Abstract:
Phosphorus (P) is an essential element and its efficient use is of globalimportance. This study evaluated the effect of growing potato under leg-ume intercrops on P uptake and use efficiency indices: P harvest index(PHI), P uptake efficiency (PuPE), P partial factor productivity (PPFP) and Ppartial balance (PPB). The experiment was carried out for four consecutiveseasons with treatments comprising potato cultivated under legume inter-crops: none (T1), dolichos (Lablab purpureus L) (T2), peas (Pisum sativum L)(T3) and beans (Phaseolus vulgaris L) (T4). Across the seasons, the meanhaulm 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. Onthe 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 T3and 15.1 kg P ha 1 in T4. This had a profound effect on PuPE, which wasequally 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 followeda similar trend, with highest values in T1 (57 kg tuber dry matter yieldkg 1 P supply, 76.4 kg tuber P uptake kg 1 total plant’s P uptake and0.20 kg tuber P uptake kg 1 P supply, respectively). Among the tested leg-ume intercrops, dolichos competed least for P with the main crop (potato)hence it can be integrated into potato-based cropping systems withoutcompromising potato tuber yield.
