Developing sustainable subsistence smallholder conservation agricultural systems in Lesotho
The average subsistence maize yield in Lesotho is very low (less than 0.3 Mg/ha) due to excessive soil erosion rates, low soil fertility, high fertilizer and herbicide cost, moisture/nutrient loss from weed competition, and high labor requirements for hand weeding. The break-even yields for subsistence farmers are approximately 2 Mg/ha or approximately seven times the average yield. This study was conducted to determine the economically viable nitrogen and phosphorus fertilizer rates, planting density, cover crop weed suppression effectiveness, and cultivation methods for maize production. The soils at the experiment site were silty clay loam and located near Mohale's Hoek. The 2009 results indicated that the most expensive smallholder farming method was the hired tractor or animal draft that used hired labor for weeding and was followed closely by likoti ('pothole' method). The most cost effective method was the use of no-till planter. Cover crops suppressed up to 90% of Common Thistle and Cape Tulip (Moraea flaccida), with Grazing Vetch (Vicia sativa) the most effective weed suppressor. Both higher N and P rates and population densities are needed because yields continued to increase at the higher fertilizer rates and population densities. Results from the first year of data suggest that cover crops will be an important component in weed control. Fertilizer N and P rates need to be increased as do the target plant populations.