Sustainable Maize Production Using Gliricidia/Maize Intercropping in Southern Malawi

Abstract

Maize production in Malawi is limited by high costs and sub-optimal use of chemical fertilizers under continuous cultivation. A long-term gliricidia/maize trial was undertaken on a Ferric Lixisol from 1991/92 to 2001/02. The purpose of the study was to assess the performance of a gliricidia/maize intercropping system as a low-input soil fertility replenishment option in southern Malawi. The experiment was a 2 × 3 × 3 factorial design with three replications. Treatments included two maize cropping systems (with and without gliricidia trees), and three rates of inorganic N fertilizer (0, 24 and 48 N kg ha−1 representing 0, 25 and 50% of the national recommended N rate), and three rates of P fertilizer application (0, 20 and 40 P ha−1 representing 0, 50 and 100% of the recommended rate). No effect of P was detected on yield early in the trial, and this treatment was discontinued. The gliricidia pruning biomass did not decline after 10 years of intensive pruning, with strong correlation between tree biomass production and years after establishment (r = 0.91, p < 0.001). Application of gliricidia prunings increased maize yields by three times compared to the yield of unfertilized sole maize. Maize yield from the unfertilized gliricidia pruning treatment was superior to the yield from sole maize supplemented with a quarter or half the recommended N rate. The study confirmed that a gliricidia/maize intercropping system is a promising soil fertility replenishment option in southern Malawi and elsewhere in southern Africa.

Biodiversity can support a greener revolution in Africa

“…This gain in efficiency occurred across >1,000 farms, with diverse soil types (soil C by agroecozone ranged from 0.7% to 1.8%) and variable climate (annual rainfall of 660-1,060 mm). These region-wide results are consistent with findings from long-term experimentation in Malawi, where gains in maize fertilizer use efficiency were >100% with an intercropped perennial legume (21). The fertilizer efficiency metric we used provided a conservative measure, and did not indicate the cause, which we expect were related to N inputs from symbiotic fixation and soil biophysical improvements.…”

“…The observed CV for maize was 18-30% (Fig. S3), and others have observed even higher variability (CVs of 28-88%) (21). Access to fertilizer may help reduce this exposure, as shown by the reduction in maize yield variability with fertilization (CVs of 12-26%).…”

“…Agroforestry systems further "perennialize" cereal farming (21). Agroforestry species produce large amounts of leafy residues and fuel wood, but no grain.…”

Impact of Soil Fertility Improving Trees on Crop Productivity and Farmer Wealth in Zambia

“…It is expected that where farmers perceived private benefits, the demand for the technologies would be higher. This expectation is reasonable for Sub Saharan Africa region where the majority of small scale farmers are unable to afford and apply the inorganic fertilizers at recommended rates and at the appropriate time because of high cost and delivery delays (Kwesiga et al, 2003;Akinnifesi et al, 2006). However, there have been low levels of the soil fertility tree technologies" adoption among the small scale farmers in the region (Akinnifesi et al, 2006;Ajayi et al, 2007).…”

Yield Responses of Maize to Organic and Mineral Fertilizers at Different Inclinations in Tropical Smallholder Farming Systems

“…Due to continuous cultivation and soil erosion soil fertility often declines in tropical regions, jeopardizing food production on smallholder farms (Kwesiga et al, 2003;Akinnifesi et al, 2006). Agroforestry is a valuable alternative in such systems for regenerating soil fertility, and thus enhancing food security and household income, especially where mineral fertilizers are too expensive for smallholder farmers Kimaro et al, 2008).…”