The 2011–2012 rainy season has been difficult. Rainfall has been erratic and well below normal for most of the season. The first significant rain — over 20mm — did not fall until Christmas Day (21mm).
In low-rainfall conditions, the role of organic residues and loose soil as mulch has proved critical to successful germination. Where a good layer of residue was present over the seed, germination rates were noticeably higher, even in dry conditions, because the mulch slowed evaporation from the seed zone.
This season we have refined and adopted the dibble stick planting method as our primary planting technique. Three people working together can plant one hectare per day. The method requires minimal tools, makes efficient use of seed and manure, and ensures good seed-to-soil contact.
We are trialling ground velvet beans (Mucuna pruriens) as a primary fertility source for the following season. A portion of the field has been left with standing velvet bean residue to study the effect on soil moisture retention and weed suppression during the dry season.
Early-planted maize — sown on the Christmas rain — is looking good. Late-planted plots are behind, but germination across all varieties has been satisfactory given the rainfall.
Tags: Cropping · Maize · Rainfall · Seasonal