Achieving sustainable agricultural production under farmer conditions in maize-gliricidia intercropping in Salima District, central Malawi

Heliyon. 2019 Oct 18;5(10):e02632. doi: 10.1016/j.heliyon.2019.e02632. eCollection 2019 Oct.

Abstract

Smallholder farmers in Malawi are faced with limited options for climate smart agriculture that would restore soil fertility and increase maize yield. Ten plots of maize intercropped with Gliricidia sepium (MIG) and 10 traditional sole-maize (TSM) plots (0.2 ha each) were studied under farmer conditions from 2013/14 to 2017/18 in Salima District, central Malawi. The aim was to assess performance of MIG on soil fertility restoration and maize yield in degraded agricultural land. G. sepium trimmings were incorporated in MIG in October, January and September of every season. A total of 92 kg N ha-1 was applied in both treatments. Soil and maize yield measurements were done from 10 m x 10 ridges centre of each plot and a paired t-test in R Statistical Software was used for data analysis. Organic matter (p < 0.001) and nitrogen (p < 0.011) were significantly higher in MIG than in TSM while bulk density was significantly lower (p < 0.006) in MIG than in TSM. Higher maize yield was achieved in MIG (5.52 t/ha) than in TSM (1.48 t ha-1) (p < 0.001). Nonsignificant differences between MIG and TSM fields for potassium (p > 0.678) and phosphorus (p > 0.149) suggests that the nutrients were not affected by presence or absence of G. sepium and may not have contributed to differences in yields. Effective gestation period for maize-gliricidia intercropping was at least two years where significant maize yields were first achieved. The findings in MIG provide farmers with sustainable agricultural option for soil health renewal and maize yield increase in central Malawi.

Keywords: Agricultural science; Biological sciences; Earth sciences; Environmental science; Gestation period; Malawi; Organic matter; Social sciences; Yield trend.