Physiological responses of maize and cowpea to intercropping

Abstract

The effect of intercropping on plant water status, gas exchange and productivity of maize (Zea mays L.) cv. Centralmex, and cowpea (Vigna unguiculata L. (Walp)) cv. Pitiuba were evaluated under semi-arid conditions at the Embrapa-Centro de Pesquisa Agropecuária do Trópico Semi-Árido (CPATSA) at Petrolina, PE, Brazil. The treatments were: maize and cowpea as sole crops, at a population of 40,000 plants ha-1, and intercropped at a population of 20,000 plants ha-1. The results obtained in this paper appear to be related to the degree of competition experienced by the components, mainly for water and light. Maize intercropped had higher values of leaf water potential, stomatal conductance, transpiration and photosynthesis than as sole crop. Intercropped cowpea had higher values of leaf water potential but lower stomatal conductance, transpiration and photosynthesis than sole cowpea. Maize productivity increased 18% in relation to sole crop whereas a 5% decrease was observed with cowpea. Despite these facts the Land Equivalent Ratio obtained was 1.13 indicating intercropping advantage over the sole system. The higher partial Land Equivalent Ratio observed for maize suggests that this specie was the main component influencing the final productivity of the intercropping system studied.

Maize-Soybean Integration for Managing <i>Striga hermonthica</i> (Del.) Benth in the Sudan Savannah Zone of Ghana

“…In a similar study, [31] also did not find any significant differences in LAI between maize monocrop and maize intercropped with sugar beans or groundnuts. These findings are consistent with results of [36] who did not find any significant differences in LAI between sole maize and maize intercropped with cowpea. The leaf area (LA) describes the size of the assimilatory apparatus of a plant stand and is the main factor that determines the rate of dry matter production in a closed stand.…”

Root Length Density in Maize/Cowpea Intercropping under a Basin Tillage System in a Semi-Arid Area of Zimbabwe

“…Another factor that could have contributed to the high maize grain yield is that of reduced evapotranspiration of the component crops resulting in better water use efficiency. This agrees with [10] who found out that the modification of the light environment by the plant canopy affected positively the water relations of the intercropped plants by increasing the water use efficiency which would result in increased yields particularly benefiting farmers who live in the arid and semi-arid areas like those found in natural region III-IV in Zimbabwe. Modification of the light environment also means that the soil temperatures are kept to at a minimum hence less moisture is lost to the atmosphere through soil surface evaporation hence maintaining the soil moisture regime thus increasing water use efficiency by the component crops.…”

“…One of the main principles of CA encourages farmers to mix and rotate crops of different species [9]. The mixing of crops of different species ensures maximum exploration of the different layers of the soil profile at different times which will result in less competition between the component crops and attainment of better yield [10]. [11] advocated that intercropping increased crop productivity and yield in dry areas.…”

Unravelling the causes of variability in crop yields and treatment responses for better tailoring of options for sustainable intensification in southern Mali

“…7), indicating no detrimental competition between maize and cowpea. Cowpea creates a "live mulch" that lowers surface soil temperature and evaporation, thus improving water conservation compared with sole cropping (Lima Filho, 2000). Rusinamhodzi et al (2012) also reported LER values ranging from 1 to 2.4 in additive and substitutive maize/cowpea intercropping in central Mozambique.…”