19872015
  • Authors:
    • Burow, G.
    • Xin, Z. Q.
    • Chen, J. P.
    • Payton, P.
    • Burke, J. J.
    • Hayes, C.
  • Source: Crop Science
  • Volume: 55
  • Issue: 1
  • Year: 2015
  • Summary: Water-deficit stress responses in sorghum [Sorghum bicolor (L.) Moench] have been described in the literature as preflowering drought tolerant (postflowering senescent) or postflowering drought tolerant (preflowering drought sensitive). The underlying physiological mechanisms associated with these drought traits remain unclear. It was hypothesized that the preflowering drought sensitivity of stay-green lines could be related to reported differences in osmotic potential among stay-green and senescent lines resulting in an inability of the cultivars to either sense or respond the soil drying until the rate of drying is too great for the stay-green lines to compensate. The objective of this study was to measure stress-induced changes in relative water content, abscisic acid (ABA), proline, dhurrin, sucrose, and carbon assimilation during the onset of water-deficit stress in the preflowering drought-tolerant line SC1211-11E and the postflowering drought-tolerant line BTx642 to determine if there were differential responses to the onset of soil drying. In both greenhouse and field studies, it was found that SC1211-11E had lower relative water contents and accumulated higher levels of ABA and proline than the BTx642. The SC1211-11E also showed increases in carbon assimilation shortly after the cessation of irrigation that declined with prolonged stress. These results provide new insights into the differential responses of pre and postflowering drought-tolerant sorghum lines.
  • Authors:
    • Novak, J. M.
    • Cantrell, K. B.
    • Hunt, P. G.
    • Stone, K. C.
    • Sigua, G. C.
  • Source: AGRONOMY FOR SUSTAINABLE DEVELOPMENT
  • Volume: 35
  • Issue: 2
  • Year: 2015
  • Summary: Biochar is a black solid formed by pyrolysis of biomass such as crop residues. Biochar could be used for soil fertilization, carbon sequestration, and improvement of soil structure. Here, we tested the effect of sorghum biochars on winter wheat, with or without supplemental inorganic phosphorus, in a greenhouse. The application rate for sorghum residues and sorghum biochars based on a yield goal of 200 bushels ha(-1) was 13 Mg ha(-1). Inorganic phosphorus was added at the rate of 40 kg P ha(-1). Results show that addition of sorghum biochars increased the total biomass of winter wheat grown by about 31 % over the control plants. Addition of supplemental inorganic phosphorus did not increase the total biomass. Our findings suggest that the pyrolitic transformation of sorghum residues into sorghum biochars is a better strategy for both environmental and crop productivity improvement in the Coastal Plains region.
  • Authors:
    • Buerkert, Andreas
    • Bruentrup, Michael
    • Lamers, John P. A.
  • Source: Nutrient Cycling in Agroecosystems
  • Volume: 102
  • Issue: 1
  • Year: 2015
  • Summary: Low concentrations of phosphorus (P) also limit crop production on the acid, sandy soils in Sudano-Sahelian West Africa (SSWA). An increased P-use is thus a key leverage for enhancing food security and alleviating poverty. Therefore, P-imports into the predominating agro-pastoral farming systems are indispensable, but most smallholders are cash-poor and risk averse, face labor-constraints, and P-fertiliser responses are site-specific. Key to the adoption of any new technology is a high financial performance with low risk levels of failure, low demands of labor and cash, and adaptation to the prevailing farming systems. Financial performances were assessed from nine, annually applied fertilising practices during 4 years in five SSWA zones. Information about the farming systems, labor demands, and input-output prices stem from secondary sources. The profitability largely depended on rainfall and location-specific soil conditions, but those of annually repeated mineral and organic P-strategies increased over time. Several P-fertilisations were profitable on a per land unit basis, but could not compete with farmers' practices on a per labor unit basis. Mulching with and without P (13 kg P ha(-1)) were not financially superior, but the broadcast application of 13 kg P ha(-1) became profitable over time. Hill-placed P (4 kg P ha(-1)), also known as micro-dosing, was a profitable alternative to farmers' practices particularly in the intermediate rainfall zone. The results showed the importance of recommendations following rainfall zones, which are of interest across a spectrum of users including policy makers, land use practitioners, private firms, NGOs and research for development implementers.
  • Authors:
    • Agostini,Alessandro
    • Battini,Ferdinando
    • Giuntoli,Jacopo
    • Tabaglio,Vincenzo
    • Padella,Monica
    • Baxter,David
    • Marelli,Luisa
    • Amaducci,Stefano
  • Source: Desarrollo Tecnológico - Institut De Reconeixement Molecular I Desenvolupament Tecnològic
  • Volume: 8
  • Issue: 6
  • Year: 2015
  • Summary: We analysed the environmental impacts of three biogas systems based on dairy manure, sorghum and maize. The geographical scope of the analysis is the Po valley, in Italy. The anaerobic digestion of manure guarantees high GHG (Green House Gases) savings thanks to the avoided emissions from the traditional storage and management of raw manure as organic fertiliser. GHG emissions for maize and sorghum-based systems, on the other hand, are similar to those of the Italian electricity mix. In crop-based systems, the plants with open-tank storage of digestate emit 50% more GHG than those with gas-tight tanks. In all the environmental impact categories analysed (acidification, particulate matter emissions, and eutrophication), energy crops based systems have much higher impacts than the Italian electricity mix. Maize-based systems cause higher impacts than sorghum, due to more intensive cultivation. Manure-based pathways have always lower impacts than the energy crops based pathways, however, all biogas systems cause much higher impacts than the current Italian electricity mix. We conclude that manure digestion is the most efficient way to reduce GHG emissions; although there are trade-offs with other local environmental impacts. Biogas production from crops; although not providing environmental benefits per se; may be regarded as an option to facilitate the deployment of manure digestion.
  • Authors:
    • Prasad,J. V. N. S.
    • Rao,Ch S.
    • Ravichandra,K.
    • Jyothi,Ch N.
    • Babu,M. B. B. P.
    • Babu,V. R.
    • Raju,B. M. K.
    • Rao,B. B.
    • Rao,V. U. M.
    • Venkateswarlu,B.
    • Devasree Naik
    • Singh,V. P.
  • Source: Journal of Agrometeorology
  • Volume: 17
  • Issue: 1
  • Year: 2015
  • Summary: Carbon dioxide (CO 2), methane (CH 4) and nitrous oxide (N 2O) are important biogenic green house gases (GHGSs) from agricultural sector contributing to global warming. Temperature and rainfall play an important role in GHGS fluxes and information on their role in rainfed crops and systems is very scanty. Field studies were conducted at Hyderabad, India during 2012 rainy season to quantify GHGSs fluxes from two important food crops grown widely in rainfed regions viz. sorghum and pigeonpea. Quantum of fluxes ranged from 26-85 mg CO 2 - C m -2 h -1 in case of CO 2 and 18-68 g N 2O-N m -2 h -1 in case of N 2O at different stages of crop growth. Cumulative seasonal fluxes are 1.18 and 1.24 Mg CO 2-C ha -1 and 0.78 and 0.94 kg N 2O-N ha -1, in sorghum and pigeonpea, respectively. Ambient temperature and rainfall significantly influenced CO 2 fluxes. CO 2 fluxes increased with increase in temperature from 25.9°C to 31°C and fluxes were highest at 28.4°C in pigeonpea and at 27.7°C in sorghum. Quantum of CO 2 fluxes were highest at grain filling stage in sorghum and grand growth period in pigeonpea. N 2O fluxes increased with increase in temperature and moisture availability. These results provide evidence that rainfed crops in semi-arid regions contribute significant CO 2 and N 2O fluxes which are influenced by temperature and rainfall, thus warrant further studies.
  • Authors:
    • Mereu,Valentina
    • Carboni,Gianluca
    • Gallo,Andrea
    • Cervigni,Raffaello
    • Spano,Donatella
  • Source: Climatic Change
  • Volume: 132
  • Issue: 2
  • Year: 2015
  • Summary: Climate change impact on the agricultural sector is expected to be significant and extensive in Sub-Saharan Africa, where projected increase in temperature and changes in precipitation patterns could determine sensible reductions in crop yields and concerns for food security achievement. This study presents a multi-model approach to analysing climate change impacts and associated risks for staple food crops in Nigeria. Previous attempts to evaluate climate change impacts in Nigeria had mainly focused on a reduced number of crops, with analysis limited to single experimental fields or specific areas, and in many cases considering only a limited number of climate models. In this work, crop simulation models implemented in the DSSAT-CSM software were used to evaluate climate change impacts on crop production in different Agro-Ecological Zones, considering multiple combinations of soils and climate conditions, varieties and crop management. The climate impact assessment was made using an ensemble of future climate projections, to include uncertainty related to climate projections. Even if precipitations could increase in most parts of Nigeria, this is not likely to offset the crop yield reduction due to the increase in temperatures, particularly over the medium-term period (2050), with yield decreases projected especially for cereals. The short-term effects are more uncertain and yields for cassava and millet might actually increase by 2020. Moreover, yield reductions are only partially mitigated by the direct effect of increased CO2 atmospheric concentration enhancing crop yield. In both periods and for all crops, there is a higher risk that crop yields may fall below the actual risk threshold.
  • Authors:
    • Karasawa,Toshihiko
    • Takahashi,Shigeru
  • Source: Nutrient Cycling in Agroecosystems
  • Volume: 103
  • Issue: 1
  • Year: 2015
  • Summary: Field experiments were conducted to clarify whether the introduction of several cover crop species increases P uptake of the following wheat and soybean. Four summer cover crops (sorghum, buckwheat, groundnut and crotalaria) and four winter cover crops (oat, rye, vetch and lupin) were tested. Growth and P uptake of succeeding wheat were significantly increased by P fertilizer application and tended to be increased by sorghum, groundnut or crotalaria incorporation, whereas buckwheat did not show positive effects. Growth and P uptake of succeeding soybean were significantly increased by oat or vetch incorporation and tended to be increased by P fertilizer or other cover crop incorporation. These positive effects of cover crops were attributed to the large amount of P incorporation, increase in the P-solubilizing fungal population and/or biomass P in soil. Sorghum, oat, rye and vetch were thought to be suitable cover crops to accelerate P uptake of the following crops since a large amount of P would be incorporated. Sorghum, groundnut and lupin were thought to be suitable cover crops because they increased the indigenous P-solubilizing fungal population in soil. Soil biomass P correlated with P uptake of wheat. Incorporation of suitable cover crops as a P source and activation of indigenous soil microorganisms by the carbon supply were thought to have accelerated P uptake of the following wheat and soybean. It is therefore thought that introduction of suitable cover crops could be an effective means to reduce P fertilizer application for the following crops.
  • Authors:
    • Siles,J. A.
    • Cajthaml,T.
    • Hernandez,P.
    • Perez-Mendoza,D.
    • Garcia-Romera,I.
    • Sampedro,I.
  • Source: Microbial Ecology
  • Volume: 70
  • Issue: 1
  • Year: 2015
  • Summary: Dry olive residue (DOR) is a waste product derived from olive oil extraction and has been proposed as an organic amendment. However, it has been demonstrated that a pre-treatment, such as its transformation by saprophytic fungi, is required before DOR soil application. A greenhouse experiment was designed where 0 and 50 g kg -1 of raw DOR (DOR), Coriolopsis floccosa-transformed DOR (CORDOR) and Fusarium oxysporum-transformed DOR (FUSDOR) were added to soil. Analyses of the soil chemical properties as well as the structure and relative abundance of bacterial and actinobacterial communities were conducted after 0, 30 and 60 days following amendment. The different amendments produced a slight decrease in soil pH and significant increases in carbon fractions, C/N ratios, phenols and K, with these increases being more significant after DOR application. Quantitative PCR assays of the 16S rRNA gene and PLFA analyses showed that all amendments favoured bacterial growth at 30 and 60 days, although actinobacterial proliferation was more evident after CORDOR and FUSDOR application at 60 days. Bacterial and actinobacterial DGGE multivariate analyses showed that the amendments produced structural changes in both communities, especially after 60 days of amendment. PLFA data analysis identified changes in soil microbial communities according to the amendment considered, with FUSDOR and CORDOR being less disruptive than DOR. Finally, integrated analysis of all data monitored in the present study enabled us to conclude that the greatest impact on soil properties was caused by DOR at 30 days and that soil showed some degree of resilience after this time.
  • Authors:
    • Eggleston, G.
    • Lima, I.
  • Source: Sustainability
  • Volume: 7
  • Issue: 9
  • Year: 2015
  • Summary: Like many other industries, the sugar and sugar-bioproduct industries are facing important sustainability issues and opportunities. The relatively low and fluctuating profit for sugar, surpluses of sugar, world-wide trend to produce alternative, renewable bio-based fuels and chemicals to those derived from petroleum and reduce greenhouse gases, water- and energy-intensive factories and refineries, and increased consumer demands for sustainably manufactured products are putting pressure on the industries to diversify for sustainability. Sugar crops, including sugar and energy cane (Saccharum officinarum), sugar and energy beets (Beta vulgaris), and sweet sorghum (Sorghum bicolor L. Moench), are excellent, renewable biomass feedstocks because of their availability, their being amongst the plants that give the highest yields of carbohydrates per hectare, and high sugar contents. While much research has been focused on conversion technologies for advanced biofuels and bioproducts, attention is now focused on developing sustainable supply chains of sugar feedstocks for the new, flexible biorefineries, with customers wanting maximum feedstock reliability and quality, while minimizing cost. All biomass from sugar crops are potential feedstocks. The cogeneration of bioelectricity from bagasse and leaf residues is being increasingly manufactured in more countries and, due to the high carbon content of bagasse and leaves, can also be converted into value-added products such as biochar. Sugar crops are superior feedstocks for the production of platform chemicals for the manufacture of a range of end-products, e.g., bioplastics, chemicals, and biomaterials. In several countries and regions, green sustainability criteria are now in place and have to be met to count against national biofuel targets. Processes to convert high-fiber sugar crop biomass into biofuel have been developed but there has only been limited commercialization at the large-scale.
  • Authors:
    • Maxted, N.
    • Kang, D.
    • Wei, W.
    • Ford-Lloyd,B.
    • Chen, B.
    • Qin, H.
    • Kell, S.
  • Source: Science Article
  • Volume: 209
  • Year: 2015
  • Summary: The potentially devastating impacts of climate change on crop production and food security are now widely acknowledged. An important component of efforts to mitigate these impacts is the production of new varieties of crops which will be able to thrive in more extreme and changeable environmental conditions. There is therefore an urgent need to find new sources of genetic diversity for crop improvement. Wild plant species closely related to crops (crop wild relatives) contain vital sources of such genes, yet these resources themselves are threatened by the effects of climate change, as well as by a range of other human-induced pressures and socio-economic changes. The flora of China comprises more than 20,000 native higher plant species, a proportion of which have known or potential value as gene donors for crop improvement. However, until now, the full range of these valuable crop wild relative species had not been identified. In this paper we present a methodology for creating a checklist of, and prioritizing China's crop wild relatives, and reveal that 871 native species are related to crops that are of particularly high socio-economic importance in China-including rice, wheat, soybean, potato, sweet potato, millet and yam-crops which are also of notably high value for food and economic security in other parts of the world. Within this list we have identified species that are in particular need of conservation assessment based on their relative Red List status and potential for use in crop improvement programs. Endemic species that have particularly high economic value potential in China and that are under severe threat of genetic erosion and thus in need of urgent conservation action include wild relatives of tea ( Camellia fangchengensis S. Yun Liang et Y.C. Zhong and C. grandibracteata H.T. Chang et F.L. Yu), apple ( e.g., Malus honanensis Rehder, M. ombrophila Hand.-Mazz. and M. toringoides (Rehder) Hughes), and pear ( Pyrus pseudopashia T.T. Yu). We provide recommendations for developing a systematic and comprehensive national CWR conservation strategy for China, highlighting the challenges and requirements of taking the strategy forward to the implementation phase.