• Authors:
    • Liscano,J. F.
    • Boquet, D. J.
    • Breitenbeck, G. A.
    • Mascagni, H. J.,Jr.
    • Clawson, E. L.
    • McCarter, K. S.
  • Source: Journal of Plant Nutrition
  • Volume: 34
  • Issue: 6
  • Year: 2011
  • Summary: Soil nitrogen (N)-supplying capacity bioassays could present alternatives to traditional soil tests. Objectives were to identify winter crops and associated characteristics with bioassay potential. Saint Joseph and Bossier City, LA experiments used randomized complete block designs with factorial N fertilizer and winter crop treatment arrangements. Nitrogen rates were applied to corn (Zea mays L.) in 2004. Unfertilized winter wheat (Triticum aestivum L.), cereal rye (Secale cereale L.), native winter vegetation, and weed-free winter fallow treatments followed corn. At Saint Joseph, cotton (Gossypium hirsutum L.) followed winter crop treatments. Greater corn N rate consistently increased winter crop biomass and N accumulation, suggesting potential as bioassays, and increased Saint Joseph seedcotton yield. Winter crop-seedcotton yield N-response relationships were non-significant by familywise error rate criteria. However, some winter crop characteristics, such as rye N accumulation, for which a relationship to seedcotton yield closely approached significance, may merit further research as soil N-supplying capacity bioassays.
  • Authors:
    • Barnes, P. L.
    • Sheshukov, A. Y.
    • Douglas-Mankin, K. R.
    • Daggupati, P.
    • Devlin, D. L.
  • Source: Transactions of the ASABE
  • Volume: 54
  • Issue: 2
  • Year: 2011
  • Summary: Soil erosion from agricultural fields is a fundamental water quality and quantity concern throughout the U.S. Watershed models can help target general areas where soil conservation measures are needed, but they have been less effective at making field-level recommendations. The objectives of this study were to demonstrate a method of field-scale targeting using ArcSWAT and to assess the impact of topography, soil, land use, and land management source data on field-scale targeting results. The study was implemented in Black Kettle Creek watershed (7,818 ha) in south-central Kansas. An ArcGIS toolbar was developed to post-process SWAT hydrologic response unit (HRU) output to generate sediment yields for individual fields. The relative impact of each input data source on field-level targeting was assessed by comparing ranked lists of fields on the basis of modeled sediment-yield density (Mg ha -1) from each data-source scenario. Baseline data of field-reconnaissance land use and management were compared to NASS and NLCD data, 10 m DEM topography were compared to 30 m, and SSURGO soil data were compared to STATSGO. Misclassification of cropland as pasture by NASS and aggregation of all cropland types to a single category by NLCD led to as much as 75% and 82% disagreement, respectively, in fields identified as having the greatest sediment-yield densities. Neither NASS nor NLCD data include land management data (such as terraces, contour farming, or no-till), but such inclusion changed targeted fields by as much as 71%. Impacts of 10 m versus 30 m DEM topographic data and STATSGO versus SSURGO soil data altered the fields targeted as having the highest sediment-yield densities to a lesser extent (about 10% to 25%). SWAT results post-processed to field boundaries were demonstrated to be useful for field-scale targeting. However, use of incorrect source data directly translated into incorrect field-level sediment-yield ranking, and thus incorrect field targeting. Sensitivity was greatest for land use data source, followed closely by inclusion of land management practices, with less sensitivity to topographic and soil data sources.
  • 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:
    • 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.
  • Authors:
    • Stuchi, E. S.
    • Souza, M. C. de
    • Goes, A. de
  • Source: Crop Breeding and Applied Biotechnology
  • Volume: 11
  • Issue: 1
  • Year: 2011
  • Summary: A citrus scab disease, caused by Elsinoe fawcettii, is currently found in all citrus areas throughout Brazil. That being, given the importance of this casual agent, the behavior of tangerines and hybrids influenced by this pathogen was evaluated under natural infection conditions. This study was performed with plants around 15 years old without irrigation; 100 fruits of three plants were collected during harvest season, using a grade scale varying from 0 (absence of symptoms) to 6 (severe symptoms) the level of disease severity was determined. Among the cultivars, citrus scab resistance was observed in Citrus deliciosa, C. tangerina, C. nobilis; a mandarin hybrid ( C. nobilis * C. deliciosa) and a satsuma hybrid ( C. unshiu * C. sinensis). Among the other genotypes, symptoms were observed with levels of severity ranging from 1 to 3, indicating moderate resistance.