Comparison of return on investment (ROI %) among the six treatments in Yopal and Santana.

<p>Comparison of return on investment (ROI %) among the six treatments in Yopal and Santana.</p

Simulation of return on investment (ROI %) with varying prices of <i>in vitro</i>- produced AMF inoculum and increasing P fertilizer prices.

<p>(a) Simulation based on sale of dry cassava root produced in Yopal. (b) Simulation based on sale of fresh cassava root produced in Yopal. (c) Simulation based on sale of fresh cassava root produced in Santana. The diagonal red line represents the ROI for the most profitable treatment with AMF inoculation, at that site, when simulating varying inoculum price. The top horizontal blue line represents the ROI for the most profitable non-inoculated treatment at current P fertilizer prices, even though this may not necessarily be what farmers normally practice. Blue horizontal lines below represent a simulation of ROI for this treatment with a scenario of increasing P fertilizer prices (+20%, +40%, +60%, +80% and +100% price increase). Vertical dashed lines represent the price for the amount of inoculum used in these experiments (right) and the price for half of the amount of inoculum which represents the recommended dose (left).</p

Colonization (represented as a % of root length) by AMF in the roots of cassava for the duration of the experiment in Yopal.

<p>The axis Time represents the number of days after planting. Error bars represent ±1 S.E.</p

Effects of inoculation with AMF and P fertilization on cassava root fresh weight or yield (t.ha⁻¹) in Santana.

<p>Black shaded bars represent the weight of AMF-inoculated cassava and white bars represent the weight of non-inoculated cassava. Error bars represent +1 S.E. Different letters above bars represent significant differences at <i>P</i>≤0.05.</p

Colonization (represented as a % of root length) by AMF in the roots of inoculated and non-inoculated cassava and with different levels of P fertilization at the final harvest in Santana.

<p>Error bars represent +1 S.E. Different letters above bars represent significant differences at <i>P</i>≤0.05.</p

Phosphate concentration in carrot roots colonized by <i>R</i>. <i>irregularis</i> in experiment 2 and 10 different P solubilizing bacterial strains.

<p>The distal compartment contained tri-calcium phosphate. The white bars represent the treatments where roots were colonized by AMF but no bacteria where added, and with tricalcium phosphate (Control) and no tri-calcium phosphate (NTP) in distal compartment. Error bars represent + 1 S.E. Different letters above bars represent significant differences (<i>P</i> ≤ 0.05) according to a Tukey test.</p

Photographs of bacterial colonies on the hyphae of <i>R</i>. <i>irregularis</i> in <i>in vitro</i> cultures in experiment 1.

<p>a. Growth around branching absorbing structures; b. on and around hyphae; c. around subtending hyphae of <i>R</i>. <i>irregularis</i>.</p

Growth of bacteria and growth of extraradical hyphae in Experiment 1.

<p>a. Growth of ten different P solubilizing bacteria strains on the surface of extraradical hyphae of <i>R</i>. <i>irregularis</i> growing in the distal compartment of a split <i>in vitro</i> culture in experiment 1. b. Growth of extraradical hyphae of <i>R</i>. <i>irregularis</i> in the distal compartment of a split <i>in vitro</i> culture in the presence of ten different P solubilizing bacteria strains. Measurements represent mean length per treatment per 1 cm². Error bars represent + 1 S.E. Different letters above bars represent significant differences (<i>P</i> ≤ 0.05) according to a Tukey test.</p

Mean leaf P concentration of potato plants in experiment 3.

<p>Plants were inoculated with ten different strains of P solubilizing bacteria (P28 –P108), with added inoculum of <i>R</i>. <i>irregularis</i> and insoluble P in the form of rock phosphate. AMF + Insol P = added inoculum of <i>R</i>. <i>irregularis</i> and insoluble P in the form of rock phosphate but no added bacteria. Sol P = addition of soluble P but no added bacteria or <i>R</i>. <i>irregularis</i>. Insol P = addition of insoluble P in the form of rock phosphate but no added bacteria or <i>R</i>. <i>irregularis</i>. No P = no addition of any P source and no added bacteria or <i>R</i>. <i>irregularis</i>. All plants in all treatments are planted in non-sterile soil containing an existing microbial community. Error bars represent + 1 S.E. Different letters above bars represent significant differences (<i>P</i> ≤ 0.05) according to a Tukey test.</p

Fungal OTUs distribution in plots

Fungal OTUs distribution in plot