• Authors:
    • Rickman, R. W.
    • Liang, Y.
    • Albrecht, S. L.
    • Machado, S.
    • Kang, S.
    • Gollany, H. T.
  • Source: Agronomy Journal
  • Volume: 103
  • Issue: 1
  • Year: 2011
  • Summary: Long-term field experiments (LTE) are ideal for predicting the influence of agricultural management on soil organic carbon (SOC) dynamics and examining biofuel crop residue removal policy questions. Our objectives were (i) to simulate SOC dynamics in LTE soils under various climates, crop rotations, fertilizer or organic amendments, and crop residue managements using the CQESTR model and (ii) to predict the potential of no-tillage (NT) management to maintain SOC stocks while removing crop residue. Classical LTEs at Champaign, IL (1876), Columbia, MO (1888), Lethbridge, AB (1911), Breton, AB (1930), and Pendleton, OR (1931) were selected for their documented history of management practice and periodic soil organic matter (SOM) measurements. Management practices ranged from monoculture to 2- or 3-yr crop rotations, manure, no fertilizer or fertilizer additions, and crop residue returned, burned, or harvested. Measured and CQESTR predicted SOC stocks under diverse agronomic practices, mean annual temperature (2.1-19 degrees C), precipitation (402-973 mm), and SOC (5.89-33.58 g SOC kg(-1)) at the LTE sites were significantly related (r(2) = 0.94, n = 186, P < 0.0001) with a slope not significantly different than 1. The simulation results indicated that the quantities of crop residue that can be sustainably harvested without jeopardizing SOC stocks were influenced by initial SOC stocks, crop rotation intensity, tillage practices, crop yield, and climate. Manure or a cover crop/intensified crop rotation under NT are options to mitigate loss of crop residue C, as using fertilizer alone is insufficient to overcome residue removal impact on SOC stocks.
  • Authors:
    • Hammond, R.
  • Source: IOBC/WPRS Bulletin
  • Volume: 64
  • Year: 2011
  • Summary: Slugs are often problems in field crops grown using conservation tillage practices in the eastern United States, as well as certain locations in the Midwest and the southern USA, as well as in Canada. Although most concern has been on corn and soybean, reports of problems from dry beans, cotton, oil-seed rape, sunflowers, winter wheat, and fall planted alfalfa are often received. Although most problems are in fields located in the original forested areas of eastern and southern USA, reports are also being received from the Great Plains' grass lands of slug issues in irrigated no-till fields. Overall, slug problems have increased in geographical area as growers in the USA and Canada have adopted conservation tillage practices. As in other areas of the world, determining new methods of slug control is of utmost importance in order to allow growers to continue using conservation tillage practices. In areas that are new to slugs, a primary concern is educating growers on IPM approaches to slug management.
  • Authors:
    • Avci, M.
  • Source: Agronomy for Sustainable Development
  • Volume: 31
  • Issue: 2
  • Year: 2011
  • Summary: Central Anatolian soils have high risk of erosion, degradation and intensive cultivation. Consequently, they are in danger of exhausting their agricultural use unless conservation agricultural practices are adopted. Conservation agriculture is a key tool in sustainable production systems throughout the world and is developed around soil management technology that minimizes soil disturbance, maximizes the soil cover and promotes crop diversity to offer benefits to farmers and to the environment. It has been particularly effective at sustaining crop production in semi-arid rain-fed regions such as the Central Anatolian soils, where potential evaporation exceeds precipitation during most months of the year, dry farming is extensively practiced, water and wind erosion is common, and proper application of water- and soil-conserving tillage technology is critical. The area under plow expanded its limits as the number of tractors in agriculture dramatically increased in the 1960s. This is the starting point for inappropriate use of the agricultural land. The conservation agricultural technologies, therefore, are of utmost importance for the region. Common farmers' practices of a fallow-wheat system in the central plateau of Turkey are incompatible with the conservation agriculture concept. The objective of this review is to re-evaluate the performances of the partial and full conservation tillage practices previously tried in the region. This review reached the following conclusions: (1) agreeing with the conservation principles, fall tillage as a primary operation in the fallow phase was found to be useless compared with leaving the land without tillage; (2) therefore, much research has focused on spring tillage as a primary operation and employed conventional, semi-conservative and conservative methods. Results showed that the conventional system, in addition to being ecologically unfriendly, is unprofitable as compared with other conservation practices regarding the updated cost analysis; (3) similarly, tillage depth in primary spring tillage was determined to be shallower than the depths currently practiced by farmers, in agreement with the conservation principles; (4) fallow tillage operations in summer to create dust mulch for eliminating soil moisture loss did not increase the crop yields and soil moisture as compared with chemical fallow; (5) no-till fallow was similar to the conventional clean fallow system in terms of moisture and yield levels. However, no-tillage resulted in 50% reduction in the cost of tillage besides its ecologically-friendly effects; (6) the existing dryland agricultural systems in the plateau should be transformed into or changed toward sustainable systems, although further research is required on residue and stubble management, and integrated weed control methods to drill the soil with high amounts of residue on the field.
  • Authors:
    • Beres, B. L.
    • Carcamo, H. A.
    • Dosdall, L. M.
    • Yang, R. C.
    • Evenden, M. L.
    • Spaner, D. M.
  • Source: Agronomy Journal
  • Volume: 103
  • Issue: 6
  • Year: 2011
  • Summary: Most semiarid regions of the northern Great Plains are prone to wheat stem sawfly (Hymenoptera: Cephidae, Cephus cinctus Norton) attack. As an alternative to the wheat ( Triticum aestivum L.)-fallow system, our objective was to determine if continuous cropping infested wheat stubble would inhibit wheat stem sawfly (WSS) emergence. Adult sawfly emergence from undisturbed stubble was compared to stubble harrowed with heavy tine or rotary drum harrows before recropping. Adult emergence from a control of "no recropping" was compared to direct seeding infested stubble with (i) air drills configured with knife-type openers spaced 23 or 30 cm apart, (ii) an air drill configured with high disturbance shovel-type sweep openers, and (iii) a low disturbance air drill equipped with disc openers. Pre-seed heavy tine harrowing reduced adult sawfly emergence but usually required a high tension setting. No-till planting into infested spring wheat stubble also lowered WSS emergence compared to leaving the field fallow. A system of heavy tine harrows and an air drill equipped with knife openers spaced 30 cm apart reduced WSS adult emergence in spring by 50 to 70%. Grain yield was optimized in spring wheat with air drills equipped with narrow knife openers; in winter wheat optimal yield was obtained with the low disturbance disc drill configurations. Our results indicate incremental benefits from continuous cropping rather than fallowing fields infested with WSS, which is a sustainable alternative to conventional tillage. A systems approach is recommended that integrates these practices with diversified nonhost crop phases and resistant cultivars.
  • Authors:
    • Barbercheck, M. E.
    • Curran, W. S.
    • Ryan, M. R.
    • Ward, M. J.
    • Mortensen, D. A.
  • Source: Weed Science
  • Volume: 59
  • Issue: 1
  • Year: 2011
  • Summary: The activity-density of Amara aenea (DeGeer) and Harpalus pensylvanicus (DeGeer) (Coleoptera: Carabidae) was monitored in an experiment that compared five management treatments representing a range of disturbance frequencies, crops, and aboveground biomass production. In 2004 and 2005, three treatments comprised of multiple summer cover crops were compared to bare fallow and soybean, the latter of which used mechanical cultivation to manage weeds. In 2005 weed seed predation was assessed from June to September in two of the treatments (bare fallow and oat-pea/rye-hairy vetch). Beetle activity-density varied with treatment, time of sampling, and year. In 2004 peak activity-density of A. aenea was highest in the mustard/buckwheat/canola, but there was no difference in H. pensylvanicus activity-density. In 2005 activity-density of H. pensylvanicus was higher in oat-pea/rye-hairy vetch than in soybean treatment. Seed predation rates were relatively consistent across treatments, averaging between 38 and 63%. In fallow and oat-pea/rye-hairy vetch, H. pensylvanicus activity-density accounted for 29 and 33% of the variation in seed predation, respectively. Our findings suggest cover crops have a positive effect on the activity-density of A. aenea and H. pensylvanicus and that disturbance negatively influences their activity-density in the absence of cover crops.
  • Authors:
    • Leistrumaite, A.
    • Ceseviciene, J.
    • Kalvaityte, V.
    • Juodeikiene, G.
    • Basinskiene, L.
  • Source: Conference Proceedings of the 6th Baltic Conference on Food Science and Technology FOODBALT-2011, Jelgava, Latvia, 5-6 May, 2011. Innovations for food science and production
  • Year: 2011
  • Summary: Enzymes play an important role in cereal processing not only because in many instances they have an impact on processability, but also they add to final product quality. High activities of different hydrolytic enzymes could cause the losses of grain quality and lead to processing problems and unsatisfactory end-products. However, the information on the impact of various cultural practices and conditions on the variation of enzymes activity levels in cereals is rather limited. The present study is therefore aimed to compare the activity levels of most important hydrolytic enzymes (alpha-amylase, endoxylanase and protease) in wheat, barely, rye and oats grown by organic and conventional agricultural practices. To address this issue, different registered cultivars and up-and-coming lines of winter wheat (4 varieties), winter rye (3 varieties), spring barley (6 varieties), and oats (3 varieties) grown during 2009 harvest year were involved in the test: The alpha-amylase activity in organically and conventionally grown cereals varied from 224 till 1335 U (units) g -1 and from 814 till 1546 U g -1, endoxylanase activity - from 0.13 till 0.65 U g -1 and from 0.06 till 0.15 U g -1, protease activity - from 4.89 till 4.95 U g -1 and from 4.87 till 4.95 U g -1, respectively. The data demonstrated that organic wheat, rye, and oats had lower alpha-amylase activity in compare with conventional counterparts. Also organic rye, barley and oats distinguished much higher endoxylanase activity than conventional ones. Contrary tendency was found during investigation of alpha-amylase activity in barley and endoxylanase activity in wheat. Comparing protease activity, significant differences have not been found between various agricultural practices. These results warrant further studies investigating links between specific agricultural practices and enzyme activities in important food cereals.
  • Authors:
    • McLean, E.
    • Mclean, K.
    • Bilski, J.
  • Source: Electronic Journal of Environmental, Agricultural and Food Chemistry
  • Volume: 10
  • Issue: 6
  • Year: 2011
  • Summary: A vegetative cover is a remedial technique utilized on coal FA landfills for soil stabilization and for the physical and chemical immobilization of contaminants. Many herbaceous plants, primarily grasses which exhibit rapid growth, are moderately resistant to environmental stress, and are therefore often used as cover crops in environmental restoration and remediation projects. However, there is a great concern, that plants planted or voluntarily growing on media with high content of FA may absorb toxic amounts of Se and/or heavy metals. If such plants are ingested, it may result in toxicity to animals and humans. Despite these objections, the utilization of FA as a growth medium for plants is an attractive alternative for disposal of FA in landfills. We hypothesized that selected plants will grow in media containing FA and/or bottom ash (BA) from several sources. Therefore, the objective of this experiment was to determine the effects of growth media containing FA and/or BA on several cereal crop plants growth including germination, seedlings growth and heavy metals, B and Se accumulation in the seedlings. Two selected coal FA, from Montana semi-bituminous coal and from North Dakota lignite alone or in combination with BA from Montana semi-bituminous coal have been tested as plant growth media (growth media are listed in Table below) for the following plant species: barley ( Hordeum vulgare), oats ( Avena sativa), rye ( Secale cereale), wheat ( Triticum aestivum), regreen; a hybrid between wheatgrass ( Agropyron cristatum) and winter wheat ( Triticum aestivum), and triticale; a hybrid between wheat ( Triticum aestivum) and rye ( Secale cereale). The concentrations of Al, As, B, Ba, Be, Co, Cd, Cr, Cu, Mo, Pb, Sr, Ti, Tl, and V in growth media was determined, and the concentrations of the same elements in young plants was analyzed. Chemical analysis was performed using inductively coupled plasma (ICP) emission spectrophotometry (3). The data were analyzed statistically using ANOVA and Statistical Analysis System. All plant species tested in our experiments showed significant adaptability to the growth on FA based media, with no excessive accumulation of tested elements in plant seedlings. There were noticeable differences in seedlings growth, depending on the type and source of coal ash used. It suggests the necessity to perform pre-plantation tests in case of planning to provide green cover over FA piles. Large scale implementation of plant cover over coal ash landfills will require to conduct in-depth and large scale research.
  • Authors:
    • Riley, H.
    • Mangerud, K.
    • Bakken, A.
    • Brandsater, L.
    • Eltun, R.
    • Fykse, H.
  • Source: European Journal of Agronomy
  • Volume: 34
  • Issue: 4
  • Year: 2011
  • Summary: To ensure optimum conditions for organic cereal growing, it is important to minimize both compaction and soil inversion depth. The relative effects of using light versus heavier tractors, shallow versus deeper ploughing and on-land versus in-furrow wheel placement during ploughing were investigated in three-year organic rotations dominated by cereals with naturally infested stands of perennial weeds. The second part of the experiments was carried out in continuous barley with transplanted root fragments of Cirsium arvense (L.) Scop. and rhizome pieces of Elymus repens (L.) Gould. Ploughing was performed in spring under favourable weather conditions. Neither tractor weight nor wheel placement influenced decisively the numbers and above-ground biomass of perennial weeds. Depth of ploughing, on the other hand, affected both perennial weed infestation and yield levels consistently. Weed numbers and the total above-ground weed biomass were mostly 50% lower with deep ploughing (25 cm) than with shallow ploughing (15 cm). The greatest advantage of deep ploughing appeared in the control of C. arvense, which in some cases was reduced by more than 90% compared to shallow ploughing. In organic rotations dominated by cereals, therefore, combating of perennial weeds by deep ploughing may be more important than factors such as tractor weight and wheel placement.
  • Authors:
    • Boban, S.
    • Gherman, R.
    • Ciolac, R.
    • Balan, I.
    • Dincu, A.
  • Source: Research Journal of Agricultural Science
  • Volume: 43
  • Issue: 3
  • Year: 2011
  • Summary: Specific agricultural production showed very different dynamics, both sector (plant and animal) and the regional profile, depending on the diversity of agro-climatic suitability, and the utilization of production factors. The structure of cultivated areas is a technical indicator of the major influences on economic performance and reflect the share that each culture deals with arable land. It does not take random values, but must be directed strictly according to the demand for food products shown on the agricultural products market. Lowland area of Timis county is occupied by the Western Plain. This is the second largest pool of grain production after the Romanian Plain and the Lower Danube. The structure of grain growing areas have 70-75% share, well above normal values. Typically grain must not exceed the maximum weight of two thirds of the arable land. Among cereal grains, namely wheat, barley, barley, rye and oats together have 40-50% share. Local climatic conditions offer many possibilities for agricultural development. Natural landscape is favorable most types of specific crops and continental temperate zone as a consequence of the West region has extensive agricultural land, Arad and Timis counties topping, in this respect among the first in the country. Cereals is one of the oldest and most important agricultural activity in Arad and Timis counties, which have the largest areas of arable. Romanian agricultural production in general, including the west of the country, turned to grain production, not to put too much problem recovery products. Farmer has no means of production, so that technological support has been achieved and is still performed in the services system. In 2008, global agricultural production calculated in current prices was 2,415,821 thousand. Of that total global production plant is 1,708,457 thousand, which meant 70, 7% of total world production was 674 351 Animal thousand, respectively 27, 9%, and the difference, ie 1.4% is represented by various services of the agriculture holdings. Structure of gross agricultural production in an angrarian economy healthy, normally should take the following value: 48-55% global production plant, animal production 45-52% overall, Romania is still far from these value. We could say that we have developed an agricultural production sector in the Western states of Europe, wehre animal production will exceed the overall 50% share of total gross agricultural production structure.
  • Authors:
    • Baranova, B.
    • Balazs, P.
    • Kotorova, D.
    • Fazekasova, D.
    • Bobul'ska, L.
  • Source: Ekologia (Bratislava)
  • Volume: 30
  • Issue: 1
  • Year: 2011
  • Summary: In 2005-2009 the temporal and spatial dimensions in the six research sites were studied in order to assess the impact of environmental management on change of basic physical properties of the soil. Crop rotation was as follows: perennial fodder crops - perennial fodder crops - winter crops - root crops - spring crops - annual fodder crops. Soil sampling to determine bulk density, porosity and maximum capillary capacity was realised two times a year in spring and autumn at the six locations (I.-VI.) from the depth of 0.05 to 0.15 m. The results obtained were tested by statistical methods (analysis of variance, LSD-test). Soil bulk density is influenced by ecological farming in the five-year time series in comparison with 1996 and decreased its value in the interval ranging from 0.91 to 1.36 t m -3 in both samples. The porosity corresponded with bulk density, which in 2009 increased in all locations to the optimal levels for plant growth. The maximum capillary capacity in 1996 reached very low values (17.40 to 20.65%). In 2009 its value increased from 25.59 to 42.84%, which maybe associated with sum of precipitation and ecological farming, too. The positive change of soil bulk density and porosity and increasing the maximum capillary capacity was recorded in comparison with 1996. Test of obtained results confirmed a statistically significant effect of experimental year and localities on the bulk density, porosity and maximum capillary capacity. The date of sampling significantly influenced the values of porosity and the maximum capillary capacity.