• Authors:
    • Herr, A.
    • Dunlop, M.
  • Source: Biomass and Bioenergy
  • Volume: 35
  • Issue: 5
  • Year: 2011
  • Authors:
    • Shelton, H. M.
    • Radrizzani, A.
    • Kirchhof, G.
    • Dalzell, S. A.
  • Source: Crop and Pasture Science
  • Volume: 62
  • Issue: 4
  • Year: 2011
  • Summary: Soil organic carbon (OC) and total nitrogen (TN) accumulation in the top 0–0.15 m of leucaena–grass pastures were compared with native pastures and with continuously cropped land. OC and TN levels were highest under long-term leucaena–grass pasture (P < 0.05). For leucaena–grass pastures that had been established for 20, 31, and 38 years, OC accumulated at rates that exceeded those of the adjacent native grass pasture by 267, 140, and 79 kg/ha.year, respectively, while TN accumulated at rates that exceeded those of the native grass pastures by 16.7, 10.8, and 14.0 kg/ha.year, respectively. At a site where 14-year-old leucaena–grass pasture was adjacent to continuously cropped land, there were benefits in OC accumulation of 762 kg/ha.year and in TN accumulation of 61.9 kg/ha.year associated with the establishment of leucaena–grass pastures. Similar C : N ratios (range 12.7–14.5) of soil OC in leucaena and grass-only pastures indicated that plant-available N limited soil OC accumulation in pure grass swards. Higher OC accumulation occurred near leucaena hedgerows than in the middle of the inter-row in most leucaena–grass pastures. Rates of C sequestration were compared with simple models of greenhouse gas (GHG) emissions from the grazed pastures. The amount of carbon dioxide equivalent (CO2-e) accumulated in additional topsoil OC of leucaena–grass pastures ≤20 years old offset estimates of the amount of CO2-e emitted in methane and nitrous oxide from beef cattle grazing these pastures, thus giving positive GHG balances. Less productive, aging leucaena pastures >20 years old had negative GHG balances; lower additional topsoil OC accumulation rates compared with native grass pastures failed to offset animal emissions
  • Authors:
    • Richards, A. E.
    • Cook, G. D.
    • Lynch, B. T.
  • Source: Ecosystems
  • Volume: 14
  • Issue: 3
  • Year: 2011
  • Authors:
    • Basso, F. C.
    • Andreotti, M.
    • P. e Carvalho, M. de
    • Lodo, B. N.
    • Montanari, R.
  • Source: Revista Brasileira de Ciências Agrárias
  • Volume: 6
  • Issue: 3
  • Year: 2011
  • Summary: With the use of no-till farming, the soil physical and chemical properties are constantly changed, directly reflecting on plant yield and composition. In 2006, in the municipality of Selviria, Mato Grosso do Sul, Brazil, the linear and spatial correlations between the plant attributes and the attributes of a Rhodic Hapludox were analyzed. The objective of this work was to select among the analyzed soil attributes the one that best explained the variability of agricultural yield. For this, the geostatistical grid was installed for the soil and plant collection in 124 sampling points in a 4,000 m2 area. In the soil samples, collected at three depths (0-0.10 m, 0.20-0.30 m and 0.10-0.20 m), the microporosity, macroporosity, total porosity, bulk density and organic matter content were determined. In the plant, the yield (fresh and dry matter) and the crude protein content were determined. From the spatial viewpoint, there was a direct correlation between the dry matter yield and the soil organic matter content, as well as an inverse correlation between the crude protein content and the macroporosity and total porosity of soil. Therefore, the surface organic matter content behaved as a soil chemical quality indicator to estimate the dry matter yield of Cajanus cajan L. under the conditions of this research.
  • Authors:
    • Campos, L. P.
    • Leite, L. F. C.
    • Maciel, G. A.
    • Iwata, B. de F.
    • Nobrega, J. C. A.
  • Source: Pesquisa Agropecuária Brasileira
  • Volume: 46
  • Issue: 12
  • Year: 2011
  • Summary: The objective of this work was to evaluate the chemical attributes in a Xanthic Ferralsol under different tillage systems in the cerrado of Piaui State, Brazil. Four tillage systems were evaluated: three-year-old conventional tillage; no-tillage with three (NT3) and five years old (NT5), using millet as cover crop; and no-tillage with nine years old (NT9), of which seven years used millet as cover crop and two used forage. A native cerrado area was taken as reference. Soil samples were collected in wet and dry seasons at soil depths, 0.00-0.05, 0.05-0.10, 0.10-0.20 and 0.20-0.40 m, and analyzed for pH, Al 3+, H+Al, Ca 2+, Mg 2+, K +, sum of bases (SB), effective (t) and potential (T) cation exchangeable capacity, base (BS) and Al 3+ saturation (m%), available P and total organic carbon (TOC). The system NT9 showed the highest values of pH and lowest of Al 3+, H+Al, and m%. The highest values for Ca 2+, K, SB, t, T, V% and P, were observed under NT5 and NT9, until 0.20 m depth. The highest TOC contents were verified also under NT5 and NT9, except for 0.00-0.05 m soil depth. Organic matter accumulation associated with pasture under no-till increases TOC content at deeper soil layers in the dry period.
  • Authors:
    • Duboc, O.
    • Zehetner, F.
    • Gerzabek, M. H.
  • Source: Journal of Sustainable Agriculture
  • Volume: 35
  • Issue: 6
  • Year: 2011
  • Summary: The increase in crop production brought by the green revolution in India is now shadowed by new challenges related to soil degradation (e.g., erosion, decline of soil organic matter content, salinization) and scarcity of water resources. The present work particularly discusses the contribution of no-till and organic farming, which are increasingly being adopted in India, to meet the increasing food demand in a sustainable way. Under no-till, erosion is reduced to rates close to those found in natural ecosystems, provided enough mulch is retained at the surface which is usually not the case in India, because of competing uses, for example, fodder, fuel, construction material, and also crop residue burning for land preparation. No-till should therefore not be considered separately from complementary measures, aiming at retaining mulch on the soil surface. Efficient recycling of organic material needs to be implemented concomitantly with diversifying fodder and fuel sources which requires enhancing the multifunctionality of farming systems. These prerequisites make it difficult for farmers to adopt no-till, particularly the poorer ones for whom experimentation with new techniques often involve unbearable financial risks. Organic farming apprehends the farm as an organism, and is thus a good option to improve sustainability as introduced above, by e.g., closing nutrient cycling. However, organic farming typically implies tillage for weed control (no chemical herbicides). "Natural farming," as promoted by Fukuoka (197834. Fukuoka, M. 1978. The one-straw revolution: an introduction to natural farming, Rodale Press. View all references) combines no-till with organic farming. An overview of available literature on Indian experiences with "natural farming," most of it originating from unconventional sources (i.e., reports available on Internet, but no peer reviewed literature) indicates that crop yields can compare well with the highest yields in a particular region. Increased productivity and environmental benefits are also often mentioned. The limited accuracy of these sources makes it necessary to pursue further investigations, and we conclude with propositions for future work in this context. This should start with a rigorous assessment of existing " natural farming" systems regarding their productivity and environmental benefits, in order to demonstrate its potential before starting projects that promote the system for broader adoption.
  • Authors:
    • Fasinmirin, J. T.
    • Reichert, J. M.
  • Source: Soil & Tillage Research
  • Volume: 113
  • Issue: 1
  • Year: 2011
  • Summary: Cassava ( Manihot esculenta crantz) is often cultivated on tilled plots, traditionally on mounds and ridges with the use of hand hoes or tractor driven implements. These two conditions alter the soil structural parameters and most times increase the vulnerability of soil to erosion or compaction as a result of frequent machine movement under the conventional tillage system. A review of the effects of tillage systems on soil bulk density, total porosity and penetration resistance was conducted to investigate the effectiveness of soil conservation for the optimum production of cassava in the tropics. Tillage treatments under review were: conventional tillage (CT), no-till (NT), minimum tillage (MT) and soil compaction (CP). Our review indicated that the bulk density (BD) in plots under CT was not significantly different ( p<0.05) from the value of BD in plots under minimum tillage (MT) within the 0-5 cm soil layer, but was highest in soils under compaction due to traffic passes of heavy duty equipment. Soils under no-till were characterized with lowest bulk density within the 0-5 cm layer, but gradually increased in BD within the 10-20 cm soil layer, which offers the soil some structural stability. However, the difference in bulk densities between plots under NT and CP treatments were highly significant at p<0.05, with CP plots having the highest bulk density within the 0-30 cm soil layer. Total porosity was highest in soils under conventional tillage (CT) comparatively with other tillage systems. Organic matter accumulation in NT treatment resulted to higher total porosity compared with other systems except CT at the surface soil (0-5 cm) but with reduced porosity at the sub-surface soil. Total porosity was least in plots under traffic passes (compacted plots). Statistically, there were no significant differences in total porosity among plots under conventional tillage with mulch residues, conventional tillage without mulch residues and minimum tillage with mouldboard at the p<0.05. However, plots under minimum tillage without mouldboard had lower total porosity. Penetration resistance was higher in NT plots when compared with plots under CT system, except from compacted plots (CP), which offered highest resistance to penetration. A long term experiment showed that cassava root yield was highest under NT with mulch residues, with or without fertilizer application. The reviewed work further confirmed that cassava can be grown successfully under no-till (NT) to give the optimum growth and yield required of the crop, while conserving the soil physical properties.
  • 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:
    • Rizzi, N. E.
    • Fey, E.
    • Lana, M. do C.
    • Bertol, O. J.
  • Source: Ciência Rural
  • Volume: 41
  • Issue: 11
  • Year: 2011
  • Summary: The no-tillage system, has contributed to improvements in agricultural soils, among them the like increases in nutrient concentrations of mineral elements in soil. However, it has been found that this increase concentration occurs mainly in the first few centimeters of the superficial top layer and so risks of nutrient losses by runoff, and associated of the soil, which concurs for losses of mineral elements through of runoff, with economic and environmental damages, are high. This study evaluated the total concentration, in runoff, of mineral elements potassium (K), calcium (Ca), magnesium (Mg) and copper (Cu) in total form and the soluble and particulate concentration form of K, in runoff caused to simulated rainfall of different intensitiesy applied over soil under no-till system and submitted to simulated after application of organic or mineral fertilizers in no-till soil. The fertilizers did not affect the concentration of mineral elements studied nutrients in runoff, except in condition of more high intense rainfall and soil under after organic manure application, which promoted runoff with showed the higher highest concentration of soluble and total K. Independent Irrespective of the type of fertilizers utilized type, the rainfall of higher intensity resulted in higher concentrations of all the mineral elements and forms studied, either in total, soluble or particulate form, evidencing the economic and environmental benefices, risks and suggesting that with the adoption of practices for runoff contention of runoff practices must be adopted, even in tilled croplands areas managed under no-till system.
  • Authors:
    • Srivastava, A. K.
    • Panigrahi, P.
  • Source: Indian Journal of Soil Conservation
  • Volume: 39
  • Issue: 2
  • Year: 2011
  • Summary: A field experiment was conducted during 2006-08 to assess the response of deficit irrigation (DI) in 16 year old drip-irrigated Nagpur mandarin ( Citrus reticulata) trees budded on Rough lemon ( Citrus jambhiri L.) root stock at Nagpur, Maharashtra. The DI regimes imposed were at 30, 50, and 70% of Full irrigation (FI) and compared with FI (control). The annual increase in vegetative growth parameters (tree height and canopy volume) of trees under FI was found to be superior over DI treatments. The soil moisture status measured at 30 cm, 45 cm and 60 cm depths showed that the mean monthly soil moisture content was significantly affected at 30 cm depth, with highest magnitude (27.6-30.7%, v/v) under FI. Leaf nutrients (N, P, K, Fe, Mn, Cu, and Zn) analysis indicates that FI registered the maximum leaf N, K, and Fe, followed by 70% FI. The highest fruit yield (14.10 t ha -1) recorded under FI was at par with DI at 70% FI (13.35 t ha -1). More number and smaller size of fruits were recorded in FI as compared to DI at 70% FI. However, DI at 70% FI produced 36% higher water productivity with superior quality fruits (more fruit weight, higher TSS and lower acidity) over FI.