• Authors:
    • Frisvold, G. B.
    • Konyar, K.
  • Source: Water Resources Research
  • Volume: 48
  • Issue: 5
  • Year: 2012
  • Summary: This study examined how agriculture in six southwestern states might adapt to large reductions in water supplies, using the U.S. Agricultural Resource Model (USARM), a multiregion, multicommodity agricultural sector model. In the simulation, irrigation water supplies were reduced 25% in five Southern Mountain (SM) states and by 5% in California. USARM results were compared to those from a "rationing" model, which assumes no input substitution or changes in water use intensity, relying on land fallowing as the only means of adapting to water scarcity. The rationing model also ignores changes in output prices. Results quantify the importance of economic adjustment mechanisms and changes in output prices. Under the rationing model, SM irrigators lose $65 in net income. Compared to this price exogenous, "land-fallowing only" response, allowing irrigators to change cropping patterns, practice deficit irrigation, and adjust use of other inputs reduced irrigator costs of water shortages to $22 million. Allowing irrigators to pass on price increases to purchasers reduced income losses further, to $15 million. Higher crop prices from reduced production imposed direct losses of $130 million on first purchasers of crops, which include livestock and dairy producers, and cotton gins. SM agriculture, as a whole, was resilient to the water supply shock, with production of high value specialty crops along the Lower Colorado River little affected. Particular crops were vulnerable however. Cotton production and net returns fell substantially, while reductions in water devoted to alfalfa accounted for 57% of regional water reduction.
  • Authors:
    • Blanco-Canqui, H.
    • Claassen, M. M.
    • Presley, D. R.
  • Source: Agronomy Journal
  • Volume: 104
  • Issue: 1
  • Year: 2012
  • Summary: Impact of cover crops (CCs) on winter wheat ( Triticum aestivum L.) and grain sorghum [ Sorghum bicolor (L.) Moench] yields is not well understood. We assessed crop yield and its relationships with CC-induced changes in soil properties for a 15-yr CC experiment in wheat-sorghum rotation at 0, 33, 66, and 100 kg ha -1 of N application in south central Kansas. Hairy vetch ( Vicia villosa Roth) was used as a winter CC from 1995 to 2000, while sunn hemp (SH; Crotalaria juncea L.) and late-maturing soybean [LMS; Glycine max (L.) Merr.] were used as summer CCs in no-till from 2002 to 2008. Summer CCs increased crop yields particularly at low rates of N application. At 0 kg N ha -1, SH increased sorghum yield by 1.18 to 1.54 times, while wheat yield increased by 1.60 times in the first year (2004) after CC establishment relative to non-CC plots. At 66 kg N ha -1, SH had no effects on sorghum yield, but it increased wheat yield in 2 of 3 yr. Cover crops increased soil total N pool by 270 kg ha -1 for the 0- to 7.5-cm depth. Crop yield increased with the CC-induced decrease in soil maximum compactibility (soil's susceptibility to compaction) and soil temperature, and increase in soil aggregate stability, soil organic carbon (SOC) and total N concentration, and soil water content, particularly at 0 kg N ha -1. Principal component analysis (PCA) selected soil compactibility and total N as the best yield predictors. Inclusion of summer legume CCs in no-till fixes N, increases crop yield, and improves soil-crop relationships.
  • Authors:
    • Canbolat, O.
  • Source: KAFKAS UNIVERSITESI VETERINER FAKULTESI DERGISI
  • Volume: 18
  • Issue: 4
  • Year: 2012
  • Summary: The aim of this study was to compare the chemical composition, in vitro gas production, metabolizable energy (ME) organic matter digestibility (OMD), relative feed values (RFV) of the cereal forages from maize, sorghum, wheat, barley, oats, rye and triticale. Gas production were determined at 0, 3, 6, 12, 24, 48, 72 and 96 h and their kinetics were described using the equation y=a+b(1-e -ct). There were significant differences among cereal hay in terms of chemical composition (P
  • Authors:
    • Arendt, E.
    • Zannini, E.
    • Bez, J.
    • Czerny, M.
    • Wolter, A.
    • Hager, A.
    • Czerny, M.
  • Source: European Food Research and Technology
  • Volume: 235
  • Issue: 2
  • Year: 2012
  • Summary: Bread is a major staple food consumed daily in all parts of the world. A significant part of the human population cannot tolerate gluten, a storage protein found in wheat, rye and barley, and therefore, products made from alternative cereals are required. During this study, the bread-making potential of seven gluten-free flours, wheat and wholemeal wheat flour was compared. Fermentation potential of the different flours was determined, showing that dough development height of gluten-free and wholemeal wheat samples was lower than for wheat and oat flour. Apart from standard bread quality parameters such as loaf-specific volume and physical crumb texture, also water activity and shelf life have been determined. The shelf life of gluten-free breads was reduced compared to wheat bread. Aroma profiles were evaluated by a trained panel. Wheat, oat and wholemeal wheat breads were liked moderately, while the remaining samples had lower liking scores. Crumb grain characteristics were investigated using image analysis, and microstructure was observed by scanning electron microscopy. Overall, only breads produced from oat flour were of similar quality to wheat bread, and the utilization of buckwheat, rice, maize, quinoa, sorghum and teff flours resulted in breads of inferior quality.
  • Authors:
    • Schlegel, A.
    • Halvorson, A.
  • Source: Agronomy Journal
  • Volume: 104
  • Issue: 5
  • Year: 2012
  • Summary: Limited irrigation management practices are being used in the Central Great Plains to conserve water by optimizing crop water use efficiency. Limited irrigation may reduce total crop biomass production and amount of crop residue returned to the soil. Crop residue production within four no-till (NT) crop rotations [continuous corn ( Zea mays L.) (CC); corn-winter wheat ( Triticum aestivum L.) (CW); corn-winter wheat-grain sorghum ( Sorghum bicolor L. Moench) (CWS); corn-winter wheat-grain sorghum-soybean [ Glycine max (L.) Merr.] (CWSSb)] was measured and changes in soil organic carbon (SOC) and total soil nitrogen (TSN) stocks were monitored for 10 yr. Crop residue yields varied with crop being produced and with rotation, as did residue N and C returned to the soil. The C/N ratio of the residue varied with crop. The SOC and TSN pools increased with time in all rotations. The rate of gain in SOC and TSN mass for each rotation was 717, 477, 335, and 270 kg SOC ha -1 yr -1 and 114, 92, 87, and 84 kg TSN ha -1 yr -1 for the CC, CW, CWS, and CWSSb rotations, respectively, in the 0- to 30.5-cm soil depth. The rate of change in SOC and TSN mass was lowest with CWSSb (8.7 Mg residue ha -1 yr -1) and highest with CC (12.0 Mg residue ha -1 yr -1). Approximately 6.8 to 7.6 Mg residue ha -1 yr -1 would be needed to maintain SOC stocks under limited irrigation.
  • Authors:
    • Neumann, M.
    • Lacerda, M.
    • Lago, W.
  • Source: REVISTA BRASILEIRA DE ENGENHARIA AGRICOLA E AMBIENTAL
  • Volume: 16
  • Issue: 7
  • Year: 2012
  • Summary: The intensively increasing agricultural use of Distrito Federal soils may compromise their quality and trigger environmental problems in the region. Given this fact, the objective of this work was to study the soil quality (SQ) indicators, in areas under no tillage (PD), with diversified managements (corn-soybean rotation and bean-sorghum succession), at the Riberao Extrema watershed, Distrito Federal. Soil bulk density (Ds), flocculation index (GF), organic matter (MO), cation exchange capacity (CTC), microbial respiration (Rmic) and microbial biomass carbon (Cmic) were the attributes of SQ evaluated. Statistical analysis was performed using the statistical software Statistics Analysis System (SAS) and consisted of analysis of variance (ANOVA) followed by Tukey test for comparison of means. Results show that some of the evaluated SQ indicators were affected by different types of soil management under evaluation (Ds, Cmic and MO), while others were not sensitive to them (GF, CTC and Rmic). Positive correlation was found between MO and CTC of the soils in both investigated treatments, highlighting the importance of no tillage system on the chemical properties of soil.
  • Authors:
    • Maity, S.
    • Suresh, G.
    • Nag, S.
    • Kundu, S.
    • Sultan, S.
  • Source: Indian Journal of Animal Sciences
  • Volume: 82
  • Issue: 3
  • Year: 2012
  • Summary: A feeding trial was conducted for 3 months on 12 Tharparkar heifers equally distributed between inorganic (G 1) and organic dietary groups (G 2), (n,6) in each with mean body weight of 216.08.30 and 218.67.09 kg were offered ad lib. sorghum hay (cv PC 6) grown under inorganic and organic agronomic practices, respectively. Barley grain/oat grown inorganically and organically was used as energy sources in concentrate mixture with linseed cake as protein source to determine the intake, eating pattern, nutrients utilization, nitrogen balance and growth rate under both the feeding regimes. DMI (kg/d) was comparable in animals fed inorganic (G 1) and organically produced diets (G 2). OM and hemicellulose digestibility was significantly higher in animals of G 2 than G 1. The digestibility of fiber fractions was 3-3.5 units more in animals of G 2 than G 1. N retention was more animals fed organic diet (6.70) than inorganically produced diet (2.46%). Heifers fed organic fodder consumed more at early 2 and 4 h feeding than animals fed inorganic fodder and feed, however at later stages of eating animals offered inorganic fodder/feed, consumed relatively more. Growth rate (g/d) was identical in heifers of G 1 and G 2 dietary groups. Results revealed that nutrients digestibility and nitrogen balance is higher in animals fed organically grown fodder and feeds.
  • Authors:
    • Zatta, A.
    • Zegada-Lizarazu, W.
    • Monti, A.
  • Source: PLANT AND SOIL
  • Volume: 351
  • Issue: 1-2
  • Year: 2012
  • Summary: Lately sweet sorghum (S) has attracted great interest as an alternative feedstock for biofuel production due to its high yielding potential and better adaptation to drought than maize (M). However, little is known about the response of newly developed sweet sorghum genotypes to water deficits, especially at the root level and its water uptake patterns. The objective of this study was to compare the water uptake capacity, growth and developmental characteristics at the root and canopy levels of a sweet sorghum hybrid (Sorghum bicolor cv. Sucro 506) with those of maize (Zea mays cv. PR32F73) at two water regimes. The trial was setup in a total of 20 rhizotrons (1 m(3)), where calibrated soil moisture probes were installed for monitoring and adjusting the soil moisture content to 25% (well-watered, W) and 12% (drought stress, D). DS was able to sustain its physiological activity close to that of WS plants, while maize was not. The biomass production potential of DS was reduced about 38%, while in maize the reduction was 47%. The water use efficiency (WUE), however, was increased by 20% in sweet sorghum and reduced in 5% in maize. Moreover, in contrast to maize the root length density and water uptake capacity of DS was enhanced. Root water uptake efficiency in DM was sustained close to its potential, but not in sweet sorghum. In summary, the better adaptation to drought of sweet sorghum is explained by increased WUE, sustained physiological activity and enlarged root system. It is also associated with a reduced water uptake efficiency compared to its control but maintained compared to maize.
  • Authors:
    • Sharma, K. L.
    • Venkateswarlu, B.
    • Ramesh, V.
    • Wani, S. P.
  • Source: Communications in Soil Science and Plant Analysis
  • Volume: 43
  • Issue: 14
  • Year: 2012
  • Summary: The long-term effects of plant legume [horse gram (Macrotyloma uniflorum)] biomass incorporations were assessed in terms of carbon dioxide (CO2) emissions, soil quality parameters, and climatically influenced soil parameters in a dryland Alfisol under varying soil fertility conditions. Six selected treatments consisted of off-season legume incorporation (I) and no incorporation/fallow (F), each under three varying nitrogen and phosphorus fertilizer levels (viz., N0P0, N25P30, and N50P30). Soil moisture, soil temperature, soil surface carbon dioxide emission, soil dehydrogenases, and microbial biomass carbon (MBC) were monitored at three different crop situations [viz., Kharif period (KP), legume/fallow period (LP), and no crop period (NP)] at 14 different periods of the year. Incorporation practices resulted in greater rates of CO2 emission over fallow conditions during the Kharif and legume periods, whereas the emission rate was greater in fallow soils during the end of the legume and no crop periods. The increased rates of fertilizer doses also significantly increased the soil CO2 flux during the majority of the measurements. Beneficial effects of incorporation practices were observed in terms of high soil moisture (5-11%), low soil temperature (3-7%), and high content of MBC over without incorporations. Correlation studies indicated that the soil property MBC was found to be the greatest significant variable with CO2 emission in all the fertilizer treatments under biomass-incorporated soils. These results indicated the undesirable (in terms of CO2 fluxes) and desirable (soil biological and other parameters) effects of legume biomass incorporation and fertilizer application and their significance in improving soil quality and greenhouse gas (GHG) emissions in dryland Alfisols of semi-arid tropics.
  • Authors:
    • Howell, T. A.
    • Evett, S. R.
    • Schwartz, R. C.
    • Colaizzi, P. D.
    • Gowda, P. H.
    • Tolk, J. A.
  • Source: Agronomy Journal
  • Volume: 104
  • Issue: 2
  • Year: 2012
  • Summary: Relatively few radiation transfer studies have considered the impact of varying vegetation cover that typifies row crops, and methods to account for partial row crop cover have not been well investigated. Our objective was to evaluate a widely used radiation model that was modified for row crops having sparse to full vegetation cover. The radiation model was combined with geometric view factors based on elliptical hedgerows that account for the spatial distribution of row crop vegetation, and this approach was compared with the more commonly used clumping index approach. Irradiance measurements included transmitted and reflected visible and shortwave, outgoing longwave, and total net radiation. The model used optimized parameters for corn ( Zea mays L.), grain sorghum [ Sorghum bicolor (L.) Moench], and cotton ( Gossypium hirsutum L.). The elliptical hedgerow and clumping index approaches resulted in similar model agreement; however, the former resulted in up to 7.3 W m -2 smaller RMSE and up to 7.5 W m -2 smaller mean bias error compared with the latter. Both approaches resulted in similar model sensitivities to inputs, which varied 25%. Calculated shortwave irradiance fluxes were most sensitive to leaf area index (LAI; -3.25), canopy width (-1.94), ellipsoid leaf angle parameter (-0.77), and visible leaf absorption (-5.54) when LAI=2.95 m 2 m -2, and visible soil reflectance (0.89) when LAI=0.21 m 2 m -2. Calculated outgoing longwave irradiance and net radiation were most sensitive to the soil directional brightness temperature (0.55 and -0.61, respectively) when LAI=0.21 m 2 m -2.