19. Yield performance and complementarity in mixtures of bread wheat (triticum aestivum l.) And pea (pisum sativum l.).
Publ.of the Inst. of Agronomy, Univ. of Tuscia, 01100 Viterbo, Italy, 1991
Intercropping of cereals and grain legumes often gives higher resource use efficiency compared to homologous sole crop systems. Complementarity between bread wheat and grain pea can derive from their different growth habits, earliness, and ability to use different sources of N and/or, presumably, other nutrients owing to root stratification in the mixture.
As to plant morphology and growth habits, consistent variation also occurs among pea cultivars. Results are reported of a study carried out during two cycles (1989/90 and 1990/91) at Viterbo (central Italy) where four pea varieties (the early "leafy" cv. 'Stehgolt' and the early "semileafless" cv. 'Consort'; the medium early "leafy" cv. 'Frijaune' and the medium early "semileafless" cv. 'Countess') were intercropped with the medium early bread wheat cv. 'Pandas' under two different inorganic N conditions (9.0 g/m2 and 16.1 g/m2). Both wheat and pea intercrops were compared with their respective sole crops under the same conditions. Complementarity clearly occurred in both years in two cases out of four (mixture of wheat with the early cvs. Consort and Stehgolt), only under the lower N availability conditions. LER values were about 1.20 for both Pandas/Consort and Panda/Stehgolt mixture; partial LERs showed a great yield advantage of wheat and a moderate yield disadvantage for pea. In the most balanced mixture (Pandas/Consort), grain yields of wheat and pea intercrops compared to sole crops were 7180 vs 4380 kg ha-1 and 3340 vs 4380 kg ha-1, respectively. Both medium-early cultivars (cv. Countess and cv. Frijaune did not show complementarity with wheat, and components did not give yield advantages. Under high N availability conditions (16.1 gm/m2), complementarity between wheat and pea never occurred. Wheat was more competitive than the early cultivars of pea (cv. Stehgolt and cv. Consort), but equally competitive against the medium-early ones (cv. Frijaune and cv. Countess). Intercropping of wheat with early, standing pea cultivars represents a promising solution to obtain yield advantages under low to moderate N input conditions.
1109 92 - 4/152
Asia, Philippines, study, rice, green manure, economic feasibility, azolla fertilizer
ROSEGRANT, M.W. and J.A. ROUMASSET
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