• Authors:
    • Fernandez, M. R.
    • Ulrich, D.
    • Brandt, S. A.
    • Zentner, R. P.
    • Wang, H.
    • Thomas, A. G.
    • Olfert, O.
  • Source: Agronomy Journal
  • Volume: 103
  • Issue: 3
  • Year: 2011
  • Summary: The impact of cropping system management on root and crown rot of spring wheat ( Triticum aestivum L.) was examined on a Dark Brown Chernozem (Typic Boroll) soil in the Canadian Prairies. This systems approach tried to reflect the most common practices of organic and conventional producers in this region. The study consisted of a factorial combination of three input levels (high, with tillage, fertilizer and pesticides; reduced [RED], with conservation tillage, targeted fertilizer and weed control; and organic [ORG] with tillage and N-fixing legumes); and three levels of cropping diversity (low diversity with wheat and summerfallow or legume green manure fallow; diversified using annual grain crops; and diversified using annual grain crops and perennial forages). All rotations were 6 yr long. Subcrown internodes and crowns/lower culms of wheat plants were scored for discoloration, and fungi in discolored tissue were identified and quantified. Overall, input level had a greater impact on disease levels and fungal frequency than cropping diversity. Discoloration severity was lowest in the RED systems, which was attributed to lower percentage isolation of Cochliobolus sativus, the most common pathogen. Fusarium species varied with input level. The pathogens F. avenaceum and F. culmorum were most associated with RED and/or least associated with ORG systems, whereas the weak pathogen/saprophyte F. equiseti was most associated with ORG systems. Thus, ORG management helped to reduce populations of F. avenaceum and F. culmorum, two of the most important Fusarium pathogens in the Canadian Prairies.
  • Authors:
    • Ferreira, R.
    • Galvao, R.
    • Miranda Junior, E.
    • Araujo Neto, S.
    • Negreiros, J.
    • Parmejiani, R.
  • Source: Horticultura Brasileira
  • Volume: 29
  • Issue: 3
  • Year: 2011
  • Summary: The use of volunteer plants and live coverage of peanut ( Arachis pintoi) was evaluated, associating the application of organic compost in organic production of radish in no-till. The experiment was carried out at Federal University of Acre, in Rio Branco, Acre State, Brazil. A randomized complete block design with a split plot arrangement (4*3) and four replications was used. The plots consisted of the no-tillage systems with live coverage of peanut, with live coverage of spontaneous plants (weeds), with mulching of spontaneous plants, and conventional soil tillage with no-mulching soil. The subplots were composed of the doses of organic compost of 5, 10 and 15 t ha -1 in dry basis. The no-tillage with straw weed mulch had similar performance to the conventional soil tillage, both superior to the crop on the no-tillage with live mulch. The productivity of the radish cv. Cometa, was not affected by increasing doses of organic compost, being possible to apply only 5 t ha -1, whereas in the conventional tillage, the increasing productivity was higher compared to the direct planting only in the higher dose of compost (15 t ha -1).
  • Authors:
    • Fourie, J.
    • Joubert, M.
    • Freitag, K.
  • Source: SA Fruit Journal
  • Volume: 10
  • Issue: 1
  • Year: 2011
  • Summary: Five soil management practices applied in a micro-sprinkler irrigated 'Pink Lady' (Cripps Pink/M7) orchard established on a loam soil near Grabouw were evaluated from October 2003 to March 2010. Dry matter production by the cover crops at the end of September was higher under integrated soil management (IP) than under organic soil management (Organic) during 2004, 2007 and 2008, with the same trend being observed during 2005, 2006, and 2009. Cover crops in the IP and Organic treatments suppressed the winter growing weeds significantly over all seasons compared to treatments in which no cover crop was sown and weeds were slashed during the growing season of the trees (Weeds (IP) and Weeds (Organic) treatments). Except for September 2004, a similar result was achieved where a full surface straw mulch was packed out annually during October, followed by hand weeding during the growing season of the trees (Straw Mulch (Organic) treatment). Summer growing weeds were controlled effectively by the Cover Crop (IP) and Straw Mulch (Organic) treatments. Weeds (IP) and Weeds (Organic) caused broad leaf weeds to disappear and perennial grasses to dominate the weed spectrum. Although not as drastic, a similar trend developed in the Cover Crop (Organic) treatment. In contrast, annual weed species became dominant where Cover Crop (IP) was applied. All soil cultivation practices caused changes in the weed spectrum, with species dominance shifting with time. This aspect of weed control should be studied more extensively in future.
  • Authors:
    • Robertson,G. P.
    • Hamilton,S. K.
    • Jasrotia,P.
    • Bhardwaj,A. K.
  • Source: Agriculture, Ecosystems & Environment
  • Volume: 140
  • Issue: 3-4
  • Year: 2011
  • Summary: Intensively cropped agricultural production systems should be managed to improve soil quality and ecological processes and ultimately strengthen system capacity for sustained biological productivity. We examined the long-term changes (>20 years) in soil quality and productivity with incorporation of ecological management principles in a set of intensively managed row crop systems of the upper Midwest, USA. Replicated experimental treatments include corn (maize)-soybean-wheat cropping systems under four different management regimes: (a) conventional tillage and fertilizer/chemical inputs ( Conventional), (b) no tillage with conventional fertilizer/chemical inputs ( No-till), (c) conventional tillage with 30% of conventional fertilizer/chemical inputs and a leguminous cover crop ( Reduced Input), and (d) conventional tillage with no fertilizer/chemical input and a leguminous cover crop ( Organic). Effects of these treatments on soils were compared by developing a soil quality index (SQI) from 19 selected soil health indicators. An old field community maintained in early succession provided a benchmark for comparison. Reduction in tillage or fertilizer ( No-till, Reduced Input and Organic) resulted in increased SQI and improved crop production. The No-till (SQI=1.02) and Reduced Input (SQI=1.01) systems outperformed Conventional management (SQI=0.92) in nitrogen availability and use efficiency, soil stability and structure improvement, and microbial nitrogen processing. Improvements in soil quality corresponded with increased primary production and crop yield in these systems, illustrating the value of an ecologically defined SQI for assessing the long-term effects of fertility and tillage management regimes in agricultural production systems.
  • Authors:
    • Lezaún, J. A.
    • Lacasta, C.
    • Ciria, P.
    • Aibar, J.
    • Pardo, G.
    • Zaragoza, C.
  • Source: Chilean Journal of Agricultural Research
  • Volume: 71
  • Issue: 2
  • Year: 2011
  • Summary: Under semiarid conditions the response of cereal crops to chemical fertilizers and weed control practices with herbicides is often reduced. In fact, the economic profitability of agricultural production in many dryland regions is critically affected by high costs of inputs and low crop yields. As a solution, cropping systems like organic farming, obtaining similar yields and promoting environmental sustainability by reducing fertilizer and herbicides, could be an alternative to conventional systems. In this study, 23 trials were performed in five semiarid regions of Spain during 5 yr to compare different fertilizers and weed control methods on durum wheat ( Triticum durum Desf.) and barley ( Hordeum vulgare L.) yields. The following rotation pattern was developed on the experimental plots: fallow-barley-ground ploughed vetch ( Vicia sativa L.)-durum wheat. Plots either received organic fertilizer, chemical fertilizer, or no fertilizer. In addition, three levels of weed control were applied in cereal plots: flex-tine harrow tillage, conventional herbicide, and no weeding. The results indicated that neither the fertilization nor the weed control have effect on the yield crop.
  • Authors:
    • Alonso, J. C.
    • Magana, M.
    • Garcia de Leon, D.
    • Bravo, C.
    • Ponce, C.
  • Source: Agriculture, Ecosystems & Environment
  • Volume: 141
  • Issue: 1/2
  • Year: 2011
  • Summary: Organic farming is considered an important way to preserve biodiversity in agricultural landscapes. However, more work is still necessary to enable a full appraisal of the potential benefits of this way of farming, since studies differ in the evaluation of its effectiveness. Studies are particularly scarce in the Mediterranean region, where different climatic and ecological conditions prevent simple extrapolations from work carried out at northern latitudes. In the present study, an analysis of weed and arthropod communities was conducted in 28 pairs of organic and conventional fields in a dry cereal farmland in central Spain. Plants were identified to the species level, and arthropods to the family level. Pitfalls and sweep nets were used to sample respectively, ground-dwelling and plant-visiting arthropods. Abundance (total numbers of individuals), richness (total numbers of plant species or arthropod families), diversity (Shannon-Wiener index) and biomass (milligrams per pitfall/sweep-net) were calculated for each field and compared between organic and conventional fields using Generalized Linear Mixed Models (GLMMs). To explore the effect of predictor variables on weed richness and arthropod biomass, GLMMs were used. Organic fields showed higher abundance of weeds and arthropods (3.01 and 1.43 times, respectively), higher weed richness and diversity (2.76 and 2.33 times, respectively), and a 24% reduction in cereal plants. Arthropod diversity was lower in organic fields due to the presence of three dominant groups: Collembola, Chloropidae (Diptera), and Aphididae (Hemiptera). Weed richness increased as cereal cover decreased in organic fields. Total arthropod biomass was slightly higher in organic fields, and was affected by weed abundance and diversity. The differences between organic and conventional fields found in this study were higher than those reported for northern latitudes. This could be explained by the richer weed flora in the Mediterranean region, and a higher weed seed availability favored by the two-year rotation system typical of Iberian dry cereal farmland. We conclude that organic farming may contribute to preserve biodiversity in dryland cereal agroecosystems in the Mediterranean region.
  • Authors:
    • Abubakar, M. M.
    • Kushwaha, S.
    • Sani, M. H.
    • Ayoola, G. B.
  • Source: Journal of Development and Agricultural Economics
  • Volume: 3
  • Issue: 9
  • Year: 2011
  • Summary: The application of modified compromise weighted multi-objective programming to Fadama farming in Dass Local Government Area of Bauchi State was the main focus of the study. Samples of 106 Fadama vegetable cultivars were randomly selected from 12 Fadama user's associations in the study area. The farm sizes were grouped and formed into three categories namely: below 1 ha, 1 to 2.99 ha and 3 to 4.99 ha farms, with sample size of 37, 39 and 30 farmers, respectively. It was assumed that farming could be optimized using four specific objectives (maximization of income, and employment; minimization of fertilizer and ground water use). Modified compromise weighted multi-objective programming technique was used to analyze the four objectives, which were optimized individually and combined. The results disclosed that the 3 to 4.99 ha farm size had the best maximum income level of N302,199.26 (+28.11%) and employment of 1125 man days (+33.61%) and minimum level of fertilizer use of 182 kg (-8.08%) and ground water use of 3962 mm (-17.25%) at their respective existing farm levels compared to the other categories of farms. This implied that the farmers were characterized by preponderance of high level of adoption of agricultural technology, resulting from intensive cropping, leading to a high level of chemical fertilizer and increased use of ground water for irrigation which consequently led to reduction of ground water table in the study area. It was therefore recommended that the farmers in the study area should concentrate in the cultivation of the major Fadama crops like onion, tomato, pepper, okro, cabbage and lettuce instead of spreading out their resources to grow potato, carrot and garden-egg.
  • 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:
    • 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:
    • Du, X.
    • Zhang, D.
    • Dong, M.
  • Source: Acta Phytophylacica Sinica
  • Volume: 38
  • Issue: 4
  • Year: 2011
  • Summary: Aphids are primary pests of peach in early organic field. In order to know the relationship between aphids and their natural enemies and the ecological management, we design three ecological control mode, which are the treatment of planting garlic+mulch plastic film, the treatment of planting 100% alfalfa and the treatment of planting 70% alfalfa+30% Lagopsis supine. We investigate the insect community, analyse the natural enemies of aphids and the effect of ecological management. The results showed the main natural enemies of Myzus persicae (Sulzer), Hyalopterus amygdali (Blanchard) and Tuberocephalus momonis (Matsumura) were Propylea japonica (Thunberg), Orius sauteri (Poppius) and Coccinella septempunctata (Linnaeusaeus). There was negative relationship between aphids and natural enemy/pest index. The natural enemy/pest index and evenness of natural enemies was significantly higher and the abundance of M. persicae, H. amygdali and T. momonis were significantly lower in the treatment of planting 100% alfalfa and in the treatment of planting 70% alfalfa +30% L. supina than those of control treatment. It is benefit to control green peach aphids with planting 100% alfalfa and it is benefit to control M. persicae, H. amygdali and T. momonis with planting 70% alfalfa+30% L. supina.