• Authors:
    • Diaz-Rossello, R.
    • Duran, H.
  • Source: Agrociencia
  • Volume: 15
  • Issue: 2
  • Year: 2011
  • Summary: Pastoral dairy farming systems in Uruguay exhibit an accelerated process of intensification with major changes in soil management during the last four decades. However, the production systems were always based on the same concept of sustainable rotations of annual forage crops and perennial grasses sown in association with legumes. The soil organic carbon (OC) in the plots of the Dairy Experimental Farm at La Estanzuela was monitored since 1974 up to 2010. Those records quantify the effect on OC dynamics of four production systems with different soil management carried out in long periods. This information is extremely relevant considering that survey studies showed that commercial dairy farming systems followed the same general pathway of technical changes. The extreme modification in tillage, animal stocking rate and feed imported to the farm determined two contrasting periods in the OC dynamics. Heavy losses of OC were estimated at an average of 0.89 Mg ha -1 year -1 during a first period of 17 years. This tendency was reversed for the following 18 years when OC increased at 0.94 Mg ha -1 year -1. Three major management factors are discussed to explain the fast build up of OC: the progressive tillage reduction, improvements in pasture and forage crop productivity and imported feed coming into the system. The large OC and N gains in semi-confinement paddocks are discussed as an opportunity to capitalize the high nutrient availability in the soil for crop production.
  • Authors:
    • Grebennikov, V.
    • Shipilov, I.
    • Kushch, E.
  • Source: Kormoproizvodstvo
  • Issue: 2
  • Year: 2011
  • Summary: Impacts of perennial legume-grass mixtures on regulation of soil fertility processes were studied in the Stavropol region, Russia in 2006-09. The mixtures consisted of wheat grass, sainfoin, melilot, alfalfa and bluegrass. Growth and development of roots, above-ground biomass and accumulation of organic compounds in soil were measured during the experiment. The total biomass yield of the 5-component mixture reached 9.62 t/ha at the end of the fourth year. Authors recommend this mixture for phytomelioration. The detailed data on yield dynamics of legume-grass mixtures are presented in 2 tables.
  • Authors:
    • Backiyavathy, M. R.
  • Source: Advances in Plant Sciences
  • Volume: 24
  • Issue: 1
  • Year: 2011
  • Summary: A field experiment was conducted to evaluate the effect of different organic manures and its sources at different levels (FYM - 20, 25 & 30 t ha -1, vermicompost - 2.5, 5.0 & 7.5 t ha -1, poultry manure - 2.5, 5.0 & 7.5 t ha -1 and pig manure - 2.5, 5.0 & 7.5 t ha -1) on yield and quality of fodder in perennial fodder crops. The field experiment was conducted at New Area Farm, Department of Forage Crops, TNAU, Coimbatore. The experiment was laid out in randomized block design replicated twice with 14 treatments. Perennial fodder crops viz., cumbu napier hybrid grass CO 3, guinea grass CO 2, sorghum COFS 29, lucerne CO 1 and hedge lucerne were studied under this investigation. The results revealed that the organic manure treatments were compared with recommended dose of inorganic fertilizers with respect to each fodder crop. Among different organics, application of FYM @ 30 t ha -1 registered the maximum green fodder, dry fodder and crude protein yields in all perennial fodders. However the maximum green, dry fodder and crude protein yields were recorded in RDF treatment over the rest of the other treatments.
  • 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.
  • Authors:
    • Mueller-Warrant, G.
    • Dick, R.
    • Banowetz, G.
    • Griffith, S.
    • Whittaker, G.
  • Source: Agronomy Journal
  • Volume: 103
  • Issue: 4
  • Year: 2011
  • Summary: Understanding the impact of crop rotation and residue management in grass seed production systems on soil quality and, in particular soil C dynamics, is critical in making long-term soil management decisions supporting farm sustainability. The effects of a 6-yr rotation and residue management (high vs. low residue) on soil quality were investigated at three locations in Oregon, each contrasting in soil drainage classification. The crop rotations were continuous perennial grass seed production, grass/legume seed production, and grass/legume/cereal seed production. The grass species grown at each location were different and represented those most commonly produced in each environment; perennial ryegrass ( Lolium perenne L.), tall fescue [ Schedonorus phoenix (Scop.) Holub], and creeping red fescue ( Festuca rubra L.). All three grass seed crop rotations and residue methods maintained high soil quality in conventional or direct seeded soils, but under some situations, soil quality was higher with continuous grass rotation and high residue. Data suggest that straw removal for value-added use, like bioenergy production, can be accomplished in the Pacific Northwest Marine climate without appreciably affecting soil quality. Furthermore, grass seed cropping systems play an important role in soil C storage and enhancement, a valuable ecosystem service in this region where grass seed is produced on land that is not suitable for production of conventional crops that require better-drained soil. We conclude that by nature perennial grass seed crops promote high soil fertility and enriched soil C pools and consequently contribute to the tolerance of these systems to the use of less conservation-oriented crop management methods at times when crop loss could be potentially high. This attribute provides producers greater latitude in selecting soil and crop management options to address issues of soil fertility, pest, weed, or seed certification to minimize economic crop yield losses.
  • Authors:
    • Martiniello, P.
  • Source: European Journal of Agronomy
  • Volume: 35
  • Issue: 4
  • Year: 2011
  • Summary: Rotations experiment have been investigated from 1991 to 2008 under irrigated and rainfed condition in Mediterranean environment. The crops studied were: annual winter binary mixture (BM), perennial meadow (ME) and durum wheat (W) continuously rotated for 3 years and W rotated on itself for all period of experiment (CW). The forage rotations emphasized on the impact made on biochemical characteristics of topsoil and productivity of the crops. The 3 years continuous wheat rotation over forage crops assess the advantage of forage crops left in the soil on seed yield and on quality of kernel. The continuous wheat rotation (CW) reduced the soil biochemical parameters, seed yield and quality of kernel. The value of organic carbon, C/N and total nitrogen, under rainfed in comparison to the values present in the topsoil at the beginning of experiment were 6.4% and 2.48 higher and 11.2% lower in ME and lower 5.2% in organic carbon and 2.8% total nitrogen and 0.21 higher in C/N in BM. The agronomic advantages allowed by forage rotations expire their effect after 3 years of continuous wheat. Yearly yield W gain under rainfed was 11.3 kg (ha yr) -1 in BM and 62 kg (ha yr) -1 in ME. The qualitative traits of wheat kernel rotated on forage were higher than those of continuous wheat CW. Results of biochemical characteristics obtained at the end of experiment evidenced that W after BM and ME rotations sustained, under irrigated and rainfed condition, the content of organic carbon and total nitrogen and C/N in the topsoil of the cropping system while continuously CW allowed strong impact of the parameter values present at beginning of experiment (organic carbon, total nitrogen and C/N was reduced under rainfed by 23.5%, 18.2 and 0.32 and 30.3%, 15.4% and 1.72 under irrigated, respectively).
  • Authors:
    • Hoffmann, A. A.
    • Penfold, C. M.
    • Sharley, D. J.
    • Thomson, L. J.
    • Danne, A.
  • Source: Environmental Entomology
  • Volume: 39
  • Issue: 3
  • Year: 2010
  • Summary: Indigenous cover crops have the potential to promote an increase in natural enemies providing fortuitous control of pest species and other ecosystem services. We test this idea in a vineyard in south eastern Australia, where reduced water availability because of drought coupled with increased temperatures has generated interest in sustainable alternatives to the exotic perennial cover crops commonly planted. Three endemic perennial cover crops, comprising the grasses Austrodanthonia richardsonii and Chloris truncata and a mix of two saltbushes ( Atriplex semibaccata and Atriplex suberecta) were established as cover crops and compared with introduced oats ( Avena sativa). Abundance of a range of predators and parasitoids was higher in vines with native cover crops compared with the oat control. In addition, predation levels of sentinel eggs of a common vineyard pest, light brown apple moth ( Epiphyas postvittana), were increased in the native cover crops. However, the native cover crops also increased the abundance of some potential pest species. Native plants therefore have potential to increase abundance of beneficial invertebrates that assist in pest control, but need to be used carefully to ensure that they do not increase local pest problems.
  • Authors:
    • Rocha, D.
    • Cano, M.
    • Patino, H.
    • Medeiros, F.
    • Gonzalez, F.
  • Source: Ciencia Rural
  • Volume: 40
  • Issue: 1
  • Year: 2010
  • Summary: The impact of energy supplementation on the performance and carcass characteristics of 24 Aberdeen-Angus * Charolais steers grazing an annual ryegrass ( Lolium multiflorum) and oat ( Avena strigosa [ Avena nuda]) pasture managed in order to avoid constrains to animal performance was evaluated. Treatments were levels of supplementation of 0, 0.4, 0.8 and 1.2% BW with a corn and mineral based supplement. Animals were slaughtered after reaching 4.5 mm of fat cover in the rump (P8) evaluated ultrasonography. No differences were observed in fat deposition, measured in live animals with ultrasound at the end of performance period, and in liveweight gain, which showed average values of 3.9 mm and 1.54 kg/day, respectively. Blood serum levels of urea were linearly decreased and cholesterol linearly increased by energy supplementation, with no differences in the serum levels of glucose and triglycerides. Energy supplementation linearly increased the killing-out proportion and carcass weight gain, but no differences were observed on the rib eye area, slaughter weight and hot carcass weight, which averaged 67.85 cm 2, 438.95 kg and 227.75 kg, respectively. Increasing the levels of supplementation resulted in higher killing-out proportion and higher carcass daily gains, without changes in performance and carcass parameters evaluated.
  • Authors:
    • Ristolainen, A.
    • Sarikka, I.
    • Hurme, T.
    • Alakukku, L.
  • Source: Agricultural and Food Science
  • Volume: 19
  • Issue: 4
  • Year: 2010
  • Summary: Surface water ponding and crop hampering due to soil wetness was monitored in order to evaluate the effects of conservation tillage practices and perennial grass cover on soil infiltrability for five years in situ in gently sloping clayey fields. Thirteen experimental areas, each having three experimental fields, were established in southern Finland. The fields belonged to: autumn mouldboard ploughing (AP), conservation tillage (CT) and perennial grass in the crop rotation (PG). In the third year, direct drilled (DD) fields were established in five areas. Excluding PG, mainly spring cereals were grown in the fields. Location and surface area of ponded water (in the spring and autumn) as well as hampered crop growth (during June-July) were determined in each field by using GPS devices and GIS programs. Surface water ponding or crop hampering occurred when the amount of rainfall was clearly greater than the long-term average. The mean of the relative area of the ponded surface water, indicating the risk of surface runoff, and hampered crop growth was larger in the CT fields than in the AP fields. The differences between means were, however, not statistically significant. Complementary soil physical measurements are required to investigate the reasons for the repeated surface water ponding.
  • Authors:
    • Sun, Y.
    • Dowd, S.
    • Acosta-Martinez, V.
    • Wester, D.
    • Allen, V.
  • Source: Applied Soil Ecology
  • Volume: 45
  • Issue: 1
  • Year: 2010
  • Summary: Bacterial tag-encoded FLX amplicon pyrosequencing of the 16S rDNA gene was used to evaluate bacterial diversity of a clay loam soil (fine, mixed, thermic Torrertic Paleustolls) after 10 years under an integrated livestock (beef)-cotton ( Gossypium hirsutum L.) production system compared to continuous cotton in a semiarid region. In the integrated system, cattle alternatively grazed a perennial warm-season grass [ Bothriochloa bladhii (Retz) S.T. Blake] paddock and small grains grown in two paddocks of a wheat ( Triticum aestivum L.)-fallow-rye ( Secale cereal L.)-cotton rotation. Areas excluded from grazing in the integrated system were also evaluated. Maximum observed number of unique sequences operational taxonomic units (OTU) at 3% dissimilarity level (roughly corresponding to the species level) corresponded to 1200 and 1100 at 0-5 and 5-15 cm depths, respectively. Predominant phyla (up to 65% of abundance) at 0-5 and 5-15 cm in this soil were Proteobacteria, Actinobacteria and Gemmatimonadetes. Proteobacteria were predominant in soil under all components of the integrated livestock-cotton system compared to continuous cotton whereas Bacteroidetes were predominant under continuous cotton. Firmicutes (i.e., Clostridia) and Chlorofexi (i.e., Thermomicrobia) were more abundant in soil under fallow periods of the rotation compared to under cotton (Rye- Cotton-Wheat-Fallow or continuous cotton) or grass (i.e., pasture). The lowest OTUs were detected in soil under fallow periods of the rotation (Wheat- Fallow-Rye-Cotton) compared to the other treatments. Grazing effects were significant for Actinobacteria, Proteobacteria and Chlorofexi. Compared to the continuous cotton system, this study revealed significant changes in bacterial phyla distribution under integrated livestock-cotton systems for a semiarid soil after 10 years. Positive correlations were found between certain bacteria ( Proteobacteria, Firmicutes, Chloroflexi, Verrucomicrobiae and Fibrobacteres) and the activities of alkaline phosphatase and beta-glucosidase or beta-glucosaminidase.