• Authors:
    • Fernando,Ana Luisa
    • Duarte,Maria Paula
    • Vatsanidou,Anna
    • Alexopoulou,Efi
  • Source: Industrial Crops & Products
  • Volume: 68
  • Year: 2015
  • Summary: Bioenergy and biomaterials from fiber crops are regarded as promising substitutes for conventional ones, considering the growing concern about oil and other non-renewable resources depletion and the environmental impacts of the conventional systems. In this paper, the environmental aspects of fiber crops cultivation and use are reviewed. The analysis was based on the following categories: use of resources, emission of gases, effects on the quality of soil and water and biological and landscape diversity. As bioenergy and biomaterials carriers, fiber crops offer ecological advantages over conventional ones by contributing to carbon sequestration and energy savings, and to the reduction of greenhouse gases and non-renewable resources. However, other environmental outcomes, such as acidifying and eutrophication emissions, may limit the conversion and use of fiber crops. Even so, the low input requirements associated with this class of crops and its phytoremediation aptness for wastewaters or contaminated land, are some of the environmental advantages associated with fiber crops. Crop management options and processing choices can influence the outcomes, but site specific factors should be accurately assessed to evaluate the adequacy between crop and location. Opportunities for improvement are indicated, in order to provide new insights for the future development of these crops in a sustainable agro-industrial framework. (C) 2014 Elsevier B.V. All rights reserved.
  • Authors:
    • Hurisso,T. T.
    • Norton,J. B.
    • Mukhwana,E. J.
    • Norton,U.
  • Source: Soil Science Society of America Journal
  • Volume: 79
  • Issue: 3
  • Year: 2015
  • Summary: Soil organic matter (SOM) fractions were determined using extraction-, incubation-, and density-based fractionation techniques on samples collected from a range of furrow-irrigated sugar beet (Beta vulgaris L.) based rotations on the same soil series on farmers' fields in Wyoming. We hypothesized that extending the period of time between sugar beet crops in rotations beyond the 2-yr sugar beet-barley (Hordeum vulgare L.) (SB-BA) rotation by adding perennial or annual legumes would lead to higher levels of surface-soil (0-15-cm) organic C and N. Four rotations were compared: SB-BA, sugar beet-dry bean (Phaseolus vulgaris L.) (SB-DB), sugar beetbarley-dry bean (SB-BA-DB), and sugar beet-sugar beet-alfalfa (Medicago sativa L)-alfalfa (SB-SB-Alf-Alf). Soils under SB-BA and SB-DB rotations on average contained 607 g soil organic C (SOC) m-2 in the upper 15 cm, or 46% of the SOC found within SB-BA-DB and SB-SB-Alf-Alf soils. Potentially mineralizable C and N and microbial biomass C (MBC) were lower in SB-BA and SB-DB soils than SB-BA-DB and SB-SB-Alf-Alf soils, but, when normalized by SOC and total soil N (TSN), these labile C and N fractions were >1.5 times higher in SB-BA and SB-DB soils, suggesting greater SOM mineralization. Moreover, light-fraction C in SB-BA and SB-DB soils was about half that of SB-SB-Alf-Alf soils. Sugar beet sucrose yield was also higher in the SB-SB-Alf-Alf than any other rotation. There were strong linear relationships (r2 = 0.50-0.84) between sugar beet sucrose yield and TSN, SOC, and MBC across all four rotations. To conserve high surface-soil organic C and N fractions on furrow-irrigated farm fields without sacrificing sugar beet sucrose yield, extending the 2-yr SB-BA rotation by adding 2 yr of alfalfa is recommended. © Soil Science Society of America, 5585 Guilford Rd., Madison Wl 53711 USA.
  • Authors:
    • Ladoni,M.
    • Basir,A.
    • Kravchenko,A.
  • Source: Soil Science Society of America Journal
  • Volume: 79
  • Issue: 3
  • Year: 2015
  • Summary: Active fractions of soil C such as particulate organic C (POC) and short-term mineralizable C (SMC) respond faster than total organic C (TOC) to management induced changes in soil C. However, the active fractions of organic C can possibly have larger variability that decreases the detectability of management effects on soil C. The objectives of this study were to (i) assess the relative usefulness of TOC, POC, and SMC as criteria of management induced changes on soil C and (ii) investigate if using auxiliary soil and topographical information can aid in increasing the usefulness of these criteria in studies conducted across large spatial scales. Data were collected at locations with two contrasting topographical positions (slope and depression) within 10 agricultural fields in conventional and cover crop based row crop managements at the 0- to 20-, 35- to 50-, and 70- to 90-cm depths. The results showed that to detect differences between the management systems with an acceptable type II error of 0.20, an 80% difference in TOC and a 50% difference in SMC were needed. The statistical power for POC was never in an acceptable range. The use of auxiliary soil and topography information via analysis of covariance decreased the sizes of the minimal detectable differences. Given the faster reaction to management of SMC as compared with TOC, and its lower variability as compared with POC, we recommend SMC as the preferred C fraction for detecting treatment induced differences in organic C stocks in agricultural field experiments, especially in deeper soil layers. © Soil Science Society of America, 5585 Guilford Rd., Madison Wl 53711 USA.
  • Authors:
    • Margenot,A. J.
    • Calderón,F. J.
    • Bowles,T. M.
    • Parikh,S. J.
    • Jackson,L. E.
  • Source: Soil Science Society of America Journal
  • Volume: 79
  • Issue: 3
  • Year: 2015
  • Summary: The objectives of this study were to examine soil organic matter (SOM) functional group composition and its relationship to labile SOM fractions with diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS). We analyzed soils from 13 organically managed tomato (Solatium lycopersicum) fields in northern California for labile organic C, N, and P fractions and by DRIFTS for bands representing organic functional groups, including aliphatic C-H (2924, 2850, 1470, 1405, 1390 cm-1), aromatic C=C (1650 cm-1) and C-H (920, 840 cm-1), polysaccharide and phenol C-O (1270, 1110, 1080 cm-1), and amine and amide N-H (3400, 1575 cm-1). Significant differences in relative band intensities occurred among the 13 organic tomato fields, in particular a relative increase in absorbance of bands representing aliphatic C-H positively associated with soil organic carbon (SOC), as well as permanganate-oxidizable carbon (POXC), extractable organic carbon (EOC) and nitrogen (EON), and potentially mineralizable N (PMN). In comparison, organic P fractions like sodium bicarbonate extractable (NaHCO3-P0) and sodium hydroxide extractable organic P (NaOH-P0) were poorly associated with SOC and functional groups represented by bands, including aliphatic C-H. This could reflect limitations of DRIFTS, but is consistent with hypotheses of greater decoupling of C and P vs. C and N in soils. This study implicates relative differences in organic functional groups with differences in SOC and labile SOM fractions, and in agreement with previous studies, identifies absorbance of infrared bands representing aliphatic C-H functional groups in these systems as a potential indicator of SOM transformations related to changes in its labile fractions. © Soil Science Society of America, 5585 Guilford Rd., Madison Wl 53711 USA.
  • Authors:
    • Messerli,J.
    • Bertrand,A.
    • Bourassa,J.
    • Belanger,G.
    • Castonguay,Y.
    • Tremblay,G.
    • Baron,V.
    • Seguin,P.
  • Source: Agronomy Journal
  • Volume: 107
  • Issue: 3
  • Year: 2015
  • Summary: The increase in atmospheric carbon dioxide concentration ([CO 2]) and consequent increase in air temperature is expected to have significant effects on plant growth and nutritive value. Studies examining the effects of elevated [CO 2] on plants under field conditions have been limited by the inherent difficulty to modify air composition in open air. Here we describe an efficient and inexpensive open-top chamber (OTC) system designed to study the effects of elevated atmospheric [CO 2] and temperature on perennial alfalfa-timothy ( Medicago sativa L.)-( Phleum pratense L.) mixture. The design and construction of these OTCs are described in detail, along with cost estimation for each component. Eight OTCs, each with 1.2 m 2 of ground area (four with elevated [CO 2] and four with ambient [CO 2]) were fabricated and four control plots of the same dimension were established to assess the chamber effects on plant responses to CO 2. The [CO 2] in elevated-CO 2 chambers fell 93% of the time within 20% of the targeted 600 mol mol -1 CO 2, based on 10 min averages. The CO 2 consumption in elevated-CO 2 chambers averaged 3.0 kg CO 2 m -2 d -1. To ensure that the environment within OTCs was similar to the surrounding field, growing conditions were determined in all chambers and control plots. Adequate light transmission was observed compared to control plots (93%) and the temperature increase was 0.7°C on average. After two growing seasons of continued use, this system has proven its effectiveness for studying the effects of CO 2 and climate change in the field at low cost.
  • Authors:
    • O'Dea,Justin K.
    • Jones,Clain A.
    • Zabinski,Catherine A.
    • Miller,Perry R.
    • Keren,Ilai N.
  • Source: Nutrient Cycling in Agroecosystems
  • Volume: 102
  • Issue: 2
  • Year: 2015
  • Summary: In the North American northern Great Plains (NGP), legumes are promising summer fallow replacement/cropping intensification options that may decrease dependence on nitrogen (N) fertilizer in small grain systems and mitigate effects of soil organic matter (SOM) losses from summer fallow. Benefits may not be realized immediately in semiarid conditions though, and longer-term effects of legumes and intensified cropping in this region are unclear, particularly in no-till systems. We compared effects of four no-till wheat (Triticum aestivum L.) cropping systems-summer fallow-wheat (F-W), continuous wheat (CW), legume green manure (pea, Pisum sativum L.)-wheat (LGM-W), and pea-wheat (P-W)-on select soil attributes in an 8-year-old rotation study, and N fertilizer effects on C and N mineralization on a duplicate soil set in a laboratory experiment. We analyzed potentially mineralizable carbon and nitrogen (PMC and PMN) and mineralization trends with a nonlinear model, microbial biomass carbon (MB-C), and wet aggregate stability (WAS). Legume-containing systems generally resulted in higher PMC, PMN, and MB-C, while intensified systems (CW and P-W) had higher WAS. Half-lives of PMC were shortest in intensified systems, and were longest in legume systems (LGM-W and P-W) for PMN. Nitrogen addition depressed C and N mineralization, particularly in CW, and generally shortened the half-life of mineralizable C. Legumes may increase long-term, no-till NGP agroecosystem resilience and sustainability by (1) increasing the available N-supply (similar to 26-50 %) compared to wheat-only systems, thereby reducing the need for N fertilizer for subsequent crops, and (2) by potentially mitigating negative effects of SOM loss from summer fallow.
  • Authors:
    • Schlegel,A. J.
    • Assefa,Y.
    • Bond,H. D.
    • Wetter,S. M.
    • Stone,L. R.
  • Source: Soil Science Society of America Journal
  • Volume: 79
  • Issue: 3
  • Year: 2015
  • Summary: Application of animal waste to cropland provides a method of waste disposal and benefits both soil and crops. The objective of this study was to evaluate the long-term effects of land application of animal waste and inorganic fertilizer on selected soil chemical and physical properties. The animal waste applications were conducted from 1999 through 2008 near Tribune, KS, with 10 treatments (three levels each of cattle manure and swine effluent [P, N, and 2N], three levels of N fertilizer, and a control). Soil chemical and physical properties were measured to evaluate the effect of 10 yr of application of these treatments. Cattle manure application at the 2N level increased Mehlich-3 P, total N, total C, and organic matter (OM) concentrations to about 19, 2.8, 2.5, and 2.5 times, respectively, compared with those of the untreated check. Physical properties of the soil such as water content at -1.5 MPa, modulus of rupture, Proctor maximum bulk density, and optimum water content for compaction improved with the application of cattle manure. Highly significant relationships (P < 0.001) were observed between soil OM and soil water content at -1.5 MPa, both Proctor maximum and field bulk densities, optimum water content for compaction, and steady-state infiltration rate. Cattle manure treatments improved soil resistance to compaction, largely due to the additional OM that builds in soil with the application of cattle manure. © Soil Science Society of America, 5585 Guilford Rd., Madison Wl 53711 USA.
  • Authors:
    • Wu,Yiping
    • Liu,Shuguang
    • Young,Claudia J.
    • Dahal,Devendra
    • Sohl,Terry L.
    • Davis,Brian
  • Source: Scientific Reports
  • Volume: 5
  • Year: 2015
  • Summary: Terrestrial carbon sequestration potential is widely considered as a realistic option for mitigating greenhouse gas emissions. However, this potential may be threatened by global changes including climate, land use, and management changes such as increased corn stover harvesting for rising production of cellulosic biofuel. Therefore, it is critical to investigate the dynamics of soil organic carbon (SOC) at regional or global scale. This study simulated the corn production and spatiotemporal changes of SOC in the U.S. Temperate Prairies, which covers over one-third of the U.S. corn acreage, using a biogeochemical model with multiple climate and land-use change projections. The corn production (either grain yield or stover biomass) could reach 88.7-104.7 TgC as of 2050, 70-101% increase when compared to the base year of 2010. A removal of 50% stover at the regional scale could be a reasonable cap in view of maintaining SOC content and soil fertility especially in the beginning years. The projected SOC dynamics indicated that the average carbon sequestration potential across the entire region may vary from 12.7 to 19.6 g C/m(2)/yr (i.e., 6.6-10.2 g TgC/yr). This study not only helps understand SOC dynamics but also provides decision support for sustainable biofuel development.
  • Authors:
    • Zuber,S. M.
    • Behnke,G. D.
    • Nafziger,E. D.
    • Villamil,M. B.
  • Source: Agronomy Journal
  • Volume: 107
  • Issue: 3
  • Year: 2015
  • Summary: Recent increases in corn ( Zea mays L.) production in the U.S. Corn Belt have necessitated the conversion of rotations to continuous corn, and an increase in the frequency of tillage. The objective of this study was to assess the effect of rotation and tillage on soil physical and chemical properties in soils typical of Illinois. Sequences of continuous corn (CCC), 2-yr corn-soybean [ Glycine max (L.) Merr.] (CS) rotation, 3-yr corn-soybean-wheat ( Triticum aestivum L.) (CSW) rotation, and continuous soybean (SSS) were split into conventional tillage (CT) and no-till (NT) subplots at two Illinois sites. After 15 yr, bulk density (BD) under NT was 2.4% greater than under CT. Water aggregate stability (WAS) was 0.84 kg kg -1 under NT compared to 0.81 kg kg -1 under CT. Similarly, soil organic carbon (SOC) and total nitrogen (TN) were greater under NT than under CT with SOC values for 0 to 60 cm of 96.0 and 91.0 Mg ha -1 and TN values of 8.87 and 8.40 Mg ha -1 for NT and CT, respectively. Rotations affected WAS, TN, and K levels with WAS being greatest for the CSW rotation at 0.87 kg kg -1, decreasing with more soybean years (CS, 0.82 kg kg -1 and SSS, 0.79 kg kg -1). A similar pattern was detected for TN and exchangeable K. Results indicated that while the use of NT improved soil quality, long-term implementation of continuous corn had similar soil quality parameters to those found under a corn-soybean rotation.
  • Authors:
    • Deng,Q.
    • Hui,D. F.
    • Wang,J. M.
    • Iwuozo,S.
    • Yu,C. L.
    • Jima,T.
    • Smart,D.
    • Reddy,C.
    • Dennis,S.
  • Source: Web Of Knowledge
  • Volume: 10
  • Issue: 4
  • Year: 2015
  • Summary: Background: A three-year field experiment was conducted to examine the responses of corn yield and soil nitrous oxide (N 2O) emission to various management practices in middle Tennessee. Methodology/Principal Findings: The management practices include no-tillage + regular applications of urea ammonium nitrate (NT-URAN); no-tillage + regular applications of URAN + denitrification inhibitor (NT-inhibitor); no-tillage + regular applications of URAN + biochar (NT-biochar); no-tillage + 20% applications of URAN + chicken litter (NT-litter), no-tillage + split applications of URAN (NT-split); and conventional tillage + regular applications of URAN as a control (CT-URAN). Fertilizer equivalent to 217 kg N ha -1 was applied to each of the experimental plots. Results showed that no-tillage (NT-URAN) significantly increased corn yield by 28% over the conventional tillage (CT-URAN) due to soil water conservation. The management practices significantly altered soil N 2O emission, with the highest in the CT-URAN (0.48 mg N 2O m -2 h -1) and the lowest in the NT-inhibitor (0.20 mg N 2O m -2 h -1) and NT-biochar (0.16 mg N 2O m -2 h -1) treatments. Significant exponential relationships between soil N 2O emission and water filled pore space were revealed in all treatments. However, variations in soil N 2O emission among the treatments were positively correlated with the moisture sensitivity of soil N 2O emission that likely reflects an interactive effect between soil properties and WFPS. Conclusion/Significance: Our results indicated that improved fertilizer and soil management have the potential to maintain highly productive corn yield while reducing greenhouse gas emissions.