Yield and soil system changes from conservation tillage in dryland farming: A case study from North Eastern Tanzania

Elin Enfors, Jennie Barron, Hodson Makurira, Johan Rockstrom, Siza Tumbo

Research output: Contribution to journalArticlepeer-review

Abstract

This paper presents the result from an on-farm conservation tillage experiment (combining ripping with mulch and manure application) that was carried out in North Eastern Tanzania from 2005 to 2008. Special attention was given to the effects of the tested treatment on the capacity of the soil to retain moisture. The tested conservation treatment only had a clear yield increasing effect during one of the six experimental seasons (maize grain yields increased by 41%, and biomass by 65%), and this was a season that received exceptional amounts of rainfall (549 mm). While the other seasons provided mixed results, there seemed to be an increasing yield gap between the conservation tillage treatment and the control towards the end of the experiment, and cumulatively the yield increased with 17%. Regarding soil system changes, small but significant effects on chemical and microbiological properties, but not on physical properties, were observed. This raises questions about the suggested water harvesting effect and its potential to contribute to stabilized yield levels under semi-arid conditions. The authors conclude that, at least in a shorter time perspective, the tested type of conservation tillage seems to boost productivity during already good seasons, rather than stabilize harvests during poor rainfall seasons. Highlighting the challenges involved in upgrading these farming systems, we discuss the potential contribution of conservation tillage towards improved water availability in the crop root zone in a longer term perspective.
Original languageEnglish
Pages (from-to)1687-1695
Number of pages9
JournalAgricultural water management
Volume98
Issue number11
Early online date7 Apr 2010
DOIs
Publication statusPublished - Sep 2011

Keywords

  • Conservation tillage
  • Ripping
  • Agricultural droughts
  • In situ water harvesting
  • Maize yields
  • Soil health
  • Short- and long-term effects
  • Tanzania

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