The 58 articles from the systematic review led to a series of varying results for agroecological yield data and agroecological return on investment data. Due to differences in reporting some data was difficult to compare, while other factors such as region, crop type and type of agroecological practice also played significant roles in varying results. 23 articles were utilized to identify percent change in agroecological yield compared to a conventional or control baseline, reporting an average change of 58%. Return on Investment (ROI) was calculated for 15 articles, reporting and average of 97.8% ROI for agroecological practices.
Change in Agroecological Yield where x axis = % change in agroecological yield compared to conventional and control baselines. n = 23, where 20 of the articles’ agroecological data is compared to conventional practices, while three are compared to a control.
Percentage Return on Investment (ROI) from application of agroecological practice, where n= 15.
Two standard deviation were calculated and change in actual agroecological yield was plotted across two normal distribution graphs, one measuring in kg/ha-1 and the other in Mg ha-1. Land Equivalent Ratios (LERs) and nutritional yield were also taken into account in this study. The focus on LERs for intercropping in future research was highlighted.
A table consisting of gross profit and gross variable cost that led to the calculation of ROI was included in the paper; however, different reporting years and currencies account for some existing variance. Benefit Cost Ratios (BCRs) by agroecological practice, income data, gendered income data and market data were also taken into account in the study. These expressed key differences in adoptions of practices and their outcomes depending on market, gender, region and crop type.
Suggestions for investors/donors, smallholders and researchers based on the data reported were posed as follows:
Recommendations for Smallholders and Investors
The data has proven that agroecology can be beneficial under differing practices, but lack of comparable data reported made it difficult to state that overall benefits would be positive with certainty. The following recommendations, based on the data examined, should be made to smallholder farmers and investors/donors:
1) Consider entire system change when switching to agroecology with the help of investors/donors, as it provides the greatest ROI.
2) Consider intercropping of more than one staple crop to increase net yield, protein yield, nutrient yield, and nutrition security.
3) Consider low input cost agroecology where it is difficult to secure funding, as it still provides positive return on investment, yield gain and has less adverse environmental impacts than conventional agriculture.
4) Consider expanding to regional markets for greater return on investment.
Recommendations for Researchers:
Limitations of data can be mitigated by a standard of reporting agroecological data and economic data by researchers. The following recommendations will enable researchers to meet this standard and therefore contribute to the creation of more cohesive data sets.
1) Economic data should be reported in local currency in addition to a major standard currency.
2) Researchers should note the date of the economic data reported to aid researchers in comparing different economic data with the ability to account for the variable exchange rate. Variable exchange rate equations should also be utilized for conversion of economic data to a standard exchange rate and year. To calculate an exchange rate adjustment researchers can use the following: (Current Exchange Rate – Previous Exchange Rate)/Current Exchange Rate.
3) Researchers should take into account the inflation rates of each year and report not only nominal income, but also real income. Real income will allow researchers to compare the impacts of different agroecological practices without the burden of inflation rate variance.
4) Consumer Price Indexes (CPI), farm gate prices and other market data should be reported for each year, as this shows variance in income due to inflation and change of market prices. Reporting this as a standard will enable comparison of ROI over different years.
5) Not only should researchers report overall yield data, but LERs and nutritional yield also should be reported, particularly for different intercropping scenarios. For the eight articles focusing on intercropping only three reported LER data, and only four articles reported nutritional yield. This is a knowledge gap that researchers can bridge with better reporting (author’s own work).