Effects of mulching on biomass, nutrients, and soil water in banana inoculated with nematodes

Abstract

The objective of this study was to determine whether mulching mitigated the impact of nematodes on banana (Musa AAA) inoculated with Radopholus similis (Cobb) Thorne and Helicotylenchus multicinctus (Cobb) Golden. The study was conducted at International Institute of Tropical Agriculture's (IITA's) Sendusu station, Uganda. Treatments included mulched and bare soil with or without nematode inoculation. Mulched treatments produced over three times more biomass than bare soil treatments. This increase in biomass was likely due to improved fertility as a result of mulching, since mulched treatments had higher concentrations of soil organic C, P, and exchangeable K and Mg, and foliar K. Mulched banana took up more water from both the 0- to 0.3-m and 0.3- to 0.5-m depths than banana grown without mulch and soil water recharged more quickly in the mulched treatments as a result of increased porosity from 0- to 0.3-m depth. Nematode inoculation had little effect on biomass or foliar nutrient concentrations of P, K, Ca, and Mg in the bare soil treatments. In contrast, in the mulched treatments nematode inoculation reduced banana biomass and yield. In both cases, more root necrosis was observed in the inoculated treatments. It appears that growth was so restricted by low fertility in the bare soil treatment that nematode damage was not a limiting factor. As mulching increased soil fertility, nematode damage did appear to restrict the growth potential of banana. Our study suggests that mulching may mitigate the impact of nematodes on bananas when applied to low fertility systems.