Deficit irrigation and nitrogen effects on maize in a Sahelian environment: II. Shoot growth, nitrogen uptake and water extraction
Introduction
There has been an increasing interest in scheduling deficit irrigation in order to conserve water and maintain crop productivity in the Sahel of West Africa. In these areas, total biomass production is often as important to farmers as grain since animals are a significant part of their livelihood. We reported on the effect of seasonal water deficit and nitrogen (N) rate on grain yield and yield components (Pandey et al., 2000). This research suggested that irrigation deficit during the vegetative stages of maize (Zea mays L.) growth was possible without sacrificing significant grain yield. This irrigation response was dependent on the N application rate. Research has shown the importance of water and N interactions in optimizing maize productivity (Eck, 1984, Eghball and Maranville, 1993a). Most studies suggest that water shortage during vegetative growth reduces leaf area (Boyer, 1970, Acevedo et al., 1971, NeSmith and Ritchie, 1992, McCullough et al., 1994), internode elongation (Novoa and Loomis, 1981), and leaf and stem weight (Denmead and Shaw, 1960, Eck, 1984). In a field study conducted under semi arid environment of Texas, water deficits imposed 41 days after planting reduced leaf, stalk and ear yields of maize, while those imposed 55 days after planting reduced only stalk and ear yields. Water deficit during grain filling did not affect leaf and stalk yields (Eck, 1984). Management of water shortage through frequency and quantity of irrigaiton water during vegetative growth and/or reproductive growth merits attention in high evaporative environments to minimize curtailment of crop growth and yield and achieve higher water use efficiency (Eck, 1985, Chapman and Barreto, 1997).
Nitrogen requirement by maize compared with other nutrients is large in Sahelian soils for optimum vegetative and reproductive growth. Many physiological processes associated with maize growth are enhanced by N supply (Eck, 1984). Nitrogen has dramatic effects on maize growth, development and grain yield on soils that are limiting in N supply. Numerous studies have shown the effects of reduced N supply on leaf area index (LAI), plant height, shoot weight and plant N uptake (Eck, 1984, Pandey et al., 1984, Muchow, 1988, McCullough et al., 1994). In most maize producing areas, increasing rate of N supply results in greater LAI and leaf N (McCullough et al., 1994). Variation in N supply affects crop growth, development and potential kernel set and grain yield (Greenwood, 1976, Pandey et al., 2000). Leaf area index, leaf area duration, crop photosynthetic rate, radiation interception and radiation use efficiency are increased by N supply (Muchow, 1988). Reduced N supply decreases crop growth (Cox et al., 1993); however, N response is modified by water supply under field condition (Greenwood, 1976, Pandey et al., 2000). Variable water supply either due to shortage of water or failure of the irrigation system to supply water during vegetative and/or reproductive growth stages in many irrigated areas of sub-Saharan Africa, particularly in the Sahel, is common and often results in deficit irrigation.
Information on frequency and quantity of irrigation water and effect of deficit irrigation on shoot and root growth of maize and the subsequent water and N extraction patterns have not been well elucidated under the stressful Sahelian environment, more so with differential rates of N supply. Further, information on crop growth responses and morphological/physiological yield determinants are needed to analyze crop productivity that relate to crop water production function and economic returns. The objectives of this study were to (i) determine the effects of timing and duration of deficit irrigation on maize shoot growth and water extraction, (ii) evaluate water deficit and N rate effects on N uptake, and (iii) analyze relationships between grain yield, plant growth and deficit irrigation and N supply.
Section snippets
Materials and methods
A field experiment was conducted for 2 years (1996–1997 and 1997–1998) at INRAN (Institut National de Recherche Agrononmique du Niger) research station near Konni (lat. 11°N, long. 12°E) on a Tropudalph clay loam soil (fine kaolintic thermic kanolic tropudalph). The site description, crop culture, and weather conditions were previously described (Pandey et al., 2000). Water deficits were imposed as previously described (Pandey et al., 2000). Irrigation was withheld at various crop growth stages (
Aboveground biomass
Aboveground biomass production was different each season and presented separately in Table 1. There was less differential in biomass production between zero N and 160 kg ha−1 in 1996/1997 than in 1997/1998. The greater rates of N in 1997/1998 resulted in markedly more biomass production than those rates in 1996/1997 and markedly less biomass at the low N rates for the second season. Response to applied N was quadratic each year. There was little difference, however, between the two seasons for
Conclusions
Maize is commonly grown in humid and subhumid tropics, but in Sahelian countries, it is grown either in high rainfall zones or with supplementary irrigation in low rainfall zones. Water limitation is a major constraint to maize production. High evaporative demand and warm temperatures expose the crop to water stress if irrigation is not adequately provided. Efficient production of maize where soils are extremely poor in N and where rainfall is highly variable, requires simultaneous attention to
References (28)
Nitrogen stress in plants
Adv. Agron.
(1976)Effect of nitrogen supply on the comparative productivity of maize and sorghum in semi-arid tropical environment I. Leaf growth and leaf nitrogen
Field Crops Res.
(1988)- et al.
Deficit irrigation and nitrogen effects on maize in a Sahelian envrionment. I. Grain yield and yield components
Agric. Water Manage.
(2000) - et al.
Immediate and subsequent growth response of maize leaves to changes in water stress
Plant Physiol.
(1971) - et al.
Use of a chlorophyll meter to monitor nitrogen status and schedule fertigation in corn
J. Prod. Agric.
(1995) Leaf enlargement and metabolic rates in corn soybean and sunflower at various leaf water potentials
Plant Physiol.
(1970)- Champigny, M.L., Talouizte, A., 1981. Photosynthetic distribution and metabolic fate in relation to nitrogen metabolism...
- et al.
Using a chlorophyll meter to estimate specific leaf nitrogen of tropical maize during vegetative growth
Agron. J.
(1997) - et al.
Growth, yield and quality of forage maize under different nitrogen management practices
Agron. J.
(1993) - et al.
The effects of soil moisture stress at different stages of growth on the development and yield of corn
Agron. J.
(1960)
Irrigated corn yield response to nitrogen and water
Agron. J.
Effects of water deficits on yield, yield components, and water use efficiency of irrigated corn
Agron. J.
Root development and nitrogen influx of corn genotypes grown under combined drought and nitrogen stresses
Agron. J.
Fractal analysis for morphological description of corn roots under nitrogen stress
Agron. J.
Cited by (189)
Grain yield, actual evapotranspiration and water productivity responses of maize crop to deficit irrigation: A global meta-analysis
2022, Agricultural Water ManagementCitation Excerpt :Thus, the application of DI stress on maize crops only at the vegetative stage, or at the vegetative stage prior to a stress at the reproductive stage may induce an adaptation strategy of maize plants to limit the reduction of grain yield (Kang et al., 2000). With DI stress under the vegetative stage, maize plants use an adaptive strategy that involves the extension of root depth and the increase of water extraction from the deeper soil profile (Pandey et al., 2000b). Maize production consumes 400–750 mm of water per growing period (FAO, 1992; Tan and Zheng, 2017).
Soil and water conservation management on hill slopes in southwest Ethiopia. II. Modeling effects of soil bunds on surface runoff and maize yield using AquaCrop
2021, Journal of Environmental ManagementPerformance of polymer-coated cotton seeds under various moisture stress conditions
2024, Journal of Applied Biology and BiotechnologyInvestigating PGPR bacteria for their competence to protect hybrid maize from the factor drought stress
2024, Cereal Research Communications
- 1
Agronomist, Program Leader and technician, PNRA/INRAN, PB 429, Niamey.
- 2
Professor, University of Nebraska, Lincoln, NE.