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Phosphorus (P) is an essential element and its efficient use is of global importance. This study evaluated the effect of growing potato under legume intercrops on P uptake and use efficiency indices: P harvest index (PHI), P uptake efficiency (PuPE), P partial factor productivity (PPFP) and P partial balance (PPB). The experiment was carried out for four consecutive seasons with treatments comprising potato cultivated under legume intercrops: none (T1), dolichos (Lablab purpureus L) (T2), peas (Pisum sativum L) (T3) and beans (Phaseolus vulgaris L) (T4). Across the seasons, the mean haulm P uptake for T2 (6.7 kg P ha−1), T4 (5.5) and T3 (4.5) were 6%, 23% and 36% lower than that observed in T1 (7.1 kg P ha−1), respectively. On the other hand, tuber P uptake was highest in T1 (21.8 kg P ha−1) and T2 (21.3 kg P ha−1) and were significantly higher than 13.2 kg P ha−1 in T3 and 15.1 kg P ha−1 in T4. This had a profound effect on PuPE, which was equally highest in T1 (0.26 kg total P uptake kg−1 P supply) and T2 (0.25) and lowest in T3 (0.16) and T4 (0.18). Similarly, PPFP, PHI and PPB followed a similar trend, with highest values in T1 (57 kg tuber dry matter yield kg−1 P supply, 76.4 kg tuber P uptake kg−1 total plant's P uptake and 0.20 kg tuber P uptake kg−1 P supply, respectively). Among the tested legume intercrops, dolichos competed least for P with the main crop (potato) hence it can be integrated into potato-based cropping systems without compromising potato tuber yield. [ABSTRACT FROM AUTHOR]

Two rice genotypes, JX17 (Oryza sativa ssp. japonica) and ZYQ8 (Oryza sativa ssp. indica), which had been the parents of the 127-line double haploid (DH) population for construction of molecular linkage map, were chosen to study their response to low phosphorus (P) stress. The results indicated that JX17 had advantages over ZYQ8 on some traits associated with phosphorus uptake efficiency, such as root dry weight, root-exuded acid phosphatase activity, root-exuded organic acids and proton. Consequently, JX17 had higher relative total dry weight and was regarded as the non-sensitive genotype to low phosphorus stress. Physiological response of the two genotypes to P deficiency was studied in monoculture and in mixed culture. The results showed that, compared with monoculture, JX17 absorbed more P and had higher biomass in mixed culture condition under P stress. ZYQ8, by contrast, suffered from P stress to a much greater extent, with lower P uptake and biomass. JX17 had a higher P uptake rate expressed as P amount per root length which is suggested to be the main reason for its insensitivity to low P stress. [ABSTRACT FROM AUTHOR]