Intercropping with pulses to concentrate nitrogen and sulphur in wheat

Abstract

The effects of intercropping wheat with faba bean (Denmark, Germany, Italy and UK) and wheat with pea (France), in additive and replacement designs on grain nitrogen and sulphur concentrations were studied in field experiments in the 2002/03, 2003/04 and 2004/05 growing seasons. Intercropping wheat with grain legumes regularly increased the nitrogen concentration of the cereal grain, irrespective of design or location. Sulphur concentration of the cereal was also increased by intercropping, but less regularly and to a lesser extent compared with effects on nitrogen concentration. Nitrogen concentration (g/kg) in wheat additively intercropped with faba bean was increased by 8% across all sites (weighted for inverse of variance), but sulphur concentration was only increased by 4%, so N:S ratio was also increased by 4%. Intercropping wheat with grain legumes increased sodium dodecyl sulphate (SDS)-sedimentation volume. The effect of intercropping on wheat nitrogen concentration was greatest when intercropping had the most deleterious effect on wheat yield and the least deleterious effect on pulse yield. Over all sites and seasons, and irrespective of whether the design was additive or replacement, increases in crude protein concentration in the wheat of 10 g/kg by intercropping with faba bean were associated with 25?30% yield reduction of the wheat, compared with sole-cropped wheat. It was concluded that the increase in protein concentration of wheat grain in intercrops could be of economic benefit when selling wheat for breadmaking, but only if the bean crop was also marketed effectively

Ecological principles underlying the increase of productivity achieved by cereal-grain legume intercrops in organic farming. A review

“…Yet, as we indicated above, intercrops would be a way of improving harvested grain quality and in particular its protein concentration compared with the traditional sole cropping (e.g. Jensen 1996a; Knudsen et al 2004;Gooding et al 2007;Bedoussac and Justes 2010a;Naudin et al 2010). Our results confirm that the protein concentration of the intercropped cereal is almost always greater than that of the respective cereal sole crop (Fig.…”

“…15). Gooding et al (2007) confirmed by Bedoussac andJustes (2010a, 2010b) explained that the intercropping effect on grain protein concentration of wheat was due to a higher soil N availability for the cereal on a per plant or a per grain basis in intercrop in comparison with sole crops. It was shown to be the result of: (i) the low competitiveness of legumes for mineral N compared with cereals, combined with (ii) competition for light, water and other nutrients, between the two species, which lead to limit intercropped cereal biomass and Fig. 14 Cereal partial land equivalent ratio for grain protein concentration as a function of cereal partial land equivalent ratio for grain yield (y=1.06x -0.16 ; R 2 =0.34***).…”

“…The most obvious advantages emphasized when trying to convince farmers to adopt intercropping strategies are to improve and stabilize yields (Hauggaard-Nielsen et al 2009b;Lithourgidis et al 2006) and also to increase the cereal grain protein concentration as compared to the respective sole crops (Gooding et al 2007). Cereal/legume intercropping is regarded as highly relevant in low-N-input systems and organic farming where nitrogen is often a limiting resource for crop growth (Willey 1979a;Ofori and Stern 1987;Vandermeer 1989;Willey 1990;Fukai and Trenbath 1993;HauggaardNielsen et al 2003;David et al 2005;Desclaux et al 2008;Bedoussac andJustes 2010a, 2010b;Naudin et al 2010).…”

“…Similarly, the selling price of soft wheat increased by 60€Mg −1 when the grain protein concentration is higher than 11.5 % for a basic price of 270€Mg −1 . Focusing on soft wheat/faba bean intercrops, Gooding et al (2007) included sites and seasons for five different regions across Europe and showed that increases in crude protein concentration in the wheat of 10 g kg −1 associated with 25-30 % yield reduction of the wheat in IC could be of economic benefit when selling wheat for bread making, but only if the bean crop is also effectively marketed (Gooding et al 2007).…”

Cereal-pea intercrops to improve sustainability in bioethanol production

“…Pea was preferred to faba bean (Vicia faba L. sub. minor) because in previous studies in a similar environment in Southern Italy (Gooding et al 2007), a leafless pea cultivar performed better than faba bean in intercrop with the latter causing reduction in cereal yields. Sole crop (SC) treatments (WSC, BSC, OSC, TSC, PSC) were sown at the recommended seed density of 90 seeds m −2 for pea, 300 seeds m −2 for oat and barley and 400 seeds m −2 for wheat and triticale.…”