Authors
E Chikwari, A Manyanga, L Mhaka, C Mukungurutse, T Chipangura, N Nyapwere, F Mapanda, J Gotosa
Publication date
2018
Journal
IAEA TECDOC SERIES
Pages
40
Description
In a study that has run since the 2012 and 2013 cropping season, reduced tillage (RT) and conventional tillage (CT) were compared with and without mulching. Nitrogen fertilisation (+) or no nitrogen fertilisation (−) was the sole agronomic variable that was tested along with tillage-mulch interactions. Tillage is historically a factor that addresses soil physical properties while mulching is seen to influence the extent tillage has on both physical and chemical dynamics. Measurements on infiltration rates, bulk density (Bρ) and aggregate stability showed the significance of RT on soil conditioning since these portray the potential of soil to receive, retain and distribute water without implications on soil and nutrient loss. Significantly higher rates of hydraulic conductivity, corresponding to the steady state (final) infiltration were obtained (0.11–0.18 mm min-1) when mulch was used compared to 0.07–0.10 mm min-1 obtained without mulch cover for both reduced and conventional tillage. These results show the importance of mulches in improving water infiltration with reduction in surface runoff and increased soil water seepage. Bulk density ranges showed the benefits from RT with values of 1.58–1.64 kg m-3 compared to CT (1.65–1.69 kg m-3). The influence of mulching was evident and the following orders were noted:+ Mulch+ N<− Mulch+ N<− Mulch–N<+ Mulch RN, corresponding to the following ranges of BD; 1.58–1.77, 1.58–1.87, 1.60–1.83 and 1.64–1.87 kg m-3 for RT and+ Mulch+ N< Mulch− N<− Mulch+ N<− Mulch− N, corresponding to the following ranges of BD; 1.66–1.76, 1.69–1.83, 1.65–1.86 kg m-3 for CT, respectively. Stratification ratios (SR …