• Authors:
    • Sarpe,N.
    • Poienaru,S.
  • Source: Lucrari Stiintifice, Universitatea de Stiinte Agricole Si Medicina Veterinara "Ion Ionescu de la Brad" Iasi, Seria Agronomie, Romania
  • Volume: 48
  • Year: 2005
  • Summary: Results are presented of an experiment in the Plain of Danube (Romania) with genetically modified soyabean (0094RR) in successive culture after barley under no-stripping system. Roundup Ready (containing 360 g glyphosate/l) was used to control grassy weeds, including Sorghum halepense. Roundup Ready at 3+3 l/ha resulted in 100% control of annual and perennial grasses. It also recorded the highest yield of 2800 kg/ha under 2 irrigations with a watering rate of 400 m 3/ha. With barley culture+soyabean in successive culture on the traditional system, 122 l of fuel oil was consumed for mechanical work, whereas on the system of no-stripping only 48 l/ha. Calculations concerning economic efficiency revealed that barley culture+soyabean in successive culture recorded a profit of ~28 million lei/ha.
  • Authors:
    • Arshad, M.
    • Soon, Y.
  • Source: Soil & Tillage Research
  • Volume: 80
  • Issue: 1/2
  • Year: 2005
  • Summary: Limited information is available on soil management effects on crop production and nitrogen (N) cycling in acid soils. The effects of conventional tillage (CT) versus no-till (NT) and liming (0 versus 7.5 Mg ha -1), and their interaction, on labile N pools in an acid soil were evaluated during the 7th to 10th year of a 3-course small grain rotation. Crop production and N uptake, N 2 fixation by pea ( Pisum sativum L.), and labile soil N were determined. Liming increased the pH from 5.3 to 6.0 in the top 10 cm of soil and had no influence below 10 cm depth. No-till increased average crop yield and N uptake by 12 and 14%, respectively, compared to CT. The corresponding increases due to lime application were 13 and 20%. There was no treatment effect on N concentrations in plant tissues (probably because of adequate N fertilizer application), or on N 2 fixation in pea. The percent N derived from the atmosphere varied from 12% in one dry year to 68% in a moister year. Soil NO 3 in spring and autumn was significantly higher where the preceding crop was field pea, particularly in the surface soil layer. Soil inorganic N was little influenced by tillage and liming. In contrast, soil microbial biomass N concentration was consistently greater with liming than without (30-64% difference) and with NT than with CT (7-36% difference), but little affected by crop sequence. Liming enhanced the positive effect of NT on soil microbial biomass N. Crop total N uptake was significantly correlated with microbial biomass N ( r=0.69* for barley ( Hordeum vulgare L.), and 0.70** for canola ( Brassica rapa L.)). Liming with NT can be effective in increasing N turnover and crop growth in acid soils.
  • Authors:
    • Arshad, M.
    • Klein-Gebbinck, H.
    • Soon, Y.
  • Source: Canadian Journal of Plant Science
  • Volume: 85
  • Issue: 1
  • Year: 2005
  • Summary: Brown girdling root rot (BGRR) is a serious and widespread disease of canola ( Brassica rapa L.) in the Peace River region of northwestern Canada. There is no chemical control treatment for the pathogen, and farmers have observed that the disease is more severe when canola follows red fescue ( Festuca rubra L.) or clover ( Trifolium spp.) compared to summer fallow. A field study was conducted to determine how crop sequences following red fescue termination can be combined with residue and tillage management to reduce BGRR infection and increase canola yield. The five treatments consisted of rotations of: continuous canola (CCC) and oat ( Avena sativa L.)-oat-canola (OOC), both managed using reduced tillage (RT), and wheat ( Triticum aestivum L.)-wheat-canola (WWC), managed using RT, conventional tillage (CT) or no-till (NT). Canola yield followed the trend: OOC(RT)=WWC(RT) > WWC(CT) > CCC(RT)=WWC(NT). BGRR infection increased with tillage intensity: WWC(CT) > CCC(RT)=WWC(RT)=OOC(RT) > WWC(NT), and was reduced when canola followed two cereal break crops. Yield was highest when canola was preceded by a cereal crop and lowest without a break crop. The low yield with NT was attributed to poor crop emergence from a hard seed bed with unbroken turf and to competition from re-emerged fescue in the third year after fescue breaking. This study demonstrated that the cropping sequence and tillage system used influenced canola yield to a greater extent than did BGRR infection.
  • Authors:
    • Quine, T. A.
    • Djurhuus, J.
    • Heckrath, G.
    • Van Oost, K.
    • Govers, G.
    • Zhang, Y.
  • Source: Journal of Environmental Quality
  • Volume: 34
  • Issue: 1
  • Year: 2005
  • Summary: Tillage erosion had been identified as a major process of soil redistribution on sloping arable land. The objectives of our study were to investigate the extent of tillage erosion and its effect on soil quality and productivity under Danish conditions. Soil samples were collected to a 0.45-m depth on a regular grid from a 1.9-ha site and analyzed for Cs-137 inventories, as a measure of soil redistribution, soil texture, soil organic carbon (SOC) contents, and phosphorus (P) contents. Grain yield was determined at the same sampling points. Substantial soil redistribution had occurred during the past decades, mainly due to tillage. Average tillage erosion rates of 2.7 kg m(-2) yr(-1) occurred on the shoulderslopes, while deposition amounted to 1.2 kg m(-2) yr(-1) on foot- and toeslopes. The pattern of soil redistribution could not be explained by water erosion. Soil organic carbon and P contents in soil profiles increased from the shoulder- toward the toeslopes. Tillage translocation rates were strongly correlated with SOC contents, A-horizon depth, and P contents. Thus, tillage erosion had led to truncated soils on shoulderslopes and deep, colluvial soils on the foot- and toeslopes, substantially affecting within-field variability of soil properties. We concluded that tillage erosion has important implications for SOC dynamics on hummocky land and increases the risk for nutrient losses by overland flow and leaching. Despite the occurrence of deep soils across the study area, evidence suggested that crop productivity was affected by tillage-induced soil redistribution. However, tillage erosion effects on crop yield were confounded by topography-yield relationships.
  • Authors:
    • Clayton, G. W.
    • Harker, K. N.
    • Blackshaw, R. E.
    • O'Donovan, J.
    • Maurice, D. C.
  • Source: Canadian Journal of Plant Science
  • Volume: 85
  • Issue: 4
  • Year: 2005
  • Summary: Various regression equations based on weed density alone, or relative time of weed and crop emergence or crop density in addition to weed density have been developed in western Canada to estimate the effects of wild oat (Avena fatua L.) and volunteer cereals on yield loss of field crops, and to advise farmers on the economics of weed control with herbicides. In 1997, 1998, and 1999, several of these equations were evaluated in 9 barley (Hordeum vulgare L.), 9 wheat (Triticum aestivum L.) and 11 canola (Brassica napus L.) fields in Alberta. Wild oat was the dominant weed in the barley and wheat fields, and wild oat or volunteer cereals in the canola fields. In barley and wheat, more complex equations based on both weed density and either crop density or relative time of weed and crop emergence were more reliable in estimating yield losses due to wild oat than those based on weed density alone. In canola, an equation based on volunteer barley and canola density provided the most reliable estimates. Under the assumed crop prices and herbicide costs, these equations also resulted in the best estimates of whether or not a herbicide application resulted in a net profit or loss. Herbicide application was rarely economical in barley, but usually economical in wheat and canola reflecting the different market value of the crops. The implementation of the weed economic threshold concept is likely to be more feasible in low-value crops such as feed barley than in higher-value crops such as canola.
  • Authors:
    • Turkington, T. K.
    • Johnston, A. M.
    • Harker, K. N.
    • Clayton, G. W.
    • O'Donovan, J. T.
    • Kutcher, H. R.
    • Stevenson, F. C.
  • Source: Canadian Journal of Plant Science
  • Volume: 85
  • Issue: 1
  • Year: 2005
  • Summary: A field experiment was conducted at Lacombe and Beaverlodge, AB, and Melfort, SK, in 1999 and 2000 to evaluate the effect of seed placement and herbicide application timing on productivity of a general purpose (AC Lacombe) and hull-less (Falcon) barley (Hordeum vulgare L.) cultivars. Barley plant density was often less and dockage greater when seed was spread in a 20-cm band with 28-cm sweeps spaced 23 cm apart compared to seeding in distinct rows with hoe openers spaced 23 or 30 cm apart. Method of seed placement had little effect on barley grain yield or yield was significantly lower with the sweep compared to the distinct rows. Herbicide application timing effects were variable for barley grain yield. Grain yield was often greater and dockage less when herbicides were applied at the one- to two- or three- to four-leaf stage of barley compared to the five- to six-leaf stage. Method of seed placement did not influence barley responses to time of herbicide application with either cultivar. Barley silage yield was mainly higher with the distinct 23-cm row spacing than with the other seed placement methods. Herbicide application timing did not affect silage yield.
  • Authors:
    • Alakukku, L.
    • Pietola, L.
  • Source: Agriculture, Ecosystems & Environment
  • Volume: 108
  • Issue: 2
  • Year: 2005
  • Summary: Roots are an important sink for photoassimilates and carbon input to soil. Here the root growth and biomass of different spring sown annuals was determined to estimate the shoot:root (S:R) ratios and carbon inputs in the typical Nordic agroecosystem. The data, collected in southern Finland, present evidence for large difference in root growth dynamics and biomass input between spring oilseed rape (Brassica rapa L) and annual ryegrass (Lolium multiflorum Lam. var. italicum) whereas the rooting of spring sown barley (Hordeum vulgare) and oats (Avena sativa) was related. The four crops were sown at the same time in a field with a fine sand soil (Eutric Cambisol) with good nutrient and water supply. During one growing season, root growth was determined 12 times to a soil depth of 50 cm by using a minirhizotron-micro-video camera technology. At anthesis, root biomass and morphological parameters were measured to 60 cm soil depth at 5 cm intervals, with destructive soil sampling and image analysis of washed roots. The root growth rate of oilseed rape was clearly faster and that of rye grass slower compared with the other crops. At anthesis, the average total root dry biomass (0-60 cm) was 160 g for barley, 260 g for oats, 340 g for ryegrass, and 110 g m(-3) for oilseed rape. Also, the root length density and surface area of oilseed rape was less than that of other crops. Most of the biomass (59-80%) was accumulated the upper 20 cm of the soil. Shoot to root ratios (at anthesis for the seed crops) of 7.1, 4.4, 4.2 and 2.5 for barley, oats, oilseed rape, and ryegrass respectively, could be used for an approximation to estimate the amount of root biomass left in the 0-60 cm soil layer under Nordic long day conditions. In contrast to the seed crops, the root growth rate and density of ryegrass was high in the late season. Thus, ryegrass would be an efficient catch crop after harvest of cereals. (c) 2005 Elsevier B.V. All rights reserved.
  • Authors:
    • Mattsson, L.
    • Andren, O.
    • Roing, K.
  • Source: Acta Agriculturae Scandinavica Section B, Soil and Plant Science
  • Volume: 55
  • Issue: 1
  • Year: 2005
  • Summary: Estimates of soil N mineralization capacity and the factors that control the rates are necessary for optimal N management. Long-term field experiments can be used to measure how different management options affect the amount and quality of soil organic matter (SOM) - the substrate for N mineralization. Net N mineralization was estimated in a pot experiment as N uptake by ryegrass ( Lolium perenne) grown in pots with soils from 30 Swedish long-term field fertility experimental treatments ( 16 - 40 years). The long-term management effects of cereal and ley rotations, crop residue removal and return and inorganic N application on ryegrass N uptake were investigated and related to soil organic carbon (SOC) content. Total plant N uptake during three months varied between 9 and 27 mg N kg(-1) ( 23 - 67 kg N ha(-1)) and increased with SOC concentration and previous application levels of inorganic N. Soil from crop rotations with ley mineralized about 50% more N than soil from crop rotations with only cereals. Plant N uptake and SOC were not significantly affected by crop residue return.
  • Authors:
    • Gyuricza, C.
    • Bencsik, K.
    • Ujj, A.
    • Singh, M. K.
  • Source: Cereal Research Communications
  • Volume: 33
  • Issue: 1
  • Year: 2005
  • Authors:
    • Sturny, W. G.
    • Ramseier, L.
    • Chervet, A.
    • Tschannen, S.
  • Source: Revue Suisse d'Agriculture
  • Volume: 12
  • Issue: 5
  • Year: 2005
  • Summary: Over the last ten years, conventional plough tillage has been compared to no-tillage on six crop rotation plots in the long-term field trial Oberacker at the Inforama Ruetti in Zollikofen, Switzerland. The deep cambisol of the trial plots contains 15% clay and 3% organic matter. The absence of tillage operations in no-tillage makes a more complex strategy for weed control necessary. Options such as a balanced crop rotation, permanent soil cover, adapted crop residue management and immediate seeding of subsequent crops are used alongside chemical, mechanical, and thermal strategies of weed control. Land use is sustainable in the no-tillage system: No-tilled soil has a higher structural stability and load capacity while being markedly less prone to erosion; less machine usage and traffic reduce (fuel) costs. After seven years of no-tillage, continuous release of soil-borne nitrogen leads to crop yields and qualities at least equal to those obtained with conventional tillage. Two challenges remain only partly solved: (a) the greater dependence on herbicides such as glyphosate and (b) the greater risk of mycotoxin formation in no-tilled winter cereal crops that follow maize. Remedies include adaptations of the crop rotation, chopping of residual maize straw/stalks and cropping of cereal varieties less susceptible to fusarium. In conclusion, no-tillage contributes substantially to maintaining soil fertility on a long-term basis.