Principally caused by soil water stress and declining soil fertility, low crop productivity results in both food and income insecurity. The effects of nitrogen and phosphorus fertilizer micro-dosing with inter-row rainwater harvesting practices for maize and pigeon-pea inter-cropping on yield and land use efficiency are inadequately documented in sub humid tropics. A field experiment on sandy loam soils in sub humid conditions using a split-split plot design was conducted. Plots used in situ rainwater harvesting practices of tied ridges, open ridges, and flat cultivation. Sub-plots were sole maize, sole pigeon-pea, and 1:1 maize-pigeon pea inter-cropping. The sub-sub plots were control, fertilizer (N and P) application at the micro-dose level, and recommended rates. Tied ridges significantly (p < 0.001) conserved more soil moisture than flat cultivation at 30 cm depth after ten days of rainfall. Ridges increased maize yield by 0.3 t ha−1 over flat cultivation. Fertilizer application significantly (p < 0.001) increased maize yield by 1.12 t ha−1 with micro-dosing and by 1.60 t ha−1 with recommended rates over the control. Combining tied ridges and fertilizer significantly (p < 0.040) increased maize yield by 132–156% compared to flat cultivation without fertilizer. Reflecting a land equivalent ratio, land use efficiency was 67–122% higher in inter-cropping than sole crop. Tied ridges conserved more soil moisture than flat cultivation, enhancing fertilizer use efficiency that improved crop yields and land equivalent ratio under inter-cropping. This strategy could increase food availability and income generation under smallholder farming systems in sub-humid tropic areas.

Authors: Saidia, P.S.; Asch, F.; Kimaro, A.A.; Germer, J.; Kahimba, F.C.; Graef, F.; Semoka, J.M.; Rweyemamu, C.L.

Subjects: crop production, legume, soil fertility, soil water, crop production, soil

Publication type: ISI, Journal Article, Publication

Year: 2019

ISSN: 0378-3774

DOI: https://doi.org/10.1016/j.agwat.2019.105712