A deep-rooting upland rice variety (Kinandang Patong) was evaluated for its growth response to bio-fertilization at early stages. Five non-native plant growth-promoting bacteria previously isolated from yams (Dioscorea spp.) were inoculated to upland rice under growth chamber and greenhouse conditions. Effects of the inoculation varied depending on bacterial strains and growing conditions. Growth of 14-day rice seedlings was improved by all tested bacterial strains. Under growth chamber, the strain S-333 increased plant length, shoot dry weight and nitrogen content as compared to the control, but total dry weight, nitrogen uptake, leaf chlorophyll content and number of tillers were higher with N fertilizer application. Under greenhouse conditions, most rice growth parameters were improved by inoculation with the strain S-7. The correlations between the bacterial plant-growth-promoting traits and rice growth parameters under growth chamber conditions were all negative for phosphate solubilization indexes. Our results suggest that bacterial inoculation can replace half (S-343 and S-611) of or the full (S-7) rate of chemical N fertilizer required, depending on bacterial strains and growing environments, although δ¹⁵N value in control plants was lower than in inoculated plants under growth chamber conditions, suggesting that the bacteria improve rice growth through mechanisms other than biological nitrogen fixation.

Agricultural productivity impacts the environment and natural resources in various ways. The severity of these impacts has triggered the emergence of natural resource management and the related, highly criticized science of agroecology. Vegetable production has known environmental impacts. However, the extent of its participation in sustainable production has not been adequately explored. This review sought to explore the spaciotemporal position of vegetables in a suite of existing sustainable agricultural practices, explore regional variations and discover lessons that can guide the future of vegetable production. There are regional differences regarding sustainable production practices and the associated barriers to their adoption. Generally, sustainable agricultural practices with a societal history in a region tend to be successful, unlike when they are “new” innovations. The major barriers to sustainable agricultural practices in vegetable production are economy-related (total investment cost) and crop-related and are also related to the technology transmission approaches. Unfulfilled expectations and a lack of community participation in technology development are noted challenges, which have led to dis-adoption. A farmer-centered approach to technology promotion could help. Comparatively, southern Africa has the most challenges in the adoption of sustainable agricultural practices. From the lessons learned from other regions, agroecology in vegetable cultivation is not unachievable in Africa. The projected challenges mean that sustainable vegetable production is inevitable.

Globally, Hibiscus sabdariffa L. (Malvaceae), commonly known as roselle or hibiscus, is a multipurpose vegetable crop. In Malawi, where it is referred to as ‘Chidede’ (Chichewa), it is recognized as an underutilized traditional plant with significant potential. Traditional vegetable production in Malawi is being promoted to enhance nutritional food security and climate change mitigation. Recently, biochar has become increasingly used to improve agricultural productivity through climate-smart technologies. To date, the influence of rice husk biochar (RHB) on H. sabdariffa remains underexplored. This study aims to evaluate the effects of RHB on the vegetative growth, response to water stress, and post-stress recovery of H. sabdariffa using a greenhouse pot experiment. Our findings indicate that biochar-amended soil enhanced plant height, stem thickness, and total leaf area by 16.5%, 12.0%, and 12.9%, respectively. Water stress significantly reduced all assessed growth parameters (p < 0.05) except total leaf area and average leaf area per plant. Under water stress conditions, biochar-treated plants were significantly taller (p < 0.05) and had a higher specific leaf area (p < 0.05), demonstrating a positive effect. A post-stress recovery analysis revealed that H. sabdariffa fully recovered in height and biomass, while partial recovery was observed for root collar diameter and compensatory recovery for total leaf area and average leaf area. Biochar-treated plants exhibited superior post-stress recovery compared to those grown in unamended soil. Overall, plants grown with biochar were taller and had a larger root collar diameter, higher stem and leaf fresh biomass, and greater total leaf area. These findings underscore biochar’s potential as a sustainable soil amendment for enhancing growth and resilience in underutilized crops. Further studies should explore field experiments to access environmental heterogeneity and examine the diverse factors influencing biochar efficiency.