Luxury Absorption of Phosphorus Exists in Maize When Intercropping with Legumes or Oilseed Rape—Covering Different Locations and Years

Abstract

Rational regulation of phosphorus (P) use in the soil–rhizosphere–plant system is challenging in the development of sustainable, intensive, and healthy agriculture. Rational maize (Zea mays L.) based intercropping with legumes/oilseed rape across six experimental sites from 2008 to 2017 proved advantageous over monoculture in terms of both maize biomass production and P uptake. The partial land equivalent ratio (PLER) for P uptake by intercropped maize averaged from 0.58 to 0.92, which was significantly higher than that for biomass production (0.51–0.78), indicating that the advantage of P acquisition by intercropped maize was superior to that of biomass accumulation. It was the excessive accumulation of P in intercropped maize compared to monoculture, especially higher P concentrations in grains that led to the superior P acquisition advantage and luxury absorption of P. P concentrations in maize grains were significantly increased from 1.89–2.91 mg kg−1 in monoculture to 2.09–3.65 mg kg−1, in intercropping, by 8.3%–25.5%. The plant internal P use efficiency of maize was significantly decreased from the initial 411.7–775.7 kg kg−1 in monoculture to 345.7–710.4 kg kg−1 in intercropping by 4.9%–16.0%, and 100 kg maize grain P quantities were significantly increased from 0.25–0.46 kg to 0.27–0.54 kg by 7.0%–17.4%. Rational fertilizer P input maximized maize yields and P use without decreasing the interspecific ecological advantages and harvest indexes of grain yields and P. These findings promoted better understanding of P allocation status within maize plants, and yield and P acquisition advantages through the exploitation of the biological potential of plants for the efficient utilization of P resources in diverse species combinations.

Interspecific root interactions increase maize yields in intercropping with different companion crops

“…These findings indicate that N and P uptake in IC is probably higher than in monocropping. This is in accordance with previous studies showing that N and/or P uptake of maize were higher when intercropped with soy (Chen et al., 2019; Xia et al., 2019), lupin (Lelei & Onwonga, 2014), or turnip rape (Xia et al., 2013, 2019) than in monocropping. Our finding that total biomass, maize AGB, and maize AGB P uptake were significantly higher in maize monocropping than in IC in the rb treatment (Figure 4 and Supporting Information 1) further indicates that interspecific root interactions were important for IC effects on maize, as discussed above.…”

“…For example, soy enhanced AGB production and grain yields of maize in IC resulting in a global mean LER of 1.32 for soy/maize IC (Chen et al., 2019; Xu et al., 2020). Overyielding has also been found when maize was intercropped with soy, faba bean (Li et al., 2018; Xia et al., 2019), or lupins (Lelei and Onwonga, 2014). Similarly, overyielding has been found when maize was intercropped with turnip rape ( Brassica campestris L.; Xia et al., 2013, 2019).…”

“…Overyielding has also been found when maize was intercropped with soy, faba bean (Li et al., 2018; Xia et al., 2019), or lupins (Lelei and Onwonga, 2014). Similarly, overyielding has been found when maize was intercropped with turnip rape ( Brassica campestris L.; Xia et al., 2013, 2019). In addition, another meta‐analysis revealed that Brassicaceae, including mustard, increased maize AGB and grain yields when used as a cover crop (Hallama et al., 2019).…”

Integrative Physiological, Transcriptome, and Proteome Analyses Provide Insights into the Photosynthetic Changes in Maize in a Maize–Peanut Intercropping System

“…Maize originating from the tropics has two pathways for fixed CO 2 : the C4 and Calvin cycles [ 5 , 12 ]. In the C4 pathway, the receptor for CO 2 is phosphoenolpyruvate (PEP), and the fixation of CO 2 occurs in the cytoplasm of mesophyll cells.…”

“…This will be the direction of development for achieving high-yield and high-efficiency agriculture in the future. Intercropping is an intensive planting pattern in time and space, which can improve the utilization efficiency of light, temperature, water, fertilizer, the atmosphere, and other resources as well as the efficiency of light energy utilization and land productivity with a marginal effect [ 3 , 4 , 5 ]. It plays a critical role in agricultural production around the world.…”