guest column:Achieford Mhondera IT has been established that Zimbabwe’s total annual greenhouse gas emissions as of 2015 added up to 22,0 Mt CO2e, which is about 0,045% of the global emissions. This is coming at a time anthropogenic activities such as power generation, land use practices and other agricultural activities have been scaled up. An estimated 16,4% increase in deforestation rate has been reported in recent years. This is a result of rampant deforestation and forest degradation which act as carbon sinks due to over-exploitation for firewood, land clearing for farming and tobacco curing and increased incidents of veldfires, coupled with lack of knowledge on the goods and services provided by trees in agricultural production. Consequently, carbon and nitrogen cycles are disturbed, soil quality is compromised, water infiltration rate is reduced while loss of essential nutrients is enhanced through erosion as vegetation is lost. To this effect, promotion of climate smart and conservation agriculture must among other things such as the popular Pfumvudza concept, including education on the advantages of alley cropping. Alley cropping or hedgerow inter-cropping is a form of conservation agriculture meant to redo the damage caused by the popular gospel of the plough. In the conventional methods of farming, proper farming is perceived as involving total clearance of the land, addition of manure, basal and top dressing fertilisers. However, this has proved to be unsustainable particularly in the changing climate coupled with high costs of farming inputs. Alley cropping, therefore, becomes an alternative and one form of climate smart agriculture with mitigatory co-benefits. Alley cropping is an agroforestry system in which crops are grown in alleys formed by trees or shrubs managed as hedgerows. Common tree types which can be used include leucaena, pigeon pea, gliricidia sepium as well as acacia angustissima and of late, an experimentation with zumbani recently proved to be yielding favourable results. The choice of trees although most of them are exotic must be hinged on the fact that they must necessarily provide heavy foliage (leaves), be easy to establish (grow very rapidly), have a deep root system to enable them to extract mineral nutrients and water to tolerate drought and be able to regenerate after pruning. In addition, they must be able to cope with the changing climatic conditions and have multiple uses such as food, pesticides among other uses. More significantly, these trees must be easy to eradicate when no longer needed because other tree species cause some weeds which are difficult to eradicate. All the trees identified above are nitrogen-fixing trees except zumbani, but its leaves provide essential nutrients for other crops as well as acting as a pest repellent. The trees are cut at planting so that the leaves will provide mulch and manure so that basal fertilisers such as Compound D become unnecessary. The roots provide nitrogen so that top dressing fertilisers such as ammonium nitrate also become u