• Authors:
    • Rosa Becker, A.
    • Camilo Bedano, J.
    • Dominguez, A.
  • Source: Soil & Tillage Research
  • Volume: 110
  • Issue: 1
  • Year: 2010
  • Summary: No-till (NT) has been recognized as a management system of low environmental impact when applied in combination with crop residue mulch and rotations involving cover crops. It has been suggested, however, that, if these conditions are not met, NT may result in physical, chemical and biological soil degradation. This study evaluates the effect of NT on the litter decomposition process and on soil macrofauna communities and how changes in soil physical, chemical, and physicochemical properties affect litter decomposition and soil macrofauna. We hypothesised (1) that macrofaunal abundance, richness and diversity would be lower in NT soils than in natural grasslands; (2) that this would be a consequence of unfavourable physical and chemical soil conditions and high inputs of agrochemicals; and (3) that these changes in macrofauna would influence soil functioning, reducing litter decomposition rate. The study was conducted during winter and spring 2007 on Typic Haplustolls from southern Cordoba, Argentina (32 degrees 41' and 32 degrees 50'S; 63 degrees 58' and 63 degrees 44'W). Macrofauna was sampled twice in NT and in natural grasslands (NA) - as a reference situation - by extracting five soil monoliths of 25 cm x 25 cm x 30 cm at each plot. Soil properties were measured using standard methods. The decomposition rate was determined by the litterbag method, using a 2 mm and a 10 mm size meshes to evaluate litter decomposition mediated by macrofauna. NT greatly reduced richness (from 33 species in NA to 12 species in NT) and abundance (from 1870 ind/m(2) in NA to 475 ind/m(2) in NT) of macroinvertebrates, confirming our first hypothesis. Changes in macrofauna community under NT were mainly explained by high compaction and low organic matter content, confirming our second hypothesis. The reduction in earthworm abundance may also be explained by the influence of the intense use of toxic agrochemicals. No-till increased surface horizon bulk density (from 1.22 to 1.33 g/cm(3)) and decreased organic matter content (from 3.51% to 2.58%) and pH (from 6.74 to 6.01) compared with NA. The litter decomposition rate was lower in NT, confirming our third hypothesis, and it was correlated with low earthworms abundance and activity. We conclude that in our study area the capacity of soils under NT to maintain ecosystem functions would be at risk. (C) 2010 Elsevier B.V. All rights reserved.
  • Authors:
    • Egli, D. B.
  • Source: Crop Science
  • Volume: 50
  • Issue: 5
  • Year: 2010
  • Summary: The number of pods and seeds produced by soybean [ Glycine max (L.) Merr.] is related to canopy photosynthesis during flowering. The effect of low photosynthesis during only a portion of flowering (growth stage R1 to R5), however, is not well defined. Two field experiments were conducted at Lexington, KY (38degreesN), with seeds sown in mid-May in 0.76-m rows (20 seeds m -1 of row) and all plots irrigated as needed. In 2005/2006, plants (cultivars Pennyrile and Ripley) were shaded (60% in 2005 and 80% in 2006) for 4- to 9-d periods just before or just after peak pod production. These treatments had almost no effect on seed number (significant reduction in only one of eight comparisons). In a second experiment (cv. Pennyrile, 2007/2008), shade cloth (60%) was placed over plants at growth stage R1.6 and removed at 7-d intervals. The first 7 d of shade did not affect seed number, but 14 d of shade ending at roughly growth stage R3.0 reduced seed number by 16% and longer periods caused proportionally larger reductions. When shade cloth (80%) was put in place at 7-d intervals (starting at R3.4) and left in place until maturity, seed number was reduced until the last treatment (put in place 4-7 d after the beginning of growth stage R6). Seed number was tolerant of short periods (4-9 d) of low assimilate supply during flowering, but could not recover from longer periods of shade (≥14 d), even when they occurred relatively early in the flowering period.
  • Authors:
    • Bayer, C.
    • Vieira, R. C. B.
    • Fontoura, S. M. V.
    • Ernani, P. R.
    • Moraes, R. P. de
  • Source: Revista Brasileira de Ciência do Solo
  • Volume: 34
  • Issue: 6
  • Year: 2010
  • Summary: Little is known about the agronomic effectiveness of phosphate rocks in high-yielding crop rotation systems under no-till in the Center-South of the state of Parana, Brazil. This field study was undertaken to compare the effectiveness of rock phosphates and soluble P fertilizers to increase the yield of several annual crops grown in two consecutive triennial crop-rotation cycles under no-tillage. The experiment was carried out in an Oxisol, in Guarapuava, PR, from 2000 until 2006. Two phosphate rocks (PR - Gafsa and Arad) and a soluble P fertilizer (TSP - triple superphosphate) were broadcast over the soil surface at rates of 0, 40, 80 and 160 kg ha -1 P 2O 5, at the beginning of the first and the second rotation cycle of the triennial crops (oat, maize, wheat, soybean, barley and soybean). With exception of barley, crop yields were not affected in the first rotation cycle by any phosphate fertilizer regardless of type and rate, probably due to the high P contents available in the soil (8.7 mg dm -3 in the 0-10 cm layer). In the second rotation cycle, when soil available P was 4.1 mg dm -3; P application at oat sowing increased the yield of summer crops by 11% and of winter crops by 20%. The yield increment was lowest for maize (8%) and highest for barley (44%). In this cycle, TSP resulted in higher yield than PR, though only for winter crops (oat, wheat and barley), in a mean of 11%, with no difference between Gafsa and Arad. Water soluble fertilizer (TSP) was more efficient than phosphate rocks in soils under no-till system both in the short and long term. Nevertheless, it is not necessary to apply phosphates for high yields in soils with high available P contents under no-till, except for species with high P requirement, e.g., barley.
  • Authors:
    • Fourie, J. C.
  • Source: South African Journal of Enology and Viticulture
  • Volume: 31
  • Issue: 1
  • Year: 2010
  • Summary: Eight cover crop treatments were applied for 12 consecutive years on a medium-textured soil in a vineyard near Robertson (33 degrees 50'S, 19 degrees 54'E). A treatment with full surface straw mulch and full surface post-emergence chemical control applied from just before grapevine bud break to harvest (BB), and one with no cover crop combined with BB, were also applied. The control consisted of mechanical control in the work row and post-emergence chemical control in the vine row applied from bud break to harvest. Rotating Triticale v. Usgen 18 (triticale) and Vicia dasycarpa Ten. (vetch) did not improve the dry matter production (DMP) of either species. Average DMP decreased as follows: triticale > Secale cereale L. v. Henog (rye)/Vicia faba L. v. Fiord (faba bean) mixture > triticale/vetch biennial rotation > triticale/vetch annual rotation > vetch. Triticale (BB) resulted in total winter weed suppression from 1995 to 1996 and from 2001 to 2004. Total weed control from bud break to the pea size berry stage of the grapevines was achieved with straw mulch (BB), triticale (BB), rye/faba bean mixture (BB) and triticale/vetch rotated biennially (BB) from 2001 to 2003. For triticale combined with full surface post-emergence chemical control applied from grapevine berry set (AB), and for triticale/vetch rotated annually (BB), this was restricted to 2001 and 2003. From the pea size berry stage to harvest, straw mulch (BB), triticale (BB), vetch (BB), rye/faba bean mixture (BB) and triticale (AB) reduced the weed stand significantly in comparison to the control.
  • Authors:
    • Zhang, J. P.
    • Sun, J. S.
    • Liu, Z. G.
    • Qiu, X. Q.
    • Duan, A. W.
    • Gao, Y.
    • Wang, H. Z.
  • Source: Agricultural Water Management
  • Volume: 98
  • Issue: 1
  • Year: 2010
  • Summary: In a field experiment in the Yellow River Basin conducted in 2007 and 2008, it was found that, under full irrigation, the roots of maize not only penetrated deeper than those of soybean but also extended into soybean stands underneath the space between inner rows of soybean. The roots of soybean, however, were confined mainly to the zone near the plants. Horizontal growth of the roots of both the crops was confined mainly to the soil layer 16-22 cm below the surface, a layer that lay above an existing plough pan. Root length density (RLD) was much higher in the top layer (0-30 cm deep) and in the zone closer to the plants. The exponential model proved suitable to describe the RLD vertically and horizontally in both sole cropping and in intercropping.
  • Authors:
    • Guerra, L. C.
    • Persson, T.
    • Garcia y Garcia, A.
    • Hoogenboom, G.
  • Source: Agricultural Water Management
  • Volume: 97
  • Issue: 7
  • Year: 2010
  • Summary: Studies on irrigation scheduling for soybean have demonstrated that avoiding irrigation during the vegetative growth stages could result in yields as high as those obtained if the crop was fully irrigated during the entire growing season. This could ultimately also lead to an improvement of the irrigation water use efficiency. The objective of this study was to determine the effect of different irrigation regimes (IRs) on growth and yield of four soybean genotypes and to determine their irrigation water use efficiency. A field experiment consisting of three IR using a lateral move sprinkler system and four soybean genotypes was conducted at the Bledsoe Research Farm of The University of Georgia, USA. The irrigation treatments consisted of full season irrigated (FSI), start irrigation at flowering (SIF), and rainfed (RFD); the soybean genotypes represented maturity groups (MGs) V, VI, VII, and VIII. A completely randomized block design in a split-plot array with four replicates was used with IR as the main treatment and the soybean MGs as the sub-treatment. Weather variables and soil moisture were recorded with an automatic weather station located nearby, while rainfall and irrigation amounts were recorded with rain gauges located in the experimental field. Samplings for growth analysis of the plant and its components as well as leaf area index (LAI) and canopy height were obtained every 12 days. The irrigation water use efficiency ( IWUE) or ratio of the difference between irrigated and rainfed yield to the amount of irrigation water applied was estimated. The results showed significant differences ( P
  • Authors:
    • Radmann, E. B.
    • Casagrande Junior, J. G.
    • Carpena Carvalho, F. L.
    • Gomes, C. B.
  • Source: Revista Brasileira de Fruticultura
  • Volume: 32
  • Issue: 1
  • Year: 2010
  • Summary: In a field naturally infested with ring nematode (Mesocriconema xenoplax), green covering were tested for their suppressing potential in winter and summer crops comparing to plots kept in fallow lands. Tree crop rotation system with the same plant species tested before (black oat/pig bean/millet/forage radish; forage radish/millet/white oat/corn; and white oat/dwarf velvet bean/wheat/sorghum) were evaluated for suppression potential to nematode M xenoplax for two years, using as control, plots that were kept in fallow lands. The experiments were conducted in the field in a randomized block design with six repetitions. Before and after the establishment of each plot, the nematode populations were evaluated on the number of M xenoplax/100cm3 of soil and the reproduction factor (RF=final population/initial population) of the ring nematode, where RF1,00, favoring of the reproduction. Most of the crops analyzed were unfavorable host (RF
  • Authors:
    • Verma, R. P. S.
    • Sharma, R. K.
  • Source: Cereal Research Communications
  • Volume: 38
  • Issue: 3
  • Year: 2010
  • Summary: A study was undertaken at the Directorate of Wheat Research experimental station, Karnal, India, to evaluate the effect of nitrogen (30, 60 and 90 kg/ha) and irrigation (one, two and three) on yield and grain quality traits of two and six row type malt barley genotypes. The mean grain yield significantly increased from 41.9 to 45.8 q/ha with increase in nitrogen dose from 30 to 90 kg/ha and 41.8 to 45.9 q/ha with increase in irrigations from one to three. The two and six row barleys had almost similar yield potential at higher nitrogen application and irrigation frequency but the six-row type had advantage at lower nitrogen and irrigation. Varietal effects were significant for all the traits, while N significantly affected only grain yield, spikes per unit area, 1000-grain weight and husk content. Irrigation effects were significant for bulk density, grain yield, spikes per unit area, and grains per spike. Traits like grain bulk density, proportion of bold and thin grains and husk content are mainly affected by variety and less affected by management practices.
  • Authors:
    • Singh, B. K.
    • Singh, D. K.
    • Yadav, V. P. S.
    • Singh, L.
  • Source: Indian Research Journal of Extension Education
  • Volume: 10
  • Issue: 3
  • Year: 2010
  • Summary: The cultivation of vegetables, which is done mainly for economic gain or for marketing purpose, is known as Commercial Vegetable Cultivation. India is one of the largest producer of raw materials for the food processing industries in the world (only 2%). The value addition in food sector is as low as 7 percent and will go up to 35 percent. There is need for increasing food processing from 2 percent to 10 percent by 2010 which will be reflected, in the corresponding increase in Gross National Product. Vegetable cultivation has great potentiality and scope for improving socio-economic condition of small and marginal farmers since it provides higher yield and high economic return in short time as compared to food grains. It is an indispensable part of balanced diet and according to Indian Council of Medical Research recommendation; average person should consume nearly 300 g of vegetable daily. Growing of vegetables is 4 to 8 times more remunerative than cereals and it also generate employment in the rural areas. Commercial vegetable cultivation is not getting as popular as it should be among growers because of high input costs, lack of irrigation facilities and difficulties in their marketing and storage. It is estimated that by 2010 country's vegetable demand would be around 135 million tonnes. There is an urgent need to increase the productivity of vegetable in order to provide nutritional security to increasing population of India. Uttar Pradesh is second largest producer state of vegetable. Due to its proximity to National Capital Territory of Delhi, Ghaziabad has a great potential for commercial vegetable cultivation. Hence, the study was carried out in eight blocks of this district. In this study adoption level refers to the level of adoption of recommended cultivation practices of cabbage by the respondents. Fifteen recommended practices included in the package of practices in vegetable cultivation were used for measuring this adoption. The findings of this study highlighted that about 85 percent of the vegetable growers had low or medium adoption of commercial cabbage cultivation practices meaning there by medium adopters were more energetic, knowledgeable, dynamic and having more interest in adopting modern vegetable technologies.
  • Authors:
    • Thenua, O. V. S.
    • Sharma, U. C.
    • Abraham, T.
    • Shivakumar, B. G.
  • Source: The Indian Journal of Agricultural Sciences
  • Volume: 80
  • Issue: 5
  • Year: 2010
  • Summary: A field experiment was conducted during winter ( rabi) season of 2005-06 and 2006-07 in the Agronomy Research Farm of Amar Singh College, Lakhaoti, Uttar Pradesh to study the effect of levels of irrigation and fertility on chickpea ( Cicer arietinum L.) and mustard ( Brassica juncea L. czernj & coss.) in sole and intercropping systems. The experiment was conducted in split-plot design with 3 replications. The combination of treatments consisted of 3 cropping systems, namely sole mustard (C 1), sole chickpea (C 2) and chickpea+mustard intercropping (C 3) (4:1 raw ratio) and 4 irrigation levels [no irrigation (I 0), irrigation at pre-flowering (I 1), at pod formation (I 2) at both pre-flowering and pod formation (I 3)] for chickpea allotted to main plots and 3 fertility levels [F 1 (20:40:10 kg N, P 2O 5 and S/ha) F 2 (40:60:20 kg N, P 2O 5 and S/ha) and F 3 recommended dose of fertilisers (RDF)] for both the crops on row length basis to sub-plots. The sole Indian mustard recorded higher seed yield compared to intercropping. The yield reduction in mustard was to the tune of 58.9% and 60.0% in the first and second year, respectively, due to intercropping chickpea. Irrigation, on an average increased the mustard yield by 6.47% (I 1), 12.18% (I 2) and 13.18% (I 3) compared to no irrigation (I 0). Similarly fertilizer treatments F 2 and F 3 on an average increased mustard yield by 10.17% and 18.46%, respectively, over the F 1. The intercropping of chickpea and mustard in 4:1 raw ratio was significantly superior to sole crops of either chickpea or mustard in terms of yield and economics. Between the sole crops, chickpea was better as compared to mustard. Application of recommended dose of fertilizers (20:60:20 kg, N, P 2O 5 and S/ha) on area basis was superior.