@misc{PradhanFischerVelthuizenetal.2015,
  author    = {Pradhan, Prajal and Fischer, G{\"u}nther and Velthuizen, Harrij van and Reusser, Dominik Edwin and Kropp, J{\"u}rgen},
  title     = {Closing yield gaps},
  series = {Postprints der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe},
  journal   = {Postprints der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe},
  number    = {491},
  issn      = {1866-8372},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-408105},
  pages     = {18},
  year      = {2015},
  abstract  = {Global food production needs to be increased by 60-110\% between 2005 and 2050 to meet growing food and feed demand. Intensification and/or expansion of agriculture are the two main options available to meet the growing crop demands. Land conversion to expand cultivated land increases GHG emissions and impacts biodiversity and ecosystem services. Closing yield gaps to attain potential yields may be a viable option to increase the global crop production. Traditional methods of agricultural intensification often have negative externalities. Therefore, there is a need to explore location-specific methods of sustainable agricultural intensification. We identified regions where the achievement of potential crop calorie production on currently cultivated land will meet the present and future food demand based on scenario analyses considering population growth and changes in dietary habits. By closing yield gaps in the current irrigated and rain-fed cultivated land, about 24\% and 80\% more crop calories can respectively be produced compared to 2000. Most countries will reach food self-sufficiency or improve their current food self-sufficiency levels if potential crop production levels are achieved. As a novel approach, we defined specific input and agricultural management strategies required to achieve the potential production by overcoming biophysical and socioeconomic constraints causing yield gaps. The management strategies include: fertilizers, pesticides, advanced soil management, land improvement, management strategies coping with weather induced yield variability, and improving market accessibility. Finally, we estimated the required fertilizers (N, P2O5, and K2O) to attain the potential yields. Globally, N-fertilizer application needs to increase by 45-73\%, P2O5-fertilizer by 22-46\%, and K2O-fertilizer by 2-3 times compared to the year 2010 to attain potential crop production. The sustainability of such agricultural intensification largely depends on the way management strategies for closing yield gaps are chosen and implemented.},
  language  = {en}
}
@article{NeillJankowskiBrandoetal.2017,
  author    = {Neill, Christopher and Jankowski, KathiJo and Brando, Paulo M. and Coe, Michael T. and Deegan, Linda A. and Macedo, Marcia N. and Riskin, Shelby H. and Porder, Stephen and Elsenbeer, Helmut and Krusche, Alex V.},
  title     = {Surprisingly Modest Water Quality Impacts From Expansion and Intensification of Large-Sscale Commercial Agriculture in the Brazilian Amazon-Cerrado Region},
  series = {Tropical conservation science},
  volume    = {10},
  journal   = {Tropical conservation science},
  publisher = {Sage Publ.},
  address   = {Thousand Oaks},
  issn      = {1940-0829},
  doi       = {10.1177/1940082917720669},
  pages     = {5},
  year      = {2017},
  abstract  = {Large-scale commercial cropping of soybeans expanded in the tropical Amazon and Cerrado biomes of Brazil after 1990. More recently, cropping intensified from single-cropping of soybeans to double-cropping of soybeans with corn or cotton. Cropland expansion and intensification, and the accompanying use of mineral fertilizers, raise concerns about whether nutrient runoff and impacts to surface waters will be similar to those experienced in commercial cropland regions at temperate latitudes. We quantified water infiltration through soils, water yield, and streamwater chemistry in watersheds draining native tropical forest and single-and double-cropped areas on the level, deep, highly weathered soils where cropland expansion and intensification typically occurs. Although water yield increased four-fold from croplands, streamwater chemistry remained largely unchanged. Soil characteristics exerted important control over the movement of nitrogen (N) and phosphorus (P) into streams. High soil infiltration rates prevented surface erosion and movement of particulate P, while P fixation in surface soils restricted P movement to deeper soil layers. Nitrogen retention in deep soils, likely by anion exchange, also appeared to limit N leaching and export in streamwater from both single-and double-cropped watersheds that received nitrogen fertilizer. These mechanisms led to lower streamwater P and N concentrations and lower watershed N and P export than would be expected, based on studies from temperate croplands with similar cropping and fertilizer application practices.},
  language  = {en}
}
@article{JaenickeGoddardSteinetal.2022,
  author    = {J{\"a}nicke, Clemens and Goddard, Adam and Stein, Susanne and Steinmann, Horst-Henning and Lakes, Tobia and Nendel, Claas and M{\"u}ller, Daniel},
  title     = {Field-level land-use data reveal heterogeneous crop sequences with distinct regional differences in Germany},
  series = {European journal of agronomy},
  volume    = {141},
  journal   = {European journal of agronomy},
  publisher = {Elsevier},
  address   = {Amsterdam},
  issn      = {1161-0301},
  doi       = {10.1016/j.eja.2022.126632},
  pages     = {12},
  year      = {2022},
  abstract  = {Crop cultivation intensifies globally, which can jeopardize biodiversity and the resilience of cropping systems. We investigate changes in crop rotations as one intensification metric for half of the croplands in Germany with annual field-level land-use data from 2005 to 2018. We proxy crop rotations with crop sequences and compare how these sequences changed among three seven-year periods. The results reveal an overall high diversity of crop sequences in Germany. Half of the cropland has crop sequences with four or more crops within a seven-year period, while continuous cultivation of the same crop is present on only 2\% of the cropland. Larger farms tend to have more diverse crop sequences and organic farms have lower shares of cereal crops. In three federal states, crop rotations became less structurally diverse over time, i.e. the number of crops and the number of changes between crops decreased. In one state, structural diversity increased and the proportion of monocropping decreased. The functional diversity of the crop sequences, which measures the share of winter and spring crops as well as the share of leaf and cereal crops per sequence, remained largely stable. Trends towards cereal-or leaf -crop dominated sequences varied between the states, and no clear overall dynamic could be observed. However, the share of winter crops per sequence decreased in all four federal states. Quantifying the dynamics of crop sequences at the field level is an important metric of land-use intensity and can reveal the patterns of land-use intensification.},
  language  = {en}
}