Effect of Cropping System under Tillage and Mulching on Soil Physical Properties and Water Use Efficiency by Maize (Zea mays L.) in Southern Benin

In agriculture, water has become a limiting factor because of the effects of climate change felt by farmers. This situation seriously compromises agricultural production through pockets of drought, delayed and early cessation of rains and then an increase in the length of the dry season.

Aims: This study aims to evaluate the effect of tillage and vegetative mulch on soil physical properties and maize water use efficiency in ferralitic soil of southern Benin.

Study Design: The Factorial Complete Randomized Block Design with 4 repetitions was implemented.

Place and Duration of Study: The experimental site is located at Allada, in southern Benin, and conducted between May 2017 and July 2017.

Methodology: Tillage (No-tillage, flat tillage) and straw mulch rate (0%, 50%, 75% soil cover) and their interaction was been tested during this study. The physical properties of soil and maize water use efficiency were determined.

Results: Tillage significantly reduced soil temperature by 2.65% and improved soil permeability by 60%. Tillage also significantly improved water use efficiency for maize grain from 3.88 to 7.88 kg.mm-1.ha-1 and for maize biomass from 12.67to 23.31 kg.mm-1.ha-1. Mulching significantly improved soil moisture from 11.54% to 13.13%, water use efficiency for maize grain from 4.26 to 7.58kg.mm-1.ha-1 and for maize biomass from 14.50 to 22.05 kg.mm-1.ha-1. Mulching also significantly reduced soil temperature by 11%. The combination of tillage and mulching significantly improved water use efficiency for maize grain and biomass production. The highest water use efficiency (8.87 kg.mm-1.ha-1 for maize grain and 25.17 kg.mm-1.ha-1 for maize biomass) was achieved with tillage combined with mulching at 75% soil cover. The interaction between these two factors significantly reduced soil temperature by 11.30% (tillage combined with mulch at 75% soil cover) compared to control (no-tillage and no-mulch).

Conclusion: This study showed that tillage and mulching at 50% or 75% soil cover improves soil physical properties and water use efficiency for maize production in the context of climate change.