Browsing by Subject "Herbicides"

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  • Fahmi, Mustafa Kamil Mahmoud; Dafa-Alla, Dafa-Alla Mohamed; Kanninen, Markku; Luukkanen, Olavi (2018)
    National food security has been a major policy goal in Sudan since the country gained its independence in 1956. One of the fundamental reasons is to ensure the social welfare for people living in rural areas. In this study we aimed to analyse how farmers secure their food and generate income in the semi-arid Sennar state in Sudan, using two selected sites, El Dali and El Mazmum, as examples. We interviewed 281 randomly sampled household heads, of which 145 at El Dali and 136 at El Mazmum, between July and November 2011. We identified four distinct land use systems, of which three consist of monocropping and one of cultivation in agroforestry parklands. Several statistical techniques and economic analysis were applied on the study data. Our results show that, in the two areas, the highest average yields over a 10-year period for the three crops studied, sorghum, pearl millet and sesame, were achieved in agroforestry system, except for the case of sesame at El Mazmum. Economic returns for the farmers, as indicated by net present value or benefit/cost ratio, followed the same pattern. The study concludes that farmers should rely more on agroforestry to improve their food security and cash income generation. Land use and land right policies, which currently discourage farmers from growing trees on their lands, should be revised, so as to give more incentive to them to adopt ecologically and economically more sustainable land use practices.
  • Kerminen, Kaisa Aino Maria; Moël, Romain Le; Harju, Anu Vilhelmiina; Kontro, Merja Hannele (2018)
    Pesticides leaching from soil to surface and groundwater are a global threat for drinking water safety, as no cleaning methods occur for groundwater environment. We examined whether peat, compost-peat-sand (CPS) mixture, NH4NO3, NH4NO3 with sodium citrate (Na-citrate), and the surfactant methyl-beta-cyclodextrin additions enhance atrazine, simazine, hexazinone, dichlobenil, and the degradate 2,6-dichlorobenzamide (BAM) dissipations in sediment slurries under aerobic and anaerobic conditions, with sterilized controls. The vadose zone sediment cores were drilled from a depth of 11.3-14.6m in an herbicide-contaminated groundwater area. The peat and CPS enhanced chemical atrazine and simazine dissipation, and the peat enhanced chemical hexazinone dissipation, all oxygen-independently. Dichlobenil dissipated under all conditions, while BAM dissipation was fairly slow and half-lives could not be calculated. The chemical dissipation rates could be associated with the chemical structures and properties of the herbicides, and additive compositions, not with pH. Microbial atrazine degradation was only observed in the Pseudomonas sp. ADP amended slurries, although the sediment slurries were known to contain atrazine-degrading microorganisms. The bioavailability of atrazine in the water phase seemed to be limited, which could be due to complex formation with organic and inorganic colloids. Atrazine degradation by indigenous microbes could not be stimulated by the surfactant methyl-beta-cyclodextrin, or by the additives NH4NO3 and NH4NO3 with Na-citrate, although the nitrogen additives increased microbial growth. (C) 2017 Elsevier B.V. All rights reserved.