Intercropping modulates the accumulation and translocation of dry matter and nitrogen in maize and peanut

Intercropping increases resource capture due to species complementarities, but it is not clear to which extent intercropping also affects the redistribution of carbohydrates and nitrogen (N) within the plant. Here, we examined in two years field experimentation the accumulation and translocation of dry matter and N in maize and peanut in pure stands and intercrops at five N input levels. Post-anthesis dry matter accumulation in the cob was on average 117 g plant−1 in sole maize and 159 g plant−1 in intercropped maize, of which post-anthesis dry matter translocation contributed 9 and 19 g plant−1, respectively. Intercropping increased post-anthesis N accumulation of maize from 0.77 to 1.29 g N plant−1 and N translocation to cobs from 0.94 to 1.16 g N plant−1, but it decreased the contribution of post-anthesis N translocation to grain from 54.0% in sole maize to 46.9% in intercropped maize. The kernel number was 486 per cob in sole maize and 609 per cob in intercropped maize, and the thousand-kernel weight was 320 g and 336 g, respectively. In peanut, intercropping decreased post-anthesis dry matter accumulation from 14.8 to 9.4 g plant−1, post-anthesis N accumulation from 0.37 to 0.24 g N plant−1 and N translocation to the pods from 0.25 to 0.14 g N plant−1. The pod number per plant in peanut decreased from 10.6 in the sole crop to 8.6 in intercropping. Nitrogen fertilization increased dry matter accumulation and translocation in intercropped maize, but had little impact in sole maize or in sole or intercropped peanut. In both species, dry matter translocation to the reproductive organs contributed slightly to the yield, while the post-anthesis contribution of N translocation was of the same order of magnitude as that of N uptake.