Fig 1.
Distribution of rainfall, relative humidity and maximum/minimum temperatures during the maize crop growing period at the Centro de Investigaciones Amazonicas CIMAZ Macagual in Colombia in two cropping seasons (2018) and (2019).
Dotted black lines show the two phenological stages at which the physiological evaluations were performed. These include at the tassel emergence (VT, BBCH = 51) and at the grain milk stage (R3, BBCH = 73) that corresponded to 50 and 70 days after sowing.
Fig 2.
Experimental cropping patterns: maize monocropping (MCP); maize-bean intercropping with seeding pattern of 1:1 of maize and bean (ICP 1:1); and maize-bean intercropping with seeding pattern of 2:1 of maize and bean (ICP 2:1).
Fig 3.
Photosynthetic response parameters derived from the light response curve (A/PAR) of the maize (ICA V109) leaves from plants grown under three different cropping patterns and treated with inorganic or organic fertilizer application.
Measurements were made at two growth stages, tassel emergence (VT) and grain milk (R3). (a, b) net light-saturated carbon assimilation rate (Amax); (c) dark respiration rate (Rd); (d) light saturation point (LSP); (e) light compensation point (LCP); and (f) quantum efficiency of PSII (ΦPAR); dry mass (DM). Cropping patterns: Monocropping pattern (MCP); Intercropping pattern 1:1(ICP 1:1); Intercropping pattern 2:1 (ICP 2:1). Fertilizer treatments: Nutrimins Inorganic Fertilizer (NIF); Super Magro Biofertilizer (SMB). a, b, c: indicate the significant statistical differences using the LSD Fisher mean test (P < 0.05) for each cropping pattern in relation to the type of fertilizer application (bars of the same color). The dashed red line corresponds to the mean value of each variable.
Fig 4.
Variables derived from the photosynthetic response to CO2 (A/Ci) curves of maize (ICA V109) leaves from plants grown under three different cropping patterns and treated with inorganic or organic fertilizer application.
Measurements were made at grain milk (R3) growth stage. (a) maximum carboxylation rate (Vcmax); (b) maximum rate of electron transport driving regeneration of ribulose-1,5-bisphosphate (Jmax); and (c) leaf respiration under light conditions (RD). Cropping patterns: Monocropping pattern (MCP); Intercropping pattern 1:1(ICP 1:1); Intercropping pattern 2:1 (ICP 2:1). Fertilizer treatments: Nutrimins Inorganic Fertilizer (NIF); Super Magro Biofertilizer (SMB). a, b, c: indicate the significant statistical differences using the LSD Fisher mean test (P < 0.05) for each cropping pattern in relation to the two types of fertilizer application (bars of the same color). The dashed red line corresponds to the mean value of each variable.
Fig 5.
Specific leaf area of maize (ICA V109) leaves from plants grown under three different cropping patterns and treated with inorganic or organic fertilizer application.
Measurements were made at tassel emergence (VT) and grain milk (R3) growth stages. Cropping patterns: Monocropping pattern (MCP); Intercropping pattern 1:1 (ICP 1:1); Intercropping pattern 2:1 (ICP 2:1). Fertilizer treatments: Nutrimins Inorganic Fertilizer (NIF); Super Magro Biofertilizer (SMB). a, b, c: indicate the significant statistical differences using the LSD Fisher mean test (P < 0.05) for each sowing pattern in relation to two types of fertilizer application (bars of the same color). The dashed red line corresponds to the mean value of each variable.
Fig 6.
Grain yield of maize (ICA V109) plants grown under three different cropping patterns and treated with inorganic or organic fertilizer application.
Cropping patterns: Monocropping pattern (MCP); Intercropping pattern 1:1 (ICP 1:1); Intercropping pattern 2:1 (ICP 2:1). Fertilizer treatments: Nutrimins Inorganic Fertilizer (NIF); Super Magro Biofertilizer (SMB). a, b: indicate the significant statistical differences using the LSD Fisher mean test (P < 0.05) for each cropping pattern in relation to the two types of fertilizer application (bars of the same color).
Fig 7.
Pearson correlation coefficients between different photosynthetic response variables and agronomic performance parameters.
Vcmax: maximum carboxylation rate; Jmax: maximum rate of electron transport driving regeneration of ribulose-1,5-bisphosphate (RuBP); RD: leaf respiration under light conditions; Amax: light-saturated maximum net carbon assimilation rate (Amax per area, Amax* per mass); Rd: dark respiration rate; LSP: light saturation point; LCP: light compensation point; ΦPAR: quantum efficiency of photosystem II; and SLA: specific leaf area. The gradient from green to red means positive and negative correlation of photosynthetic response and agronomic performance variables, respectively. Frame size indicates the level of the correlation, where those that are statistically significant (*P < 0.05, **P < 0.01, ***P < 0.001) are for the value of the correlation coefficient.