Integrating pigeonpea in maize based farming systems may increase food production and alleviate poverty

Høgh-Jensen H, Odgaard R, Myaka FA, Sakala WD, Adu-Gyamfi JJ & Vesterager JM1
Key words: multifunctional crops, intercrops, cash crops, gender, food security

Abstract
Pressure on natural resources implies that millions of farmers in semi-arid eastern and southern Africa face very low and declining crop yields. Major natural constraints are the nitrogen and phosphorus supply together with insufficient and highly variable rainfall. This article addresses the possibilities for improved soil fertility, increased productivity and income opportunities among smallholders in semi-arid eastern and southern Africa through the integration of improved pigeonpea in maize-based cropping systems. Specifically farmers’ experiences with cultivation and integration of pigeonpea in maize-based cropping systems are discussed. This includes how the integration of pigeonpea affects the livelihood situation of rural smallholders – male as well as female in terms of increased food security, increased income, improved gender equity in access to resources etc. While many ‘blessings’ of integrating the multi-purpose crop pigeonpea in maize-based cropping systems are confirmed, it is also shown that socio-economic and biophysical diversity must be taken into account when evaluating impact of pigeonpea on livelihoods of different groups of farmers.

Introduction
Growing population, unequal distribution of and increasing pressure on natural resources in Africa implies that cultivation takes place on more and more marginal land, causing millions of farmers in semi-arid Eastern and Southern Africa to face low and declining crop yields. Coupled with removal of fertilizer subsidies in the early 1990is, the constraints of limited nitrogen and phosphorus supply together with insufficient and variable rainfall are being felt by an increasing number of farmers. Hence, farmers are especially looking for biological alternatives to establish cropping systems characterized by high production capacity and stability in order to obtain cash income opportunities and food security but too little emphasis has been put on developing such alternatives.
Intercropping of maize and grain legumes is a common practice in many areas in Africa although the rationale behind is not always clear. Pigeonpea is a multipurpose leguminous shrub, which thrives on poor soils. It is grown with the aim of increasing household cash income and for food, fodder, firewood, and soil fertility improvement. There is an increasing international market for pigeonpea grain. Thus, maize intercropped with long-duration pigeonpea has emerged as a highly productive system with multiple beneficial effects on the farming systems. Consequently, these cropping systems are widespread in some areas of eastern and southern Africa. Intriguingly, however, few kilometres away pigeonpea may not be found without apparent socio-economic, cultural, or biophysical causes to explain the change. 
The objective of this article is to present results from a multidisciplinary and participatory on-farm study in Malawi and Tanzania. The overall theme of the study is to investigate the possibilities to improve soil fertility, increase productivity and income opportunities among smallholders in semi-arid eastern and southern Africa through the integration of pigeonpea in maize-based cropping systems. 
Throughout the research, it was assumed that the agronomic results could be interpreted through a socio-economic prism and that yields of each component of the intercropped crops of maize and pigeonpea may be affected by the composition, size and gender of the farming households, as well as these households access to farmland. 
Materials and methods
In Tanzania, maize is a major food crop, grown and consumed as stable food by the majority of the population in Tanzania. Half of all Tanzanians are considered to be basically poor and the poorest sections of the rural population are mainly found in semi-arid and remote areas. Between 12-15% of all rural households in Tanzania are female headed (World Bank, 2000). In Malawi over 90% of the total cultivated land area is planted to maize, mostly by resource poor smallholders. Eighty percent of the rural population is farming less than one hectare (Anon, 2003) which causes many families to live on the edge of hunger. Forty percent of the families with less than 0.5 hectare are female headed (Anderson, 2002).
In Tanzania, clusters of villages were selected in Babati district and Gairo Division, Kilosa District, Morogoro Region. In Malawi, two extension planning areas (EPA) were selected, each containing several villages. Nyambi EPA is located within Kawinga Rural Development Projects and Machinga Agricultural Development Division. Ntonda EPA is located within Blantyre Rural Development Projects and Blantyre Agricultural Development Division.
A total of more than 80 farmers were selected, equally distributed at the four research locations, based on their willingness to be involved in research. The selection was done at group meetings with farmers and based on (i) size of landholding, (ii) type of land tenure, and (iii) gender.
The agronomic performance of local and improved pigeonpea genotypes was studied at trial plots fully managed by farmers under farmers’ conditions. Data are included from the two cropping seasons of 2001-2002 and 2002-2003, which means that the crop yields from total of 640 plots are included in the data analysis. These data are presented as means over the two years.	
The data were analyzed by multiple regression analysis using a general linear model via the SAS GLM procedure. Open-ended questions were evaluated by calculating the mean response using the LSMEANS procedure after having identified the major categories represented by the answers. Comparison of the means for the individual treatments was done using a Waller-Duncan t-test. 
Results and Discussion
Productivity measured as grain yield showed tremendous differences both in sole maize and in maize grown together with three pigeonpea genotypes. Maize yield decreased (P<0.05) in the order Babati>Ntonda>Gairo>Nyambi. However, pigeonpea grain yield followed an order of Ntonda>Babati>Nyambi>Gairo.
The importance of pigeonpea in producing protein is illustrated as the highest nitrogen yield is obtained in some of the areas with the lowest maize yield. Inclusion of the other crop parts only enlarges these differences as the differences in nitrogen content accounts to the residues also. This is important, as large proportions of the residues are re-circulated. 
Across all environments, maize yields tended to decrease (P=12) in female-headed households compared to male (data not shown). Maize yields even further decreased at households headed by single parents or females. In contrast, the pigeonpea grain yields were unaffected (P=0.69; data not shown) by gender of household head, although the pigeonpea grain yields of single parent/female headed households tended to be higher than for the other types of households. 
In the literature it is often argued that female farmers are less productive than male farmers in relation to maize yields because women have less access to chemical inputs and technical know-how than men. The current study shows that women’s productivity in relation to other crops than maize, such as pigeonpea, in some cases can be even higher than that of men without access to special inputs.
Across all environments, the access of households to land influenced maize yields (P=0.12) and pigeonpea yields in particular (P=0.006) (data partly shown in Fig. 1). Clearly those households with most land obtained the highest maize yields. However, pigeonpea showed exactly the opposite effect; favoured by the households with small land access. 

Figure 1.  Relation between land size and mean grain yields from four sites of maize and pigeonpea over two consecutive cropping seasons. Bars represent  ±SE; n varies depending on category.

The data yields no clear indication of why grain yield of pigeonpea should be higher at the smaller holdings. However, as there is no relation (R2 = 0.08) between land size and household size, it is hypothesized that the lower pigeonpea grain yields at those households with the largest land holdings can possibly be sought in constraints in seed availability at planting; a common feature for many of the trial farmers and also reported elsewhere (Snapp et al., 2002). 
Labour constraint during weeding of the crop is well known to reduce maize yield but pigeonpea yield is not affected by a few weeks delay in weeding which gives farmers more flexibility in coping with the agricultural tasks during peak seasons. The present data confirm that household size has no effect (P=0.55) on grain yield of pigeonpea but significantly affected (P=0.01) maize grain yield (Fig. 2). 

Figure 2. Relation between household size and mean grain yields of maize and pigeonpea over two consecutive cropping seasons. Bars represent  ±SE; n=480 for pigeonpea and 640 for maize.

Conclusions and perspectives
Integration of pigeonpea into the maize based farming systems in all cases significant increased total productivity of food and fuelwood and it generated a potential high-value cash crop. In perspective, there is effective market demand for both whole grain as well as processed pigeonpea products from Eastern and Southern Africa in several global markets. Further a local market for green pods is rapidly developing in the larger cities. A significant backup must however be created to make a market-approach a realistic strategy for resource-poor farmers despite the multifunctional advantages of pigeonpea. 
References 
Anderson A.S. (2002): The effect of cash cropping, credit, and household composition on household food security in southern Malawi. African Studies Quarterly 6 (1&2): web.africa.ufl.edu/asq/v6/v6i1a7.htm (accessed 2007-06-26).
Anon. (2003): FAO.  www.fao.org/WAICENT/FAOINFO/ECONOMIC/ESS/census/wcares/1mala93.asp (assessed 2003-04-30). 
Myaka F.A., Sakala W.D., Adu-Gyamfi J.J., Kamalongo D., Ngwira A., Odgaard R., Nielsen N.E. and Høgh-Jensen H. (2006): Yields and accumulations of N and P in farmer-managed maize-pigeonpea intercrops in semi-arid Africa. Plant Soil 285:207-220.
Snapp S.S., Rohrbach D.D., Simtove F. and Freeman H.A. (2002): Sustainable soil management options for Malawi: can smallholder farmers grow more legumes? Agric. Ecosyst. Environ. 91:159-174.