The Effects of Suaeda salsa/Zea mays L. Intercropping on Plant Growth and Soil Chemical Characteristics in Saline Soil

Abstract

Halophytes possess the capacity to uptake high levels of salt through physiological processes and their root architecture. Here, we investigated whether halophyte/non-halophyte intercropping in saline soil benefits plant growth and contains root-dialogue between interspecific species. Field and pot experiments were conducted to determine the plant biomasses and salt and nutrient distributions in three suaeda (Suaeda salsa)/maize (Zea mays L.) intercropping systems, set up by non-barrier, nylon-barrier, and plastic-barrier between plant roots. The suaeda/maize intercropping obviously transferred more Na+ to the suaeda root zone and decreased salt and Na+ contents. However, the biomass of the non-barrier-treated maize was significantly lower than that of the nylon and plastic barrier-treated maize. There was lower available N content in the soil of the non-barrier treated groups compared with the plastic barrier-treated groups. In addition, the pH was lower, and the available nutrient content was higher in the nylon barrier, which suggested that rhizospheric processes might occur between the two species. Therefore, we concluded that the suaeda/maize intercropping would be beneficial to the salt removal, but it caused an adverse effect for maize growth due to interspecific competition, and also revealed potential rhizospheric effects through the role of roots. This study provides an effective way for the improvement of saline land.

Nitrogen Promotes the Salt-Gathering Capacity of Suaeda salsa and Alleviates Nutrient Competition in the Intercropping of Suaeda salsa/Zea mays L.

“…In this study, it was found that the intercropping suaeda/maize would produce the disadvantage of maize growth, which was consistent with the results of Wang et al (2022) [ 18 ]. This complex system was affected by uncertain factors, biotic as well as physical, that are essential for species development [ 27 , 28 , 29 , 30 ].…”

“…The nutrient relationship between two plants in the intercropping tends to be a mutual–competitive relationship. Wang et al (2022) found the soil nitrogen content to be reduced in the intercropping suaeda/maize, which suggested that the disadvantage of maize was caused by N competition [ 18 ]. In this study, N1 treatment could obviously promote the aboveground biomass of maize in the intercropping, not significantly different from that in the monoculture system ( Figure 1 ), which also indicated that there was nutrient competition between maize and suaeda.…”

“…This also brings crops nutrient-competitive advantages and superior yield by interspecific interactions. Rhizosphere dialogues, e.g., ions shift, signal delivery, and material transformation, are certainly present in this complex system [ 16 , 17 , 18 ]. Under high salinity, halophytes and non-halophytes might separately generate two distinct, different rhizosphere effects: non-halophyte root exudates reduce the soil pH to increase the soil nutrient availability, while halophytes improve salt-tolerant microorganisms through rhizosphere activities.…”

“…Liang et al (2021) found that it significantly displayed higher crop productivity and salt removal in the cotton/halophyte intercropping [ 19 ]. However, Wang et al showed that maize responded negatively in the suaeda/maize intercropping suaeda/maize, which might have been due to the N competition [ 18 ]. Whether or not the intercropping disadvantage of maize is caused by N competition should be further investigated.…”

Restoring Soil Functions and Agroecosystem Services Through Phytotechnologies

“…In a review paper, Panta et al (2014) (72) reported that some species of plants removed between 0.66 and 6.35 t ha -1 a -1 of NaCl. Halophytes have also been used as intercrops with watermelon (74), cotton (75), maize (76), and many other crops, as reviewed by (77). Until now, however, most of the studies on intercropping with halophytes have been done under greenhouse conditions, with both successful and unsuccessful responses (77).…”