Mitteilungen der Gesellschaft für Pflanzenbauwissenschaften Band 23

Mitt. Ges. Pflanzenbauwiss. 23: 268–269 (2011)
How to manage above-ground competition
in bush bean/spring maize strip-intercropping?
Sebastian Munz 1 , Simone Graeff-Hönninger 2 and Wilhelm Claupein 3
1 Institut für Kulturpflanzenwissenschaften, Universität Hohenheim, Stuttgart; 2 Institut für Kulturpflanzenwissenschaften,
Universität Hohenheim, Stuttgart; 3 Institut für Kulturpflanzenwissenschaften,
Universität Hohenheim, Stuttgart. E-Mail: s.munz@uni-hohenheim.de
Introduction
Intercropping is a widespread traditional agricultural production system in the North
China Plain (NCP). However, due to large migration to urban areas with higher
salaries, labor scarcity in the rural areas is defining a new framework for agricultural
production. The high intensity of manual labor and the ongoing mechanization are
causing a decline of the traditional intercropping systems (Feike et al., 2010). Strip
intercropping as a highly productive, mechanizable and sustainable agricultural
production system might be an appropriate system to meet current challenges of
environmental degradation and scarcity of rural labor in the NCP. Maize and bush
bean are locally important crops. In order to optimize this intercropping system the
spatial and temporal competition between the crops has to be balanced. Due to the
large difference of plant height between bush bean and spring maize the main focus
in this experiment is set on above-ground competition.
Material and Methods
A strip-intercropping experiment of bush bean (Phaseolus vulgaris L.) and spring
maize (Zea mays L.) was conducted at the University of Hohenheim and the Chinese
Agricultural University in Beijing in 2010. The two crops were planted in strips with
three replications in a sequence in north-south orientation. The strips consisted of 12
rows of maize (85.000 plants ha -1 ) and 9 rows (280.000 plants ha -1 ) of bush bean in
Germany and of 7 rows of maize (62.000 plants ha -1 ) and 7 rows of bush bean
(280.000 plants ha -1 ) in China, respectively. The distance between neighboring crops
was set to 60 cm to allow use of machinery while maintaining low proximity to ensure
interspecific interactions. The effect of different maize strip widths (four, six, eight and
ten rows) and plant shape of three maize cultivars, namely Companero (normal
shape), NK Ravello (increased plant height and more erect leaves) and Lapriora
(reduced plant height) on transmitted photosynthetically active radiation (TPAR) was
determined after full maize plant height at the University of Hohenheim in 2010. The
measurements of TPAR were conducted with a linear PAR ceptometer (Model
AccuPar LP-80, Decagon Devices, Pullman, WA, USA) at soil surface, 60 cm
(distance between boarder rows of bush bean and maize) away from the west side of
the maize strips at 11 am.
Results and Discussion
In China and Germany total dry matter of bush bean was increased in row two
adjacent to the maize strips compared to the centre row of the bush bean strips at
harvest. In row one next to maize total dry matter was reduced the most (Figure 1).