics covered include: difficulties in producing gluten-free breads; ingredients suitable for gluten-free bread production (pseudocereals, sorghum, oats, rice, corn, tef, dietary fibre); and improving the quality of gluten-free bread.
  • Authors:
    • Ullrich, S.
    • Baik, B.
  • Source: Journal of Cereal Science
  • Volume: 48
  • Issue: 2
  • Year: 2008
  • Summary: Barley ( Hordeum vulgare vulgare L.) is an ancient cereal grain, which upon domestication has evolved from largely a food grain to a feed and malting grain. However, barley food use today remains important in some cultures around the world, particularly in Asia and northern Africa, and there is renewed interest throughout the world in barley food because of its nutritional value. This review covers basic and general information on barley food use and barley grain processing for food use, as well as an in-depth look at several major aspects/traits of interest for barley food use including kernel hardness and colour, grain starch, and beta-glucan contents. These traits are described in terms of their effects on processing and nutrition, as well as their inheritance and the prospects for barley improvement through breeding. Whereas, the aspects listed above have been studied relatively extensively in barley in terms of content, form, genetics, physiology, and in some cases nutritional quality, little is know about functional properties for processing and food product development. Renewed interest in barley for food uses largely centres around the effects of beta-glucans on lowering blood cholesterol levels and glycemic index. Wholegrain barley foods also appear to be associated with increased satiety and weight loss. There is great potential to utilise barley in a large number of cereal-based food products as a substitute partially or wholly for currently used cereal grains such as wheat ( Triticum aestivum), oat ( Avena sativa), rice ( Oryza sativa), and maize ( Zea mays).
  • Authors:
    • Baker, B.
  • Source: Proceedings of the 5th Organic Seed Growers Conference, Salem, Oregon, USA
  • Year: 2008
  • Summary: The market for organic seed poses a great opportunity for both organic producers who want to diversify into new crops as well as for seed producers who want to enter into the rapidly growing organic market. While organic standards in the United States require the use of organic seed, organic producers are not able to find organic seed in sufficient quantity and of suitable quality to meet their production needs. Because commercial availability must be evaluated as part of the certification process, the certifying agents play an important role in assessing both the supply and demand for organic seed. Certifying agents were surveyed to identify how they assess commercial availability, what information resources are used, and what crops and varieties are considered commercially unavailable. More research is needed to forecast organic seed demand and overcome production obstacles.
  • Authors:
    • Pelissari, A.
    • Moraes, A.
    • Balbinot Junior, A.
    • Dieckow, J.
    • Veiga, M.
  • Source: PLANTA DANINHA
  • Volume: 26
  • Issue: 3
  • Year: 2008
  • Summary: Economically viable alternatives for winter soil use in southern Brazil are scarce. During this period, pasture cultivated under crop-livestock system is an alternative. The objective of this study was to evaluate the effect of different winter soil uses on weed infestation in maize cultivated in succession. Two experiments were carried out from May, 2006 to April, 2007. Five alternatives of winter soil use were investigated: (1) multi-cropping with black oat+ryegrass+vetch+arrow leaf clover without grazing and nitrogen fertilization (multi-cropping cover); (2) the same multi-cropping, with grazing and nitrogen fertilization, 100 kg ha -1 of N (pasture with N); (3) the same multi-cropping, with grazing and without nitrogen fertilization (pasture without N); (4) oil seed radish, without grazing and nitrogen fertilization (oil seed radish); and (5) natural vegetation, without grazing and nitrogen fertilization (fallow). Cover crop in the winter, cultivated without grazing, produces a high amount of straw, reducing weed summer infestation. Under the experimental conditions, winter soil use with pasture allows high weed summer infestation, due to the low amount of straw that stays on the soil.