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Little is known about how the performance of legumes symbiosis affects biomass and nutrient accumulation by intercropped cereals under the field condition. To assess the agricultural services of an intercropping system; durum wheat (Triticum turgidum durum L.cv. VITRON) and chickpea (Cicer arietinum L.cv. FLIP 90/13 C) were cultivated as both intercrops and sole cropping during two growing seasons under the field trial, to compare plant biomass, nodulation, N and phosphorus (P) uptake, and N nutrition index. Both the above-ground biomass and grain yield and consequently, the amount of N taken up by intercropped durum wheat increased significantly (44%, 48%, and 30%, respectively) compared with sole cropping during the two seasons. However, intercropping decreased P uptake by both durum wheat and chickpea. The efficiency in use of rhizobial symbiosis (EURS) for intercropped chickpea was significantly higher than for chickpea grown as sole cropping. The intercropped chickpea considerably increased N (49%) and P (75%) availability in durum wheat rhizosphere. In the case of chickpea shoot, the N nutrition (defined by the ratio between actual and critical N uptake by crop) and acquisition were higher in intercropping during only the first year of cropping. Moreover, biomass, grin yield, and resource (N and P) use efficiency were significantly improved, as indicated by higher land equivalent ratio (LER > 1) in intercropping over sole cropping treatments. Our findings suggest that change in the intercropped chickpea rhizosphere-induced parameters facilitated P and N uptake, above-ground biomass, grain yield, and land use efficiency for wheat crop.

The positive effect of intercropping under low phosphorus (P) conditions has already been reported in previous works. The aim of this study was to test the hypothesis that intercropping (common bean -maize) in P deficient soil, can enrich carbon (C) and nitrogen (N) of the microbial biomass (MB) through a transfer from root nodules of the plant and rhizospheric microbial flora in a field located in "Setif region" in northern Algerian agroecosystem(Mediterranean climate). The rate of nodular N sequestered in intercropped common bean was higher compared to sole crops and fallow. However, under intercropped and low P conditions, the rate of nodular N sequestered is highest over two years. Carbon of the microbial biomass (MB-C) is higher in the intercropping compared to sole crops and fallow but it is even higher in P deficient soil. Moreover, a strong correlation is established between nodular C and MB in intercropping under low P conditions. In these same conditions, the total soil respiration was the highest and the lowest C:N ratio of MB was recorded. These results showed that in low P soil, intercropping is a good solution to enhance the rhizospheric MB that can fertilize the soil and recycle mineral elements.

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