Evaluating the merits of climate smart technologies under smallholder agriculture in Malawi

The merits of three climate smart agriculture (CSA) technologies implemented by farmers were assessed in Machinga district of Malawi with respect to their soil quality and maize yield effects. Data were collected from farms implementing the three CSA technologies, namely conservation agriculture (CA), maize–pigeonpea (Maize-PP) intercrops and a local organic and inorganic soil amendment known as Mbeya fertilization (Mbeya-fert), from 2018 to 2019. With respect to resilience and adaptation, particulate organic matter, soil organic carbon (SOC), N, P, K, Ca and Mg all significantly improved while bulk densities were lowered under the three CSA systems. Higher annual biomass inputs and improved water infiltration from the Maize-PP intercrops were observed. With respect to productivity, CA and Mbeya-fert improved maize yields by 51 and 19%, respectively, compared to conventional farmer practices. With regard to climate change mitigation, increases in measured SOC in the top 20 cm depth compared to the conventional farmer practices amounted to 6.5, 12 and 10.5 t C ha⁻¹ for CA, Mbeya-fert, and Maize-PP intercrops, respectively, over a period of 2–6 years. This suggests higher potential for carbon sequestration from CSA technologies. Furthermore, use of drought tolerant varieties, timely weeding and optimum plant populations, increased productivity. Improved gross margins from CSA practices were also apparent. Thus, employing these CSA technologies could enable farmers to be more resilient, productive and adapt better to climate change shocks leading to improved food security and livelihoods.     

Productivity and profitability of maize-legume cropping systems under conservation agriculture among smallholder farmers in Malawi

ABSTRACT

A study was conducted from 2014 to 2017 in Malawi to elucidate the short-term effects of maize-legume intercropping and rotation systems under conservation agriculture (CA) and conventional tillage (CT) on crop productivity and profitability. Twelve farmers hosted on-farm trials per district, in three districts, with each farmer having six plots. The design of the study was randomised complete block design arranged in a split plot fashion with tillage as main plot and cropping systems as sub-plots, with each farmer acting as a replicate. CA had 1400 and 3200 kg ha^?1 more maize grain yield in the second and third seasons, respectively compared with CT. In the first two seasons, CT had 310, 180 and 270 kg ha^?1 more cowpea, soybean and pigeon pea grain yields in Salima, Mzimba and Mangochi districts, respectively, compared with CA. Similarly, CA had 1100 and 950 kg ha^?1 more groundnut grain yields than CT in Salima and Mzimba districts in the second and third seasons, respectively. Over the three-year study period, partial land equivalent ratio for maize ranged from 0.78 to 1.24. Largest net returns were achieved by intercropping maize with pigeon pea in Mangochi and rotating maize and groundnut in Mzimba and Salima districts.