Original Paper

Nutrient Cycling in Agroecosystems

, Volume 76, Issue 2, pp 341-354

First online:

Effect of manure application on crop yield and soil chemical properties in a long-term field trial of semi-arid Kenya

  • F. M. KihandaAffiliated withKenya Agricultural Research Institute, Embu Regional Research Centre Email author 
  • , G. P. WarrenAffiliated withDepartment of Soil Science, School of Human and Environmental Sciences, The University of Reading
  • , A. N. MicheniAffiliated withKenya Agricultural Research Institute, Embu Regional Research Centre

Rent the article at a discount

Rent now

* Final gross prices may vary according to local VAT.

Get Access

Abstract

The sustainability of cereal/legume intercropping was assessed by monitoring trends in grain yield, soil organic C (SOC) and soil extractable P (Olsen method) measured over 13 years at a long-term field trial on a P-deficient soil in semi-arid Kenya. Goat manure was applied annually for 13 years at 0, 5 and 10 t ha−1 and trends in grain yield were not identifiable because of season-to-season variations. SOC and Olsen P increased for the first seven years of manure application and then remained constant. The residual effect of manure applied for four years only lasted another seven to eight years when assessed by yield, SOC and Olsen P. Mineral fertilizers provided the same annual rates of N and P as in 5 t ha−1 manure and initially ,gave the same yield as manure, declining after nine years to about 80%. Therefore, manure applications could be made intermittently and nutrient requirements topped-up with fertilizers. Grain yields for sorghum with continuous manure were described well by correlations with rainfall and manure input only, if data were excluded for seasons with over 500 mm rainfall. A comprehensive simulation model should correctly describe crop losses caused by excess water.

Keywords

Manure application Phosporous Nitrogen Soil organic matter Semi-arid Kenya