Title of the dataset:
Data from: Reference values for arable crop residues: organic matter and C:N ratio

Creators:
- Isabella Selin Norén
ORCID: 0000-0003-2481-3252
Wageningen Plant Research (Open Teelten | Field Crops), Wageningen University & Research
Post box 430, 8200 AK Lelystad
Visiting address: Edelhertweg 1, 8219 PH Lelystad, The Netherlands 
T: +31(0)614317482 of/or T: +31(0)320291174
W: NL www.wur.nl/openteelten | EN www.wur.eu/fieldcrops
- Willem van Geel
Digital Author ID:eu-repo/dai/nl/155679139
Wageningen Plant Research (Open Teelten | Field Crops), Wageningen University & Research
- Janjo de Haan
ORCID: 0000-0002-5686-4348
- Imke Harms (NMI Agro, Wageningen)
- Romke Postma (NMI Agro, Wageningen)

Related publications:
- Selin Noren, I., Kooistra, K., van Geel, W., de Haan, J. (2022) Reference values for arable crop residues: organic matter and C:N ratio, Wageningen Research, Report WPR-OT 928, DOI:https://doi.org/10.18174/566378.

Description:
This dataset has contributed to establish new reference values for organic matter and nitrogen content of twelve common arable crops in the Netherlands (see related publication). It contains crop residue data of dry- and organic matter and nitrogen content from two years of field sampling of above- and belowground plant residues. This research has been conducted with funding from the LNV-funded programme Slim Landgebruik, which is aimed at exploring the potential of carbon sequestration in agricultural soils. Two of the measures researched is the effect of crops in crop rotation and the incorporation of more crop residues into the soil. The dataset used for the related publication also contains literature data (see literature references), however due to copyright issues we have removed these entries from this published dataset.

Keywords:
crop residues
organic matter
effective organic matter
dry matter
nitrogen content
barley
wheat
grass seed
sugar beet
potato
onion
grain maize
silage maize

Spatial coverage:
The Netherlands; Locations: Lelystad, Vredepeel and Valthermond.

Temporal coverage:
2020-2021

This dataset contains the following files:
Dataset_crop_residues.csv

Explanation of variables:
Crop=The crop name in English.
Botanical_name=The crop name in latin.
Cultivar_variety=The crop varietyCrop_X=The species in separated columns, up to 4 species.
Botanical_name=The latin name of the monoculture cover crop.
Cultivar_variety=The name of the cultivar of the crop. For maize the cultivar name could not be made public. The abbreviation here refer to the following: L=late variety, V=early variety, DUN=variety with thin stem, DIK=variety with thick stem, U=extremely early variety,
Plant_part=The plant part(s) from which samples data is available (3 categories).
Other_biomass_part=Refers to what plant part is available next to aboveground and belowground residues. Either straw, stubble+straw or baby potatoes which means that this doesn't apply to all crops. Before analysis of the "other" variables, make sure you check what is actually referred to by consulting this variable(Other_biomass_part).
Location=The country of location in the Netherlands where the data was gathered.
Field_ID=Identifier of field. Mainly used for data from recent samplings.
Plot_ID=Identifier of plot. Mainly used for own data from recent samplings.
Soil_type=The soil type where the data was gathered, either clay, loam, sand or reclaimed peat soil(NL:dalgrond).
Type_sowing=Either the cover crop is sown after the main crop/pre-crop or it is sown at the same time as the main crop(Sown with main crop), or a short period after the main crop/pre-crop(Undersowing).
Sowing/planting_date_[dd/mm]=The date of planting or sowing the crop. Can be transformed to dd/mm format from this numerical format.
Sampling_date_[dd/mm]=The date of field sampling. Can be transformed to dd/mm format from this numerical format.
Year_of_study=The growing year, if available, otherwise the publication year.
Lower_potato_diameter_limit_[mm]=All potatoes with a diameter below this value were included as crop residues. 
Earliness_class_potato=Potato variety classification, following the Dutch classification system of the Dutch national catalogue of potato varieties
Leaf_development_class_potato=Potato variety classification, following the Dutch classification system of the Dutch national catalogue of potato varieties
Comment=Comments that might be relevant for interpretation of the data
Source=For literature data a short paper reference. For other data, the sampling year.
Data=Two categories: sampled data in 2020-2021 or literature data.
Product_yield_[kg/ha]=The fresh weight yield of the crop.
Product_yield_[kg_DM/ha]=The dry weight yield of the crop.
aboveground_fresh_[kg/ha]=The amount of aboveground biomass before drying.
aboveground_DM_content_[g/kg DS]=The dry matter(DM) concentration of aboveground biomass.
aboveground_DM_[kg/ha]=The amount of aboveground biomass after drying.
aboveground_crude_ash_[g/kg_DM]=The concentration of crude ash in aboveground biomass.
aboveground_OM_content_[g/kg_DM]=The concentration of organic matter in aboveground biomass. Is determined by taking 1000 minus the crude ash concentration in g/kg DM.
Weights_above=The number of repetitions on which the values are based. Also applies to "Other parts", if aboveground.
aboveground_OM_[kg/ha]= The amount of organic matter in aboveground biomass. Calculated by the concentration multiplied by the dry matter biomass. 
aboveground_N_content_[g/kg_DM]=The concentration of nitrogen in aboveground biomass.
aboveground_N_total_[kg/ha]=The amount of nitrogen in aboveground biomass. Calculated by the concentration multiplied by the dry matter biomass.
belowground_fresh_[kg/ha]=The amount of aboveground biomass before drying.
belowground_DM_content_[g/kg DS]=The dry matter(DM) concentration of belowground biomass.
belowground_DM_[kg/ha]=The amount of aboveground biomass after drying.
belowground_crude_ash_[g/kg_DM]=The concentration of crude ash in belowground biomass.
belowground_OM_content_[g/kg_DM]=The concentration of organic matter in belowground biomass. Is determined by taking 1000 minus the crude ash concentration in g/kg DM.
Weights_below=The number of repetitions on which the values are based. Also applies to "Other parts", if belowground.
belowground_OM_[kg/ha]= The amount of organic matter in belowground biomass. Calculated by the concentration multiplied by the dry matter biomass. 
belowground_N_content_[g/kg_DM]=The concentration of nitrogen in belowground biomass.
belowground_N_total_[kg/ha]=The amount of nitrogen in belowground biomass. Calculated by the concentration multiplied by the dry matter biomass.
other_fresh_[kg/ha]=The amount of aboveground biomass before drying.
other_DM_content_[g/kg DS]=The dry matter(DM) concentration of the biomass.
other_DM_[kg/ha]=The amount of aboveground biomass after drying.
other_crude_ash_[g/kg_DM]=The concentration of crude ash in biomass of the other variable.
other_OM_content_[g/kg_DM]=The concentration of organic matter in biomass of the other part. Is determined by taking 1000 minus the crude ash concentration in g/kg DM.
other_OM_[kg/ha]= The amount of organic matter in biomass. Calculated by the concentration multiplied by the dry matter biomass. 
other_N_content_[g/kg_DM]=The concentration of nitrogen in aboveground biomass.
other_N_total_[kg/ha]=The amount of nitrogen in biomass of the other variable. Calculated by the concentration multiplied by the dry matter biomass.
Total_above_OM[kg/ha]=The OM of the total aboveground plant matter (if the other variable was an aboveground plant part)
Total_below_OM[kg/ha]=The OM of the total belowground plant matter (if the other variable was a belowground plant part)
Total_OM[kg/ha]=The OM of the total above- and belowground plant matter(if all variables were available).
Ratio_fresh_yield_above=The ratio between the fresh weight of the crop yield and the aboveground OM.
Ratio_DM_yield_above=The ratio between the dry weight of the crop yield and the aboveground OM.
C:N_ratio_above=The ratio of carbon and nitrogen in aboveground biomass.
C:N_ratio_below=The ratio of carbon and nitrogen in belowground biomass.
C:N_ratio_other=The ratio of carbon and nitrogen in biomass of the other variable.

Literature references:
- Bolinder, M. A., Kätterer, T., Poeplau, C., Börjesson, G., & Parent, L. E. (2015). Net primary productivity and below-ground crop residue inputs for root crops: Potato (Solanum tuberosum L.) and sugar beet (Beta vulgaris L.). Canadian Journal of Soil Science, 95(2), 87-93. DOI: https://doi.org/10.4141/cjss-2014-091
- Buysse P, Roisin C, Aubinet M (2013) Fifty years of contrasted residue management of an agricultural crop: Impacts on the soil carbon budget and on soil heterotrophic respiration. Agriculture, Ecosystems & Environment 167:52–59. DOI: https://doi.org/10.1016/j.agee.2013.01.006
- de Haan, J., Wesselink, M., van Dijk, W., Verstegen, H., van Geel, W., & van den Berg, W. (2018). Effect van organische stofbeheer op opbrengst, bodemkwaliteit en stikstofverliezen op een zuidelijke zandgrond: Resultaten van de gangbare bedrijfssystemen van het project Bodemkwaliteit op zand in de periode 2011-2016 (No. WPR-754). Wageningen University & Research, Praktijkonderzoek AGV. DOI: https://doi.org/10.18174/440226
- Hu T, Sørensen P, Wahlström EM, Chirinda N, Sharif B, Li X, Olesen JE (2018) Root biomass in cereals, catch crops and weeds can be reliably estimated without considering aboveground biomass. Agriculture, Ecosystem and Environment 251:141–148. DOI: https://doi.org/10.1016/j.agee.2017.09.024
- Jørgensen H, van Hecke J, Zhang H, Malik PL, Felby C, Schjoerring JK (2019) Wheat as a dual crop for biorefining: Straw quality parameters and their interactions with nitrogen supply in modern elite cultivars. GCB Bioenergy 11:400–415. DOI: https://doi.org/10.1111/gcbb.12560
- Komainda M, Taube F, Kluß C, Herrmann A (2018) The effects of maize (Zea mays L.) hybrid and harvest date on above- and belowground biomass dynamics, forage yield and quality – A trade-off for carbon inputs? European Journal of Agronomy 92:51–62. DOI: https://doi.org/10.1016/j.eja.2017.10.003
- Sagoo, L (2019) Biomass data for vegetable crop residues in the UK, unpublished, personal communication.
- Mattsson, L (1991) Nitrogen mineralization and root production in some common arable crops. Swedish University of Agricultural Sciences, Department of Soil Sciences, Uppsala, Sweden. Report no. 182 [in Swedish].
- Sleutel S, Neve S de, Hofman G (2007) Assessing causes of recent organic carbon losses from cropland soils by means of regional-scaled input balances for the case of Flanders (Belgium). Nutrient Cycling in Agroecosystems 78:265–278. DOI: https://doi.org/10.1007/s10705-007-9090-x
- Steen, E & Andrén, O (1990) Effects of metribuzin on potato root growth. Swedish Journal of Agricultural Research 20: 127-133.
- Thomsen IK, Christensen BT (1998) Cropping system and residue management effects on nitrate leaching and crop yields. Agriculture, Ecosystems & Environment 68:73–84. DOI: https://doi.org/10.1016/S0167-8809(97)00134-5 
- Van Noordwijk, M, Brouver, G, Koning, H, Meijboom, FW, Grzebisz, W (1994) Production and decay of structural root material of winter wheat and sugar beet in conventional and integrated cropping systems. Agriculture, Ecosystem and Environment 51: 99-113. DOI: https://doi.org/10.1016/0167-8809(94)90037-X
- Xu, H., Vandecasteele, B., Zavattaro, L., Sacco, D., Wendland, M., Boeckx, P., Haesaert, G. & Sleutel, S. (2019). Maize root‐derived C in soil and the role of physical protection on its relative stability over shoot‐derived C. European Journal of Soil Science, 70(5), 935-946. DOI: https://doi.org/10.1111/ejss.12792



Methods, materials and software:
Data from 2020 and 2021:
In the growing seasons of 2020 and 2021 measurements were made in a variety in twelve different crops. Sampling was done in crop experiments, as well as in farmer fields, on three different soil types; sand, clay and reclaimed peat soil. The number of repetitions per object was 2-4. Aboveground biomass was cut at 1-3 cm above the ground and subsequently dried and was weighed to determine the dry matter biomass. Roots were sampled crop the whole area or by making cores, depending on the crop. The roots were rinsed dried and weighed. Roots from the depth 15-30 cm were not rinsed if there were none or a negligible amount of roots present determined by visual assessment. The samples were thereafter analysed for ash and N concentration using accredited and certified methods (Eurofins, 2020).

This dataset is published under the CC BY (Attribution) license.
This license allows reusers to distribute, remix, adapt, and build upon the material in any medium or format, so long as attribution is given to the creator.

