2.3. Agronomic trials
Yield data from the three experimental trials described above from
the 2012–2013 through 2013–2014 growing seasons were used in this
study. Each trial included seven treatments, replicated three times
each in 5 m × 5 m plots and arranged in a randomized complete block
design. (Table 2, also see supplementary data Table S1). Treatments re-
flect a mix of current farmer practice, along with two DLR systems. Crop
varieties used in each trial were recommended by the Malawi government
as appropriate for the local environment.
All crops were planted in December. Crops were planted on ridges
formed by hand-hoe, following local practice. Intercrops used a semiadditive
design, in which total plant density was highest in intercrop,
and each intercrop partner was planted at a slightly lower density
than in monocrop. Fertilizer applications in treatments receiving
35 kg N/ha or 69 kg N/ha were split between a basal application at
planting and a top-dress application. Crop grain yields were measured
in each trial for all crops except for pigeonpea in the 2012–2013 and
2013–2014 growing seasons. All plants within the three planting ridges
in the center of each five by five meter plot were harvested. Harvested
grains were sun-dried for at least four weeks until grain moisture had
dropped to between 14 and 16%, and then weighed. Grain moisture
was determined using a moisture meter and all grain yields are reported
at 12.5% moisture content. Pigeonpea biomass was measured in 2014 at
the Lintipe and Kandeu locations. Final plant densities for maize weremeasured in the 2013–2014 and 2014–2015 growing seasons, while
legume final plant densities were measured only in the 2014–2015
growing season.