Biological nitrogen fixation in mixed legume-cereal cropping systems

Abstract

References 156 Fujita et al. AbstractCereal/legume intercropping increases dry matter production and grain yield more than their monocultures. When fertilizer N is limited, biological nitrogen fixation (BNF) is the major source of N in legume-cereal mixed cropping systems. The soil N use patterns of component crops depend on the N source and legume species. Nitrogen transfer from legume to cereal increases the cropping system's yield and efficiency of N use. The use of nitrate-tolerant legumes, whose BNF is thought to be little affected by application of combined N, may increase the quantity of N available for the cereal component. The distance between the cereal and legume root systems is important because N is transferred through the intermingling of root systems. Consequently, the most effective planting distance varies with type of legume and cereal. Mutual shading by component crops, especially the taller cereals, reduces BNF and yield of the associated legume. Light interception by the legume can be improved by selecting a suitable plant type and architecture. Planting pattern and population at which maximum yield is achieved also vary among component species and environments. Crops can be mixed in different proportions from additive to replacement or substitution mixtures. At an ideal population ratio a semi-additive mixture may produce higher gross returns.

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

“…This implies that intercropping may be advantageous when nitrogen availability corresponding to soil nitrogen plus N-fertilizer is below a determined threshold (12 g N m −2 in these experiments) due to a high degree of complementary nitrogen use between the two species for low N levels. Such results have been reported for several cereal/legume intercrops grown in arid, semi-arid, tropical and temperate climates (Fujita et al 1992;Ofori and Stern 1987;Jensen 1996a;Naudin et al 2010). Present results confirm that there is a negative correlation between grain yield-based LER and mean yield of the sole crops (Fig.…”

“…This support the previous explanation that the effect of intercropping is small or absent when large soil mineral N is available. Again, intercropping shows its greatest potentials in systems with low nitrogen availability, where the equilibrium between fixation and absorption of soil mineral nitrogen by the two species allows an adjustment of the availability to the needs (Fujita et al 1992;Tofinga et al 1993;Hauggaard-Nielsen et al 2001a, 2001bCorre-Hellou et al 2006;Naudin et al 2010;Hauggaard-Nielsen et al 2003).…”

Permaculture for agroecology: design, movement, practice, and worldview. A review

“…This lack of consideration of spatial relationships in agronomy has been noted by many authors (Cavazza 1996;Veldkamp et al 2001;Hatfield 2007;Osty 2008;cited in Benoit et al 2012). Configuration is a nevertheless an implicit issue for land use functions that depend on spatial and topographic relationships, including windbreaks, runoff filtration, habitat provision, nitrogen fixation in polycropping (Ajayi 1987;Fujita et al 1992), contour cultivation (Tacio 1993;Bunch 2002), and soil and water conservation. At larger scales, configuration is regarded as a Fig.…”

“…The design and use of perennial polycultures is a core theme of the permaculture literature (Mollison and Holmgren 1978;Mollison 1988;Mollison and Slay 1997;Jacke and Toensmeier 2005;Hemenway 2009;Frey 2011;Bane 2012) and strongly reflects the criterion of ecosystem mimicry. The design of plant/animal or other multi-kingdom polycultures receives somewhat less attention (Mollison and Holmgren 1978;Holzer 2011;Shepard 2013).…”

“…The productivity and multifunctionality of such systems have been demonstrated across multiple contexts, including arid land agriculture (Evenari et al 1982;Bruins et al 1986;Boyd and Gross 2000;Mussery et al 2013), hillside agriculture in humid zones (Holt-Gimenez 2006), and in aquaculture/ irrigation systems in a wide range of contexts (Prein 2002;Boyd and Gross 2000;Smukler et al 2010). Despite the frequency with which water harvesting earthworks are addressed in the permaculture literature, discussion of quantitative planning tools is rare (Lancaster and Marshall 2008;Frey 2011). Discussion of the risks posed by dispersive soils, which are highly vulnerable to tunnel erosion and thereby to catastrophic failure (Sherard et al 1976), is entirely absent.…”