Page 1

Intercropping in sustainable maize cultivation Abeya Temesgen, Shu Fukai and Daniel Rodriguez, The University of Queensland, Australia 1 Introduction 2 Intercropping under different conditions: moisture and nitrogen levels 3 Resource capture and use efficiency in maize-based intercropping: water, nitrogen and light 4 Competition and complementary interactions in maize–legumes intercropping 5 Maize–legume intercropping evaluation 6 Conclusions 7 Where to look for further information 8 References

1 Introduction Sustainable intensification of agriculture, defined as the capacity to continuously produce more food from less land (Bryan et al., 2014), has been proposed as one of the strategies to mitigate food insecurity in smallholder farming. Intercropping, the simultaneous growth of two or more crops on the same area of land, is widely practised in Africa and elsewhere in tropics as an intensified system. Maize/legume intercropping systems have the potential to improve soil fertility through N fixation (Chowdhury and Rosario, 1992; Ghaley et al., 2005; Hauggaard-Nielsen et al., 2001b), to conserve soil moisture by providing additional ground cover (Jahansooz et al., 2004) and to outcompete weeds (Hauggaard-Nielsen et al., 2001a; Workayehu and Wortmann, 2011). Intercropping is believed to provide insurance in an unpredictable environment, poor soil fertility and unstable market prices. There is evidence that intercrops have higher productivity per unit area of land than sole crops (Belay et al., 2008; Ouda et al., 2007; Vahdettin et al., 2006; Ogindo and Walker, 2005; Tsubo et al., 2004). This might be as a result of improved resources capture (RC), and/or higher resource-use efficiencies (RUEs) in intercrops than the sole crops (Yang et al., 2011; Belay et al., 2008; Szumigalski and Van Acker, 2006; Kanton and Dennett, 2004; Zhang and Li, 2003; Hauggaard-Nielsen et al., 2001; Pilbeam et al., 1994; Morris and Garrity, 1993; Willey, 1990; Natarajan and Willey, 1986). However, the question of http://dx.doi.org/10.19103/AS.2016.0002.11 © Burleigh Dodds Science Publishing Limited, 2016. All rights reserved.


2

Intercropping in sustainable maize cultivation

whether intercropping should be favoured over sole cropping as the level of resource input increases due to maize intensification is unclear. The interactive effects between component crops of intercropping systems can be highly complex. Component crops compete for belowground resources, such as water and nutrients. The aboveground competition (for solar radiation) is equally as important, particularly as the taller maize canopy shades legume crops. Reported advantages in RC and use efficiencies between sole crops and intercrops are still not well understood. It has been proposed that the increased performance of intercrops compared to sole crops might be related to the differences in the spatial and temporal use of available resources by the component crops (Tsubo et al., 2005). Differences between intercrops and sole crops in terms of resource use and RUEs in response to environmental factors (i.e. water, nitrogen and canopy stresses) under maize-dominated farming systems have yet to be properly analysed. In this chapter, the performance of intercropping under various rainfall and N nutrition environments in maize-dominated farming systems is reviewed. Interactions of interest include potential synergisms, and competition between the component crops, in relation to the capture and use of water, N and solar radiation. In addition, socio-economic and biophysical factors influencing adoption of a maize–legume intercropping system as well as the performance of intercropping compared to sole crops in expected climate change is discussed in this chapter.

2 Intercropping under different conditions: moisture and nitrogen levels 2.1  Intercropping under contrasting moisture conditions Intercropping systems have been identified as being more productive per unit land area than sole crops (Li et al., 2011; Yang et al., 2011; Zhang et al., 2008; Belay et al., 2008; Kanton and Dennett, 2004; Tsubo et al., 2004; Hauggaard-Nielsen et al., 2001; Pilbeam et al., 1994; Morris and Garrity, 1993; Willey, 1990; Natarajan and Willey, 1986). However, as technological improvements and farmers’ investments increase the level of crop productivity, factors affecting the yield response in the intercropping systems as well as whether intercropping or sole cropping systems remain the best option is not known. Published reports from experiments conducted in semi-arid Africa (Belay et al., 2008; Pilbeam et al., 1994) show the benefits of maize–bean intercrops in dryer environments, as compared to more humid environments. The advantages of intercrops over sole crops are usually quantified by using productivity measurements such as the land equivalent ratio (LER), that is, the relative land area required as sole crops to produce the same yields as intercrops (Mead and Willey, 1980). The LER is also considered as relative yield (Willey, 1979). The relative yield performance of intercrops is compared with sole crops by calculating the LER for productivity assessment as in Yang et al. (2009, 2011) and Kutu et al. (2009). The total LER is the sum of the partial LER. It is estimated by using the following formula: Y  Y  LER =  IA  +  IB  (1)  YSA   YSB 

© Burleigh Dodds Science Publishing Limited, 2016. All rights reserved.


Bean + maize

Bean + maize

Bean + maize

Bean + maize

Climbing bean + maize

Bean + maize

Bean + maize

Bean + maize

Bean + maize

Soybean + maize

Soybean + maize

Bean + maize

Bean + maize

Pilbeam et al., 1994

Pilbeam et al., 1994

Belay, 2008

Belay, 2008

Niringiye et al., 2005

Niringiye et al., 2005

Santalla et al., 1999

Santalla et al., 1999

Ouda et al., 2007

Ouda et al., 2007

Ouda et al., 2007

Morales et al., 2009

Morales et al., 2009

1.78

1.72 800

558 1

Simultaneously1

Simultaneously

80

0.8*

a

1.76

80

80

1.2* 1.0*

67

67

64

64

Simultaneously

80/90/00

80/90/00

Not indicated Not indicated

107/19.5/58.58

107/19.5/58.58

107/19.5/58.58

127/75/122

50:100

50:100

50:100

57:43

1

1

2

2

2

1

1

1

57:43

127/75/122

Not mentioned

2

Mean

1

1

1

Not mentioned

64/46

50:100

1

1

1

Year

Mean2

64/46

50:100

1

0/40

N/P2O5 K(i) 0/40

Additive series

Crop proportion Additive series

Simultaneously

70

70

Concurrency

1608

974

519.9

406.3

541.1

763.0

257.6

179.5

RF (mm)

1.71a

1.72 a

1.01

0.93

1.26

1

1.4

1.1

0.84

1.12

LER

Mexico

Mexico

Egypt

Egypt

Egypt

Spain

Spain

Uganda

Uganda

Ethiopia

Ethiopia

Kenya

Kenya

Country

2

The crops were planted simultaneously at both sites (no date of sowing and harvest is indicated). Mean for plant population ranges from 25 000 to 40 000 for maize and 57 152 to 95 238 for beans, while 44 000 and 111 111 is for the pure stands, respectively. a Estimated from mean yield data. *Irrigation using 1.2 pan evaporation coefficient (PEC; control), irrigation using 1.0 PEC (about 7% reductions in irrigation water than the control) and irrigation using 0.8 PEC (about 14% reductions in irrigation water than the control).

1

Crop species

Reference

Table 1 Land equivalent ratio (LER) and rainfall in maize/legume intercrops across various environments

Intercropping in sustainable maize cultivation3

© Burleigh Dodds Science Publishing Limited, 2016. All rights reserved.

Intercropping in sustainable maize  

As the level of productivity in sub-Saharan cropping increases, driven by technology adoption, the question whether intercropping should sti...

Read more
Read more
Similar to
Popular now
Just for you