Yield response of corn to deficit irrigation in a semiarid climate

• Published in: Agricultural water management Vol. 84; no. 1; pp. 101 - 112
• Main Authors: Payero, José O., Melvin, Steven R., Irmak, Suat, Tarkalson, David
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 16-07-2006; Elsevier Science; Elsevier
• Series: Agricultural Water Management
• Subjects: Agricultural and forest climatology and meteorology. Irrigation. Drainage; Agronomy. Soil science and plant productions; Biological and medical sciences; Corn; Crop water productivity; Deficit irrigation; Evapotranspiration; Fundamental and applied biological sciences. Psychology; General agronomy. Plant production; grain yield; Irrigation. Drainage; Maize; rain; seasonal variation; semiarid zones; Water use efficiency; Water variable; Zea mays; Nebraska; Great Plains of America; Northern Great Plains; United States; North America; America; Water variable; Deficit irrigation; Evapotranspiration; Corn; Maize; Water use efficiency; Crop water productivity; Monocotyledones; Water deficit; Water resource management; Environmental factor; C4-Type; Physical environment; Irrigation water; Continental climate; Temperate zone; Cereal crop; Climatic condition; Gramineae; Semi arid zone; Irrigated farming; Angiospermae; Water engineering; Production factor; Response modality; Water productivity; Zea mays; Supplemental irrigation; Agroclimatology; Semi arid climate; Spermatophyta; Yield; Sprinkler irrigation
• ISSN: 0378-3774; 1873-2283
• DOI: 10.1016/j.agwat.2006.01.009

Irrigation water supplies are decreasing in many areas of the US Great Plains, which is requiring many farmers to consider deficit-irrigating corn (
Zea mays L.) or growing crops like winter wheat (
Triticum aestivum L.) that require less water, but that are less profitable. The objectives of this study were to: (1) quantify the yield response of corn to deficit irrigation, and (2) determine which of several seasonal water variables correlated best to corn yield in a semiarid climate. Eight (T1–T8) and nine (T1–T9) deficit-irrigated treatments (including dryland), were compared in 2003 and 2004 in North Platte, Nebraska. The actual seasonal crop evapotranspiration (ET
d) (calculated with procedures in FAO-56) for the different treatments was 37–79% in 2003 and 63–91% in 2004 compared with the seasonal crop evapotranspiration when water is not limited (ET
w). Quantitative relationships between grain yield and several seasonal water variables were developed. Water variables included, irrigation (
I), total water (
W
all), rain
+
irrigation (
W
R+
I
), evaporation (
E), crop evapotranspiration (ET
d), crop transpiration (
T
d), and the ratios of ET
d and
T
d to evapotranspiration and transpiration when water is not limited (ET
w and
T
w). Both years, yield increased linearly with seasonal irrigation, but the relationship varied from year to year. Combining data from both years, ET
d had the best correlation to grain yield (yield
=
0.028ET
d–5.04,
R
2
=
0.95), and the water variables could be ranked from higher to lower
R
2 when related to grain yield as:
E
T
d
(
R
2
=
0.95
)
>
T
d
(
R
2
=
0.93
)
>
E
T
d
/
E
T
w
(
R
2
=
0.90
)
=
T
d
/
T
w
(
R
2
=
0.90
)
>
W
all
(
R
2
=
0.89
)
>
E
(
R
2
=
0.75
)
>
W
R
+
I
(
R
2
=
0.65
)
>
I
(
R
2
=
0.06
)
. Crop water productivity (CWP) (yield per unit ET
d) linearly increased with ET
d/ET
w (
R
2
=
0.75), which suggests that trying to increase CWP by deficit-irrigating corn is not a good strategy under the conditions of this study.