• Authors:
    • Pettigrew, W. T.
    • Dowd, M. K.
  • Source: Journal of Cotton Science
  • Volume: 16
  • Issue: 1
  • Year: 2012
  • Summary: The value of whole cottonseed and cottonseed products has increased as demand has grown from the dairy and food related industries. Although cottonseed composition has previously been documented to be affected by variety, planting date, and irrigation, interactions between varieties and irrigation regimes have not been adequately described. Six different varieties were planted on two planting dates and grown under irrigated or dryland conditions to document how varieties interacted with irrigation regimes to impact various seed composition traits. Variety was a major source of variation for all the seed composition traits quantified. Individual seed mass variation among varieties could explain some of the seed composition variation observed, particularly for protein. For many of these seed composition traits, variety also interacted statistically with irrigation regimes to impact trait expression. Most seed composition traits of the varieties responded in the same direction to irrigation, but there was sufficient variety variation in the response that significant interactions were produced. 'ST 5599BR' often exhibited a different irrigation response compared to the other varieties, particularly for the different fatty acid components. These results indicate that a pairing of varieties and management practices could be utilized to help achieve desired seed composition traits. Although lint production is the primary economic incentive for cotton producers, improved cottonseed composition offers an important, consistent, and reliable secondary revenue stream for producers.
  • Authors:
    • Shevtsov, V.
    • El-Haramein, F.
    • Grando, S.
    • Sariev, B.
    • Abugalieva, A.
  • Source: Russian Agricultural Sciences
  • Volume: 38
  • Issue: 2
  • Year: 2012
  • Summary: A method is given for determining the content of beta-glucan in grain of barley varieties, and polymorphism of the species in this trait, including collection and breeding accessions, is shown. Within the breeding nurseries of Kazakhstan, the beta-glucan content varies from 2.6 to 6.2% in spring and from 2.2 to 5.7% in winter barley grain, increasing under dry-farming conditions. For brewing purposes, accessions with a value of this index lower than 4%, some of which displayed relative stability across reseedings, are singled out. The need for purposeful breeding for the given trait, for which it is necessary to introduce it into the selection scheme, and use of identification methods are substantiated.
  • Authors:
    • Limon, M.
    • Blanco-Moure, N.
    • Lopez, M.
    • Gracia, R.
  • Source: Soil & Tillage Research
  • Volume: 118
  • Year: 2012
  • Summary: Conservation tillage has been encouraged as a management alternative to preserve soil and water resources in semiarid Aragon (NE Spain). In fact, its adoption by farmers, and especially of no tillage (NT) systems, has increased in recent years. However, little information concerning the soils on which these techniques are applied is available for this region. The objective of this study was to assess the potential of NT to increase organic carbon content at the soil surface (0-20 cm) in rainfed Aragon. To this aim, 22 pairs of adjacent farm fields under NT and conventional tillage (CT) were compared in different cereal production areas. The fields were under continuous NT between 5 and 19 years but half were over 10 years. Soil organic carbon (SOC) in NT ranged from 7.06 to 18.53 g kg -1 (0-20 cm depth) and was higher than 12 g kg -1 in nearly 30% of the fields. These contents represented between 8% less (only one case) and 55% more SOC under NT than under CT with an average gain of 20% in favour of NT. The highest SOC contents were found in the NT fields of longer duration (>10 years) and/or managed with practices that enhance the return of more crop biomass to the soil (complete residue return, cropping intensification and manure application). The identification of the current management practices used by farmers has allowed us to know the diversity of the NT-based cropping systems and the reality of the conservation agriculture in our region. Overall, results from this on-farm study indicate that NT can be recommended as a viable alternative to CT to increase organic carbon at the soil surface in cereal production areas of Aragon.
  • Authors:
    • Thomashow, L.
    • Weller, D.
    • Mavrodi, O.
    • Mavrodi, D.
    • Parejko, J.
  • Source: Microbial Ecology
  • Volume: 64
  • Issue: 1
  • Year: 2012
  • Summary: Certain strains of the rhizosphere bacterium Pseudomonas fluorescens contain the phenazine biosynthesis operon ( phzABCDEFG) and produce redox-active phenazine antibiotics that suppress a wide variety of soilborne plant pathogens. In 2007 and 2008, we isolated 412 phenazine-producing (Phz +) fluorescent Pseudomonas strains from roots of dryland wheat and barley grown in the low-precipitation region (
  • Authors:
    • Sadeghi, H.
  • Source: International Journal of Agriculture: Research and Review
  • Volume: 2
  • Issue: 3
  • Year: 2012
  • Summary: Residue burning is a quick, labor-saving practice to remove residue that is viewed as a nuisance by producers in the most southern provinces of Iran. However, residue burning has several adverse environmental and ecological impacts. The burning of dead plant material adds considerable amount of CO 2 and particulate matter to the atmosphere and can reduce a lot of returned needed C and other nutrients to the soil. Whereas, crop residues incorporation can improve soil quality and reduce air pollution on a long term basis. However, where residues have been soil incorporated, farmers often have concern for reduced soil fertility from nutrient immobilization and problems for cultivation associated with slow rates of residues decomposition. The experiment was conducted as strip split plot with four replications. Horizontal plots were three crop residues rates (0, 750 and 1500 kg ha -1), vertical plots consisted of two dryland current barley cultivars (CVs) (Afzal and Reyhan), and sub-plots were three N rates (0, 40, and 80 kg N ha -1). Number of spike per plant, grains per spike, grains per plant and 1000-grain weight of both CVs significantly increased by N and residue rates increasing in both years. The lowest grain yield was obtained from 1500 kg ha -1 residue incorporation without N application showing the soil N imbalance. The optimum crop growth and the highest grain yield was achieved from the highest crop residues and N rates, indicating that the most reliable system for dryland barley production in the region is complete residues incorporation into the soil following disking, seeding with chisel seeder and application of 80 kg N ha -1.
  • Authors:
    • Kazemayni, S.
    • Sadeghi, H.
  • Source: Iranian Journal of Field Crop Science
  • Volume: 42
  • Issue: 4
  • Year: 2012
  • Summary: A 2-years (2007-2009) field study was carried out at the college of Agriculture, Shiraz University, to evaluate the influence of crop residues management and nitrogen (N) rates on soil quality and barley grain protein under dryland conditions. The experiment was conducted as strip split plot with four replications. Horizontal plots were three crop residues rates (0, 750 and 1500 kg ha -1), vertical plots consisted of two barley cultivars (CVs) (Afzal and Reyhan), and sub-plots were three N rates (0, 40, and 80 kg N ha -1). The Results of ANOVA showed that there were significant differences for year effects and Y * C * N for total N grain and protein percentage. When the crop residues were completely added (100%), N rates should be added according to residues rates. Increasing crop residue level increased soil organic carbon. Crop residue application had no effect on grain protein percentage. There were no significant differences between two cultivars for Crop residue application. High N increased grain protein percentage significantly.
  • Authors:
    • Lartey, R.
    • Jabro, J.
    • Caesar-Tonthat, T.
    • Lenssen, A.
    • Sainju, U.
    • Evans, R.
    • Allen, B.
  • Source: Nutrient Cycling in Agroecosystems
  • Volume: 93
  • Issue: 3
  • Year: 2012
  • Summary: Management practices may influence dryland soil N cycling. We evaluated the effects of tillage, crop rotation, and cultural practice on dryland crop biomass (stems and leaves) N, surface residue N, and soil N fractions at the 0-20 cm depth in a Williams loam from 2004 to 2008 in eastern Montana, USA. Treatments were two tillage practices (no-tillage [NT] and conventional tillage [CT]), two crop rotations (continuous spring wheat [ Triticum aestivum L.] [CW] and spring wheat-barley [ Hordeum vulgaris L.] hay-corn [ Zea mays L.]-pea [ Pisum sativum L.] [W-B-C-P]), and two cultural practices (regular [conventional seed rates and plant spacing, conventional planting date, broadcast N fertilization, and reduced stubble height] and ecological [variable seed rates and plant spacing, delayed planting, banded N fertilization, and increased stubble height]). Nitrogen fractions were soil total N (STN), particulate organic N (PON), microbial biomass N (MBN), potential N mineralization (PNM), NH 4-N, and NO 3-N. Crop biomass N was 30% greater in W-B-C-P than in CW in 2005. Surface residue N was 30-34% greater in NT with the regular and ecological practices than in CT with the regular practice. The STN, PON, and MBN at 10-20 and 0-20 cm were 5-41% greater in NT or CW with the regular practice than in CT or CW with the ecological practice. The PNM at 5-10 cm was 22% greater in the regular than in the ecological practice. The NH 4-N and NO 3-N contents at 10-20 and 0-20 cm were greater in CT with W-B-C-P and the regular practice than with most other treatments in 2007. Surface residue and soil N fractions, except PNM and NO 3-N, declined from autumn 2007 to spring 2008. In 2008, NT with W-B-C-P and the regular practice gained 400 kg N ha -1 compared with a loss of 221 kg N ha -1 to a gain of 219 kg N ha -1 in other treatments. No-tillage with the regular cultural practice increased surface residue and soil N storage but conventional tillage with diversified crop rotation and the regular practice increased soil N availability. Because of continuous N mineralization, surface residue and soil N storage decreased without influencing N availability from autumn to the following spring.
  • Authors:
    • Samarasinghe, S.
    • Safa, M.
  • Source: Environmental Pollution
  • Volume: 171
  • Issue: December
  • Year: 2012
  • Summary: This review paper concentrates on carbon dioxide emissions, discussing its agricultural sources and the possibilities for minimizing emissions from these sources in wheat production in Canterbury, New Zealand. This study was conducted over 35,300 ha of irrigated and dryland wheat fields in Canterbury. Total CO2 emissions were 1032 kg CO2/ha in wheat production. Around 52% of the total CO2 emissions were released from fertilizer use and around 20% were released from fuel used in wheat production. Nitrogen fertilizers were responsible for 48% (499 kg CO2/ha) of CO2 emissions. The link between nitrogen consumption, CO2 emissions and crop production showed that reducing the CO2 emissions would decrease crop production and net financial benefits to farmers. (C) 2012 Elsevier Ltd. All rights reserved.
  • Authors:
    • Caesar, A.
    • Caesar-TonThat, T.
    • Sainju, U. M.
  • Source: Soil and Tillage Research
  • Volume: 118
  • Issue: January
  • Year: 2012
  • Summary: Portable chamber provides simple, rapid, and inexpensive measurement of soil CO2 flux but its effectiveness and precision compared with the static chamber in various soil and management practices is little known. Soil CO2 flux measured by a portable chamber using infrared analyzer was compared with a static chamber using gas chromatograph in various management practices from May to October 2008 in loam soil (Luvisols) in eastern Montana and in sandy loam soil (Kastanozems) in western North Dakota, USA. Management practices include combinations of tillage, cropping sequence, and N fertilization in loam and irrigation, tillage, crop rotation, and N fertilization in sandy loam. It was hypothesized that the portable chamber would measure CO2 flux similar to that measured by the static chamber, regardless of soil types and management practices. In both soils, CO2 flux peaked during the summer following substantial precipitation and/or irrigation (>15 mm), regardless of treatments and measurement methods. The flux varied with measurement dates more in the portable than in the static chamber. In loam, CO2 flux was 14-87% greater in the portable than in the static chamber from July to mid-August but 15-68% greater in the static than in the portable chamber from late August to October in all management practices. In sandy loam, CO2 flux was 10-229% greater in the portable than in the static chamber at all measurement dates in all treatments. Average CO2 flux across treatments and measurement dates was 9% lower in loam but 84% greater in sandy loam in the portable than in the static chamber. The CO2 fluxes in the portable and static chambers were linearly to exponentially related (R-2 = 0.68-0.70, P < 0.01, n = 40-56). Although the trends of CO2 fluxes with treatments and measurement dates were similar in both methods, the flux varied with the methods in various soil types. Measurement of soil CO2 flux by the portable chamber agreed more closely with the static chamber within 0-10 kg C ha(-1) d(-1) in loam soil under dryland than in sandy loam soil under irrigated and non-irrigated cropping systems. Published by Elsevier B.V.
  • Authors:
    • Barsotti, J. L.
    • Lenssen, A. W.
    • Caesar-TonThat, T.
    • Sainju, U. M.
  • Source: Soil Science Society of America Journal
  • Volume: 76
  • Issue: 5
  • Year: 2012
  • Summary: Information is needed to mitigate dryland soil greenhouse gas (GHG) emissions by using novel management practices. We evaluated the effects of cropping sequence and N fertilization on dryland soil temperature and water content at the 0- to 15-cm depth and surface CO2, N2O, and CH4 fluxes in a Williams loam (fine-loamy, mixed, superactive, frigid, Typic Argiustolls) in eastern Montana. Treatments were no-tilled continuous malt barley (Hordeum vulgaris L.) (NTCB), no-tilled malt barley-pea (Pisum sativum L.) (NTB-P), and conventional-tilled malt barley-fallow (CTB-F) (control), each with 0 and 80 kg N ha(-1). Gas fluxes were measured at 3 to 14 d intervals using static, vented chambers from March to November 2008 to 2011. Soil temperature varied but water content was greater in CTB-F than in other treatments. The GHG fluxes varied with date of sampling, peaking immediately after substantial precipitation (>15 mm) and N fertilization during increased soil temperature. Total CO2 flux from March to November was greater in NTCB and NTB-P with 80 kg N ha(-1) than in other treatments from 2008 to 2010. Total N2O flux was greater in NTCB with 0 kg N ha(-1) and in NTB-P with 80 kg N ha(-1) than in other treatments in 2008 and 2011. Total CH4 uptake was greater with 80 than with 0 kg N ha(-1) in NTCB in 2009 and 2011. Because of intermediate level of CO2 equivalent of GHG emissions and known favorable effect on malt barley yield, NTB-P with 0 kg N ha(-1) might mitigate GHG emissions and sustain crop yields compared to other treatments in eastern Montana. For accounting global warming potential of management practices, however, additional information on soil C dynamics and CO2 associated with production inputs and machinery use are needed.