Maize–Soybean Intercropping Interactions Above and Below Ground

Abstract

Above‐ground and below‐ground interactions of the maize–soybean intercrop were studied in a 2‐yr field experiment with measurements of grain and total biological yield; N, P, and K uptake; and photosynthesis. Four intercrop treatments included no shoot or root separation (T1), shoot and root separation (T2), root separation (T3), and shoot separation (T4); two controls were solo maize (T5) and solo soybean (T6). Results indicated that competition between above‐ground and/or below‐ground plant parts is a key factor in describing intercropping advantage, and that intercropping is not advantageous in the absence of competition. Specific results showed significant intercrop advantages when roots and shoots were not separated, the differences between component species in above‐ground and below‐ground competition, and a greater contribution to intercrop advantages from below‐ground interactions than above‐ground interactions. Although competition for nutrients, water, and sunlight is the primary explanation often used to explain intercrop advantages, our results indicate that competition for nutrients was of more importance than competition for sunlight. Differences in nutrient uptake data were closely related to those of yields, confirming the importance of below‐ground competition. Relatively less competition above ground was confirmed by minimal differences in photosynthesis among treatments. More refined studies of resource competition could further confirm the different contributions of above‐ground and below‐ground interactions. One potential application of results could be their use in intercrop systems modeling.

Narrow‐wide‐row planting pattern increases the radiation use efficiency and seed yield of intercrop species in relay‐intercropping system

“…Our findings are similar with the results of Raza et al () and Yang et al () they revealed the RI advantage with narrow‐wide‐row planting arrangement. Moreover, less gap (52 cm) between soybean and maize reduced the light transmittance at the top soybean plant (Lv, Francis, Wu, Chen, & Zhao, ; Oseni, ); thus, it is an appropriate method to decrease the negative impacts of maize shading by increasing gap (20:180 or 40:160) between soybean and maize rows for growing soybean, which produced higher soybean seed yield and total LER of RI. Additionally, in 2013, a higher LER value in P2 when compared with P1 was due to the higher seed yield of maize (Table ), and similar findings were reported by Raza et al () under planting pattern of 40:160.…”

Effect of Two Patterns of Intercropping Soybean with Maize on Yield and Its Components under Different Nitrogen Fertilizer Levels

“…This duplicate density in each hill caused a reductive activity of maize roots in all soil layers and significantly decreased dry weights of shallow roots, resulting in lower root biomass and consequently lower competitive ability for maize with soybean especially below-ground competition (Jiang et al, 2013). However, Lv et al (2014) showed a greater contribution to intercrop advantages from below-ground interactions than above-ground interactions and reported that, competition for nutrients was more importance than competition Egypt. J. Agron.…”

Water and radiation use in maize–pea intercropping is enhanced with increased plant density

“…As a cereal and a C 4 crop, maize is highly efficient at light interception and utilization (Omoto, Taniguchi, & Miyake, 2012). At the same time, shading by a taller maize crop can reduce leaf area and photosynthetic rate of shorter legumes (Yue, Francis, Wu, Chen, & Zhao, 2014). Increasing maize density may compensate for reduced light interception resulting from shading and the bare strips during the early and late growth periods in maize-pea intercropping.…”