Intercropping desmodium and maize improves nitrogen and phosphorus availability and performance of maize in Kenya
Introduction
Maize (Zea mays) is a staple crop in sub-Saharan Africa (SSA) where it accounts for up to 30.0 % of the calorie intake of the population (Nuss and Tanumihardjo, 2010). Maize is also the most widely cultivated crop in the region, grown in 46 out of 53 countries in SSA (Badu-Apraku and Fakorede, 2017). Even though impressive gains have been achieved in other regions (e.g., 2.3-3.2 Mg ha−1 in South and Southeast Asia, 2.9-11.8 Mg ha−1 in Europe and 2.5 Mg ha−1 in South America), the average yields in SSA are still below 2.0 Mg ha−1 (Schils et al., 2018; Abate et al., 2017; Grassini et al., 2013; Wood et al., 2004), and projected to decline in many countries (Iizumi et al., 2014; Ray et al., 2013). Hundreds of locally adapted varieties with better yields have been developed (Abate et al., 2017). These include early and extra-early maturing, those resistant or tolerant to drought, striga, or those that use nutrients efficiently (Badu-Apraku and Fakorede, 2017). Despite these efforts and notable increase in area under maize, its production is still very low. For example, data from FAOSTAT (2020) indicate a dramatic increase in harvested area under maize in the last decade (2007 and 2017). During this period, the area on which maize is grown in SSA increased by 30.2 % while yield increased by 8.5 % in the same period (FAOSTAT, 2020). This highlights the need for innovative cropping systems to overcome constraints to maize production.
Nutrient limitation is a major constraint in crop production in SSA. In western Kenya, nitrogen (N) and phosphorus (P) are the major nutrients that limit maize productivity (Kihara and Njoroge, 2013; Boddey et al., 1997). This is attributed to continuous cropping without replenishing the depleted nutrients. In soils where these nutrients are adequate, maize develop robust roots and strong stalks, mature early and uniformly, and produce large quantities of grain. Generally, N limits growth of maize in all cases where P deficiency is overcome (Nziguheba et al., 2016); phosphorous deficiency is easily overcome by use of fertilizers because it is relatively stable and moves less in the soil. However, use of fertilizers is limited by high cost and limited access (Nziguheba et al., 2016). Farmers who cannot apply fertilizers therefore rely on residues and manure application to provide N and P for plant nutrition (Bouwman et al., 2009). A limitation to this approach is that crop residues and livestock manure have low P and N content (Nziguheba et al., 2016; Sharma et al., 2013) and hardly sustain maize production above 1.0 Mg ha−1 (Peoples et al., 1995). Innovative ways of managing N and P in cropping systems is required to maintain productivity in maize based systems.
Intercropping maize with legumes is one of the options used by smallholder farmers to overcome constraints associated with maize monoculture. Intercropping maize and legumes is a common practice in western Kenya where famers plant maize in combination with common bean (Phaseolus vulgaris L.), cowpea (Vigna unguiculata (L.) Walp.), soybean (Glycine max (L.) Merr.), pigeon pea (Cajanus cajan (L.) Millsp.), groundnut (Arachis hypogaea L.), Bambara groundnut (Vigna subterranean (L.) Verdc.) or fodder legumes (Ndayisaba et al., 2020; Khan et al., 2009). Desmodium (Desmodium uncinatum (Mill.) Urb., – silverleaf or Desmodium intortum – Greenleaf) is a perennial fodder legume intercropped in a cereal crop in push-pull technology (Khan et al., 2006, 2002). Farmers mix maize with legumes to obtain higher yields, efficient use of growth resources, manage weeds and as an insurance against total crop failure (Sadeghi and Sasanfar, 2013; Woomer et al., 2004). Beneficial effects of legumes on soil health are well documented, and include addition of organic matter, biological nitrogen fixation (Peoples and Crasswell, 1992), and improving availability of N and P in soil solution through mineralization of N and P from root exudates, dead nodules and roots, and fallen leaves (Nziguheba et al., 2016; Sharma et al., 2013; Vanlauwe et al., 2000). Legumes, however, can compete with the cereal crop, leading to low yields (S. Kuyah, personal communication). Increasing yields through mixed cropping requires correct application of the technology, based on knowledge of the kind of constraints in the area and the mechanism by which different companion crops improve productivity of the system. For example, in push-pull strategy, desmodium boosts productivity of maize by improving soil fertility and controlling stem-borers, fall armyworm and striga (Mutyambai et al., 2019; Midega et al., 2018; Khan et al., 2006; 2000). It can fix 90 kg N ha−1 from atmosphere (biologically) per season (Ojiem et al., 2007) and has a high N fertilizer equivalency which can be as high as 120 kg N ha−1 (Midega et al., 2013). However, there is a general shortage of literature on relative effects of different legumes in improving availability of plant nutrients. The few studies on the subject e.g. Vanlauwe et al. (2008) are still inconclusive. This study aimed at assessing the availability of N and P due to desmodium and food legumes such as bean, cowpea, crotalaria (Crotalaria ochroleuca G. Don), green gram [Vigna radiata (L.) Wilczek] and groundnut commonly intercropped with cereals in western Kenya, and assessing the effect of these legumes on maize shoot weight and productivity. Because changes in soils need time (Vanlauwe et al., 2008; Peoples et al., 1995), we used a fifteen years old experiment in which the effect of desmodium, common bean, cowpea, crotalaria, green gram and groundnut on striga was assessed with reference to maize monocrop (Midega et al., 2014; Khan et al., 2007).
Section snippets
Study area
The study was conducted on a long-term experiment established in 2003 at the International Centre of Insect Physiology and Ecology (icipe) Mbita Point Field station located at the eastern shores of Lake Victoria in Suba North constituency, Homabay county in western Kenya at 0°25′S and 34°12′E, and 1200 m of altitude (Khan et al., 2007). The climate in the area is tropical with annual mean temperature of 27 °C (minimum =15 °C, maximum =30 °C). The area receives an annual rainfall of
Effect of legumes on available N and P
Intercropping maize and desmodium significantly improved availability of N and P (Table 2). Total available N for maize-desmodium at 12 WAP for 2017 LR (15.3 kg ha−1), 2017 SR (15.7 kg ha−1) and 2018 LR (17.8 kg ha−1) was significantly higher than that found in maize monocrop for the same period (Table 2, P for 2017 LR at 12 WAP = 0.064). Similarly, the total available N measured at 8 WAP in 2018 LR (23.5 kg ha−1) was twice the amount found in maize monocrop (Table 2). Maize-desmodium intercrop
Effect of legumes on available N and P
Growing maize in combination with desmodium increased available N compared to growing maize alone or in combination with other legumes. This could have been due to increased soil organic matter and its rate of mineralization, and/ or release of biologically fixed N to the soil (Urbatzka et al., 2009; Wu et al., 2008; Birch and Dougall, 1967). Indeed, N from legumes (including desmodium) mineralizes slowly with relatively low loss and high synchrony with crops needs (Crews and Peoples, 2005).
Conclusions
Desmodium improved availability of N and P hence performance of the main crop; maize and the desmodium itself. This suggests that desmodium has high biological N fixation capacity than other legumes. The high biomass of desmodium means higher soil organic matter and subsequent effects in the soil. Bean, cowpea, crotalaria, green gram and groundnut did not increase the availability of N and P probably due to their low rate of biological N fixation or simply due to competitive uptake with
CRediT authorship contribution statement
Pierre Celestin Ndayisaba: Investigation, Methodology, Formal analysis, Writing - original draft. Shem Kuyah: Writing - review & editing, Supervision. Charles Aura Odhiambo Midega: Writing - review & editing, Supervision. Peter Njoroge Mwangi: Writing - review & editing, Supervision. Zeyaur Rahman Khan: Funding acquisition, Project administration, Supervision, Writing - review & editing.
Declaration of Competing Interest
The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
Acknowledgements
We gratefully acknowledge the financial support for this research by the following organizations and agencies: European Union, Biovision foundation, Rothamsted Research UK, UK's Foreign, Commonwealth & Development Office (FCDO), Swedish International Development Cooperation Agency (Sida), the Swiss Agency for Development and Cooperation (SDC) and the Kenyan Government. Pierre Celestin Ndayisaba was supported by a German Academic Exchange Service (DAAD) In-Region Postgraduate Scholarship -
References (60)
- et al.
Farmers’ perceptions and adoption of new agricultural technology: evidence from analysis in Burkina Paso and Guinea, West Africa
Agric. Econ.
(1995) - et al.
The contribution of biological nitrogen fixation for sustainable agricultral systems in the tropics
Soil Biol. Biochem.
(1997) - et al.
Combined control of Striga hermonthica and stemborers by maize-Desmodium spp. Intercrops
Crop Prot.
(2006) - et al.
Integration of edible beans (Phaseolus vulgaris L.) into the push–pull technology developed for stemborer and Striga control in maize-based cropping systems
Crop Prot.
(2009) - et al.
The impact of Desmodium spp. and cutting regimes on the agronomic and economic performance of Desmodium-maize intercropping system in western Kenya
Field Crop. Res.
(2012) - et al.
Phosphorus agronomic efficiency in maize-based cropping systems: a focus on western Kenya
Field Crop. Res.
(2013) - et al.
Effects of mulching, N-fertilization and intercropping with Desmodium uncinatum on Striga hermonthica infestation in maize
Crop Prot.
(2013) - et al.
Cumulative effects and economic benefits of intercropping maize with food legumes on Striga hermonthica infestation
Field Crop Res.
(2014) - et al.
A climate-adapted push-pull system effectively controls fall armyworm, Spodoptera frugiperda (J E Smith), in maize in East Africa
Crop Prot.
(2018) - et al.
Push-pull technology improves maize grain yield and total aboveground biomass in maize-based systems in Western Kenya
Field Crops Res.
(2020)
Do NERICA rice cultivars express resistance to Striga hermonthica (Del.) Benth. and Striga asiatica (L.) Kuntze under field conditions?
Field Crop Res.
Cereal yield gaps across Europe
Eur. J. Agron.
Fate of legume-derived nitrogen in monocultures and mixtures with cereals
Agric., Ecosyst. Environ., Appl. Soil Ecol.
Utilization of rock phosphate by crops on a representative toposequence in the Northern Guinea savanna zone of Nigeria: response by Mucuna pruriens, Lablab purpureus and maize
Soil Biol. Biochem.
Integrated management of Striga hermonthica, stemborers, and declining soil fertility in western Kenya
Field Crop Res.
Characteristics of maize cultivars in Africa: How modern are they and how many do smallholder farmers grow?
Agric. Food Secur.
Maize in sub-saharan Africa: importance and production constraints
Advances in Genetic Enhancement of Early and Extra-Early Maize for Sub-Saharan Africa
Effect of a legume on soil nitrogen mineralisation and percentage nitrogen in grasses
Plant Soil
Human alteration of the global nitrogen and phosphorus soil balances for the period 1970–2050
Global Biogeochem. Cy
Can the synchrony of nitrogen supply and crop demand be improved in legume and fertilizer-based agroecosystems? A review
Nutr. Cycl. Agroecosys.
Economic analysis of different options in integrated pest and soil fertility management in maize systems of Western Kenya
Agr. Econ.
Legume-based cropping systems have reduced carbon and nitrogen losses
Lett to Nat
Farmers’ perception of the striga problem and its control in Northern Nigeria
Exp. Agric.
Crops
Distinguishing between yield advances and yield plateaus in historical crop production trends
Nat. Commun.
A review of chemical reactions of nitrification intermediates and their role in nitrogen cycling and nitrogen trace gas formation in soil
Eur. J. Soil Sci.
Mechanism of nitrogen fixation by nitrogenase: the next stage
Chem. Rev.
Historical changes in global yields: major cereal and legume crops from 1982 to 2006
Glob. Ecol. Biogeogr.
Pre-attachment Striga hermonthica resistance of New Rice for Africa (NERICA) cultivars based on low strigolactone production
New Phytol.
Exploiting chemical ecology and species diversity: stem borer and striga control for maize and sorghum in Africa
Pest Manag. Sci.
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