At the Nkhotakota research sites, soils were sandy with low soil
C and the climate was hot with high vapor pressure deficits. This
can result in rapid drainage, low water-holding capacity, and high
potential evapotranspiration (Tallec et al., 2012). Under these
conditions, increasing the amount of residue retained on the field
played a key role in increasing infiltration and soil water content.
While increased infiltration and soil moisture content is beneficial
for preventing moisture deficits, it can lead to water-logging in
more humid environments and in periods of high rainfall (Baudron
et al., 2012b; Rusinamhodzi et al., 2011). In Dowa, total soil water
content was similar among all soil management practices despite
greater soil moisture content at 20 cm in NTM and CAR. This
suggests that tillage and residue retention impacted the distribution of soil water, with greater soil moisture content at 40 cm in
CTR, but did not influence the amount of soil water. Water-use
efficiency was greater in Dowa than Nkhotakota, which may be
partially explained by lower potential evapotranspiration derived
from lower soil and air temperatures and vapor pressure deficits.
The soil moisture benefits derived from NTM and CAR in
Nkhotakota did not have a positive impact on crop yields, with
rainfall being sufficient in every year of this study. Many of the
changes in soil quality that affect water dynamics, such as