Facilitated legume nodulation, phosphate uptake and nitrogen transfer by arbuscular inoculation in an upland rice and mung bean intercropping system

Abstract

Intercropping of upland rice with shortduration grain legumes has major advantages in increasing crop yields and soil productivity. However, the contribution of arbuscular mycorrhizas, the common mutualistic symbiosis between most crops and mycorrhizal fungi, is not fully understood in intercropping systems. We assayed the contribution of inoculation of the arbuscular mycorrhizal fungus (AMF) Glomus caledonium on nutrient acquisition and biomass yield. Using the method of plastic film and nylon net partition and tracing 15 N transferred between the intercropped upland rice (Oryza sativa ssp. Japonica Nipponbare) and mung bean (Vigna radiata L. Chuanyuan), we compared the intercropping, with separation of the whole root systems by a plastic film, with and without a barrier of nylon net to allow penetration of the fungal hyphae. Intercropping significantly improved the formation of arbuscular mycorrhizas, particularly in the upland rice roots. The improved formation of mycorrhizas by the intercropping increased total P uptake by 57% in rice, total P and N acquisition by 65% and 64% respectively in mung bean, and nodulation by 54% in mung bean. The percentage of total 15 N transfer from mung bean to rice leaves was increased from 5.4% to 15.7% by inoculation with AMF. In contrast, there was only 2.7% of 15 N transfer from rice to mung bean and no AMF effect on N transfer. It is concluded that cereal and legume crop intercropping increase mycorrhiza formation, which in turn improves nodulation, N and P acquisition and N transfer in the legumes.

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

“…However, this mechanism has never been explored in cereal/legume intercropping (Hinsinger et al, 2011), in which only the status of soil carbon and N stocks has been studied recently (Cong et al, 2014. Direct transfer of nutrients between intercropped species via common mycorrhizal networks is better documented for N (Johansen and Jensen, 1996;He et al, 2009) than for P (Li et al, 2009;Merrild et al, 2013;Qiao et al, 2015).…”

Multiple cropping systems as drivers for providing multiple ecosystem services: from concepts to design

“…3-group A), such flows can reach up to 20 % of the nitrogen contained in the cereal derived from the legume (Hauggaard-Nielsen and Jensen 2005), which has itself been obtained by symbiotic fixation of atmospheric nitrogen by rhizobia. Most of these results were obtained in pot experiments, some of which showed that common mycorrhizal networks could contribute to a significant proportion of such plant-plant transfers (Li et al 2009). However, it is difficult to quantify such transfers in field conditions, and so the effect has not been established in the field.…”

Evaluation of Mixed Cropping of Oat and Hairy Vetch as Green Manure for Succeeding Corn Production

“…3a). Some workers reported the beneficial effect of mixed cropping with a leguminous crop on the growth and nutrient uptake of the associated gramineous crop, especially regarding N transfer from legumes (Chu et al, 2004;Xiao et al, 2004;Rasmussen et al, 2007;Li et al, 2009), whereas others described that there was no evidence of substantial transfer of legume N to the neighboring crops until the legume leaves and stems were cut or grazed (Thorsted et al, 2006;Ayres et al, 2007). In the present experiment, there was no significant difference in shoot dry weight of oat between the Sole Oat and Mix plots on 10 April, before blooming of hairy vetch growth stage (Table 3).…”