Waterlogging and low application efficiency are the main problems inherent with surface irrigation in the Nile Delta. Develop surface irrigation using gated pipes (GP) is a new method to be used to distribute water into furrow irrigated fields as strategy based on water saving. Laboratory calibration was conducted out to evaluate the hydraulic characteristics of pipe gates. Field experiments were conducted at the Experimental Farm of the Agriculture Faculty, Minufiya University during 2013 and 2014 seasons to evaluate the performance of utilize gated pipes technique for irrigating five maize varieties (S.C 10, S.C 130, S.C 131, S.C 2031 and T.W.C 321). The results revealed that the highest amount of water applied was with traditional surface irrigation (6423.81 m 3·ha -1. Use of gated pipes system GP1 as compared to traditional irrigation reduced water application by 923.81 m 3·ha -1 with grain and stover yields increases of 5.7% and 3.4%, respectively. Traditional irrigation system achieved lowest irrigation performance parameters compared to gated pipes systems. Maize physiological attributes, yield, water use efficiency (WUE) and nitrogen accumulation were significantly decreased by either deficit or surplus irrigation than of GP1 rate. S.C 2031 variety significantly surpassed other varieties in abovementioned traits. Significant interaction effects were detected in both seasons. Maize varieties respond differently to irrigation systems. The highest values of grain yield (11062.6 and 10911.8 kg·ha -1 and stover yield (13639.0 and 13902.2 kg·ha -1) were obtained by S.C 2031 irrigated with GP1 system in both seasons. From the above mentioned results, it is concluded that the gated pipes technique is better than traditional irrigation for improving WUE and maize productivity under Nile Delta conditions.
Maize (Zea mays L.) is one of the most important cereal crops grown principally during the summer season in Egypt. Great attention has been paid to increase maize total production. This could be achieved by using of high yielding varieties and avoid water flooding and deficit stress. [
Water scarcity is a growing global problem challenging sustainable development and placing a constraint on producing enough food to meet increasing food requirements. Egypt is mainly an agricultural country depending on the Nile water and consumes about 80% - 85% for agriculture annually [
The efficient use of water through modern irrigation systems is becoming increasingly important in arid and semi-arid regions with limited water resources [
The main objectives of this study were to find out some practical effective ways regarding saving water particularly under the present status of water shortage facing Egypt. So, this study was planned to 1) improve the distribution uniformity of water discharge along the gated pipe and control of the water direction and reduce erosion in front of the gate, by designing a new outside gate locally to take the place of the side gate; and 2) evaluate the performance of some maize hybrids in light of use gated pipes technique for improving surface irrigation under the old lands of the Nile Delta.
Laboratory experiment was conducted at National Laboratory for Testing Irrigation Equipment, Agricultural Engineering Research Institute, Egypt to evaluate the hydraulic characteristics of a modified gate. The gate was designed from a gate valve (3.45 cm D.) installed on the pipe orifice using rubber and external flexible hose mounted in front of the valve to control the direction of water. The laboratory testing equipments contained an electric centrifugal pump, flow meter, pressure gauges, manometer and control valve. The gate discharge along line was experimentally measured by direct method using bucket with capacity of 30 liter and stopwatch. Gated pipes line used for laboratory test was 12 m length with 150 mm inner diameter and 156 mm outer diameter. The velocity of water flow in the pipe was calculated according to the continuity equation, where discharge was measured by a flow meter. The distance between gates was fixed along the pipe line (0.70 m). Average discharge of water flowing in the gates was calculated by the following steps:
Calculation of the Reynold’s number (Re) according to Equation (1) as given by [
where:
The used value of kinematic viscosity (υ) was taken 1 × 10−6 considering that the water was at 20˚C.
Calculation of head losses due to friction from Equation (2)
where:
The value of Darcy coefficient (f) was calculated by using the Equation (3) consider that Re is up to 3.2 ´ 106.
Calculation of head
where:
Determination of the total head inside the pipe (hm) at any discharging outlet this was determined from Equation (5).
where:
Considering the value of
Determination of the average velocity (v), the Equation (7) was used to calculate the average velocity at any gate (i)
Discharge of water at any gate was determined from Equation (8).
where:
Two field experiments were conducted at the Experimental Farm of the Faculty of Agriculture, Minufiya University in Shebin El-Kom, Egypt (latitude 30˚31'39''N, longitude 31˚04'03''E) during the two summer growing seasons of 2013 and 2014. Properties of the experimental soil are given in
The feasibility of producing maize under gated pipes technique was investigated comparing with traditional surface irrigation. The field experiment included twenty treatments which were all possible combinations between four irrigation treatments (traditional surface “flooding” and gated pipes with three discharge rates, i.e. 3.6 m3∙h−1 “GP1”, 4.8 m3∙h−1 “GP2” and 6 m3∙h−1 “GP3”) and five maize hybrids (S.C 10, S.C 130, S.C 131, S.C 2031 and T.W.C 321). The outside diameter of gated pipe is 6" and 6 m length. Pipe is made of UPVC with gates spacing 0.70 m. The flow rate out of each gate system is controlled by the percent of opening the main valve according to the discharge rates. Maize hybrids used for study were white color varieties produced by Agricultural Research Center, Egypt except S.C 2031 which produced by Hi-Tech Co.
A layout of the experimental plots is shown in
Soil depth (cm) | Particle size distribution (%) | Texture class | Bulk density g∙cm−3 | Field capacity % | Permanent wilting point % | Available soil water % | ||
---|---|---|---|---|---|---|---|---|
Sand | Silt | Clay | ||||||
0 - 20 | 20.27 | 41.17 | 38.56 | Clay loam | 1.29 | 42.45 | 21.90 | 20.55 |
20 - 40 | 20.80 | 40.51 | 38.69 | Clay loam | 1.31 | 40.95 | 20.45 | 20.50 |
40 - 60 | 17.32 | 36.75 | 45.93 | Clay | 1.33 | 38.89 | 19.14 | 19.75 |
Soil depth (cm) | Soluble cations meq∙l−1 | Soluble anions meq∙l−1 | Soil nutrients ppm | |||||||
---|---|---|---|---|---|---|---|---|---|---|
Na+ | K+ | Ca2+ | Mg2+ | Cl− | N | P | K | |||
0 - 20 | 6.60 | 0.84 | 2.40 | 1.46 | 7.65 | 0.60 | 3.05 | 34.8 | 9.3 | 302.5 |
20 - 40 | 4.85 | 0.70 | 1.53 | 1.42 | 5.75 | 0.45 | 2.30 | 32.4 | 8.4 | 287.1 |
40 - 60 | 4.55 | 0.65 | 1.45 | 1.35 | 5.63 | 0.40 | 1.97 | 30.2 | 8.1 | 274.6 |
Using field stalks and surveying tape, the furrows were divided into number of six stations having equal distances between them (10 m). Irrigation water advanced into the furrow (arrival times) were recorded at the end of each station. When water uncovers the field surface completely as a wave moving at the same direction of flow, recession times were observed and recorded at each station. This mark is the initiation of the water drying or recession front.
The water infiltration opportunity time along furrow length is the difference between the last time when water disappeared and the first time when water started at the same point along furrow. It can be determined according to [
where:
to = infiltration opportunity time (min)
tl = advance time (min)
tr = recession time (min)
Cutoff time of water flow (min∙furrow−1) is cumulative time since the initiation of irrigation until the inflow is terminated. It was recorded when the water has been totally arrived in the end of each furrow. Irrigation water applied (m3∙ha−1) was calculated according to the cutoff time and discharge rate depends on the maize growth stage and environmental conditions.
Water infiltration in soil depth (Z) was measured in the upper 30 cm of soil surface using double ring infiltrometer in beginning of experiment at site location. The two rings were driven into the soil to 15 cm depth. The two rings were set to measure infiltration rate in the next 15 cm soil layer. Filling water rate into inner cylinder was also recorded. The disappeared irrigation depth was recorded with interval time. Water infiltration was determined according to Equation (10).
System coefficient of variation (CV%) was estimated from Equation (11).
where:
S = Standard deviation
The schedule parameter (α) specifies the deviation of any schedule irrigation depth (d) to average of water distribution depth
where:
d = Water depth expressing the plant water requirement calculated from ET.
The uniformity coefficient (UC) can be expressed in power distribution for water infiltrated depth which determined from Equation (13) as stated by [
The distribution uniformity (DU) is a measure of how uniformly water is applied to the area being watered, expressed as a percentage. It determined from Equation (14).
Application and storage efficiencies were used to evaluate the design of the irrigation system synchronizing with the irrigation scheduling.
Storage efficiency (Es) defined as the ratio of amount of water stored to the water needed into root zone. It was calculated as from Equation (15).
The deficit percentage (PD) is defined as the ratio of water deficit to the required water into the root zone, can be formulated using linear distribution for water applied by the irrigation system (
When the linear distribution is used to express the water profile of irrigation system, α will range from −1.725 to 1.725 under optimum irrigation, α ≥ 1.725 in deficit irrigation, and α ≥ −1.725 in excess irrigation according to [
Application efficiency (Ea) is defined as the ratio of water stored in the root zone to the total water applied. Ea was calculated from Equation (18).
where:
Ps = deep seepage percent.
The deep seepage percent can be described using a linear distribution as derivative from the basic analyses by [
When a ≤ −1.725, deep seepage percentage could be calculated from Equation (20).
Water saving is referring to the consumption differences among surface irrigation systems.
During the growth phase, total chlorophyll (Chl) was measured at 50 days after sowing (DAS) with a hand-held chlorophyll meter (SPAD-502, Konica Minolta Company, Tokyo, Japan). At the period of 60 - 75 DAS crop growth rate (CGR) g plant−1 day−1 was determined as the following formula:
where: W1 and W2 = plant dry weight (g.) at T1 and T2 (date of sampling), respectively. After 75 DAS, ear leaf area (ELA) was determined as formula, ELA = ear blade length × maximum blade width × 0.75 (cm2).
At maturity, grain and stover yields (based on 15.5% moisture content) were determined by hand harvesting the area of two inner furrows and converted to kg∙ha−1. Yield samples of eighteen plants were collected along the furrow from each plot to determine yield components.
Irrigation water use efficiency (WUE) in kg∙m−3 was calculated according to formula, WUE = Grain yield kg∙ha−1/amount of irrigation water applied m3∙ha−1.
Plant chemical composition was determined by plant partitioned into stover (stalk and leaves) and grains. Samples were dried in air-oven at 70˚C to constant weight before grinding with a mill to pass through a 0.5 mm sieve. The samples were chemically analyzed to determine their contents of nitrogen. The total nitrogen percentage was determined by the Kjeldahl method as described by [
The experimental field was ploughed twice, harrowed and leveled with slope 0.1% after wheat harvesting. Maize planting was done on 8th and 10th May 2013 and 2014, respectively using two grains per hill at a spacing of 25 cm and thinned to one plant at 21 DAS, to give a population of 57,140 plants ha−1. The experiment was irrigated seven times, where the first irrigation was applied at 21 DAS and the following irrigations were applied every 13 days until physiological maturity. All experimental plots were fertilized with NPK. Calcium superphosphate (15.5% P2O5) was added during soil preparation at the rate of 74 kg P2O5 ha−1. Nitrogen fertilizer at a rate of 286 kg N ha−1 in the form of urea (46.5% N) was added in two equal doses, the first dose was added after thinning (before the first irrigation), while the second dose was applied before the second irrigation. Potassium fertilizer was added in the form of potassium sulfate (48% K2O) at the rate of 57 kg K2O ha−1 before the first irrigation. Weed control was done chemically before seedling emergence and mechanically after emergence in a timely manner.
Data were analyzed using an analysis of variance split plot design with three replicates described by [
Laboratory calibration of modified gate along pipe line was illustrated in
Gate number | Q (m3∙h−1) | V (m∙sec−1) | Re | f | Hf (m) | Hsi (m) | Hm (m) | Vi (m∙sec−1) | q (m3∙h−1) |
---|---|---|---|---|---|---|---|---|---|
GP1 system (3.6 m3∙h−1) | |||||||||
1 | 36.0 | 0.5657 | 84848.48 | 0.0182 | 0.0020 | 0.0000 | 0.1280 | 1.5849 | 3.4682 |
2 | 32.4 | 0.5091 | 76363.64 | 0.0186 | 0.0028 | 0.0031 | 0.1303 | 1.5990 | 3.4992 |
3 | 28.8 | 0.4525 | 67878.79 | 0.0190 | 0.0032 | 0.0059 | 0.1327 | 1.6136 | 3.5311 |
4 | 25.2 | 0.3960 | 59393.94 | 0.0195 | 0.0032 | 0.0083 | 0.1351 | 1.6281 | 3.5628 |
5 | 21.6 | 0.3394 | 50909.09 | 0.0201 | 0.0030 | 0.0104 | 0.1375 | 1.6422 | 3.5937 |
6 | 18.0 | 0.2828 | 42424.24 | 0.0209 | 0.0026 | 0.0122 | 0.1397 | 1.6555 | 3.6228 |
7 | 14.4 | 0.2263 | 33939.39 | 0.0218 | 0.0020 | 0.0137 | 0.1417 | 1.6676 | 3.6493 |
8 | 10.8 | 0.1697 | 25454.55 | 0.0232 | 0.0013 | 0.0149 | 0.1435 | 1.6780 | 3.6722 |
9 | 7.2 | 0.1131 | 16969.70 | 0.0252 | 0.0007 | 0.0157 | 0.1449 | 1.6864 | 3.6904 |
10 | 3.6 | 0.0566 | 8484.85 | 0.0291 | 0.0002 | 0.0162 | 0.1459 | 1.6921 | 3.7029 |
GP2 system (4.8 m3∙h−1) | |||||||||
1 | 48.0 | 0.7542 | 113131.3 | 0.0172 | 0.0033 | 0.0000 | 0.2267 | 2.1089 | 4.6150 |
2 | 43.2 | 0.6788 | 101818.2 | 0.0176 | 0.0047 | 0.0055 | 0.2308 | 2.1282 | 4.6572 |
3 | 38.4 | 0.6034 | 90505.05 | 0.0180 | 0.0053 | 0.0104 | 0.2351 | 2.1478 | 4.7001 |
4 | 33.6 | 0.5279 | 79191.92 | 0.0185 | 0.0054 | 0.0148 | 0.2394 | 2.1672 | 4.7426 |
5 | 28.8 | 0.4525 | 67878.79 | 0.0190 | 0.0050 | 0.0186 | 0.2435 | 2.1859 | 4.7836 |
6 | 24.0 | 0.3771 | 56565.66 | 0.0197 | 0.0043 | 0.0218 | 0.2475 | 2.2035 | 4.8221 |
7 | 19.2 | 0.3017 | 45252.53 | 0.0206 | 0.0033 | 0.0244 | 0.2511 | 2.2194 | 4.8569 |
8 | 14.4 | 0.2263 | 33939.39 | 0.0218 | 0.0022 | 0.0264 | 0.2542 | 2.2331 | 4.8868 |
9 | 9.6 | 0.1508 | 22626.26 | 0.0237 | 0.0012 | 0.0279 | 0.2567 | 2.2440 | 4.9107 |
10 | 4.8 | 0.0754 | 11313.13 | 0.0274 | 0.0004 | 0.0287 | 0.2583 | 2.2514 | 4.9268 |
GP3 system (6 m3∙h−1) | |||||||||
1 | 60.0 | 0.9428 | 141414.1 | 0.0165 | 0.0050 | 0.0000 | 0.3600 | 2.6577 | 5.8161 |
2 | 54.0 | 0.8485 | 127272.7 | 0.0168 | 0.0041 | 0.0067 | 0.3647 | 2.6748 | 5.8534 |
3 | 48.0 | 0.7542 | 113131.3 | 0.0172 | 0.0033 | 0.0126 | 0.3696 | 2.6930 | 5.8932 |
4 | 42.0 | 0.6599 | 98989.90 | 0.0177 | 0.0026 | 0.0179 | 0.3748 | 2.7116 | 5.9340 |
5 | 36.0 | 0.5657 | 84848.48 | 0.0182 | 0.0020 | 0.0224 | 0.3799 | 2.7301 | 5.9745 |
6 | 30.0 | 0.4714 | 70707.07 | 0.0189 | 0.0014 | 0.0263 | 0.3849 | 2.7479 | 6.0134 |
7 | 24.0 | 0.3771 | 56565.66 | 0.0197 | 0.0010 | 0.0294 | 0.3895 | 2.7643 | 6.0493 |
8 | 18.0 | 0.2828 | 42424.24 | 0.0209 | 0.0006 | 0.0319 | 0.3935 | 2.7787 | 6.0807 |
9 | 12.0 | 0.1886 | 28282.83 | 0.0227 | 0.0003 | 0.0336 | 0.3968 | 2.7903 | 6.1061 |
10 | 6.0 | 0.0943 | 14141.41 | 0.0261 | 0.0001 | 0.0347 | 0.3991 | 2.7983 | 6.1237 |
m3∙h−1 respectively. The actual discharges (q) from the gates along line were nearly equal to theoretical discharges values. The coefficient of variation (CV%) of discharges gates along the pipes line was 2.28%, 2.27% and 1.80% for GP1, GP2 and GP3 systems, respectively. The values of head pressure pump were 13, 23 and 36.5 cm for GP1, GP2 and GP3, respectively. This means that gates discharges were approximately constant. Accordingly, uniformity of water flow from the first gate to last gate along gated pipe lines according to different GP systems.
Results in
Results of the advance and recession times and infiltration volume of the irrigation systems were illustrated in
Infiltration rate as a function of opportunity time to is illustrated in
Irrigation number | Traditional irrigation | Gated pipes discharge rates | |||||
---|---|---|---|---|---|---|---|
GP1 (3.6 m3∙h−1) | GP2 (4.8 m3∙h−1) | GP3 (6 m3∙h−1) | |||||
Water applied (m3∙ha−1) | Cutoff time (min.) | Water applied (m3∙ha−1) | Cutoff time (min.) | Water applied (m3∙ha−1) | Cutoff time (min.) | Water applied (m3∙ha−1) | |
1 | 880.95 | 55 | 785.71 | 36 | 685.71 | 26 | 619.05 |
2 | 861.90 | 52 | 742.86 | 35 | 666.67 | 25 | 595.24 |
3 | 907.14 | 53 | 757.14 | 32 | 609.52 | 26 | 619.05 |
4 | 1023.81 | 61 | 871.43 | 45 | 857.14 | 32 | 761.90 |
5 | 1050.00 | 63 | 900.00 | 44 | 838.10 | 28 | 666.67 |
6 | 857.14 | 53 | 757.14 | 32 | 609.52 | 24 | 571.43 |
7 | 842.86 | 48 | 685.71 | 31 | 590.48 | 24 | 571.43 |
Sum | 6423.81 | 385 | 5500.00 | 255 | 4857.14 | 185 | 4404.76 |
systems due to little quantity of water applied. These results are consistent with the findings of [
Data in
From the data in
Physiological traits were significantly affected by irrigation systems and maize hybrids (
Irrigation number | Ź (cm) | CV% | α | UC% | DU% | Ea% | Es% |
---|---|---|---|---|---|---|---|
Traditional system | |||||||
1 | 72.738 | 10.901 | −0.976 | 91.279 | 85.829 | 88.475 | 99.008 |
2 | 72.374 | 10.871 | −2.996 | 91.304 | 85.868 | 67.428 | 100.00 |
3 | 73.051 | 10.785 | −1.276 | 91.372 | 85.979 | 89.089 | 99.634 |
4 | 73.984 | 10.395 | −1.090 | 91.684 | 86.487 | 91.679 | 99.315 |
5 | 76.945 | 12.070 | −0.532 | 90.344 | 84.310 | 94.357 | 97.341 |
6 | 72.374 | 10.871 | 0.715 | 91.304 | 85.868 | 99.068 | 91.296 |
7 | 71.829 | 10.746 | 0.255 | 91.404 | 86.031 | 98.201 | 94.055 |
Mean | 73.328 a | 10.948 a | −0.843 c | 91.241 d | 85.767 d | 89.757 c | 97.236 a |
GP1 system (3.6 m3∙h−1) | |||||||
1 | 67.616 | 10.145 | −0.381 | 91.884 | 86.811 | 96.131 | 97.238 |
2 | 66.681 | 9.602 | −2.793 | 92.318 | 87.518 | 73.184 | 100.00 |
3 | 66.815 | 10.155 | −0.562 | 91.876 | 86.798 | 92.301 | 97.889 |
4 | 69.446 | 11.035 | −0.502 | 91.172 | 85.655 | 92.070 | 97.467 |
5 | 70.296 | 11.170 | 0.217 | 91.064 | 85.479 | 96.319 | 94.039 |
6 | 66.815 | 10.155 | 1.649 | 91.876 | 86.798 | 99.991 | 85.652 |
7 | 65.820 | 8.628 | 1.405 | 93.098 | 88.784 | 99.872 | 89.073 |
Mean | 67.641 b | 10.127 b | −0.138 bc | 91.898 c | 86.835 c | 92.838 ab | 94.480 a |
GP2 system (4.8 m3∙h−1) | |||||||
1 | 63.563 | 6.448 | 0.351 | 94.842 | 91.618 | 98.235 | 96.063 |
2 | 61.711 | 7.312 | −2.861 | 94.150 | 90.494 | 79.078 | 100.00 |
3 | 60.340 | 6.439 | 0.685 | 94.849 | 91.629 | 98.990 | 95.777 |
4 | 66.477 | 7.786 | −0.169 | 93.771 | 89.878 | 95.950 | 97.233 |
5 | 66.524 | 7.517 | 1.095 | 93.986 | 90.228 | 99.568 | 92.395 |
6 | 60.340 | 6.439 | 4.546 | 94.849 | 91.629 | 92.576 | 71.616 |
7 | 59.870 | 6.035 | 3.855 | 95.172 | 92.155 | 96.031 | 77.905 |
Mean | 62.689 c | 6.854 c | 1.071 b | 94.517 b | 91.090 b | 94.347 a | 90.141 b |
GP3 system (6 m3∙h−1) | |||||||
1 | 59.323 | 4.696 | 2.038 | 96.243 | 93.895 | 99.933 | 91.266 |
2 | 59.294 | 4.288 | −4.127 | 96.570 | 94.425 | 82.301 | 100.00 |
3 | 59.323 | 4.696 | 1.320 | 96.243 | 93.895 | 99.888 | 94.163 |
4 | 60.340 | 6.439 | 1.354 | 94.849 | 91.629 | 99.872 | 91.981 |
5 | 59.082 | 4.979 | 4.392 | 96.017 | 93.528 | 94.869 | 82.058 |
6 | 59.349 | 3.570 | 8.804 | 97.144 | 95.360 | 74.077 | 76.089 |
7 | 59.350 | 3.570 | 6.821 | 97.144 | 95.360 | 86.564 | 80.419 |
Mean | 59.437 d | 4.605 d | 2.943 a | 96.316 a | 94.013 a | 91.072 bc | 87.997 b |
Hybrids irrigation systems | 2013 | 2014 | |||||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
SC 10 | SC 130 | SC 131 | SC 2031 | TWC 321 | Mean | SC 10 | SC 130 | SC 131 | SC 2031 | TWC 321 | Mean | ||||||
Total chlorophyll (SPAD value) | |||||||||||||||||
Traditional | 38.41 j | 39.64 ij | 40.87 hi | 43.41 fg | 46.61 d | 41.79 C | 39.17 hij | 41.04 fgh | 38.05 ijk | 41.67 fg | 41.23 fgh | 40.23 C | |||||
GP1 | 42.50 g | 44.29 ef | 45.31 de | 54.48 a | 48.44 c | 47.01 A | 43.37 ef | 45.47 cde | 47.38 bc | 51.83 a | 45.79 cd | 46.77 A | |||||
GP2 | 38.27 j | 42.10 gh | 40.24 i | 52.32 b | 43.32 fg | 43.25 B | 40.22 ghi | 40.81 gh | 42.04 fg | 48.46 b | 44.73 de | 43.25 B | |||||
GP3 | 33.46 k | 40.15 i | 38.22 j | 45.30 de | 39.55 ij | 39.34 D | 36.42 k | 37.94 jk | 41.19 fgh | 42.00 fg | 40.78 gh | 39.67 C | |||||
Mean | 38.16 D | 41.55 C | 41.16 C | 48.88 A | 44.48 B | 39.80 D | 41.32 C | 42.17 BC | 45.99 A | 43.13 B | |||||||
Crop growth rate (g plant−1 day−1) | |||||||||||||||||
Traditional | 7.69 ijk | 8.51 fg | 9.25 de | 11.02 b | 8.80 ef | 9.05 B | 8.12 H | 10.02 e | 9.36 f | 12.14 b | 9.28 f | 9.78 B | |||||
GP1 | 8.24 f-i | 10.21 c | 11.82 a | 12.27 a | 9.73 cd | 10.46 A | 8.84 g | 11.20 c | 10.62 d | 12.74 a | 11.10 c | 10.90 A | |||||
GP2 | 7.34 k | 7.50 jk | 8.55 fg | 9.24 de | 8.28 fgh | 8.18 C | 6.66 i | 8.73 g | 9.53 f | 10.13 e | 8.66 g | 8.74 C | |||||
GP3 | 6.44 l | 7.54 jk | 7.96 g-j | 8.66 f | 7.80 h-k | 7.68 D | 6.04 j | 8.08 h | 8.57 g | 9.49 f | 8.07 h | 8.05 D | |||||
Mean | 7.43 D | 8.44 C | 9.40 B | 10.30 A | 8.65 C | 7.41 D | 9.51 B | 9.52 B | 11.12 A | 9.28 C | |||||||
Ear leaf area (cm2) | |||||||||||||||||
Traditional | 571.5 g | 587.3 f | 631.5 c | 681.3 b | 588.5 f | 612.0 B | 594.6 g | 575.0h | 623.4 de | 659.2 b | 602.4 fg | 610.9 B | |||||
GP1 | 618.5 d | 603.3 e | 686.9 b | 710.9 a | 622.4 cd | 648.4 A | 630.3 d | 618.4 e | 624.2 de | 687.5 a | 646.2 c | 641.3 A | |||||
GP2 | 531.2 i | 511.3 j | 597.4 ef | 604.5 e | 563.4 g | 561.6 C | 552.4 i | 556.1 i | 603.9 f | 620.9 e | 554.3 i | 577.5 C | |||||
GP3 | 440.3 l | 476.2 k | 567.1 g | 548.2 h | 511.4 j | 508.6 D | 461.5 m | 496.9 l | 513.4 k | 531.2 j | 536.3 j | 507.9 D | |||||
Mean | 540.4 D | 544.5 D | 620.7 B | 636.2 A | 571.4 C | 559.7 D | 561.6 D | 591.2 B | 624.7 A | 584.8 C | |||||||
lations that lead to reducing the photosynthesis activity and unbalanced relations between plant hormones and biological processes in the whole plant organs. These adverse conditions in the treated soils are undoubtedly of great importance throughout the vegetative growth and dry matter accumulation. The findings obtained in this study were in good agreement to those reported by [
There were significant differences among maize hybrids in their physiological characters (
The interaction between irrigation systems and varieties had a significant effect on physiological traits in both seasons. S.C 2031 plants irrigated with GP1 (3.6 m3∙h−1) surpassed other combinations and gave the highest values of Chl (54.48 and 51.83), CGR (12.27 and 12.74) and ELA (710.88 and 687.45) in both seasons. Meanwhile, S.C 10 irrigated with GP3 (6 m3∙h−1) achieved the lowest values. Some of the differences among genotypes in growth and photosynthesis can be traced to different capacities for water acquisition and transport at a given water status [
The data in
Results in
The interaction effect between irrigation systems and varieties had a significant effect on the most yield and its components traits. No interaction effects were detected on number of rows per ear and 100-grain weight in both seasons. The highest values of yield attributes being obtained for S.C 2031 variety irrigated with GP1. By contrast, the shortest plants were recorded by S.C 130 and S.C 10 varieties irrigated with GP3. The lowest grains number was detected by irrigated S.C 10 and S.C 130 in the first season and S.C 10, S.C 130 and S.C 131 in the second one with GP3 system. Concerning maize yields, S.C 2031 variety irrigated with GP1 exhibited the first significant rank in plant grain yield and grain and stover yields ha−1. Therefore this combination is recommended as the treatment that maximizes grain and stover yields. This combination may be exhibited better water and light utilization due to maintenance of green leaf area and leaf photosynthesis rather than other treatments. There is evidence that the variations in the grain yield response were due to variations in physiological traits that co-
Hybrids irrigation systems | 2013 | 2014 | |||||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
SC 10 | SC 130 | SC 131 | SC 2031 | TWC 321 | Mean | SC 10 | SC 130 | SC 131 | SC 2031 | TWC 321 | Mean | ||||||
Plant height (cm) | |||||||||||||||||
Traditional | 270.5 ef | 250.6 hi | 279.4 cde | 289.8 abc | 283.5 bcd | 274.8 B | 276.2 c | 246.2 de | 289.3 b | 294.3 ab | 290.9 b | 279.4 B | |||||
GP1 | 278.4 de | 256.2 gh | 287.3 bcd | 300.1 a | 292.6 ab | 282.9 A | 275.7 c | 251.5 d | 301.5 ab | 305.8 a | 292.0 b | 285.3 A | |||||
GP2 | 234.2 ij | 236.4 jk | 263.8 fg | 262.6 fg | 255.0 ghi | 250.4 C | 239.0 ef | 229.7 fgh | 268.1 c | 272.4 c | 269.0 c | 255.7 C | |||||
GP3 | 222.4 l | 227.1 kl | 244.6 ij | 253.1 fgh | 248.9 hi | 239.2 D | 224.9 gh | 218.6 h | 237.1 efg | 254.3 d | 251.9 d | 237.4 D | |||||
Mean | 251.4 C | 242.6 D | 268.8 B | 276.4 A | 270.0 B | 253.9 C | 236.5 D | 274.0 B | 281.7 A | 276.0 AB | |||||||
Number of rows per ear | |||||||||||||||||
Traditional | 13.33 | 14.00 | 14.67 | 14.67 | 14.00 | 14.13 A | 13.33 | 13.33 | 14.00 | 16.00 | 13.33 | 14.00 Ab | |||||
GP1 | 13.33 | 14.67 | 15.33 | 15.33 | 14.00 | 14.53 A | 14.00 | 14.00 | 15.33 | 16.00 | 14.00 | 14.67 A | |||||
GP2 | 12.00 | 12.67 | 12.67 | 14.00 | 13.33 | 12.93 B | 12.67 | 13.33 | 12.67 | 13.33 | 13.33 | 13.07 BC | |||||
GP3 | 11.33 | 12.67 | 12.00 | 12.67 | 12.00 | 12.13 B | 12.00 | 12.00 | 12.67 | 12.67 | 12.00 | 12.27 C | |||||
Mean | 12.50 C | 13.50 AB | 13.67 AB | 14.17 A | 13.33 B | 13.00 B | 13.17 B | 13.67 B | 14.50 A | 13.17 B | |||||||
Number of grains per row | |||||||||||||||||
Traditional | 42.67 def | 43.67 b-e | 44.00 b-e | 46.33 abc | 43.33 cde | 44.00 B | 43.33 cde | 45.33 bcd | 43.67 cde | 47.33 ab | 43.00 de | 44.53 B | |||||
GP1 | 42.67 def | 47.00 ab | 46.00 a-d | 48.00 a | 45.00 a-d | 45.73 A | 43.67 cde | 48.67 a | 46.33 abc | 49.00 a | 44.67 bcd | 46.47 A | |||||
GP2 | 36.67 hi | 39.67 fgh | 32.67 jk | 39.00 gh | 40.67 efg | 37.73 C | 38.67 fg | 37.00 ghi | 35.33 ij | 38.33 fgh | 41.00 ef | 38.07 C | |||||
GP3 | 30.67 k | 34.00 ij | 29.67 k | 31.67 jk | 34.67 ij | 32.13 D | 33.33 jkl | 30.67 l | 32.00 kl | 35.67 hij | 34.00 jk | 33.13 D | |||||
Mean | 38.17 B | 41.08 A | 38.08 B | 41.25 A | 40.92 A | 39.75 B | 40.42 B | 39.33 B | 42.58 A | 40.67 B | |||||||
100-grain weight (g.) | |||||||||||||||||
Traditional | 32.71 | 30.47 | 31.68 | 33.82 | 34.21 | 32.58 A | 33.47 | 31.01 | 32.22 | 34.37 | 34.40 | 33.10 A | |||||
GP1 | 33.06 | 30.77 | 31.81 | 34.40 | 34.66 | 32.94 A | 33.66 | 31.57 | 31.97 | 34.56 | 35.06 | 33.37 A | |||||
GP2 | 31.53 | 29.56 | 30.67 | 32.78 | 32.23 | 31.35 B | 32.06 | 29.15 | 30.64 | 32.89 | 32.80 | 31.51 B | |||||
GP3 | 28.94 | 28.25 | 29.60 | 30.32 | 30.54 | 29.53 C | 29.08 | 28.54 | 28.33 | 31.65 | 31.49 | 29.82 C | |||||
Mean | 31.56 B | 29.76 D | 30.94 C | 32.83 A | 32.91 A | 32.07 B | 30.07 D | 30.79 C | 33.37 A | 33.44 A | |||||||
determine tolerance to water stress. The interaction significance may be due to the different responses of each maize genotype to the different irrigation regimes as reported by [
Hybrids irrigation systems | 2013 | 2014 | |||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
SC 10 | SC 130 | SC 131 | SC 2031 | TWC 321 | Mean | SC 10 | SC 130 | SC 131 | SC 2031 | TWC 321 | Mean | ||||
Plant grain yield (g.) | |||||||||||||||
Traditional | 158.03 gh | 164.56 fg | 171.85 def | 209.09 a | 169.97 ef | 174.70 B | 170.64 f | 172.64 f | 181.18 def | 206.90 b | 179.17 def | 182.11 B | |||
GP1 | 172.70 def | 175.45 de | 188.51 c | 213.01 a | 179.74 d | 185.88 A | 177.48 ef | 179.30 def | 193.86 c | 218.54 a | 186.23 cde | 191.08 A | |||
GP2 | 129.58 j | 140.09 i | 151.69 h | 200.38 b | 152.40 h | 154.83 C | 135.60 i | 148.96 gh | 159.18 f | 190.04 cd | 153.07 gh | 157.37 C | |||
GP3 | 110.38 l | 118.87 k | 133.83 ij | 165.50 fg | 128.86 j | 131.49 D | 105.93 k | 122.34 j | 146.59 h | 158.85 g | 123.57 j | 131.46 D | |||
Mean | 142.67 D | 149.74 C | 161.47 B | 197.00 A | 157.74 B | 147.41 D | 155.81 C | 170.20 B | 193.58 A | 160.51 C | |||||
Grain yield (kg∙ha−1) | |||||||||||||||
Traditional | 8188.6 gh | 8816.4 f | 9149.3 e | 10523.0 b | 9254.9 de | 9186.4 B | 8524.6 fg | 9236.4 de | 9744.7 c | 10394.9 b | 8647.4 f | 9309.6 B | |||
GP1 | 8806.6 f | 9305.8 de | 9808.8 c | 11062.6 a | 9493.4 d | 9695.4 A | 8992.3 e | 9451.9 cd | 10167.6 b | 10911.8 a | 9773.5 c | 9859.4 A | |||
GP2 | 6698.6 j | 7255.4 i | 8439.4 g | 9851.5 c | 7947.4 h | 8038.5 C | 7358.2 j | 7969.2 hi | 8535.6 fg | 9728.4 c | 8186.9 gh | 8355.6 C | |||
GP3 | 5811.1 l | 6262.6 k | 7258.6 i | 8785.2 f | 6810.7 j | 6985.6 D | 5834.4 l | 7035.8 jk | 7709.3 i | 8260.1 gh | 6714.2 k | 7110.8 D | |||
Mean | 7376.2 E | 7910.0 D | 8664.0 B | 10055.6 A | 8376.6 C | 7677.4 D | 8423.3 C | 9039.3 B | 9823.8 A | 8330.5 C | |||||
Stover yield (kg∙ha−1) | |||||||||||||||
Traditional | 9653.8 ghi | 11515.9 e | 12827.0 bc | 13445.3 a | 11870.4 e | 11862.5 B | 10380.2 f | 11538.0 de | 11601.1 e | 13247.5 b | 11468.2 e | 11647.0 B | |||
GP1 | 10116.5 fg | 11980.6 de | 13330.6 ab | 13639.0 a | 12013.2 de | 12216.0 A | 10434.2 f | 11701.4 de | 12501.1 c | 13902.2 a | 11928.0 d | 12093.4 A | |||
GP2 | 7585.2 j | 9090.0 i | 10472.6 f | 12535.7 cd | 9690.5 gh | 9874.8 C | 8103.1 i | 9692.9 g | 9665.8 g | 11771.8 de | 9463.4 g | 9739.4 C | |||
GP3 | 6841.2 k | 7338.7 jk | 9311.0 hi | 9955.7 fg | 7651.0 J | 8219.5 D | 7193.8 j | 7405.7 j | 8543.8 h | 9541.7 g | 7130.6 j | 7963.1 D | |||
Mean | 8549.2 E | 9981.3 D | 11485.3 B | 12393.9 A | 10306.3 C | 9027.8 D | 10084.5 C | 10577.9 B | 12115.8 A | 9997.6 C | |||||
Water use efficiency (kg grains m−3) | |||||||||||||||
Traditional | 1.27 l | 1.37 jk | 1.42 ij | 1.64 de | 1.44 hi | 1.43 D | 1.33 i | 1.44 h | 1.52 g | 1.62 ef | 1.35 i | 1.45 D | |||
GP1 | 1.60 ef | 1.69 cd | 1.78 b | 2.01 a | 1.72 bc | 1.76 A | 1.63 ef | 1.72 cd | 1.84 b | 1.98 a | 1.77 c | 1.79 A | |||
GP2 | 1.38 ijk | 1.49 gh | 1.74 bc | 2.02 a | 1.64 de | 1.65 B | 1.51 g | 1.64 ef | 1.75 c | 2.00 a | 1.68 de | 1.72 B | |||
GP3 | 1.32 kl | 1.42 ij | 1.64 de | 1.99 a | 1.54 fg | 1.58 C | 1.32 i | 1.59 f | 1.75 c | 1.87 b | 1.52 g | 1.61 C | |||
Mean | 1.39 E | 1.49 D | 1.65 B | 1.92 A | 1.59 C | 1.45 D | 1.60 C | 1.71 B | 1.87 A | 1.58 C | |||||
The combined effects of irrigation systems and varieties on irrigation water use efficiency were significant in both seasons (
The differences among the five maize varieties in their WUE were significant in both seasons. It is clear that S.C 2031 variety recorded the highest values followed by S.C 131. On the contrary, the lowest one was obtained by S.C 10. This means that S.C 2031 variety is more able to extract water from soil zones, and convert it into plant biomass than other varieties. [
The response of maize plants to irrigation systems has been shown to change with hybrids (
Plant tissue analysis has been used to reveal the status of nitrogen element in a soil-plant system. The grains and stover nitrogen percentage and accumulations were significantly different with various irrigation regimes and varieties (
By comparing the average values of varieties, the highest nitrogen percent and accumulations were attained by S.C 2031 more than other varieties. Meanwhile, S.C 130, T.W.C 321 and S.C 10 had the lowest values of grain N, stover N and accumulations, respectively. The canopy nutritional state can be evaluated through pigment concentration, as chlorophyll concentration in leaves is usually correlated to its nitrogen content. Indices that are good indicators of Chl are usually also good indicators of N-content [
Maize varieties differently responded to irrigation systems for grain N and accumulations (
Irrigation management decisions should be made based on the amount of water applied and how this relates to the consumptive use demands of the plants and the soil water holding capacity. Adopting proper irrigation man-
Hybrids irrigation systems | 2013 | 2014 | |||||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
SC 10 | SC 130 | SC 131 | SC 2031 | TWC 321 | Mean | SC 10 | SC 130 | SC 131 | SC 2031 | TWC 321 | Mean | ||||||
Grain nitrogen (%) | |||||||||||||||||
Traditional | 1.541 cd | 1.519 fgh | 1.533 def | 1.592 a | 1.470 k | 1.531 B | 1.520 efg | 1.536 e | 1.581 ab | 1.589 a | 1.517 fg | 1.549 B | |||||
GP1 | 1.563 b | 1.537 de | 1.555 bc | 1.601 a | 1.492 j | 1.550 A | 1.571 bc | 1.556 cd | 1.593 a | 1.596 a | 1.534 e | 1.570 A | |||||
GP2 | 1.524 efg | 1.492 j | 1.512 gh | 1.547 cd | 1.451 l | 1.505 C | 1.505 gh | 1.514 g | 1.569 bcd | 1.554 d | 1.472 i | 1.523 C | |||||
GP3 | 1.509 hi | 1.483 jk | 1.496 ij | 1.525 efg | 1.436 m | 1.490 C | 1.492 h | 1.455 j | 1.456 j | 1.532 ef | 1.441 j | 1.475 D | |||||
Mean | 1.534 B | 1.508 D | 1.524 C | 1.566 A | 1.462 E | 1.522 C | 1.515 C | 1.550 B | 1.568 A | 1.491 D | |||||||
Nitrogen accumulation in grain (kg∙ha−1) | |||||||||||||||||
Traditional | 126.2 h | 133.9 g | 140.3 def | 167.5 b | 136.0 fg | 140.8 B | 129.6 gh | 141.9 ef | 154.1 c | 165.2 b | 131.2 gh | 144.4 B | |||||
GP1 | 137.7 efg | 143.0 d | 152.5 c | 177.1 a | 141.6 de | 150.4 A | 141.2 f | 147.1 de | 162.0 b | 174.1 a | 149.9 cd | 154.9 A | |||||
GP2 | 102.1 k | 108.3 j | 127.6 h | 152.4 c | 115.3 i | 121.1 C | 110.8 j | 120.6 i | 133.9 g | 151.2 cd | 120.5 i | 127.4 C | |||||
GP3 | 87.7 m | 92.9 l | 108.6 j | 134.0 g | 97.8 k | 104.2 D | 87.0 m | 102.4 k | 112.2 j | 126.5 h | 96.8 l | 105.0 D | |||||
Mean | 113.4 E | 119.5 D | 132.2 B | 157.8 A | 122.7 C | 117.2 E | 128.0 C | 140.5 B | 154.2 A | 124.6 D | |||||||
Stover nitrogen (%) | |||||||||||||||||
Traditional | 0.759 | 0.723 | 0.758 | 0.771 | 0.685 | 0.739 A | 0.733 | 0.734 | 0.764 | 0.773 | 0.663 | 0.733 B | |||||
GP1 | 0.767 | 0.763 | 0.769 | 0.775 | 0.699 | 0.755 A | 0.773 | 0.751 | 0.780 | 0.798 | 0.699 | 0.760 A | |||||
GP2 | 0.761 | 0.698 | 0.754 | 0.765 | 0.676 | 0.731 A | 0.742 | 0.678 | 0.734 | 0.768 | 0.682 | 0.721 B | |||||
GP3 | 0.728 | 0.677 | 0.652 | 0.743 | 0.645 | 0.689 B | 0.717 | 0.654 | 0.691 | 0.735 | 0.678 | 0.695 C | |||||
Mean | 0.754 A | 0.715 B | 0.733 AB | 0.764 A | 0.676 C | 0.741 AB | 0.704 BC | 0.742 AB | 0.769 A | 0.681 C | |||||||
Nitrogen accumulation in stover (kg∙ha−1) | |||||||||||||||||
Traditional | 73.3 f | 83.3 e | 97.2 bcd | 103.7 ab | 81.3 e | 87.8 B | 76.1 ef | 84.7 cd | 88.6 c | 102.4 b | 76.0 ef | 85.6 B | |||||
GP1 | 77.6 ef | 91.4 d | 102.5 abc | 105.7 a | 84.0 e | 92.2 A | 80.7 de | 87.9 cd | 97.5 b | 110.9 a | 83.4 cde | 92.1 A | |||||
GP2 | 57.7 h | 63.5 gh | 79.0 ef | 95.9 cd | 65.5 g | 72.3 C | 60.0 h | 66.0 gh | 70.9 fg | 90.5 c | 64.5 gh | 70.4 C | |||||
GP3 | 49.8 i | 49.7 i | 60.7 gh | 74.2 f | 49.4 i | 56.7 D | 51.6 i | 48.4 i | 59.0 h | 70.1 fg | 48.3 i | 55.5 D | |||||
Mean | 64.6 D | 72.0 C | 84.9 B | 94.8 A | 70.0 C | 67.1 C | 71.7 C | 79.0 B | 93.5 A | 68.1 C | |||||||
agement strategies can limit negative impacts. Using a higher efficiency gated pipes irrigation system is recommended for irrigating maize, especially under deficit irrigation in case of water scarcity from a water-saving viewpoint. Selection of maize genotypes that have more efficient water use this will affect positively on agricultural production in general and in particular maize crop. From this study, we can conclude that substantial amounts of water can be saved by applying GP1 (5500 m3∙ha−1) with significant increases in yield especially with sowing the new variety (S.C 2031) where it found that their impacts were positive on water use efficiency and productivity under old lands conditions.
The authors are grateful to staff of National Laboratory for Testing Irrigation Equipment for their precious support through laboratory work.