• Authors:
    • Klimek, S.
    • Steinmann, H-H
    • Ulber, L.
    • Isselstein, J.
  • Source: Weed Research
  • Volume: 49
  • Issue: 5
  • Year: 2009
  • Summary: Weed species diversity may benefit from organic farming due to enhanced temporal diversification of crop species in a rotation and omission of herbicide applications. However, in intensively managed conventional systems, little evidence exists as to what extent diversified crop rotations contribute to higher weed species richness. Using an on-farm approach, the effect of crop rotation (organic, conventional diverse (CD) and conventional simple (CS) crop rotations) and weed control (with vs. without) on weed species richness, cover, community composition and crop biomass, was analysed in 24 winter wheat fields. Weed species with beneficial functions for invertebrates and birds were analysed separately. Weed species richness was higher in the organic crop rotation, but did not differ between CD and CS crop rotations. Weed control treatment reduced species richness in both conventional rotations, but not in the organic one. Redundancy analyses revealed that crop rotation intensity accounted for the largest part of the explained variation in weed species composition. Results from the study indicate that the maintenance of weed species richness and conservation of species with important ecological functions requires not only temporal diversification of crop species in the rotation, but also an adjustment of weed control strategies.
  • Authors:
    • He, J.
    • Wang, X. Y.
    • Gao, H. W.
    • Li, H. W.
    • Yao, Z. L.
  • Source: Soil Research
  • Volume: 47
  • Issue: 8
  • Year: 2009
  • Summary: The furrow opening configuration used by no-till seeders can have a major effect on crop emergence in conservation tillage systems. This is particularly important in annual double-cropping regions (winter wheat and summer maize) of northern China where large volumes of residue remain on the soil surface after maize harvesting. This problem has been investigated using 3 different opening configurations for no-till wheat seeding near Beijing in 2004-05 and 2005-06, and assessing performance in terms of soil disturbance, residue cover index, soil cone index, fuel consumption, winter wheat emergence, plant growth, and subsequent yield. In this cropping system, the single-disc opening configuration significantly decreased mean soil disturbance and increased residue cover index compared with the combined strip-chop and strip-till opening configurations, but winter wheat emergence was 6-9% less, probably due to greater levels of residue cover and greater seed zone soil cone index. Winter wheat growth after seeding in combined strip-chop and strip-till seeded plots was faster than that in single-disc seeded plots and mean yield was greater. The most suitable furrow opening configuration in heavy residue cover conditions appeared to be the strip-chop one, which can provide similar crop performance with marginally better fuel economy than the strip-till opening configuration. These results should be seen as preliminary, but they are still valuable for the design and selection of no-till wheat seeders for double cropping in this region of China.
  • Authors:
    • Li, H. W.
    • He, J.
    • Zhang, X. R.
    • Li, W. Y.
  • Source: Nongye Jixie Xuebao = Transactions of the Chinese Society for Agricultural Machinery
  • Volume: 40
  • Issue: 10
  • Year: 2009
  • Summary: This paper put forward the new anti-blocking principle combining residue-throwing by powered-chain finger and residue-cutting by knife type opener, and designed the powered chain anti-blocking mechanism for no-till planter according to the problem of residue blocking of no-till wheat planting in heavy corn residue cover fields in annual double cropping areas of North China plain. Furthermore, the key parameters for powered-chain, chain finger and knife type opener were determined based on the analyses of the movement of anti-blocking mechanism. The field experiment showed that the powered-chain anti-blocking mechanism could solve the residue blocking effectively, so as to ensure the passing of wheat no-till planter. Through real-time clearing of corn residues before the knife type opener, 12.3% of opening force was decreased. Compared with the strip roto-tilling wheat planter, the powered-chain wheat no-till planter could not only seed and fertilize at the suitable depths, but also decrease soil disturbance and fuel consumption by 66.4% and 8.07%, respectively, which indicates that this new planter can meet the requirements of agronomy in North China plain.
  • Authors:
    • Zhu, W. W.
  • Source: Guizhou Agricultural Sciences
  • Issue: 6
  • Year: 2009
  • Summary: The results from analyzing the comparative superiority of main agricultural products in Hunan province by using the comparative superiority index method show that the agricultural products with obvious comparative superiority are rice, cotton, soybean, tobacco and tea, which depend on their large-scale superiority, and the agricultural products with inferior position are maize, sorghum and wheat. The market competitive power is weak because the efficiency superiority of various agricultural products is not obvious essentially. The paper puts forward the measures including maintaining the market superiority of the agricultural products with obvious comparative superiority and improving the quality of the agricultural products with significant comparative inferiority to overall promote the market competitive power of Hunan province's agricultural products.
  • Authors:
    • Zudilin, S. N.
  • Source: Kormoproizvodstvo
  • Issue: 2
  • Year: 2009
  • Summary: Productivity of fodder crop rotation was studied in the Samara Region, Russia in 1993-2004. The fodder crop rotation consisted of 7 following combinations: (1) rape and radish; (2) winter wheat; (3) pea; (4) maize; (5) vetch and oat; (6) pea and barley and (7) goat's-rue. The most productive crop was goat's-rue which showed green mass yield of 20.27 t/ha. Rape, maize, vetch and oat mix had green mass yield of 19.78, 20.11 and 16.42 t/ha, respectively. Winter wheat and pea produced 2.4 and 1.18 t/ha of grain, respectively. Application of mineral fertilizers increased yield by 25-40%. Detailed data are presented in 2 tables.
  • Authors:
    • Fonseca, A. F. da
    • Alleoni, L. R. F.
    • Caires, E. F.
    • Churka, S.
  • Source: Communications in Soil Science and Plant Analysis
  • Volume: 40
  • Issue: 17/18
  • Year: 2009
  • Summary: No-till (NT) system with crop rotation is one of the most effective strategies to improve agricultural sustainability in tropical and subtropical regions. To control soil acidity in NT, lime is broadcast on the surface without incorporation. The increase in soil pH due to surface liming may decrease zinc (Zn) availability and its uptake by crops. A field experiment was performed in Paran State, Brazil, on a loamy, kaolinitic, thermic Typic Hapludox to evaluate Zn bioavailability in a NT system after surface liming and re-liming. Dolomitic lime was surface applied on the main plots in July 1993 at the rates of 0, 2, 4, and 6 Mg ha -1. In June 2000, the main plots were divided in two subplots to study of the effect of surface re-liming at the rates of 0 and 3 Mg ha -1. The cropping sequence was soybean [ Glycine max (L.) Merrill] (2001-2 and 2002-3), wheat ( Triticum aestivum L.) (2003), soybean (2003-4), corn ( Zea mays L.) (2004-5), and soybean (2005-6). Soil samples were collected at the following depths: 0-0.05, 0.05-0.10, and 0.10-0.20 m, 10 years after surface liming and 3 years after surface re-liming. Soil Zn levels were extracted by four extractants: (i) 0.005 mol L -1 diethylenetriaminepentaacetic acid (DTPA)+0.1 mol L -1 triethanolamine (TEA)+0.01 mol L -1 calcium chloride (CaCl 2) solution at pH 7.3 (DTPA-TEA), (ii) 0.1 mol L -1 hydrochloric acid (HCl) solution, (iii) Mehlich 1 solution, and (iv) Mehlich 3 solution. Zinc concentrations in leaves and grains of soybean, wheat, and corn were also determined. Soil pH (0.01 mol L -1 CaCl 2 suspension) varied from 4.4 to 6.1, at the 0- to 0.05-m depth, from 4.2 to 5.3 at the 0.05- to 0.10-m depth, and from 4.2 to 4.8 at the 0.10- to 0.20-m depth, after liming and re-liming. Zinc concentrations evaluated by DTPA-TEA, 0.1 mol L -1 HCl, Mehlich 1, and Mehlich 3 solutions were not changed as a result of lime rate application. Re-liming increased Zn concentrations extracted by 0.1 mol L -1 HCl at 0-0.05 m deep and by DTPA-TEA at 0.05-0.10 m deep. Surface-applied lime promoted a decrease in Zn concentrations of the crops, mainly in grains, because of increased soil pH at the surface layers. Regardless of the liming treatments, levels of Zn were sufficient to soybean, wheat, and corn nutrition under NT.
  • Authors:
    • Teasdale, J. R.
    • Hanson, J. C.
    • Hima, B. L.
    • Cavigelli, M. A.
    • Conklin, A. E.
    • Lu, Y. C.
  • Source: Renewable Agriculture and Food Systems
  • Volume: 24
  • Issue: 2
  • Year: 2009
  • Summary: We present the results from enterprise budget analyses for individual crops and for complete rotations with and without organic price premiums for five cropping systems at the US Department of Agriculture-Agricultural Research Service (USDA-ARS) Beltsville Farming Systems Project (FSP) from 2000 to 2005. The FSP is a long-term cropping systems trial established in 1996 to evaluate the sustainability of organic and conventional grain crop production. The five FSP cropping systems include a conventional, three-year no-till corn ( Zea mays L.)-rye ( Secale cereale L.) cover crop/soybean ( Glycine max (L.) Merr)-wheat ( Triticum aestivum L.)/soybean rotation (no-till (NT)), a conventional, three-year chisel-till corn-rye/soybean-wheat/soybean rotation (chisel tillage (CT)), a two-year organic hairy vetch ( Vicia villosa Roth)/corn-rye/soybean rotation (Org2), a three-year organic vetch/corn-rye/soybean-wheat rotation (Org3) and a four- to six-year organic corn-rye/soybean-wheat-red clover ( Trifolium pratense L.)/orchard grass ( Dactylis glomerata L.) or alfalfa ( Medicago sativa L.) rotation (Org4+). Economic returns were calculated for rotations present from 2000 to 2005, which included some slight changes in crop rotation sequences due to weather conditions and management changes; additional analyses were conducted for 2000 to 2002 when all crops described above were present in all organic rotations. Production costs were, in general, greatest for CT, while those for the organic systems were lower than or similar to those for NT for all crops. Present value of net returns for individual crops and for full rotations were greater and risks were lower for NT than for CT. When price premiums for organic crops were included in the analysis, cumulative present value of net returns for organic systems (US$3933 to 5446 ha -1, 2000 to 2005; US$2653 to 2869 ha -1, 2000 to 2002) were always substantially greater than for the conventional systems (US$1309 to 1909 ha -1, 2000 to 2005; US$634 to 869 ha -1, 2000 to 2002). With price premiums, Org2 had greater net returns but also greater variability of returns and economic risk across all years than all other systems, primarily because economic success of this short rotation was highly dependent on the success of soybean, the crop with the highest returns. Soybean yield variability was high due to the impact of weather on the success of weed control in the organic systems. The longer, more diverse Org4+ rotation had the lowest variability of returns among organic systems and lower economic risk than Org2. With no organic price premiums, economic returns for corn and soybean in the organic systems were generally lower than those for the conventional systems due to lower grain yields in the organic systems. An exception to this pattern is that returns for corn in Org4+ were equal to or greater than those in NT in four of six years due to both lower production costs and greater revenue than for Org2 and Org3. With no organic premiums, present value of net returns for the full rotations was greatest for NT in 4 of 6 years and greatest for Org4+ the other 2 years, when returns for hay crops were high. Returns for individual crops and for full rotations were, in general, among the lowest and economic risk was, in general, among the highest for Org2 and Org3. Results indicate that Org4+, the longest and most diverse rotation, had the most stable economic returns among organic systems but that short-term returns could be greatest with Org2.
  • Authors:
    • Hedtcke, J. L.
    • Posner, J. L.
    • Chavas, J. P.
  • Source: Agronomy Journal
  • Volume: 101
  • Issue: 2
  • Year: 2009
  • Summary: This article, the second in a series looking at the Wisconsin Integrated Cropping Systems Trial (WICST), reports on the profitability of six conventional and organic systems, with a focus on net returns and associated risk exposure. Several pricing scenarios were compared to evaluate the impact of government programs and organic price premiums. When net return estimates are made using only neighboring elevator prices (no government programs or organic price premiums), we found that the no-till corn-soybean system [ Zea mays L. and Glycine max (L.) Merr.] was the most profitable grain system, and management intensive rotational grazing (MIRG) the most profitable forage system. When government programs and organic price premiums are included, returns increased by 85 to 110% for the organic grain system corn-soybean-wheat+red clover ( Triticum aestivum L.+ Trifolium pratense L.) and 35 to 40% for the organic forage system [companion seeded alfalfa with oat+field pea ( Medicago sativa L., Avena sativa L., and Pisum sativum L.), hay, and then corn]. This places both organic systems with higher returns than any of the Midwestern standards of no-till corn-soybean, continuous corn, or intensive alfalfa production. Also, the results indicate how risk exposure varied across systems. Interestingly, taking risk into consideration did not drastically affect the ranking among those systems. Our analysis shows that, under the market scenarios that prevailed between 1993 and 2006, intensive rotational grazing and organic grain and forage systems were the most profitable systems on highly productive land in southern Wisconsin.
  • Authors:
    • Kuzyakov, Y.
    • Fan, M.
    • Li, H.
    • Gong, Y.
    • Hou, R.
    • Chen, H.
  • Source: Soil & Tillage Research
  • Volume: 106
  • Issue: 1
  • Year: 2009
  • Summary: The Loess Plateau in northwest China is one of the most eroded landscapes in the world, and it is urgent that alternative practices be evaluated to control soil erosion. Our objective was to determine how three different tillage practices for monoculture of winter wheat (Triticum aestivum L) affected soil organic carbon (SOC) and N content after 11 years. Conventional tillage with residue removal (CT), shallow tillage with residue cover (ST), and no-tillage with residue cover (NT) were investigated. Carbon and N in various aggregate-size classes and various labile organic C fractions in the 0-15- and 15-30-cm soil layers were evaluated. The ST and NT treatments had 14.2 and 13.7% higher SOC stocks and 14.1 and 3.7% higher total N(N(t))stocks than CT in the upper 15 cm, respectively. Labile C fractions: particulate organic C (POC), permanganate oxidizable C (KMnO(4)-C), hot-water extractable C (HWC), microbial biomass C (MBC) and dissolved organic C (DOC) were all significantly higher in NT and ST than in CT in the upper 15 cm. KMnO(4)-C, POC and HWC were the most sensitive fractions to tillage changes. The portion of 0.25-2 mm aggregates, mean weight diameter (MWD) and geometric mean diameter (GMD) of aggregates from ST and NT treatments were larger than from CT at both 0-15- and 15-30-cm soil depths. The ST and NT treatments had significantly higher SOC and Nt in the 0.25-2 mm fraction at both depths and significantly higher N, content in the upper 15 cm. Positive significant correlations were observed between SOC, labile organic C fractions, MWD, GMD, and macroaggregate (0.25-2 mm) C within the upper 15 cm. We conclude that both variants of conservation tillage (NT and ST) increase SOC stock in the rainfed farming areas of northern China and are therefore more sustainable practices than those currently being used. (C) 2009 Elsevier B.V. All rights reserved.
  • Authors:
    • Madar, R.
    • Cosma, C.
    • Vuşcan, A.
    • Samuel, A. D.
    • Jurcă, A.
    • Ciobanu, G.
    • Domuta, C.
    • Ciobanu, C.
    • Albu, R.
    • Şandor, M.
  • Source: Bulletin of the University of Agricultural Sciences & Veterinary Medicine Cluj-Napoca
  • Volume: 66
  • Issue: 1
  • Year: 2009
  • Summary: The paper based on the research carried out during 2005-2008 in the long term trial placed in 1990 on the preluvosoil from Oradea. The monoculture of maize, maize-wheat and maize-soybean-wheat crop rotations were studied in unirrigated and irrigated conditions. The crop rotation of six years (oat+clover-clover-maize-wheat-maize-sunflower) was studied in unirrigated conditions. The research emphasized that the monoculture is the most responsible for the pest multiplication. In maize monoculture the larvae number on the roots was ranged between 4.91-8.23 and root attack degree in IOWA scale (with marks from 1 to 6 in which maximum attack is 6), had values between 3.84 and 5.62 and the frequent of attacked plants with the symptom "goose neck" ranged between 16,4% and 31.2% and larval aggressiveness being higher in the case of favorable soil moisture in irrigated condition. The maize rotation with other plants interrupts the biologic pest cycle. The results obtained emphasize that later maize sowing alongside by the utilizing of lower plant thickness level contribute to prevention of pest multiplication, while earlier sowing at high thickness favor the larvae developing.