• Authors:
    • Du YuNeng
    • Huffman,T.
    • Daneshfar,B.
    • Green,M.
    • Feng Feng
    • Liu JianGui
    • Liu TingTing
    • Liu HuanJun
  • Source: Canadian Journal of Soil Science
  • Volume: 95
  • Issue: 3
  • Year: 2015
  • Summary: Canada's terrestrial ecostratification framework provides nested spatial units for organizing national data related to soils, landforms and land use. In the agricultural domain, the lack of national, uniform crop yield data on the ecostratification framework severely hinders our ability to evaluate the biophysical data with respect to economic and climatic conditions. We developed a national crop yield database at the regional (ecodistrict) level by aggregating individual records of an existing but very broad-level sample-derived yield database according to the ecostratification hierarchy. Issues related to the different sampling frameworks and the need for confidentiality of individual records were resolved in order to generate an ecostratified crop yield dataset at a reasonably detailed spatial scale. Sixty crops were first statistically arranged into 37 agronomically similar crop groups in order to increase class size, and these crop groups were aggregated into increasingly large spatial units until confidentiality was assured. The methodology maintained data quality and confidentiality while producing crop yield estimates at the ecodistrict level. Comparison to independent crop insurance data confirmed that the resulting crop yield data are valid where estimates were derived from data released at the level of an ecodistrict or an ecoregion, but not at the ecoprovince level. Our crop yield estimates offer a reasonably high level of spatial precision while remaining within standard confidentiality constraints.
  • Authors:
    • Hou,Yong
    • Ma,Lin
    • Sardi,Katalin
    • Sisak,Istvan
    • Ma,Wenqi
  • Source: Nutrient Cycling in Agroecosystems
  • Volume: 102
  • Issue: 3
  • Year: 2015
  • Summary: Nitrogen (N) emissions from food production can cause serious environmental problems. Mitigation strategies require insights of N cycles in this complex system. A substance flow analysis for N in the Hungary food production and processing chain over the period 1961-2010 was conducted. Our results show that the history of the total N input and output for the Hungary food chain consists of four distinct periods: 1961-1974 a rapid increase; 1974-1988 a steady increase; 1988-1992 a sharp decrease; 1992-2010 a period of large annual variations. The total N input to the food chain largely depended on N fertilizer input (on average 83 % of total input). Nitrogen losses were the largest outflows, particularly via ammonia emissions and denitrification from agricultural systems. The N use efficiency (NUE) for crop production sharply decreased from 1961 to 1974, but went up since the late 1980s. The NUE of animal production increased from 11 % in 1961 to 20 % in 2010. The N cost of food production in Hungary largely varied from 3 to 10 kg kg(-1) during 1961-2010, which was related to changes in fertilizer use and human dietary preferences. Increased dependence of crop yield on weather was observed since the early 1990s where large decrease in N fertilizer use occurred. The observed weather-dependence has resulted in large yearly variations in crop yields, the NUE of crop production and also the food N cost, which may pose a threat to food security of Hungary.
  • Authors:
    • Traerup,Sara
    • Stephan,Jean
  • Source: Climatic Change
  • Volume: 131
  • Issue: 3
  • Year: 2015
  • Summary: Increasing attention is being given to climate technologies on the international climate change agenda, not least in the agricultural sector and water sectors, and to technologies for adaptation. However investments in technology-based adaptation (seeds, dams, irrigation, etc.) are complicated by the fact that it remains difficult to predict future climate change impacts, especially on a local scale. In addition, evidence for the costs and benefits of implementing adaptation technologies is relatively limited. The analysis presented in this paper shows that there is a large potential for integrating adaptation technologies into the planning and implementation of on-going and future projects. Based on local-level data from a technology needs assessment project in Lebanon, this paper presents two examples of the economic feasibility of implementing adaptation technologies in the agricultural and water sectors. The results show that the technologies can be applied at low cost and with relatively little effort.
  • Authors:
    • van Dijl,E. A.
    • Grogan,K. A.
    • Borisova,T.
  • Source: Journal of Soil and Water Conservation
  • Volume: 70
  • Issue: 4
  • Year: 2015
  • Summary: In the United States, Florida ranks second among states for both value and land area of vegetable production, but this production is affected by periodic droughts. Florida has experienced at least one severe and widespread drought every decade since 1900, and climate change projections show that meteorological droughts will occur more often in the future. While drought and climate change affect the supply side, population growth is expected to affect the demand side of water availability. Given these threats to future water availability, the adoption of drought adaptation and water conservation measures is of increasing importance in Florida. Using a 2013 survey of Florida vegetable growers, this paper addresses two main components of this problem. First, we assess the current rates of adoption of drought adaptation measures. Second, we analyze which factors influence or impede the adoption of these measures to provide policy recommendations to increase adoption in the future. We find low rates of adoption of adaptations, ranging from 13% to 55%, and factors determining who adopts a given adaptation vary by adaptation. Factors can have opposite effects on the probability of adoption across different adaptations. Unlike most previous work, we find that growers with more education have lower rates of adoption of water augmentation measures, and lack of land ownership does not necessarily impede adoption of adaptations with large initial investment.
  • Authors:
    • Wilson,T. M.
    • McGowen,B.
    • Mullock,J.
    • Arnall,D. B.
    • Warren,J. G.
  • Source: Agronomy Journal
  • Volume: 107
  • Issue: 5
  • Year: 2015
  • Summary: Fertilizer-induced N 2O-N emissions (the difference between fertilized and unfertilized soils) are estimated to be 0.01 kg N 2O-N kg -1 of applied N. One approach to limiting N 2O-N production in soils is by improving nitrogen use efficiency (NUE) in dryland agricultural systems. However, baseline data on the rate of emissions is needed to determine the potential impact that these efforts might have on N 2O-N concentrations in the atmosphere. A study was established in a long-term continuous winter wheat ( Triticum aestivum L.) fertility experiment in Stillwater, OK, to determine the effects of N rate on N 2O-N emissions from a dryland winter wheat-summer fallow system in the southern Great Plains of the United States to fill this knowledge gap. Cumulative emissions of N 2O-N varied from year to year and were influenced by environment and N rate. Emissions following N fertilizer application were typically highest following N application, as well as toward the end of the summer fallow period, when summer rainfall and temperatures were conducive for N 2O-N production chambers within plots historically receiving 134 kg N ha -1 annually went unfertilized for the 2012-2013 and 2013-2014 crop years and produced N 2O-N emissions equivalent to the 45 and 90 kg N ha -1 rate treatments. Annual cumulative emissions ranged from 0.009 to 0.024 kg N 2O-N kg -1 N applied with an average of 0.015 kg N 2O-N kg -1 N applied, illustrating the variability in N 2O-N emissions.
  • Authors:
    • Vaccari,F. P.
    • Maienza,A.
    • Miglietta,F.
    • Baronti,S.
    • Lonardo,S. di
    • Giagnoni,L.
    • Lagomarsino,A.
    • Pozzi,A.
    • Pusceddu,E.
    • Ranieri,R.
    • Valboa,G.
    • Genesio,L.
  • Source: Agriculture, Ecosystems and Environment
  • Volume: 207
  • Year: 2015
  • Summary: Biochar addition to soil is a promising option for climate change mitigation and is recognized to exert beneficial effects on soil fertility. However, recent meta-analysis documented controversial effects on soil-plant interactions and on crop yields response. The data presented in this paper are the results of a field experiment on a processing tomato crop aiming to enhance the knowledge on the real applicability of biochar at farm scale in a high fertility alkaline soil. The effects of two biochar types on soil properties and on quantitative and qualitative parameters of processing tomato were evaluated. Biochar application significantly increased the soil carbon content, the soil cation exchange capacity and the availability of NH 4+, P and K. Moreover, it stimulated plant growth and N, P and base cation contents at harvest, reducing the leaf water potential in the warmer period. These results demonstrate that also intensive cultivations in fertile soil can benefit from biochar amendment.
  • Authors:
    • Bosco,S.
    • Volpi,I.
    • o Di Nasso,N. N.
    • Triana,F.
    • Roncucci,N.
    • Tozzini,C.
    • Villani,R.
    • Laville,P.
    • Neri,S.
    • Mattei,F.
    • Virgili,G.
    • Nuvoli,S.
    • Fabbrini,L.
    • Bonari,E.
  • Source: Italian Journal of Agronomy
  • Volume: 10
  • Issue: 3
  • Year: 2015
  • Summary: Agricultural activities are co-responsible for the emission of the most important greenhouse gases: carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O). Development of methodologies to improve monitoring techniques for N2O are still needful. The LIFE+IPNOA project aims to improve the emissions monitoring of nitrous oxide from agricultural soils and to identify the agricultural practices that can limit N2O production. In order to achieve this objective, both a mobile and a stationary instrument were developed and validated. Several experimental field trials were set up in two different sites investigating the most representative crops of Tuscany (Central Italy), namely durum wheat, maize, sunflower, tomato and faba bean. The field trials were realized in order to test the effect on N2O emissions of key factors: tillage intensity, nitrogen fertiliser rate and irrigation. The field trial on durum wheat was set up in 2013 to test the effect of tillage intensity (minimum and conventional tillage) and nitrogen fertilisation rate (0, 110, 170 kg N ha-1) on soil N2O flux. Monitoring was carried out using the IPNOA mobile prototype. Preliminary results on N2O emissions for the durum wheat growing season showed that mean daily N2O fluxes ranged from –0.13 to 6.43 mg m-2 day-1 and cumulative N2O-N emissions over the period ranged from 827 to 2340 g N2O-N ha-1. Tillage did not affect N2O flux while increasing nitrogen fertilisation rate resulted to significantly increase N2O emissions. The IPNOA mobile prototype performed well during this first year of monitoring, allowing to catch both very low fluxes and peaks on N2O emissions after nitrogen supply, showing a good suitability to the field conditions. © S. Bosco et al., 2015 Licensee PAGEPress, Italy.
  • Authors:
    • Goglio,Pietro
    • Smith,Ward N.
    • Grant,Brian B.
    • Desjardins,Raymond L.
    • McConkey,Brian G.
    • Campbell,Con A.
    • Nemecek,Thomas
  • Source: Journal of Cleaner Production
  • Volume: 104
  • Year: 2015
  • Summary: Soil carbon sequestration, a climate change mitigation option for agriculture, can either increase or decrease as a result of land management change (LMC) and land use change (LUC). To estimate all greenhouse gas (GHG) exchanges associated with various agricultural systems, life cycle assessments (LCAs) are frequently undertaken. To date LCA practitioners have not had a well-defined procedure to account for soil C in their assessments and as a consequence it is often not included. In this study, various methods used to estimate soil C changes due to (i) LMC and (ii) LUC are examined to assess soil C accounting methodologies in the life cycle inventory (LCI) of agricultural LCAs. A compromise between accuracy and completeness in LCA methods is necessary. A ranking of the preference of soil C accounting methods is suggested based on user expertise and data quality. For large scale assessment, the timing of soil CO2 emissions should be taken into account. If indirect LUC is relevant, a sensitivity analysis of assessment methods should be conducted because the methods highly affect assessment results. A common soil C accounting method that can be easily applied in agricultural LCA needs to be established and an agreement on indirect LUC methods will facilitate the assessment of LMC and LUC within agricultural LCAs. Crown Copyright (C) 2015 Published by Elsevier Ltd. All rights reserved.
  • 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:
    • Aengelo Rodrigues,M.
    • Dimande,Paulo
    • Pereira,Ermelinda L.
    • Ferreira,Isabel Q.
    • Freitas,Sara
    • Correia,Carlos M.
    • Moutinho-Pereira,Jose
    • Arrobas,Margarida
  • Source: Nutrient Cycling in Agroecosystems
  • Volume: 103
  • Issue: 2
  • Year: 2015
  • Summary: Cover cropping is a major challenge in the sustainable management of rainfed olive orchards. From a 5 year study (2009-2014), the effect of a mixture of early-maturing and self-reseeding annual legumes (Legs) grown as a cover crop in a rainfed olive orchard was compared with a cover of natural vegetation fertilized with 60 kg nitrogen (N) ha(-1) year(-1) (NV +N), and a cover of natural vegetation not fertilized (NV -N). The study took place in NE Portugal. The following were assessed: (1) the performance of the covers by measuring ground cover percentages, dry matter yields and N content in aboveground biomass; (2) the soil fertility through chemical and microbiological assays and by growing plants in pot experiments; and (3) the nutritional status of olive trees and olive yields. Legumes gave higher ground-cover percentages, produced more biomass and accumulated more N in shoots in comparison to natural vegetation, whether fertilized or not. The results showed intense biological activity [microbial carbon (C) and N, CO2-C evolved in a laboratory incubation, metabolic quotient, total culturable fungi and bacteria, and acid phosphatase activity] in the 0-10 cm soil layer of the treatments producing more biomass (Legs and NV +N). However, soil available N was greater in soil samples from the Legs plot. N recoveries by turnip (Brassica rapa var. rapa L.) and rye (Secale cereale L.) grown in pot experiments were 84.4 and 60.2 mg pot(-1) in soil samples from the Legs treatment and 29.4 and 27.1 mg pot(-1) and 14.2 and 13.6 mg pot(-1), respectively in NV +N and NV -N plots. Sown legumes appeared less effective in increasing organic C than natural vegetation. Nevertheless, in the Legs plot the increase of easily mineralizable C was proportionally higher than the increase of total organic C, which may mean that a more reactive pool of organic C is created, which may reduce the turnover of organic C and N in the soil. In the 10-20 cm soil layer, total organic C was significantly lower in Legs (14.0 g kg(-1)) than in NV -N (22.1 g kg(-1)) and N +NV (25.2 g kg(-1)) treatments, likely due to a priming effect caused by mineral N coming from the surface layer. Two years after the trial started, the N nutritional status of the olive trees was significantly higher in Legs than in natural vegetation plots even when 60 kg N ha(-1) year(-1) was applied. The cumulative olive yields in NV -N and NV +N plots were only 58.6 and 77.7 % in comparison to those found in the Legs plot, if only the last four harvests were considered, which were those influenced by the ground-cover treatments (2010-2013).