• Authors:
    • Isla, R.
    • Salmeron, M.
    • Cavero, J.
  • Source: Field Crops Research
  • Volume: 123
  • Issue: 2
  • Year: 2011
  • Summary: Under semiarid Mediterranean conditions irrigated maize has been associated to diffuse nitrate pollution of surface and groundwater. Cover crops grown during winter combined with reduced N fertilization to maize could reduce N leaching risks while maintaining maize productivity. A field experiment was conducted testing two different cover crop planting methods (direct seeding versus seeding after conventional tillage operations) and four different cover crops species (barley, oilseed rape, winter rape, and common vetch), and a control (bare soil). The experiment started in November 2006 after a maize crop fertilized with 300 kg N ha(-1) and included two complete cover crop-maize rotations. Maize was fertilized with 300 kg N ha(-1) at the control treatment, and this amount was reduced to 250 kg N ha(-1) in maize after a cover crop. Direct seeding of the cover crops allowed earlier planting dates than seeding after conventional tillage, producing greater cover crop biomass and N uptake of all species in the first year. In the following year, direct seeding did not increase cover crop biomass due to a poorer plant establishment. Barley produced more biomass than the other species but its N concentration was much lower than in the other cover crops, resulting in higher C:N ratio (> 26). Cover crops reduced the N leaching risks as soil N content in spring and at maize harvest was reduced compared to the control treatment. Maize yield was reduced by 4 Mg ha(-1) after barley in 2007 and by 1 Mg ha(-1) after barley and oilseed rape in 2008. The maize yield reduction was due to an N deficiency caused by insufficient N mineralization from the cover crops due to a high C:N ratio (barley) or low biomass N content (oilseed rape) and/or lack of synchronization with maize N uptake. Indirect chlorophyll measurements in maize leaves were useful to detect N deficiency in maize after cover crops. The use of vetch, winter rape and oilseed rape cover crops combined with a reduced N fertilization to maize was efficient for reducing N leaching risks while maintaining maize productivity. However, the reduction of maize yield after barley makes difficult its use as cover crop. (C) 2011 Elsevier B.V. All rights reserved.
  • Authors:
    • Prabhakaran, N. K.
    • Chinnusamy, C.
    • Sangeetha, C.
  • Source: Madras Agricultural Journal
  • Volume: 98
  • Issue: 4/6
  • Year: 2011
  • Summary: A study was carried out to evaluate the effect of early post emergence herbicide, imazethapyr against weeds in irrigated soybean (Glycine max (L.) Merill) at Agricultural Research Station, Bhavanisagar. Weeds, viz., Dactyloctenium aegypticum, Acrach ne racemosa, Cyperus rotundus, Boerhaavia diffusa, Digera arvensis, Parthenium hysterophorous were the dominant weeds in the experimental field. Imazethapyr at 100 and 200 g ha -1 applied on 15 DAS provided 87 to 91% weed control efficiency compared to unweeded control. However, imazethapyr at 200 g ha -1 had slight phytotoxicity on soybean in the initial stages. Higher grain yield of 1645 kg ha -1 was obtained with application of imazethapyr 100 g ha -1.
  • Authors:
    • Prasad, T. V. R.
    • Kumar, V. K. K.
    • Sanjay, M. T.
    • Gowda, P. T.
  • Source: Journal of Crop and Weed
  • Volume: 7
  • Issue: 1
  • Year: 2011
  • Summary: A field experiment was conducted during Kharif 2007 and summer 2008 on sandy loam soil of Hebbal, Bangalore, University of Agricultural Sciences, Bangalore, to know the comparative performance of tank mix application of chlorimuron ethyl (Kloben 25% WP)+quizalofop-p-terfuryl (Pantera 4% EC) on controlling weeds in soybean and seed yield Tank mix combination of chlorimuron ethyl 9 g+quizalofop-p-tefuryl 40 g ai/ha -20 DAS with surfactant (1598 kg/ha) or without surfactant (1518 kg/ha) gave seed yield similar to hand weeding twice (1720 kg/ha), as result of good control of grasses, broad leaf weeds and sedge. Unweeded control lowered the yield by 61% mainly due to severe competition offered by grasses. Thus, use of chlorimuron ethyl 9 g+quizalofop-p-terfuryl 40 g ai/ha+0.2% surfactant (as tank mix) at 20 DAS can be used safely for broad spectrum weed control in irrigated soybean.
  • Authors:
    • Munkhtsetseg, E.
    • Kimura, R.
    • Şaylan, L.
    • Kamichika, M.
  • Source: Theoretical and Applied Climatology
  • Volume: 105
  • Issue: 1/2
  • Year: 2011
  • Summary: In this study, variations in carbon dioxide (CO 2) fluxes resulting from gross primary production (GPP), net ecosystem exchange (NEE), and respiration ( Re) of soybean ( Glycine max L.) were investigated by the Eddy Covariance method during the growing period from June to November 2005 on an irrigated sand field at the Arid Land Research Center, Tottori University in Tottori, Japan. Although climatic conditions were humid and temperate, the soybeans required frequent irrigation because of the low water holding capacity of the sandy soil at the field site. Finally, it has been found that the accumulated NEE, GPP, and Re fluxes of soybean over 126 days amount to -93, 319, and 226 gC m -2, respectively. Furthermore, the average ratio of GPP to Re was 1.4 and the average ratio of NEE to GPP was about -0.29 for the growth period of soybean. Daily maximum NEE of -3.8 gC m -2 occurred when LAI was 1.1.
  • Authors:
    • Yano, K.
    • Araki, H.
    • Sekiya, N.
  • Source: Plant and Soil
  • Volume: 341
  • Issue: 1/2
  • Year: 2011
  • Summary: When a plant encounters spatially heterogeneous soil moisture within its root system, usually drier surface and moister subsurface soils, water can move between these layers through the root system, a plant process known as hydraulic lift or redistribution. The water thus transferred is available not only for the plant itself but also for its neighbors. We examined application of this process as a possible biological irrigation tool. As 'donors', we used perennial forage plants with their shoots removed to minimize the effect of light-interception by them on the 'receiver' plants growing alongside them. In a horizontally split-root experiment, where an upper container was filled with sand and a lower one with water, superior donor species could maintain the upper sand in a fully hydrated condition for several weeks, increasing stomatal conductance in the receivers. The effects were also confirmed in a water-limited agricultural field, as significant differences were found in canopy temperature and yield in neighboring crop plants in the presence or absence of donor root systems. These results suggest that deep-rooting associate plants with their shoots removed function as an irrigation tool and improve crop production in water-scarce environments.
  • Authors:
    • Miah, M. N. A.
    • Paul, G. C.
    • Siddique, M. A. B.
    • Amanullah, A. S. M.
  • Source: Pakistan Sugar Journal
  • Volume: 26
  • Issue: 3
  • Year: 2011
  • Summary: An experiment was conducted at Regional Sugarcane Research Station (RSRS). Thakurgaon during 2005-06 and 2006-07 cropping seasons to asses effects of different levels of irrigation and split application of N-K fertilizers in sugarcane (var. Isd 36) intercropped with potato (var. Diamond). The intercrop, potato received recommended fertilizer as usual. Application of Urea and Potash (N-K fertilizers) in two splits (B 1) produced highest number of tiller, millable cane and also highest yield in both levels of irrigation in both years. Though the difference was not significant over B 2 and B 3. But irrigation level A 1 (Six light irrigation with 65 mm effective rainfall) had significant difference over A 2 (five comparatively deep irrigation with same effective rainfall). Highest number of tiller (215.3*10 3 ha -1), millable cane (114.7*10 3 ha -1) and cane yield (109.9 t ha -1) were produced by the treatment B 1 under A 1 level of irrigation in the crop year 2006-07. Hence split application of N-K fertilizers with two equal splits applied at plantation and at 145 days after plantation and also light irrigation, 6 to 7 number with total amount of 460-500 mm including effective rainfall may be preferred for loamy and sandy loam soils.
  • Authors:
    • Jain, K.
    • Kudrat, M.
    • Singh, N. J.
    • Pandey, K.
  • Source: International Journal of Remote Sensing
  • Volume: 32
  • Issue: 16
  • Year: 2011
  • Summary: The cropping pattern (rotation) of a region depends on the soil, water availability, economic conditions and climatic factors. Remote sensing is one of the effective tools that can provide precise and up-to-date information on the performance of agricultural systems. Four seasons data from the Indian Remote Sensing Satellite (IRS)-P6 Advanced Wide Field Sensor (AWiFS) were used for the generation of the cropping pattern of Uttar Pradesh by geographic information system (GIS)-aided integration of digitally classified crop and land use inventories of the kharif, rabi and zaid crop seasons. Twelve different cropping patterns were delineated and mapped in the Indo-Gangetic plain of Uttar Pradesh. The forests covered about 6.32% of the total geographical area. The net cropped area was 20 282 159.46 ha (84.18% of the total geographical area) and the non-agricultural area observed was 3 437 376.00 ha (14.26% of the total geographical area). Rice was the single most dominant crop of the state, occupying about 32.94% of the total geographical area during the kharif season. Maize/jowar was the second major cereal crop, accounting for 13.77% of the total geographical area of the state. The major crops grown during the rabi season were wheat and pulses/oilseed, covering areas of 7 979 267.71 ha (33.12%) and 5 974 742.58 ha (24.80%), respectively. Rice-wheat, sugarcane and rice-pulses were the major cropping patterns, occupying about 3 958 739.85 ha (16.43%), 3 609 939.74 ha (14.98%) and 2 511 298.24 ha (10.42%), respectively. The areas under pulses/oilseed were significantly higher in the rabi season. Sugarcane-wheat and pulses shared an almost equal area (6.49%). The maize/jowar-wheat cropping pattern occupied 6.14% of the total geographical area of the state. Single cropping patterns (i.e. rice-fallow, fallow-pulses, fallow-wheat, maize-fallow and sugarcane-fallow) were minor, occupying 6.08, 2.94, 4.06, 2.69 and 2.51%, respectively. Waste land, including gulley, salt-affected, waterlogged and rock land, accounted for 3.80% of the total geographical area. The results of this study indicate that temporal IRS-P6 (AWiFS) data are very useful for studying spatial cropping patterns. The values of the Multiple Cropping Index (MCI) and the Cultivated Land Utilization Index (CLUI) show that the study area has a high cropping intensity.
  • Authors:
    • Smith, J. P.
    • Smith, M. K.
    • Stirling, G. R.
  • Source: Soil & Tillage Research
  • Volume: 114
  • Issue: 2
  • Year: 2011
  • Summary: Ginger (Zingiber officinale) production is facing increasing disease and pest pressure and declining yield with continuing intensive cultivation practices. A four year experiment was established in south-eastern Queensland on a red ferrosol that had a long (>60 years) history of ginger farming. Minimal tillage and organic amendments were compared with conventional practice that involved frequent tillage and soil fumigation using 1,3-dichloropropene (Telone (R)). Ginger crops were grown in the second and fourth year of the experiment, following an annual rotation with different cover crops including oats (Avena sativa), Brassica spp., soybean (Glycine max) and forage sorghum (Sorghum bicolour X S. sudanese). A pasture ley of Pangola grass (Digitaria eriantha subsp. pentzii) provided a treatment continuum from major to minor disruption in the soil's physical fertility and biological communities, and was therefore only planted to ginger in the fourth year of the experiment. Ginger seed-pieces (sections of the rhizome used for planting) were planted into both tilled and untilled beds using a double disc opener on a specially designed ginger planter. Rhizome yield in the final year was greatest (74.2 t/ha) and losses to pathogens (Pythium myriotylum and Fusarium oxysporum f. sp. zingiberi) minimal (7.0%) in the pasture ley that had been cultivated prior to planting ginger. Furthermore, the minimum-tilled cover cropped treatment, which likewise had been cultivated prior to planting ginger, yielded well (62.0 t/ha), with few losses (5.0%) from rhizome rots. Conversely the fumigated treatment had the highest losses (35.9%) due to Pythium Soft Rot and lowest yields (20.2 t/ha). Minimum-tilled plantings of ginger, however, resulted in poor yields (30.9-43.1 t/ha) but had acceptable levels of disease. (C) 2011 Elsevier B.V. All rights reserved.
  • Authors:
    • Hyde, J.
    • Mortensen, D. A.
    • Barbercheck, M. E.
    • Smith, R. G.
    • Hulting, A. G.
  • Source: Agronomy Journal
  • Volume: 103
  • Issue: 1
  • Year: 2011
  • Summary: In the mid-Atlantic region, the demand for organic dairy has provided incentives for farmers to transition their land to organic feed grain production. At the same time, interest in minimum-tillage organic production is growing. Two field experiments were conducted to assess the effects of a first year cover crop and tillage system on weed populations, cash crop yield, and net returns over the 3-yr transition period in a cover crop-soybean (Glycine max (L.) Merr.)-corn (Zea mays L.) feed grain rotation. The cover crop treatments were rye (Secale cereale L.)-hairy vetch (Vicia villosa Roth) (hereaft er RYE) and timothy (Phleum pratense L.)-red clover (Trifolium pratense L.) (hereaft er TIM). Tillage system treatments were moldboard plow (full tillage, FT) and chisel plow (minimum tillage, MT). Across both experiments, soybean yields ranged from 1190 to 3721 kg ha(-1). Corn grain yields were affected by tillage in the first experiment only, and were 59% higher in FT (9370 kg ha(-1)) compared to MT (5906 kg ha(-1)). Weed abundance was primarily affected by tillage, with densities in corn being 244% higher in MT compared to FT. Cumulative net returns in the first experiment were profit-generating in systems where TIM was the initial cover crop (mean = U.S. $ 317 ha(-1)). Mean cumulative net returns were positive in three of the four treatment combinations in the second experiment (U.S. $ 74-299 ha(-1)). Improved strategies for minimizing the costs associated with fertilization and management of weeds in minimal tillage will be necessary to improve the profitability and sustainability of reduced-tillage organic systems.
  • Authors:
    • Calin, L.
    • Taranu, I.
    • Tabuc, C.
  • Source: Archiva Zootechnica
  • Volume: 14
  • Issue: 4
  • Year: 2011
  • Summary: Fungal mycoflora and mycotoxin contamination were determined in 86 samples (21 maize, 21 wheat, 11 barley, 4 oats, 1 rye, 12 soya, 6 sunflower, 4 colza, 3 rice, 3 triticale), coming from the south-eastern part of Romania during the 2008 to 2010 period. The most frequent fungal contaminants belonged to the Aspergillus and Fusarium genera, maize was the most contaminated cereal. The main toxinogenic species identified were A. flavus, A. fumigatus, F. graminearum, F. culmorum in all cereals Aflatoxin B1 (AFB1), ochratoxin A (OTA), deoxynivalenol (DON), zearalenone (ZEA) and fumonisins (FUMO), contents were analyzed by ELISA. More than 90% of the samples were found to be contaminated by at least one toxin. The most frequent mycotoxin was the deoxynivalenol (71.60%). Around 40% of samples were contaminated with AFB1 and FB. Ochratoxine A and zearalenone were found in 16% and 32% of samples respectively. These results demonstrated that cereals produced in Romania present a particular pattern of fungal mycoflora and mycotoxin contamination since DON, ZEA and FUMO as well as AFB1 and OTA were observed.