Integrated Soil Fertility Management Options for Maize Production and Sustainability in the Western Highlands of Cameroon
Background: Continuous cultivation without fertilizer application and soil erosion are responsible for plant nutrient depletion and yield decline of major food crops in Sub-Saharan Africa.
Methods: Nutrient status of Calliandra calothyrsus, Leucaena leucocephala, Acacia angustissima and Cassia spectabilis were characterized. Field experiments were conducted over two years in the Western Highlands of Cameroon to evaluate the effects of the application of leaf biomass of agroforestry tree species and mineral fertilizers on maize yield performance. The residual effects on soil physicochemical properties were also investigated for umbric Cambisols of Babungo and ustic Oxisols of Bansoa. Ten treatments encompassing; sole leaf biomass of Calliandra calothyrsus, Leucaena leucocephala, Acacia angustissima and Cassia spectabilis, leaf biomasses combined with NPK fertilizer, sole NPK fertilizer and absolute control were laid in a randomized complete block design and replicated three times. Data were subjected to analysis of variance and the Duncan Test (p < 0.05) used for mean separation.
Results: All the species characterized had nitrogen, polyphenol and lignin contents greater than 2.5 %, 5 % and 15 % respectively. Significant differences (p < 0.05) were observed among treatments on maize growth, productivity parameters and soil chemical properties for both soil types. The highest maize grain yields were recorded in plots amended with 1 t/ha of biomass of Calliandra calothyrsus or Leucaena leucocephala as well as
1.5 t/ha of biomass of Acacia angustissima and Cassia spectabilis plus mineral fertilizer (50 N+ 37.5 P2O5 + 45 K2O) on both soils compared to other treatments.on umbric Cambisols and ustic Oxisols respectively. The residual effects of treatments on soil chemical properties showed severe nutrient depletion in control plots and those amended with sole inorganic fertilizer.
Conclusions: Combined application of agroforestry tree biomass and inorganic fertilizers remains an appropriate technology to enhance maize yield and sustain production of resource-limited farmers of acid tropical soils..