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Research article2006Peer reviewed

Effect of organic inputs from agroforestry species and urea on crop yield and soil properties at Wondo Genet, Ethiopia

Teklay T, Nyberg G, Malmer A

Abstract

The effect of combined inputs of green manure (GM) and urea on maize (Zea mays L.) productivity and soil characteristics was studied in an on-farm trial at Wondo Genet, southern Ethiopia. The GM species used were the legumes Albizia gummifera G.F. Gmel and Milletia ferruginea (Hochst.) Baker and the non-legumes Cordia africana Lam and Croton macrostachyus Del. The GM and urea were applied separately or combined in different proportions to give equal rates of 100 kg N ha(-1), while varying amounts of P and K were supplied by the GM. The experiment was carried out for two consecutive cropping seasons, but treatments were applied only during the first season. Yield increased by 10-84% in the combined treatments compared to the control, with the increase being significant in those treatments containing GM from Cordia and Croton, which had higher P and K but lower N and total polyphenol contents than those from Albizia and Milletia. Increasing the proportion of GM from the non-legumes tended to increase yield, but the opposite was true when the proportion of GM from the legumes was increased. This suggests that N interacted negatively with polyphenols, and/or the P and K supply from GM was more important than that of N. However, treatment effects on soil properties were not pronounced. It was concluded that a 'modest' input of <= 3.0 Mg ha(-1) GM from Cordia/Croton might effect a reasonable yield but that the additional use of inorganic fertilisers is necessary for the GM to have a substantially increased effect. In addition, when organic materials having both high N and high total polyphenol contents (e.g. Albizia and Milletia) are used, they should constitute the smaller proportion of the GM/fertiliser mixture

Published in

Nutrient cycling in agroecosystems
2006, Volume: 75, number: 1-3, pages: 163-173
Publisher: SPRINGER

      SLU Authors

    • Teklay, Tesfay

      • Department of Forest Ecology, Swedish University of Agricultural Sciences

      • Nyberg, Gert

        • Department of Forest Ecology, Swedish University of Agricultural Sciences

        • Malmer, Anders

          • Department of Forest Ecology, Swedish University of Agricultural Sciences

        UKÄ Subject classification

        Environmental Sciences related to Agriculture and Land-use

        Publication identifier

        DOI: https://doi.org/10.1007/s10705-006-9020-3

        Permanent link to this page (URI)

        https://res.slu.se/id/publ/9296