• 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:
    • Garcia-Oliva, F.
    • Prat, C.
    • Medina-Orozco, L.
    • Mendoza, M. E.
    • Bravo-Espinosa, M.
    • Lopez-Granados, E.
  • Source: Land Degradation & Development
  • Volume: 20
  • Issue: 6
  • Year: 2009
  • Summary: In the Transmexican Volcanic Belt a traditional fallow system is practiced, called "ano y vez" (AV), which does not benefit soil conservation due to its low level of nutrient recycling and because soil protection is poor during the cultivation year. The objective of the present work was to measure runoff and soil and nutrient losses during three annual cycles (2002-2004) in Central Mexico under AV rotation and two alternative systems: improved traditional (IT) and traditional organic (TO). Soil losses in the three systems were moderate (
  • 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:
    • 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:
    • Miyao, G.
    • Jackson, J.
    • Mitchell, J. P.
    • Horwath, W. R.
    • Doane, T. A.
    • Brittan, K.
  • Source: Nutrient Cycling in Agroecosystems
  • Volume: 85
  • Issue: 3
  • Year: 2009
  • Summary: In spite of potential benefits and positive assessments of reducing primary tillage operations, only a small part of irrigated row crops is currently managed using reduced tillage, for reasons that include concerns about its agronomic suitability for certain crop rotations. Three years of a tomato/corn rotation under standard and no-tillage management were used to understand the fate of a fertilizer and cover crop nitrogen (N) application. Uptake of both inputs was reduced under no-tillage during the year of application, in this case a tomato crop. As a result, more input N was retained in the soil in this system. The initial challenge of reduced tomato yields diminished as no-tillage management remained in place and the soil N reservoir developed. Corn production was not affected by tillage treatment. Inclusion of a legume cover crop increased the amount of fertilizer N retained in the soil over time, more so under no-tillage than under standard tillage, emphasizing the benefit of cover crops in reducing the amount of fertilizer required to maintain productivity. While acceptance of reduced tillage ultimately depends on economic performance, the results of this study support its agronomic viability for irrigated row crops.
  • Authors:
    • Ralisch, R.
    • Nakashima, P.
    • Gasparetto, N. V. L.
    • Domingos, M. M. M.
    • Tavares Filho, J.
  • Source: Revista Brasileira de Ciência do Solo
  • Volume: 33
  • Issue: 6
  • Year: 2009
  • Summary: Structural changes caused by management systems to soil can result in compaction and may change crop root development. With the aim to evaluate the effects of the farming systems on the soil structure by qualitative (cultural profile) and quantitative (soil density) methodologies, a field study was carried out in Maringa, state of Parana, Brazil (23degrees29′S, 51degrees59′W). A conventional tillage system with crop succession of corn ( Zea mays L.) and soybean ( Glycine max) and a no-till system with crop rotation of wheat ( Triticum spp.), corn ( Zea mays L.), common bean ( Phaseolus vulgaris), black oats ( Avena strigosa), and soybean ( Glycine max) established for more than 20 years were evaluated. An area under natural forest near the experimental field was evaluated as reference. After the description of the cultural (soil) profile, deformed samples were collected from the homogeneous soil volumes: two samples under forest, two samples in the no-till system and three samples in the conventional system. The physical and morphologic analyses of the soil structures of the layers 0-20 and 20-40 cm showed: (a) the two different tillage system promoted distinct depths of anthropic horizons; (b) the soil structure affected root distribution; (c) soil compaction under conventional system occurred in vertical and horizontal directions (d) soil structure was best under the no-till system; (e) the cultural profile methodology is efficient in soil morphology evaluations.
  • Authors:
    • Rashakani, M. A.
    • Robati, J.
    • Germi, Y. S.
  • Source: Proceedings 37th International Symposium 'Actual tasks on agricultural engineering', Opatija, Croatia, 10-13 veljače, 2009
  • Year: 2009
  • Summary: Applying the precision planters such as punch planters is one of the methods for increasing yield performance by retaining the conservation tillage advantages. In this study, a type of dibble punch planter with seed plate metering device was designed and constructed for maize planting, and was tested in the field on three soil conditions (tilled, untilled with no residue, untilled with wheat residue) and at three forward speeds (1.5, 3, 4.5 km h -1). Then, the planter performance was evaluated with quality of feed index, miss index, multiple seed index, depth index and radius of contact cross section area in the field. Field test results showed that the second speed (3 km h -1) has relatively higher feed index. The difference of feed index was not significant between tilled soil and untilled soil (with residue) and also between v1 and v2. Also, the difference between the different levels of soil conditions and forward speeds was significant (p
  • Authors:
    • Kpomblekou-A, K.
    • Hamido, S. A.
  • Source: Soil & Tillage Research
  • Volume: 105
  • Issue: 2
  • Year: 2009
  • Summary: Increasing numbers of vegetable growers are adopting conservation tillage practices and including cover crops into crop rotations. The practice helps to increase or maintain an adequate level of soil organic matter and improves vegetable yields. The effects of the practices, however, on enzyme activities in southeastern soils of the United States have not been well documented. Thus, the objectives of the study were to investigate the effects of cover crops and two tillage systems on soil enzyme activity profiles following tomato and to establish relationships between enzyme activities and soil organic carbon (C) and nitrogen (N). The cover crops planted late in fall 2005 included black oat (Avena strigosa), crimson clover (Trifolium incarnatum L.), or crimson clover-black oat mixed. A weed control (no cover crop) was also included. Early in spring 2006, the plots were disk plowed and incorporated into soil (conventional tillage) or mowed and left on the soil surface (no-till). Broiler litter as source of N fertilizer was applied at a rate of 4.6 Mg ha(-1), triple super phosphate at 79.0 kg P ha(-1), and potassium chloride at 100 kg K ha(-1) were also applied according to soil testing recommendations. Tomato seedlings were transplanted and grown for 60 days on a Marvyn sandy loam soil (fine-loamy, kaolinitic, thermic Typic Kanhapludults). Ninety-six core soil samples were collected at incremental depths (0-5, 5-10, and 10-15 cm) and passed through a 2-mm sieve and kept moist to study arylamidase (EC 3.4.11.2), L-asparaginase (EC 3.5.1.1), L-glutaminase (EC 3.5.1.2), and urease (EC 3.5.1.5) activities. Tillage systems affected only L-glutaminase activity in soil while cover crops affected activities of all the enzymes studied with the exception of urease. The research clearly demonstrated that in till and no-till systems, L-asparaginase activity is greater (P
  • Authors:
    • Gao, H. W.
    • Liu, L. J.
    • Li, H. W.
    • Wang, Q. J.
    • He, J.
  • Source: Soil & Tillage Research
  • Volume: 104
  • Issue: 1
  • Year: 2009
  • Summary: In the annual double cropping areas of North China Plain, low crop yield and water availability are the main limiting factors to crop production. Conservation tillage has been proposed to improve water conservation and sustain soil productivity. The objectives of the study were to compare conservation tillage (CT) with conventional tillage (CV) under the current double cropping system of corn-winter wheat in the Hebei, North China Plain. The field study consisted of eight conservation tillage treatments and two conventional tillage treatments, with different surface ground cover (0%, 50% and 100%). The tillage treatments consisted of no-till, subsoiling, rototilling and plowing. The CT treatments maintained soil temperatures that were approximately 0.4degreesC greater during cold condition and about 0.5degreesC lower during warm condition at 5 and 10 cm soil depths than the CV treatments, respectively. The greatest differences were achieved by the double no-till system with 100% residue cover treatment in terms of soil temperature and crop growth. Winter wheat yield and water use efficiency (WUE) were improved by 6.7% and 30.1% with CT compared to the CV treatments, and for corn, 8.9% and 6.8%, respectively. We conclude that conservation tillage for the annual double cropping system is feasible, and the double no-till with 100% residue cover is the most effective way of improving crop yields and WUE on the North China Plain.
  • Authors:
    • Smith, H. J.
    • Trytsman, G.
    • Bloem, J. F.
  • Source: Biological Nitrogen Fixation: Towards Poverty Alleviation through Sustainable Agriculture
  • Volume: 48
  • Issue: 1-3
  • Year: 2009
  • Summary: Farm lands of resource-poor communities in South Africa are depleted of nutrients due to continuous mono-cropping, limited use of fertilisers, and sometimes leaching caused by high rainfall. Despite the well-known advantages of biological nitrogen fixation (BNF) in cropping systems, less than 10% of the grain crops planted annually in these areas are legumes. Using a participatory research and development approach, resource-poor farmers were introduced to conservation agriculture (CA) practices, including BNF, that promoted zero (or reduced) tillage, increased retention of soil cover, as well as crop diversification. Because crop rotation and intercropping of legumes with cereals are known to contribute to soil fertility while enhancing food security, resource-poor fanners from various Provinces in South Africa were trained on the benefits of legume culture for eight years. As a result, these resource-poor farmers did not only get training in inoculation techniques, but were also supplied with inoculants for use on their farms. Data collected from Farmers Demonstration Trials at Belvedere, Dumbarton and Lusikisiki, showed that the grain and fodder yield of maize planted after legumes, and maize intercropped with legumes, were comparable to those of maize receiving high N fertilizer dose (i.e. 54 kg N at planting and 54 kg N as top-dressing). The same data further showed that Rhizobium inoculation, when combined with application of low levels of P and K. significantly increased crop yields within farmers' trial plots. BNF therefore offers a great opportunity for resource-poor farmers in South Africa to increase their crop yields and thus improve the quality of their livelihoods through the adoption of affordable and sustainable biological technologies that enhance soil fertility.