Abstract:
Intercropping with cereal and phosphorus (P)-mobilizing leguminous crops is a traditional agricultural
practice in Sub-Saharan Africa. It is essential to evaluate the effect of intercropping (i.e., rhizosphere
sharing) on fractionated rhizosphere soil P dynamics under the various soil P conditions and legumes, to
improve the soil-plant P dynamics in this region. This study aimed to identify the effect of rhizosphere
sharing of maize (MZ)/P-mobilizing legumes intercropping on fractionated rhizosphere soil P dynamics
and plant P uptake under different P fertilization rates in strongly weathered cropland soil of Tanzania.
We conducted 60-day MZ and P-mobilizing legumes intercropping pot experiments under different
P-fertilized conditions (0, 50, and 100 kg P ha−1) with two legumes (pigeon pea (PP) and groundnut (GN))
by using three different root-separation treatments (no separation (NS) for rhizosphere sharing, nylon
mesh separation (MS), and complete separation (CS)), to compare the effect of rhizosphere sharing in one
pot. We evaluated the Hedley-fractionated P of rhizosphere soil and plant P uptake in each pot. We found
that both P-efficient legumes did not clearly decrease the less labile P (NaOH-P) of rhizosphere soil in no
P treatment, while these clearly decreased the less labile P in 100 kg P ha−1 treatment. It indicates that
P-efficient legumes can solubilize the fertilized P but not native less labile P of the soil. The NS treatment
increased the labile P of rhizosphere compared with CS by solubilizing the fertilized P, except for MZ/GN
intercropping at 50 kg P ha−1. Relative to CS, MZ/PP intercropping increased the total plant P uptake per
pot (20%–40%) under P-fertilized conditions, whereas MZ/GN intercropping decreased it (17%) at 50 kg
P ha−1 or showed no change at 100 kg P ha−1. MZ/PP intercropping improved P fertilizer recovery
efficiency, whereas MZ/GN intercropping did not. Enhanced P use efficiency through intercropping with
P-mobilizing legumes is dependent on P-solubilizing characteristics of each P-mobilizing legume
