It is well established that the global practice of burning crop residues, such as orchard biomass, harms human health and the environment. A bioeconomy for orchard biomass may reduce open burning, facilitate the recovery of nutrients that improve soil health, and boost economic growth. We present a techno-economic analysis for converting orchard waste into biochar, a charcoal-like substance that shows promise for improving soil health, but that is considered an experimental product with emerging efficacy and limited market demand. We impute values derived from a cost analysis of biochar production in California's Central Valley into a regional economic input-output model to demonstrate economic growth and a bioeconomy for biochar made with orchard waste. Results from a stochastic Monte Carlo simulation show a probable range of biochar production costs between $448.78 and $1,846.96 (USD) Mg^-1, with 90% probability that costs will range between $571 and $1,455 Mg^-1. A sensitivity analysis shows that production costs are most responsive to biochar production rates. A modifiable Excel-based biochar enterprise budget that includes fixed and variable biochar production costs is provided as Supplementary Material. The regional economic analysis demonstrates positive economic growth as defined by job creation, labor compensation, value-added product, and gross output. Stochastic cost estimates and net positive regional economic impacts support economic feasibility of a circular bioeconomy for waste orchard biomass when coupled with governmental policy initiatives. Results may contribute to developing a circular bioeconomy for biochar and orchard biomass in the study region and elsewhere in the world.

Crop diversification is a climate-smart agricultural technique which helps to improve resilience for farmers in the face of volatile weather due to climate change. Previous research on its effects on technical efficiency has shown mixed results. Despite burgeoning literature on the subject, an important research question that remains uninvestigated is: does crop diversification involve a compromise between technical efficiency and resilience (income stability) for rural farmers? Using nationally representative rural household survey data from Zambia, this study empirically answers this research question. We employ the Data Envelopment Approach (DEA) for efficiency and a two- step least-squares approach for income variability. Our results show evidence that crop diversification significantly improves income stability but significantly reduces technical efficiency. The paper provides useful implications for policies that promote crop diversification in Zambia and other countries.

We determine and compare technical efficiency (TE), technology gap ratios (TGRs) and meta-frontier technical efficiency (MTEs) of maize production between regions using nationally representative panel data collected from 4001 smallholder farm households in Zambia. We estimate the stochastic meta-frontier and region-specific stochastic frontiers based on the ‘true random effects’ framework. Our results show variations in efficiency measures and that smallholder maize production is characterised by increasing returns to scale across all regions, which clearly suggest maize farmers to reduce their average long-term costs by increasing their production scale. We find that some regions are on average more technically efficient than others while those with TE values exceeding 90 per cent operate further below their potential output than those with moderate TE values. Similarly, farm households from regions whose mean TE values are about 90 per cent employ inferior farming techniques to those employed by farmers from regions whose mean TE values are lower. This is in part due to industry-wide specific environmental factors. Most importantly, we find no region to have maize farmers that adopt the most advanced techniques. Results further indicate that all provinces have had either lower or higher TEs, TGRs and MTEs in one period than in another. Generally, our results point to the need to promote superior techniques that would withstand industry-wide specific environmental factors. While it is not possible to find the many reasons for wide variations in TEs, TGRs, and MTEs across regions and time, our results make novel contributions to literature.