Soil Amendments
Organic amendments offer the opportunity to increase soil organic matter and improve soil fertility. However, most available amendments are already applied to soils. Our research seeks to identify 'low hanging fruit' opportunities to recycle organic resources and adopt smart techniques to improve the carbon use efficiency of organic amendments so that the maximum possible benefits can be obtained by judicious use of situation appropriate amendments.
Cocoa Pod Husk Composts
Cocoa farms established on recently cleared rainforest are initially productive, but then productivity declines as soils become depleted of nutrients. To avoid deforestation of tropical rainforests we must maintain and restore the productivity of existing plantations. Inorganic fertilisers are expensive and therefore unobtainable for many smallholder cocoa farmers. When cocoa is harvested the beans are extracted from the husks on-farm and the husks are typically piled up and left to rot. Our research has demonstrated that making compost from cocoa pod husks can effectively recycle nutrients and improve soil fertility. Farmers in Ghana have started adopting this practice.
You can download a flyer explaining how to make cocoa pod husk composts here
You can watch a video outlining the process of making cocoa pod husk compost below and access a version in Twi here
Papers on Soil Amendments
van Midden, C., Harris, J., Shaw, L., Sizmur, T. and Pawlett, M., 2023. The impact of anaerobic digestate on soil life: a review. Applied Soil Ecology, 191, p.105066.
Duddigan, S., Shaw, L.J., Sizmur, T., Gogu, D., Hussain, Z., Jirra, K., Kaliki, H., Sanka, R., Sohail, M., Soma, R. and Thallam, V., 2023. Natural farming improves crop yield in SE India when compared to conventional or organic systems by enhancing soil quality. Agronomy for Sustainable Development, 43(2), p.31.
Albano, X., Whitmore, A.P., Sakrabani, R., Thomas, C.L., Sizmur, T., Ritz, K., Harris, J., Pawlett, M., Watts, C. and Haefele, S.M., 2023. Effect of different organic amendments on actual and achievable yields in a cereal-based cropping system. Journal of Soil Science and Plant Nutrition, pp.1-16.
Struijk, M., Whitmore, A.P., Mortimer, S., Shu, X. and Sizmur, T., 2022. Absence of a home-field advantage within a short-rotation arable cropping system. Plant and Soil, pp.1-17.
Shu, X., Zou, Y., Shaw, L.J., Todman, L., Tibbett, M. and Sizmur, T., 2022. Applying cover crop residues as diverse mixtures increases initial microbial assimilation of crop residue‐derived carbon. European Journal of Soil Science, 73(2), p.e13232.
Duddigan, S., Collins, C.D., Hussain, Z., Osbahr, H., Shaw, L.J., Sinclair, F., Sizmur, T., Thallam, V. and Ann Winowiecki, L., 2022. Impact of zero budget natural farming on crop yields in Andhra Pradesh, SE India. Sustainability, 14(3), p.1689.
Amponsah-Doku, B., Daymond, A., Robinson, S., Atuah, L. and Sizmur, T., 2022. Improving soil health and closing the yield gap of cocoa production in Ghana–A review. Scientific African, p.e01075.
Shu, X., Zou, Y., Shaw, L.J., Todman, L., Tibbett, M., and Sizmur, T., 2021. Cover crop residue diversity enhances microbial activity and biomass with additive effects on microbial structure. Soil Research.
Struijk, M., Whitmore, A.P., Mortimer, S.R. and Sizmur, T., 2020. Obtaining more benefits from crop residues as soil amendments by application as chemically heterogeneous mixtures. Soil, 6(2), pp.467-481.
Sizmur, T., Martin, E., Wagner, K., Parmenteir, E., Watts, C. and Whitmore, A.P. 2017 Milled cereal straw accelerates earthworm (Lumbricus terrestris) growth more than selected organic amendments. Applied Soil Ecology. 113, 166-177.
Sizmur, T., Palumbo-Roe, B. and Hodson, M.E. 2011 Impact of earthworms on trace element solubility in contaminated mine soils amended with green waste compost. Environmental Pollution. 159, 1852-1860.