• Authors:
    • Leifert, C.
    • Critchley, C. N. R.
    • Eyre, M. D.
    • Wilcockson, S. J.
  • Source: European Journal of Agronomy
  • Volume: 34
  • Issue: 3
  • Year: 2011
  • Summary: A survey of 128 plots, in 2008, of a trial where the effects of crop protection can be separated from those of fertility management, generated weed cover data within six crops (winter wheat, winter barley, spring barley, potatoes, cabbages and a grass/clover ley). The effects of the 2008 crop types, of the two preceding crops and of organic and conventional crop protection and fertility management, were assessed using mixed-effects models and constrained ordination. Cover data for 22 weed species and for monocotyledon, dicotyledon, annual, perennial and total weed cover were used. Cover of 15 weed species, and of the five weed groups, was significantly affected by 2008 crops, with cover highest in spring beans and cabbage. Nine and four weed species 2008 cover were significantly related to crops grown in 2007 and 2006 respectively, as were dicotyledon, annual and total weed cover, but not monocotyledon or perennial cover. Cover of 15 species, and the five groups, was significantly higher in plots with organic crop protection, but only eight species and annuals were significantly affected by fertility management. Crop:crop protection produced the most significant interactions with most cover in organically managed plots. Five species, perennials and total weed cover produced significant three-factor models. The greatest weed cover was in organic crop protected but conventionally fertilised spring barley and the least in totally conventional winter barley. Other factors such as crop density and mechanical weeding also affected 2008 weed cover. The ordination indicated that most of the 22 species were strongly associated with crops from all three years. The sequence of crops in the rotation had a profound effect on weed cover. Where three spring-sown, difficult to weed, crops were grown in sequence (spring beans, potatoes and vegetables, spring barley) weed cover increased. However, cover was limited in grass/clover and some cereal plots with different preceding crops. Models predicting weed cover may need to take into account crop sequences within crop rotations, as well as the more usual management inputs. (C) 2011 Elsevier B.V. All rights reserved.
  • Authors:
    • Muthukrishnan, P.
    • Fanish, S. A.
  • Source: Madras Agricultural Journal
  • Volume: 98
  • Issue: 10/12
  • Year: 2011
  • Summary: Field experiments were conducted at Agricultural College and Research Institute, Tamil Nadu Agricultural University, Coimbatore, during kharif 2008 and 2009 to study the effect of different fertigation levels and intercrops in intensive maize based intercropping system. The experiment was laid out in strip plot design with three replications. The experiment comprised of nine fertigation levels in main plot, viz M 1, Surface irrigation with soil application of 100% RDF; M 2, Drip irrigation with soil application of 100% RDF; M 3, Drip fertigation of 75% RDF; M 4, Drip fertigation of 100% RDF; M 5, Drip fertigation of 125% RDF; M 6, Drip fertigation of 150% RDF; M 7, Drip fertigation of 50% RDF (50% P and K as Water Soluble Fertilizer (WSF)); M8, Drip fertigation of 75% RDF (50% P and K as WSF); M 9, Drip fertigation of 100% RDF (50% P and K as WSF) and four intercrops in sub plot viz, S 1, Vegetable coriander; S 2, Radish; S 3, Beet root; S 4, Onion. Drip fertigation at 100 per cent RDF with 50 per cent P and K as WSF in maize+radish intercropping system recorded a higher gross income of Rs. 83438/ha whereas, higher net return and benefit cost ratio of Rs. 56858 and 3.24, respectively, were recorded by drip fertigation at 150 per cent RDF with radish as intercrop system.
  • Authors:
    • Manoharan, S.
    • Muthukrishnan, P.
    • Fanish, S. A.
  • Source: Indian Journal of Agricultural Research
  • Volume: 45
  • Issue: 3
  • Year: 2011
  • Summary: Field experiments were conducted during kharif 2008-2009 at Tamil Nadu agricultural University, Coimbatore to study the effect of drip fertigation on growth, yield and economics of intensive maize based intercropping system. Drip fertigated maize with 100 per cent recommended dose of fertilizer (RDF) with 50 per cent P and K as water soluble fertilizer recorded significantly higher grain yield followed by 150 per cent RDF. Among the different intercropping systems, radish intercropped with maize registered higher maize grain equivalent yield of 11153 kg ha -1. Drip irrigation saved water upto 43 per cent, besides enhancing the water use efficiency. Higher net returns (Rs. 56858) and B:C ratio (3.24) were obtained under dripfertigation with 150 per cent recommended dose of fertilizer and radish as intercrop.
  • Authors:
    • Bueno, O. de C.
    • Frigo, E. P.
    • Frigo, M. S.
    • Esperancini, M. S. T.
    • Klar, A. E.
  • Source: Energia na Agricultura
  • Volume: 26
  • Issue: 2
  • Year: 2011
  • Summary: The knowledge production and energy expenditure in agriculture is crucial due to strategic importance which occupies as a producer of energy inputs to other economic sectors, such as biodiesel produced from oilseed crops, so this study was attempt to determine the energy cost of partial deployment and conduct of corn intercropping agroecosystem with physic nut, under the steering and without irrigation, in an experiment conducted in accordance with the productive system of family farming in the west of Parana State. Such a study is justified due to the scarcity of energy data of the culture of physic nut under brazilian conditions, as well as in intercropping system under technological conditions of the family farm west of Parana, and especially environmental issues involved in this study as the rational use of energy sources nonrenewable. The experiment was conducted in accordance with the techniques employed by family farmers in western Parana, from February 2008 to May 2008 for corn and from February 2008 to November 2009 for the cultivation of physic nut in the Experimental Center of Agricultural Engineering (NEEA), belonging to the State University of Western Parana (UNIOESTE), campus of Cascavel/PR, in the area of tillage. The final product was assessed only corn. The technical coefficients, the workload, performance, identification of the tractor, implements and equipment, their specifications and their consumption of fuel, lubricants and greases, as well as quantification of manpower used were derived from primary data and secondary. The methodology consisted of determining the "Efficiency Cultural Partial" and "Energy Efficiency Partial". Regarding the energy balance in part, cultural and energy efficiency partial there were no major differences between the systems studied. We conclude that the conditions of the experiment the conduction system assessed in terms of energy both systems have the same performance.
  • Authors:
    • Gabriel, J. L.
    • Quemada, M.
  • Source: European Journal of Agronomy
  • Volume: 34
  • Issue: 3
  • Year: 2011
  • Summary: Cover crops in dry regions have been often limited by low nutrient and water-use efficiency. This study was conducted during 3.5 years to determine the effect of replacing bare fallow by a cover crop on yield, N uptake, and fate of labeled fertiliser in an intensive maize production system. Three treatments were studied: barley ( Hordeum vulgare L.), vetch ( Vicia villosa L.) and bare fallow during the intercropping period of maize ( Zea mays L.). All treatments were irrigated and fertilised following the same procedure, and a microplot in each plot was established with 210 kg N ha -1 of double labeled ammonium nitrate. Crop yield and N uptake, soil mineral N (N min), and recovery of 15N in plant and soil were determined after maize harvest and killing the cover crop. Replacing bare fallow with cover crops did not affect subsequent maize yield but affected N uptake. Vetch increased N supply by legume residues after the second year, and the N content in grain by the third. Nitrogen recover from fertiliser was not affected by treatment and averaged 46%. Barley recovered more 15N during the autumn-winter period than vetch or fallow. Under representative conditions, average barley N content was 47, vetch 51, and spontaneous vegetation content 0.8 kg N ha -1. Recovery of 15N in barley comprised 19% of total N content in aerial biomass, while only 4% in vetch. Vetch enhanced soil 15N recovery more than other treatments, suggesting its presence in a fairly stable organic fraction unavailable for maize uptake or lost. Replacing bare fallow by a cover crop only reduced fertiliser losses in a year with abundant precipitation. Nevertheless, reduction in soil N min in vetch and bare fallow treatments was similar, showing that N losses can be reduced in this cropping system, either by replace bare fallow with barley or smaller N fertiliser application to maize.
  • Authors:
    • Fernandez, G. E.
    • Schroeder-Moreno, M. S.
    • Garland, B. C.
    • Creamer, N. G.
  • Source: HortScience
  • Volume: 46
  • Issue: 7
  • Year: 2011
  • Summary: The effects of eight summer cover crop treatments combined with two arbuscular mycorrhizal (AM) fungal inoculants on strawberry growth and yields were examined in a 2-year field experiment. Cover crop treatments included 1) sudangrass [Sorghum bicolor (L.) Moench cv. Piper]: 2) pearl millet [Pennisetum glaucum (L.) R.Br. CV. 102 M Hybrid!: 3) soybean [Glycine max (L.) Merrill cv. Laredo]: 4) velvetbean [Mucuna deeringiana (Bort) Merr. cv. Georgia Bush]: 5) sudangrass/velvetbean combination; 6) pearl millet/soybean combination; 7) a non-mycorrhizal host consisting of rape (Brassica napus L. var. napus cv. Dwarf Essex) and buckwheat (Fagopyrum esculentum Moench) in Year 1 and Year 2, respectively; and 8) no cover crop control. Strawberry tips were inoculated with either a native mixture of several AM fungal species or a single species sold commercially, Glomus intraradices. Cover crop treatments were assessed for their aboveground biomass and nutrient uptake as well as their impacts on weed abundance and diversity, soil nutrients, and parasitic nematode populations. Cover crop and AM treatments were assessed for their impact on strawberry growth, yields, AM root colonization, and nutrient uptake. Grass-based cover crop treatments, particularly pearl millet, produced the most aboveground biomass. In both years, all cover crop treatments reduced summer weed biomass compared with the control. Neither cover crop nor AM treatments had an effect on overall strawberry plant growth or yields in either year, although some differences existed at specific growth periods. The results suggest that cover crops are a viable strategy for reducing summertime weeds and that background, native populations of AM fungi in the soil may be just as effective as a commercially available species. It is likely that no overall yield benefit was found among treatments for two reasons: 1) nutrients, especially nitrogen, were not limiting; and 2) the cover crop growth window may have been too short for a significant impact on strawberries over two seasons.
  • Authors:
    • Kumar, V.
    • Kumar, V.
    • Saharawat, Y. S.
    • Ladha, J. K.
    • Gathala, M. K.
    • Sharma, P. K.
  • Source: Soil Science Society of America Journal
  • Volume: 75
  • Issue: 5
  • Year: 2011
  • Summary: Rice-wheat (Oryza sativa L.-Triticum aestivum L.) rotation is the major production system in Asia, covering about 18 million ha. Conventional practice of growing rice (puddled transplanting) and wheat (conventional till, CT) deteriorate soil physical properties, and are input- and energy-intensive. Zero-tillage (ZT) along with drill-seeding have been promoted to overcome these problems. A 7-yr permanent plot study evaluated various tillage and crop establishment (CE) methods on soil physical properties with an aim to improve soil health and resource-use efficiency. Treatments included transplanting and direct-seeding of rice on flat and raised beds with or without tillage followed by wheat in CT and ZT soil. Bulk density (D(b)) of the 10- to 20-cm soil layer was highest under puddled treatments (1.74-1.77 Mg m(-3)) and lowest under ZT treatments (1.66-1.71 Mg m(-3)). Likewise, soil penetration resistance (SPR) was highest at the 20-cm depth in puddled treatments (3.46-3.72 MPa) and lowest in ZT treatments (2.51-2.82 MPa). Compared with conventional practice, on average, water-stable aggregates (WSAs) > 0.25 mm were 28% higher in ZT direct-seeding with positive time trend of 4.02% yr(-1). Infiltration was higher (0.29-0.40 cm h(-1)) in ZT treatments than puddled treatments (0.18 cm h(-1)). The least-limiting water range was about double in ZT direct-seeding than that of conventional practice. Gradual improvement in soil physical parameters in ZT system resulted in improvement in wheat yield and is expected to be superior in long-run on system (rice+wheat) basis. Further research is needed to understand mechanisms and requirements of two cereals with contrasting edaphic requirements in their new environment of ZT direct-seeding.
  • Authors:
    • Dadhwal, K. S.
    • Sharma, N. K.
    • Ghosh, B. N.
  • Source: Indian Journal of Soil Conservation
  • Volume: 39
  • Issue: 3
  • Year: 2011
  • Summary: Agricultural land use coupled with cropping system and integrated nutrient management (INM) can enhance crop yields, water productivity, improve soil health and income to the farmers. To test this hypothesis, four technologies namely rainfed; (i) maize+cowpea (1:2)-wheat, (ii) maizewheat+mustard (9:1), (iii) irrigated, paddy-wheat, paddy (System of rice intensification, SRI) - wheat and (iv) maize-potato-onion with INM to each crop rotations were experimented and demonstrated on farmer's fields in the agroclimatic zone of valley land of north-west Himalayas (Agro-ecological 14) in the districts of Dehradun (Uftarakhand) and Sirmour (Himachal pradesh) during 2007-09. Two years pooled data indicated that maize-potato-onion rotation rendered highest maize equivalent yield (18762 kg ha -1) among all the cropping system, followed by paddy wheat (10789 kg ha -1) and maize-wheat+mustard intercropping system (4826 kg ha -1). Of the two rainfed systems, maize-wheat+mustard gave slightly higher (1.5%) maize equivalent yield than maize- + cowpea-wheat sequence whereas under limited irrigation condition, maize-potato-onion exhibited significantly higher (73.9%) maize equivalent yield than paddy-wheat system. Results also revealed that on an average, yield, water use efficiency (WUE) and net return increased to the tune of 40.7, 44.7 and 89.9%, respectively on adoption of technology in the farmer's field over conventional farming irrespective of crop rotations. Water use in system of rice intensification (SRI) with INM technology was 80-90 mm less than fanners practice. On adoption of INM technology, the soil quality index (SQI) improved from 11.9 to 18.8% exhibiting highest in maize-potato-onion and lowest in paddy-wheat system. It is inferred that maize-potato-onion under limited irrigation treatment and maize-wheat+mustard under rainfed conditions are the best management options for maximizing water productivity, net return and soil quality.
  • Authors:
    • Huffman, R. L.
    • Grabow, G. L.
    • Evans, R. O.
  • Source: Journal of Irrigation and Drainage Engineering
  • Volume: 137
  • Issue: 1
  • Year: 2011
  • Summary: A subsurface drip irrigation (SDI) system was installed in the Piedmont of North Carolina in a clay soil in the fall of 2001 to test the effect of dripline spacing on corn and soybean yield. The system was zoned into three sections; each section was cropped to either corn ( Zea mays L.), full-season soybean [ Glycine max (L.) Merr.], or winter wheat ( Triticum aestivum) double cropped to soybean representing any year of a typical crop rotation in the region. Each section had four plots; two SDI plots with dripline spacing at either 1.52 or 2.28 m, an overhead sprinkler irrigated plot, and an unirrigated plot. There was no difference in average corn grain yield for 2002-2005 between dripline spacings or between either dripline spacing and sprinkler. Irrigation water use efficiency (IWUE) was greater for sprinkler irrigated corn than for either SDI treatment and there was no difference in IWUE in soybean. Water typically moved laterally from the driplines 0.38 to 0.50 m. SDI yield and IWUE increased relative to sprinkler yields and water use efficiency in the second and third year of the study. This may suggest that initial fracturing of the heavy clay soil during SDI system installation and subsequent settling of the soil affected water distribution.
  • Authors:
    • Carvalho, S. A. de
    • Setin, D. W.
  • Source: Citrus Research and Technology
  • Volume: 32
  • Issue: 1
  • Year: 2011
  • Summary: Citrus Sudden Death (CSD) a citrus disease of indeterminate causal agent, imposed changes to the Sao Paulo state citrus nursery tree production, with the substitution of the Rangpur lime for tolerant rootstocks as Swingle citrumelo, which, however, is less resistant to water deficit. The use of inarched nursery trees, combining resistance to water deficit and to CSD, can be interesting for planting in areas of risk, sparing the need of irrigation. The objective of this research was to evaluate different containers and grafting methods for the production of Valencia sweet orange nursery trees with double-rootstocks: Rangpur lime and Swingle citrumelo. Two containers (0.05 dm 3 and 0.25 dm 3 leaching tubes) and two grafting methods (inarching and spliced approach grafting) were evaluated for production of double-rootstocks. The comparison was performed against the single patterns (Rangpur lime or Swingle). Plant growth before and after grafting was evaluated in the final evaluation, the volume and mass of roots and mass of scion dry matter were measured. Single and double rootstocks grown initially in tubes of 0.25 dm 3, and Valencia nursery trees produced on the same container, demonstrated higher growth. Valencia nursery trees on Swingle citrumelo and Rangpur lime double rootstocks presented similar growth to trees grafted on Swingle citrumelo single rootstock. However, considering the potential of such type of nursery trees, its production may be held by sowing different rootstocks in the same tube of 0.25 dm 3, performing the graft by inarching method and the transference to bags where the canopy bud is grafted.