Studies comparing profitability of tillage systems often examine narrow historic windows or exclude annual price fluctuations. This study uses a continuous corn (Zea mays L.) (CC; 1970–1990) and corn–soybean [Glycine max (L.) Merr.] (CS; 1991–2014) Tillage × Fertilizer study in somewhat poorly drained soils in southern Illinois to reconstruct partial annual budgets with historical prices for crops, fertilizers, lime, herbicides, fuel, labor, and machinery. Combinations of tillage (moldboard plow [MP], chisel tillage [ChT], alternate tillage [AT], and no-till [NT]) and fertilizer (Control, N-only, N+NPK starter, NPK+NPK starter, and NPK broadcast) treatments were evaluated. The CC profits were highest in NPK-applied treatments followed by N-only and Control. The MP treatments were similar to ChT and more profitable than NT, while AT fell between. In CS, NPK-applied treatments were similar regardless of tillage. Combined costs for herbicide, machinery, labor, and diesel were higher in MP and ChT systems than AT and lowest in NT, but were a small percentage of total costs (26.6, 26.0, 21.5, and 18.2%, respectively). Nitrogen fertilizer offered a return on investment of 396% in CC and 133% in CS while P & K returned 78% in CC and 109% in CS. Sensitivity analysis in CS showed that NT would be less profitable than MP if herbicide costs increased 850%. A 300% machinery cost increase would have made MP less profitable than NT. These findings suggest that since 1991 CS under NT carried the same potential for profit as other tillage systems under full fertility management.
Tillage x Fertility Crop Costs and Profits 1970 to 2014
These data represent the costs and profit (in 2014 US dollars per acre) associated with each tillage x fertility treatment plot. These data were used for the analysis in the Trlica et al. 2017 manuscript. Data were converted from $/ac to $/hectare for publication, but per hectare data are not included here.
TxF_Econ_model_output.csv
Nominal Prices 1970-2014
Summary of nominal (not inflated to 2014 US dollars) prices of inputs per unit, commodity values per bushel of corn and soybean, and composited PPITW index (2011=100).
prices_final.csv
Tillage x Fertility R script for data collation
"TxF_Economics_data_collation_final.R" is the R script file used to process and data files and generate cost, price, and profit estimates used in Trlica et al. (2017). All costs and prices quoted in U.S. dollars ($). Additional price and index information gathered from other reports and sources integrated into final price sheet are detailed in the R script and in Trlica et al. (2017). The "Econ data" files can be used with this script if you direct it at the right file folder, should be able to reproduce all the output files that we used for analysis.
TxF_Economics_data_collation_final.R
Ag_lime_2014-1970_price
Econ data file: "Ag_lime_2014-1970_price.csv" — Agricultural lime (CaCO3) price, applied to field, U.S. Average, 1970–2014 (USDA NASS Quick Stats download).
Amm_nit_2014_1970_price
Econ data file: "Amm_nit_2014_1970_price.csv" — Ammonium nitrate price (nominal $/ton), U.S. Average, 1970–2014 (USDA NASS Quick Stats download).
corn_price_USDANASS
Econ data file: "corn_price_USDANASS.csv" — Corn sale price (nominal $/bu), U.S. Average, 1970-2014 (USDA NASS Quick Stats download)
Gly_2014_2001_prices
Econ data file: "Gly_2014_2001_prices.csv" — Glyphosate price (4 lb ai/U.S. gal), U.S. Average, 2001-2014 (USDA NASS Quick Stats download).
Herb_use
Econ data file: "Herb_use.csv" — schedule of post-emergent herbicide applications used on No-till plots, 1970–2014: Gly_lbsai (Glyphosate, lbs a.i./ac), Para_lbsai (Paraquat, lbs a.i. per acre) See Cook and Trlica (2016).
Labor_Unsorted
Econ data file: "Labor_Unsorted.csv" — unsorted labor wage rates, U.S. Average, 2015–1978 (USDA NASS Quick Stats download).
Lime_appl_2014_1970
Econ data file: "Lime_appl_2014_1970.csv" — schedule of lime applications to the site by plot ID (tons per acre). Rates given for applications in 1975, 1983, 1991, 2001, 2012. See Cook and Trlica (2016).
Mach_op_costs
Econ data file: "Mach_op_costs.csv" — Operation costs for machinery activities, by implement type (determined from Illinois FarmDocs calculator tool, see Trlica et al. (2017))
Mach_price_index_1990
Econ data file: "Mach_price_index_1990.csv" — Machinery Totals (1990-index), index for Price Paid 1975-1990 (USDA NASS Quick Stats download).
Mach_price_index_2011
Econ data file: "Mach_price_index_2011.csv" — Machinery Totals, index for Price Paid (2011-index), 1990-2014 (USDA NASS Quick Stats download).
Master_Yield_1970-2014_econ
Econ data file: "Master_Yield_1970-2014.csv" — table of corn yield and ancillary field data for 1970–2014 seasons. Data file identical to file used in Cook and Trlica (2016) (see Dryad Digital Repository doi:10.5061/dryad.7920c). Data missing entirely for years 1981, 2008 due to crop loss.
Para_2008_2001_prices
Econ data file: "Para_2008_2001_prices.csv" — Paraquat price (2.5 lb ai/U.S. gal), U.S. Average, 2001–2008 (USDA NASS Quick Stats download).
PPITW_2013-1975-1990index
Econ data file: "PPITW_2013-1975-1990index.csv" — PPITW (Prices Paid Index for Commodities and Services, Interest, Taxes, and Farm Wage Rates) (1990=100) for 1975–2013 (USDA NASS Quick Stats download).
PPITW_2014-1990-2011index
Econ data file: "PPITW_2014-1990-2011index.csv" — PPITW (2011=100) for 1990–2014 (USDA NASS QuickStats download).
soy_price_USDANASS
Econ data file: "soy_price_USDANASS.csv" — Soybeans sale price (nominal $/bu), U.S. Average, 1970-2014 (USDA NASS Quick Stats download).
Table7_Fert_prices_1960
Econ data file: "Table7_Fert_prices_1960.csv" — Table 7 from report "Fertilizer Use and Price" listing price (nominal $/ton) of triple superphosphate (44-46%P) and potash/potassium chloride (60% K) 1960–2013 (see USDA Economic Research Service, https://www.ers.usda.gov/data-products/fertilizer-use-and-price.aspx)
Urea_2014_1970_price
Econ data file: "Urea_2014_1970_price.csv" — Urea price (nominal $/ton), U.S. Average, 1970–2014 (USDA NASS Quick Stats download).
Tillage x Fertility Econ data sample SAS code
This is an example of the SAS code used to analyze the final dataset for the Trlica et al. 2017 publication.
TxF_Econ_SASmixedmodel.txt