Wheat Growth Is Stimulated by Interspecific Competition after Faba Bean Attains Its Maximum Growth Rate

Abstract

Competition and facilitation adequately explain high yield and high resource use efficiency in intercropping; however, little research has focused on dynamic trajectories and interaction in a wheat (Triticum aestivum L.) and faba bean (Vicia faba L.) intercropping system under different P application rates. Field experiments were conducted with three planting patterns (monocropped wheat [MW], monocropped faba bean [MB], and wheat and faba bean intercropping) and three rates of P fertilization (0 [P0], 45 [P45], and 90 kg P2O5 ha−1 [P90]). The biomass of faba bean and wheat was sequentially sampled 10 and 11 times, respectively, during each growing season, and growth parameters and species interaction were simulated and calculated. Wheat and faba bean suffered different competition pressures in intercropping, but intercropping still showed yield advantages, and the interaction between wheat and faba bean was not regulated by P rate under moderate soil P fertility. Wheat was not dominant in intercropping until faba bean reached its maximum growth rate (Rmax). The Rmax, maximum biomass production, and grain yield of wheat increased by 12 to 18, 4 to 16, and 16 to 17%, respectively, when wheat was intercropped with faba bean relative to MW, and all of these variables for intercropped wheat at P45 were equal to those for MW at P90 due to the interactions between planting pattern and P rate. The findings suggest the time to reach the Rmax of faba bean is a turning point for the intercropping effects on wheat, and intercropping shows potential to maintain higher system productivity than monocropping under reduced P application.

Effects of nitrogen regulation and strip intercropping on faba bean biomass, nitrogen accumulation and distribution, and interspecific interactions

“…Reports on whether legume crops increase production in the graminaceous-legume system are inconsistent (Hu et al, 2018;Xiao et al, 2018a). Most of the research suggests that intercropping is not conducive to increasing the yield of leguminous crops (Wang et al, 2019;Xiao et al, 2018b). The reason is that graminaceous crops used in intercropping have a higher demand for nitrogen and are strongly competitive for sun and water resources, reducing the nutrient resources available in the intercropping environment and thus insufficient resources to the leguminous crop (Xiao et al, 2004).…”

“…The reason is that graminaceous crops used in intercropping have a higher demand for nitrogen and are strongly competitive for sun and water resources, reducing the nutrient resources available in the intercropping environment and thus insufficient resources to the leguminous crop (Xiao et al, 2004). Also, leguminous crops are often considered inferior in terms of factors such as plant height, nutrient use efficiency, and interspecific competition, all of which have been shown to be lower than in the graminaceous crops and hence are unfavorable to yield production (Xiao et al, 2018b). Alternatively, some researchers have suggested that intercropping is beneficial for yield in both graminaceous and leguminous plants (Hu et al, 2016;Hu et al, 2018).…”

Arbuscular mycorrhizal fungi in oat-pea intercropping

“…Intercropping can provide many benefits. Certain intercropping options have demonstrated overyielding capacity 1 , 2 or yield stability under contrasting environments 3 – 5 . Furthermore, intercropping forage systems have delivered consistently better nutritive quality 3 .…”