Iron Nutrition of Peanut Enhanced by Mixed Cropping with Maize: Possible Role of Root Morphology and Rhizosphere Microflora

Crop acquisition of phosphorus, iron and zinc from soil in cereal/legume intercropping systems: a critical review

“…Pot experiments have demonstrated that co-culturing peanut with maize in Fe-deficient soils often increases the length and the number of lateral roots and root hairs of peanut. Simultaneously, rhizodermal transfer cells are formed in the sub-apical zone of peanut roots in response to intercropping (Zuo et al, 2003). Intercropping decreased microbial abundance and activity in the rhizosphere of peanut grown in a calcareous sandy soil; Zuo et al (2003) speculated that this may slow the degradation of mucus layers containing considerable amounts of root exudates, including PSs.…”

“…However, the roles of root morphology and microbes of the rhizosphere in Fe and Zn acquisition in intercropping remain poorly studied and understood (Table 2). Zuo et al (2003) highlighted the possibility that root morphological changes and shifts in composition and structure of microbial communities may also play a critical role in intercropping-facilitated Fe uptake. Pot experiments have demonstrated that co-culturing peanut with maize in Fe-deficient soils often increases the length and the number of lateral roots and root hairs of peanut.…”

“…For example, intercropping with barley, oat, wheat or maize increased the chlorophyll, HCl-extractable Fe (so-called 'active Fe') and total Fe concentrations in young leaves of peanut, thus alleviating Fe chlorosis in calcareous soils (Zuo et al, 2000(Zuo et al, , 2003Inal et al, 2007;Zhang, 2008, 2009; Fig. 2A, B).…”

Nutritional and management related interactions with iron-deficiency stress response mechanisms

“…Recent reports of overcoming Fe-deficiency chlorosis in field and tree crops by mixing species suggest greater impact on Fe-deficiency chlorosis than previously considered possible (Rombola et al 2004;Zuo et al 2000Zuo et al , 2003. Zuo et al (2000) attributed improvements in Fe nutrition of peanut intercropped with maize to possible rhizosphere interactions between peanut and maize, but actual mechanisms were not elucidated.…”

“…Zuo et al (2000) attributed improvements in Fe nutrition of peanut intercropped with maize to possible rhizosphere interactions between peanut and maize, but actual mechanisms were not elucidated. In a later greenhouse experiment conducted on calcareous soil (Zuo et al 2003), serious chlorosis development was observed in peanut in monoculture compared to mixed culture with com. Peanut growth in mixed culture resulted in modified root morphology (more lateral roots, longer and thinner roots and better defined rhyzodermal transfer cells in the subapical root zone-the site of Fe reduction/H ion release) and altered microbial populations (fewer bacteria and thicker mucigel layers on the root surface of mixed cropped peanut).…”