Functional crop types are more important than diversity for the productivity, profit and risk of crop sequences in the inner Argentinean Pampas

VIDELA-MENSEGUE, H.; CAVIGLIA, O.P.; SADRAS, V.O.

AGRICULTURAL SYSTEMS

ELSEVIER SCI LTD

Año: 2022 vol. 196

0308-521X

CONTEXTOver thelast 250 years, many natural ecosystems in South America, including the InnerPampas of Argentina, evolved into extremely simplified agroecosystems. In thelast 25 years, simplified soybean-based crop sequences have become widespread.Putative drivers of the wide adoption of this system include high soybean grainprice, simplified agronomic management and low cost, but comparison ofproduction, profit and risk in current and alternative crop sequences arelacking.OBJECTIVEOur aim wasto compare the production, profit, and risk of seven crop sequences varying intheir diversity, cropping intensity and the proportion of functional croptypes.METHODSWe modelledseven typical or feasible crop sequences for two locations with differentrainfall and soil water holding capacity for a 50-yr period. Crop sequencesincluded wheat (W) or fallow during winter and soybean (S) or maize (M) assingle and double crops during summer, and were characterized with indexes ofagrobiodiversity (ABDI, from 0.33 to 1.00), cropping intensity (from 0.40 to0.83) and soybean proportion (SP, from 0 to 1.00).RESULTS ANDCONCLUSIONSW/M-M hadthe highest and S-S the lowest yield in both locations. The high yielding cropsequences had a lower stability of grain yield that those with a highproportion of soybean (S-S and W/S-S). Yield stability and CVaR (conditionalvalue-at-risk) for gross margin and gross margin ratio were unrelated withABDI. The prevalent, least diverse soybean monoculture (S-S) had the lowestcost and medium profit-risk metrics. Increasing the proportion of maizecontributed to higher gross margin and gross margin ratio with a lower risk insome crop sequences. Crop sequences with high proportion of soybean (S-S andW/S-S) had low mean cost with a close to average CVaR. However, these were notthe sequences with the highest gross margin or gross margin ratio. Our resultsdemonstrated that functional crop types (cereal and legumes) were moreimportant than diversity and cropping intensity for the profit and risk of cropsequences in the Inner Argentinean Pampas.SIGNIFICANCEEconomicrisk-benefit analysis of crop sequences is necessary but not sufficient tounderstanding the drivers of grower?s choices, which are greatly influenced bycontext regarding policies for grower support, taxes, and land ownership