Agriculture Reference
In-Depth Information
Mixtures of Legumes with Cereals as a Source of Feed for Animals
http://dx.doi.org/10.5772/58358
respective sole crops showing a high degree of complementarity between pea and barley across
intercrop designs and very different growing conditions in Europe. As a mean of all site around
20% more efficient soil mineral N uptake was achieved by the intercrops than the sole crops.
Soil N uptake by barley in intercrops was associated with an increased reliance of pea on N
2
-
fixation, rising the percent of total N derived from N
2
-fixation [29]. The authors indicate the
independent of climatic growing conditions, including biotic and abiotic stresses, across
European organic farming systems pea-barley intercropping is a relevant cropping strategy to
adapt when trying to optimize N use and thereby N
2
-fixation inputs to the cropping system.
Treatment
Dose of nitrogen fertilization (kg·ha
-1
)
Mean
0
30
60
44 a*
55 a
75 a
Barley
58 a
Pea
78 b
86 b
93 b
86 b
Barley+pea
96 c
108 c
103 c
102 c
* Number within columns followed by the same letters do not differ significantly
Table 3.
Nitrogen uptake with grain yield [own study based on 30]
The dose of mineral nitrogen had a significant impact on the amount of biological fixation of
nitrogen by legumes. Increasing dose of mineral nitrogen caused a decrease in the fixation of
atmospheric nitrogen, as it is a well-known tendency that if a plant has the possibility to use
soil or fertilizer nitrogen, the assimilation of N
2
decreases. The research carried out in Poland
has shown that increasing the level of fertilization of legume-cereal mixtures by mineral
nitrogen from 0 to 90 kg ha
-1
resulted in a significant reduction of atmospheric nitrogen fixation
by legumes. Each 10 kg of the nitrogen applied in a dose of 30 and 60 kg ha
-1
in a mixture of
pea with wheat or pea with barley caused a reduction in the fixation of this element by about
7-8 kg, while at a dose of 90 kg, the reduction was higher by about 9 kg [31, 32]. Biological
nitrogen fixation also depends on the soil conditions (nitrogen content, moisture content, pH)
and the severity of disease and pests [33]. A large impact on the amount of symbiotic nitrogen
fixation has also soil temperature. The optimal temperature range which allows for the
maximum nitrogen fixation is (
o
C): for big-leaved lupine-25, common vetch-20, faba bean-20,
field pea-25, blue lupine-20-30, and for soybean-20-25 [34].
2.3. The selected factors of production
2.3.1. Species and varieties
Yielding of legume-cereal mixtures largely depend on the proper selection of species. Spring
barley can be a good component for the mixtures with peas, due to similar habitat require‐
ments, similar length of growing season and high nutritional value of seeds of such mixture,
but also spring triticale and spring wheat, especially on the better soils. Naked oats, however,
is a weaker component due to its low yield of grain which is also variable in years [35, 36].
Husked cultivars of oats and barley, however, are more useful to mixture with peas compared
