• Authors:
    • Tourdonnet, S. D.
    • Carof, M.
    • Coquet, Y.
    • Hallaire, V.
    • Roger-Estrade, J.
  • Source: Soil Use and Management
  • Volume: 23
  • Issue: 3
  • Year: 2007
  • Summary: We studied soil hydraulic conductivity (K) and porosity in five combinations of soil tillage and cover crop management systems. Treatments were winter wheat (Triticum aestivum L.) grown on a conventionally tilled soil (CT), on a no-till soil (NT), and on an NT with three different cover crops: red fescue (Festuca rubra L.; Fr), bird's-foot-trefoil (Lotus corniculatus L.; Lc) and alfalfa (Medicago sativa L.; Ms). Measurements were made on a loamy soil in Grignon, France, in November 2004, May 2005 and October 2005. K and mean size of hydraulically active pores were measured in situ at three water potentials (22120.6, 22120.2 and 22120.05 kPa) at the soil surface and at 10 cm depth. In November 2004 and May 2005, pore space was described using 2D image analysis of pores on undisturbed soil samples in the 0201310 cm layer and in the 10201320 cm layer. The major differences were caused by soil tillage that created two heterogeneous soil layers and increased K in the 0201310 cm layer relative to NT. The effects of cover crop on K and porosity were not affected by the root type: there were no major differences between the grass cover crop (fibrous-root type) and the leguminous ones (tap-root type). However, we recorded larger functional pores and more tubules in the no-till treatments with a cover crop, compared with the no-till treatment without cover crop; this was probably the result of root activity. Although these changes generally did not result in larger values of K, they participated in the maintenance of soil structure and K over time.
  • Authors:
    • Valizadeh, M.
    • Ghassemi-Golezani, K.
    • Abdulrahmani, B.
    • Asl, V.
  • Source: Journal of Food Agriculture & Environment
  • Volume: 5
  • Issue: 3/4
  • Year: 2007
  • Summary: This research was designed to compare the effects of hydropriming, osmopriming (10% PEG, 20% PEG, 2.5 mM CaCl 2 and 5 mM CaCl 2) and nutrient priming (in ZnSO 4 solutions with 10, 50 and 100 mM Zn, in KH 2PO 4 with 10, 50 and 100 mM P together with their combinations) on seedling vigor of barley. Laboratory tests were conducted as CR design and field experiment was carried out as RCB design at Dryland Agricultural Research Institute (DARI) in Iran. Analysis of variance of laboratory data showed that all traits such as percentages of viable seeds and germination, electrical conductivity (EC) of seed leachates, germination rate, root and shoot dry weight and seedling dry weight were significantly affected by seed priming. Nutrient priming in P solutions was superior, compared to other priming technics. This priming media improved root and shoot dry weight by 25 and 12.5% over unprimed seeds, respectively. The superior treatments in laboratory including hydropriming, 10% PEG, 5 mM CaCl 2, 10 mM Zn, 50 mM P, 100 mM P, 10 mM Zn+50 mM P and 10 mM Zn+100 mM P solutions were applied on seeds which subsequently sown in the field. Priming treatments had significant (p≤0.05) effects on mean seedling emergence percentage and rate in the field. Maximum seedling emergence percentage and rate were achieved with 100 mM P and 10 mM Zn+100 mM P primings, respectively. Therefore, these priming techniques could be used to improve seedling establishment of barley in the field.
  • Authors:
    • Surek, D.
    • Karacam, M.
    • Meyvec, K.
    • Akar, T.
    • Avc, M.
  • Source: Wheat production in stressed environments. Proceedings of the 7th International Wheat Conference, Mar del Plata, Argentina, 27 November - 2 December, 2005
  • Year: 2007
  • Summary: Because most of the dryland cereal varieties were improved under fallow/cereal rotation system, their performances in other cropping systems were questionable and reported unsatisfactory by some farmers. Therefore, the objective of this study was to investigate the performances and adaptation of newly registered varieties in different two course rotations for targeted recommendations. 12 cereal varieties were tried on 9 different 23-year-crop rotations plots for three consecutive years, 1999/2000, 2000/2001, 2001/2002. The varieties were 4 barley (malting two rowed Aydanhanm, and feeding Tarm and six rowed Cetin and Avci), 4 durum wheat (Altn, Ankara, Altntas, and Ylmaz), and 4 bread (Dagdas, Gun, Krgz and Mzrak) wheat. The cereal varieties were rotated with fallow, wheat, winter vetch, winter lentil, sunflower, safflower, lentil, chickpea and barley/vetch mixture. Grain and biomass yields, plant height, harvest index, kernel per spike, kernel weight and spike number per square meter were traits determined. Biplot analysis showed that responses of cereal varieties varied in dry (2001), wet and cold (2000) and normal (2003) seasons. Overall evaluations of responses indicated that some varieties adapted more to certain rotations than other varieties such as Aydanhanm for Safflower/cereal rotation. There was a general tendency that Tarm and Gun varieties performed well in winter cold and dry seasons in all rotations. Dagdas yielded pretty well following winter legumes and winter legume/cereal mixture except dry season. Six rowed barleys, Altntas and Ylmaz, were better in mild winter season in all rotations. Traits correlations indicated that spike number per square meter was always positively correlated with grain yields for all experimental seasons. While all yield components had positive contribution to the grain yields in wet season, kernel weight and kernel per spike had negative contribution to grain yields in the dry season. General evaluation showed that cereals succeeding chickpea and spring lentil crops were leading in terms of height, biomass, harvest index and grain yields, except cereals following fallow which were exceptionally superior in dry season. They also had higher kernel weight in dry and normal seasons.
  • Authors:
    • Lemke, R.
    • Malhi, S.
  • Source: Soil & Tillage Research
  • Volume: 96
  • Issue: 1/2
  • Year: 2007
  • Summary: An 8-yr (1998-2005) field experiment was conducted on a Gray Luvisol (Boralf) soil near Star City, Saskatchewan, Canada, to determine the effects of tillage (no-tillage - NT and conventional tillage - CT), straw management (straw retained - R and straw not retained - NR) and N fertilizer (0, 40, 80 and 120 kg N ha -1, except no N to pea ( Pisum sativum L.) phase of the rotation) on seed and straw yield, mass of N and C in crop, organic C and N, inorganic N and aggregation in soil, and nitrous oxide (N 2O) emissions for a second 4-yr rotation cycle (2002-2005). The plots were seeded to barley ( Hordeum vulgare L.) in 2002, pea in 2003, wheat ( Triticum aestivum L.) in 2004 and canola ( Brassica napus L.) in 2005. Seed, straw and chaff yield, root mass, and mass of N and C in crop increased with increasing N rate for barley in 2002, wheat in 2004 and canola in 2005. No-till produced greater seed (by 51%), straw (23%) and chaff (13%) yield of barley than CT in 2002, but seed yield for wheat in 2004, and seed and straw yield for canola in 2005 were greater under CT than NT. Straw retention increased seed (by 62%), straw (by 43%) and chaff (by 12%) yield, and root mass (by 11%) compared to straw removal for barley in 2002, wheat in 2004, and seed and straw yield for pea in 2003. No-till resulted in greater mass of N in seed, and mass of C in seed, straw, chaff and root than CT for barley in 2002, but mass of N and C were greater under CT than NT for wheat in 2004 and for canola in 2005 in many cases. Straw retention had greater mass of N and C in seed, straw, chaff and root in most cases compared to straw removal for barley in 2002, pea in 2003 and wheat in 2004. Soil moisture content in spring was higher under NT than CT and with R than NR in the 0-15 cm depth, with the highest moisture content in the NT + R treatment in many cases. After eight crop seasons, tillage and straw management had no effect on total organic C (TOC) and N (TON) in the 0-15 cm soil, but light fraction organic C (LFOC) and N (LFON), respectively, were greater by 1.275 Mg C ha -1 and 0.031 Mg N ha -1 with R than NR, and also greater by 0.563 Mg C ha -1 and 0.044 Mg N ha -1 under NT than CT. There was no effect of tillage, straw and N fertilization on the NH 4-N in soil in most cases, but R treatment had higher NO 3-N concentration in the 0-15 cm soil than NR. The NO 3-N concentration in the 0-15, 15-30 and 30-60 cm soil layers increased (though small) with increasing N rate. The R treatment had 6.7% lower proportion of fine (38.0 mm) dry aggregates, and 4.5 mm larger mean weight diameter (MWD) compared to NR treatment. This suggests a lower potential for soil erosion when crop residues are retained. There was no beneficial effect of elimination of tillage on soil aggregation. The amount of N lost as N 2O was higher from N-fertilized (580 g N ha -1) than from zero-N (155 g N ha -1) plots, and also higher in CT (398 g N ha -1) than NT (340 g N ha -1) in some cases. In conclusion, retaining crop residues along with no-tillage improved some soil properties and may also be better for the environment and the sustainability of high crop production. Nitrogen fertilization improved crop production and some soil quality attributes, but also increased the potential for NO 3-N leaching and N 2O-N emissions, especially when applied in excess of crop requirements.
  • Authors:
    • Gracia, R.
    • Lopez, M.
    • Arrue, J.
    • Moret, D.
  • Source: European Journal of Agronomy
  • Volume: 26
  • Issue: 1
  • Year: 2007
  • Summary: Winter barley is the major crop on semiarid drylands in central Aragon (NE Spain). In this study we compared, under both continuous cropping (BC) (5-6-month fallow) and a crop-fallow rotation (BF) (16-18-month fallow), the effects of three fallow management treatments (conventional tillage, CT; reduced tillage, RT; no-tillage, NT) on the growth, yield and water use efficiency (WUE) of winter barley during three consecutive growing seasons in the 1999-2002 period. Daily precipitation measurements and monthly measurements of soil water storage to a depth of 0.7 m were used to calculate crop water use (ET) and its components. The average growing season precipitation was 195 mm. Above-ground dry matter (DM) and corresponding WUE were high in years with high effective rainfalls (>10 mm day -1) either in autumn or spring. However, the highest values of WUE for grain yield were mainly produced by effective rainfalls during the time from stem elongation to harvest. Despite the similarity in ET for the three tillage treatments, NT provided the lowest DM production, corresponding to a higher soil water loss by evaporation and lower crop transpiration ( T), indicated by the lowest T/ET ratio values found under this treatment. No clear differences in crop yield were observed among the tillage treatments in the study period. On average, and regardless of the type of tillage, BF provided the highest values of DM and WUE and yielded 49% more grain than BC. These differences between cropping systems increased when water-limiting conditions occurred in the early stages of crop growth, probably due to the additional soil water storage under BF at sowing. Although no significant differences in precipitation use efficiency (PUE) were observed between BC and BF, PUE was higher under the BC system, which yielded 34% more grain than the BF rotation when yields were adjusted to an annual basis including the length of the fallow. The crop yield under BF was not dependent on the increase in soil water storage at the end of the long fallow. In conclusion, this study has shown that, although conventional tillage can be substituted by reduced or no-tillage systems for fallow management in semiarid dryland cereal production areas in central Aragon, the practice of long-fallowing to increase the cereal crop yields is not longer sustainable.
  • Authors:
    • Salagean, D.
    • Oprea, G.
    • Pacurar, I.
  • Source: Analele Institutului National de Cercetare-Dezvoltare Agricola Fundulea
  • Volume: 75
  • Year: 2007
  • Summary: During 50 years (1957-2007), as part of NARDI Fundulea, Romania, studies and research on producing high quality seed, in small grains were performed. These investigations had as aim to improve the methodology and technology used in winter wheat and barley seed multiplication. Research regarding the variability of some traits in winter wheat and barley varieties during different periods, allowed their morphological and physiological characterization useful to maintain initial biological value of varieties during seed multiplication. Based on these studies, the seed multiplication schedule in small grains was established. Study regarding the influence of different seed biological categories on yielding capacity emphasized the fact that, during their multiplication, there is a slightly descendant tendency of this ability, but the yield diminutions became significant starting with the fourth multiplication of basic seed. The wheat crop fertilization under dryland and irrigation, with different nitrogen and phosphorus fertilizers demonstrated that, under both conditions, the application of some optimum rates favourably influenced the obtainment of seeds which lead to the yield increasing in the first year vs. fertilization with reduced rates. Harvesting of wheat and barley seed trials in three different stages (wax ripeness, full maturity and overmaturation) emphasized the fact that, the harvesting in optimum time (about 15% seed moisture) ensures the highest seed yields with superior quality indices. Study regarding the increasing of seed multiplication coefficient of new wheat and barley varieties to rapidly extend them into production emphasized the fact that, by using some reduced seed rates at sowing (about 25% of optimum seed rate), in the first two years after their registration, the seed multiplication coefficient increases from 1:20 to 1:80, four times respectively. Thus, the time for their extension into production could be reduced with two years minimum, with favourable economical effects.
  • Authors:
    • Azarnivand, H.
    • Jafari, M.
    • Sharifani, F.
    • Abbasi, H.
    • Sori, M.
  • Source: Iranian Journal of Range and Desert Research
  • Volume: 13
  • Issue: 4
  • Year: 2007
  • Summary: The effects of plant growth on soil quality in the Sagzi plain of Isfahan (Iran) were determined to evaluate the influence of agriculture on the desertification processes in dry lands. Inappropriate crop management significantly affected soil and water salinization which is one of the important processes of desertification. To determine if agriculture is a positive or negative factor for the reclamation of saline soils, improved and degraded factors of desertification in Sagzi plain of Isfahan were considered. Medicago, wheat and barley were evaluated to determine which crop is more effective for soil reclamation. Wheat and barley were selected and compared with derelict land, which was and independent variable in this study. The soils considered were cultivated with these products successively for at least 5 years. Soil samples were then obtained at different depths (0-3, 30-60, 60-90, 90-120, 120-150 cm) and were analysed for CaCO 3, electrical conductivity, organic matter, K +, Mg +, Ca 2+, Na +, CaSO 4, Cl -, sodium adsorption ratio, HCO 3- and SO 4-. Variance analysis showed significant difference between treatments at different depths and that among the three crops, wheat cropping is the best for soil reclamation.
  • Authors:
    • Singh, K.
    • Nandita, G.
    • Sonu, S.
  • Source: Experimental Agriculture
  • Volume: 43
  • Issue: 2
  • Year: 2007
  • Summary: A two-year study was undertaken in a tropical dryland agro-ecosystem to evaluate the effect of the application of soil amendments with contrasting chemical natures on crop productivity, grain yield, N-uptake and N-use efficiencies. The treatments involved the addition of equivalent amounts of N (80 kg N ha -1) through chemical fertilizer and three organic inputs at the beginning of the annual cycle: Sesbania aculeata shoots (high quality, C/N 16), wheat straw (low quality, C/N 82) and Sesbania+wheat straw (high and low quality combined, C/N 47), together with a control treatment. Test crops consisted of an annual sequence of rice and barley, sown in the rainy and winter seasons, respectively. Fertilizer and Sesbania inputs resulted in higher total net productivity (TNP) for the rice crop (47% and 32% increases over the control, respectively) than the combined (+28%) and wheat straw treatments (+10%). During the succeeding barley crop, maximum TNP was recorded in the Sesbania+wheat straw treatment (+52%), followed by wheat straw (+43%), fertilizer (+19%) and Sesbania (+17%). The TNP and grain yields of both crops added together were higher in Sesbania+wheat straw and fertilizer treatments compared to a single applications of either Sesbania or wheat straw. The Sesbania+wheat straw and fertilizer treatments resulted in more efficient utilization of N compared to the other treatments. Crop roots played a pivotal role in N-recovery from the soil and their N concentrations differed significantly ( p
  • Authors:
    • Singh, K.
    • Nandita, G.
    • Sonu, S.
  • Source: Applied Soil Ecology
  • Volume: 36
  • Issue: 2/3
  • Year: 2007
  • Summary: A 2-year field experiment was conducted to evaluate the impact of management practices involving manipulation of quantity and quality of exogenous inputs on soil N-mineralization rate, N availability and microbial biomass in a rice-barley rotation in a tropical dryland agroecosystem. At the beginning of each annual cycle an equivalent amount of N was added through chemical fertilizer and three organic inputs: Sesbania shoot (high quality resource, C/N 16, lignin/N 3.2, polyphenol+lignin/N 4.2), wheat straw (low quality resource, C/N 82, lignin/N 34.8, polyphenol+lignin/N 36.8) and Sesbania+wheat straw (high and low quality resources mixed). The N-mineralization rate was dominated by ammonification in this dryland agroecosystem. N-mineralization exhibited a distinct seasonal pattern, decreasing from the rice period through the summer fallow period, except in Sesbania+wheat straw and wheat straw treatments which showed a slight increase during the early stages of barley period. The rate of N-mineralization showed a significant relationship with soil moisture and microbial biomass N. During the rice period, N-mineralization rate and available-N was highest in the fertilizer treatment followed by Sesbania > Sesbania+wheat straw > wheat straw. During the barley period, highest N-mineralization rate and available-N was observed in Sesbania+wheat straw followed by wheat straw > Sesbania > fertilizer. Adding Sesbania+wheat straw resulted in consistently higher levels of microbial biomass N, N-mineralization rate and available-N through the annual cycle compared to single application of Sesbania and wheat straw, indicating synergy between the two inputs, favoring more efficient utilization of N. It is suggested that mixed application of high and low quality resources can modulate N release, resulting in relatively higher synchronization which can help in minimizing N loss from agroecosystem.
  • Authors:
    • Singh, K.
    • Nandita, G.
    • Sonu, S.
  • Source: Soil Biology & Biochemistry
  • Volume: 39
  • Issue: 1
  • Year: 2007
  • Summary: The influence of exogenous organic inputs on soil microbial biomass dynamics and crop root biomass was studied through two annual cycles in rice-barley rotation in a tropical dryland agroecosystem. The treatments involved addition of equivalent amount of N (80 kg N ha -1) through chemical fertilizer and three organic inputs at the beginning of each annual cycle: Sesbania shoot (high-quality resource, C:N 16, lignin:N 3.2, polyphenol+lignin:N 4.2), wheat straw (low-quality resource, C:N 82, lignin:N 34.8, polyphenol+lignin:N 36.8) and Sesbania+wheat straw (high-and low-quality resources combined), besides control. The decomposition rates of various inputs and crop roots were determined in field conditions by mass loss method. Sesbania (decay constant, k=0.028) decomposed much faster than wheat straw ( k=0.0025); decomposition rate of Sesbania+wheat straw was twice as fast compared to wheat straw. On average, soil microbial biomass levels were: rice period, Sesbania ≥ Sesbania+wheat straw > wheat straw ≥ fertilizer; barley period, Sesbania+wheat straw > Sesbania ≥ wheat straw ≥ fertilizer; summer fallow, Sesbania+wheat straw > Sesbania > wheat straw ≥ fertilizer. Soil microbial biomass increased through rice and barley crop periods to summer fallow; however, in Sesbania shoot application a strong peak was obtained during rice crop period. In both crops soil microbial biomass C and N decreased distinctly from seedling to grain-forming stages, and then increased to the maximum at crop maturity. Crop roots, however, showed reverse trend through the cropping period, suggesting strong competition between microbial biomass and crop roots for available nutrients. It is concluded that both resource quality and crop roots had distinct effect on soil microbial biomass and combined application of Sesbania shoot and wheat straw was most effective in sustained build up of microbial biomass through the annual cycle.