Soil & Tillage Research 93 (2007) 429–437 www.elsevier.com/locate/still
Integrating rainwater harvesting with supplemental irrigation into rain-fed spring wheat farming Guoju Xiao a,b,c, Qiang Zhang b,*, Youcai Xiong d, Miaozi Lin e, Jing Wang d a
Chinese Academy of Meteorological Sciences, Beijing 100081, China Gansu Key Laboratory of Arid Climate Changes and Disaster Reduction, Institute of Arid Meteorology, China Meteorological Administration, Lanzhou, Gansu Province 730020, China c Bioengineering Institute of Ningxia University, Yinchuan, Ningxia Hui Autonomous Region 750021, China d State Key Laboratory of Arid Agroecology, Lanzhou University, Lanzhou, Gansu Province 730000, China e Biological and Chemistrical Engineering Department, Fujian Normal University, Fuqing, Fujian Province 350300, China b
Received 7 October 2005; received in revised form 19 May 2006; accepted 15 June 2006
Abstract A field experiment was conducted at the Haiyuan Experimental Station (368340 N, 1058390 E), in a semiarid region of China, from 2000 to 2003 for rain-fed spring wheat (Triticum aestivum) production to maximize the utilization of low rainfall. This paper reports the two field cultivations of rainwater harvesting with a sowing in the furrow between film-covered ridges (SFFCR), and with a sowing in the holes on film-covered ridges (SHFCR). At the same time, the periods and indices of supplemental irrigation during the whole growth stage of rain-fed spring wheat were also studied. The periods of supplemental irrigation included the three-leaf stage (irrigated once), the elongation stage to flowering stage (irrigated twice), and the flowering stage to filling stage (irrigated once). The indices of supplemental irrigation during the whole growth stage of rain-fed spring wheat must reach over 59 and 40 mm in order to realize the 2250 and 2000 kg ha1 yield, respectively. This research also presented such a concept of efficient water saving supplemental irrigation, which was considered as a new index of water saving irrigation. The experimental result showed that the efficiency of water saving supplemental irrigation of field cultivation with SFFCR was 5.5–5.8%, and with SHFCR was 9.4–9.6%. The efficiency of water saving supplemental irrigation of field cultivation with SHFCR was improved by 40.4% in comparison with SFFCR. Consequently, in this region, the integration of rainwater harvesting and supplemental irrigation can play a crucial role in the improvement of rain-fed spring wheat yields and water use. # 2006 Elsevier B.V. All rights reserved. Keywords: Efficiency of water saving supplemental irrigation; Rain-fed spring wheat; Rainwater harvesting; Supplemental irrigation; Semiarid region of China
1. Introduction Water resources are limited in semiarid areas of China, especially in mountainous areas where the prevailing farming system is rain-fed. Annual pre-
* Corresponding author. Tel.: +86 931 4670216x2464; fax: +86 931 4657630. E-mail address:
[email protected] (Q. Zhang). 0167-1987/$ – see front matter # 2006 Elsevier B.V. All rights reserved. doi:10.1016/j.still.2006.06.001
cipitation ranges from 250 to 550 mm, and the scarcity of rainfall and droughts are the main constrains to rainfed spring wheat (Triticum aestivum) production in this area (Cook et al., 2000). Therefore, it would be urgent and necessary for us to find a practical and effective pathway for further crop production. Rainwater harvesting based on the collection and concentration of surface runoff for cultivation has been practiced in different parts of the world (Pacey and Cullis, 1986; Ramalan and Nwokeocha, 2000; Herman,
430
G. Xiao et al. / Soil & Tillage Research 93 (2007) 429–437
2000; Li et al., 2003; Mintesinot et al., 2004). For example, a plastic-covered ridge and furrow rainfall harvesting system combined with mulches is used to increase the water availability of crops for improving and stabilizing agricultural production in semiarid regions of China (Li et al., 2001; Li and Gong, 2002). Many experimental studies suggest that water shortage during the whole growth stage of crops can be reduced by means of rainwater harvesting technologies in rainfed agricultural areas (Jo and Garry, 2003; Singandhape et al., 2003; Xu and Mermoud, 2003; Ali and Theib, 2004; Patrick et al., 2004). But, during some stages of crop growth, water deficits will still be unavoidable (Kang et al., 2002; Pan et al., 2003). Supplemental irrigation with water collected into small ponds could prove to be a viable solution (Xiao et al., 2005). Water scarcity demands the maximum use of every drop of rainfall. Rainwater harvesting with storage components to enable supplemental irrigation is one strategy to further mitigate dry spell effects in crop production (Fox and Rockstro˝n, 2000). The integration of rainwater harvesting and supplemental irrigation with drip-irrigation has played an important role in the improvement of crop yield in semiarid areas of China (Xiao and Wang, 2003). So, in this study, to maximize the utilization of low rainfall in semiarid regions, two field cultivations of rainwater harvesting with the sowing in the furrow between film-covered ridges, and with the sowing in the holes on film-covered ridges was conducted with rain-fed spring wheat to study the effect of rainwater harvesting and supplemental irrigation on crop yields and water use. The objectives of this study were (1) to compare crop yields and water use efficiency under different methods of field cultivation; (2) to determine the timings and ranges of soil water deficit
for supplemental irrigation; (3) to examine the effects of supplemental irrigation on crop yields. 2. Materials and methods 2.1. General situation of experiment base A field experiment was conducted at the Haiyuan Experimental Station in a semiarid region of China (368340 N, 1058390 E) located at an altitude of 1854 m above sea level. The annual average rainfall is about 400 mm, which mainly occurs from July to September. The daily average temperature in June, July, and August is 18.2, 19.8, and 18.3 8C, respectively. The annual average temperature is 7.2 8C. Alternating hills and gullies form the main geographic formation of this region, where rain-fed farming is conducted with no irrigation. Crops are planted once a year, and rain-fed spring wheat is main food crop. In this experimental field, soil is a Loess loam with a pH of 6.8. Available nitrogen (N) is 36.9 mg kg1 and total N is 89.1 mg kg1. Available phosphorus (P) is 5.21 mg kg1 and total P is 28.4 mg kg1. Organic matter content is about 10 g kg1. 2.2. Field experiment ‘‘79121-15’’, a typical rain-fed spring wheat (Triticum aestivum) variety, was sown on each 15 March from 2000 to 2003. A sowing density of 230 kg seed ha1 was used. This field experiment consisted of two groups. One was the field experiment of rainwater harvesting with a sowing in the furrow between film-covered ridges (SFFCR). Each plot of SFFCR consisted of four lines of film-covered ridges and three lines of furrows (Fig. 1). The plastic film on the ridge was white and its width was
Fig. 1. Field cultivation of rainwater harvesting with a sowing in the furrow between film-covered ridges.
G. Xiao et al. / Soil & Tillage Research 93 (2007) 429–437
431
Fig. 2. Field cultivation of rainwater harvesting with a sowing in the holes on film-covered ridges.
1.0 m. Wheat seeds were sown in the furrow with a three-row-sowing machine. The sowing depth was 6 cm and the rows were 15 cm apart. Another was the field experiment of rainwater harvesting with a sowing in the holes on film-covered ridges (SHFCR). Each plot of SHFCR consisted of three lines of film-covered ridges with holes and four lines of narrow furrows (Fig. 2). The plastic film type on the ridge was also white and its width is 1.2 m. Wheat seeds were planted in the holes on filmcovered ridges in rows 15 cm apart. Rain-fed spring wheat was sown with the holes sowing machinery. Each plot was 4.5 m width and 6.0 m length, and replicated in three randomized complete blocks. Each group had five treatments according to different levels of supplemental irrigation during the whole growth stage of rain-fed spring wheat (Table 1). 2.3. Experiment in rain shelter An additional experiment in a rain shelter was conducted at the Haiyuan Experimental Station for
the periods and indices of supplemental irrigation during the whole growth stage of rain-fed spring wheat, which can control artificially soil water supply and water consumption in different growth stage of crop. At the same time, this experiment could imitate natural rainfall with a micro-sprayer. In this condition, the practical rainfall and the utilization of rainfall during the whole growth stage of rainfed spring wheat can be controlled in time. Wheat seeds were sown in plastic barrels, which are 1 m high and 20 cm diameter on each 15 March from 2000 to 2002. Barrels were filled with soil in top layer. And along the barrel wall, two small holes (diameter 0.5 cm) were drilled along the depth at 10 cm interval. In so doing, two syringe needles connected by a syringe bottle from a higher position were inserted into these holes and then water can be applied sufficiently by soil, that is a water supply through a syringe plastic pipe. Before wheat seed was sown, soil moisture had been measured using oven dry weight method.
Table 1 The different levels of supplemental irrigation during the whole growth stage of rain-fed spring wheat Treatments
Tr.1 Tr.2 Tr.3 Tr.4 Tr.5
PR (mm)
223 223 223 223 223
UR (mm)
196 196 196 196 196
ISI (mm) Three-leaf
Elongation
Flowering
Filling
Total
0 13 13 13 13
0 21 21 21 21
0 6 16 16 20
0 0 0 9 16
0 40 50 59 70
PR is the practical rainfall during the whole growth stage of rain-fed spring wheat; UR the utilization of rainfall during the whole growth stage of rain-fed spring wheat; ISI the index of supplemental irrigation.
432
G. Xiao et al. / Soil & Tillage Research 93 (2007) 429–437
2.4. Record of experiment Natural rainfall during the whole growth stage of rain-fed spring wheat was recorded. Soil moisture in the furrow and ridge was measured weekly in 10 cm increments to 50 cm depth from the sowing to harvest stage. Supplemental irrigation was given in the threeleaf stage (irrigated once), from the elongation to flowering stage (irrigated twice), and from the flowering to filling stage (irrigated once) (Li et al., 2003). Statistical analyses was carried out using the GLM analysis of variance (ANOVA) from the SAS Institute (1989) to determine the effects of the field cultivation and supplemental irrigation on WUE, the efficiency of water saving supplemental irrigation, and wheat yield. Mean separations were accomplished by applying the Fisher protected LSD test at P < 0.05. 3. Results 3.1. Periods of supplemental irrigation Based on meteorological data from 1958 to 2003 supplied by the Meteorological Station of Haiyuan County (Fig. 3), the relationship of rainfall and water consumption of rain-fed spring wheat (Triticum aestivum) during the whole growth stage (from March to July) was shown in Fig. 4. The results showed that the total water deficits during the whole growth stage mainly existed in S1, S2 and S3 periods. All values were achieved in the average of 4 years’ data, and this trend of each year was very similar. From the sowing to elongation stage (S1), the natural rainfall could not keep up with the water consumption of rain-fed spring wheat. However, soil rainwater harvesting, as supplemental water, could satisfy water consumption. But, during July to Septem-
Fig. 4. Relationship between rainfall and water consumption during the whole growth stage of rain-fed spring wheat. S1 means from the sowing to elongation stage of rain-fed spring wheat; S2 means from the elongation to flowering stage; S3 means from the flowering to filling stage; S4 means from the filling to mature stage.
ber, the natural rainfall reduced over 50 mm in the 1990s, compared with that in the 1950s, while the loss of soil moisture through evaporation increased 35–45 mm. The experimental results showed that the water consumption deficit maintained from 12 to 15 mm (the decrease of soil water supply) from the emergence to elongation stage. From the elongation to flowering stage (S2), the water consumption increased rapidly and natural rainfall could not meet the demand. At the same time, the soil rainwater harvesting has been used up. During this critical stage, the deficit of water consumption reached to the maximum. Experimental results assumed that the deficit of water consumption should be kept between 35.8 and 45.2 mm, but the yield of rain-fed spring wheat would be dramatically improved if micro-supplemental irrigation were used in this period. From the flowering to filling stage (S3), although rainfall gradually increased, it could not completely meet the demand of water consumption of crop. Obviously, the deficit of micro-water consumption affected the grain weight per spike. From the filling to mature stage (S4), the natural rainfall could completely satisfy the need of water consumption. So, we can conclude that supplemental irrigation in S2 (from the elongation to flowering stage) and S3 (from the flowering to filling stage) periods became vital important for water consumption of rain-fed spring wheat. 3.2. Index of supplemental irrigation
Fig. 3. Changes of the annual rainfall and rainfall during the whole growth stage of rain-fed spring wheat at the Haiyuan Experimental Station during 1958–2003. A—rainfall is the annual rainfall and W— rainfall is the rainfall during the whole growth stage of rain-fed spring wheat (from March to July).
The experiment in rain shelter showed that the total water consumption of rain-fed spring wheat during the whole growth stage was about 364 mm, and the yield was improved to 2250 kg ha1 from 2000 to 2002. The relationship among rainfall, soil water supply, and total water supply during the whole growth stage of rain-fed
G. Xiao et al. / Soil & Tillage Research 93 (2007) 429–437
433
Fig. 5. Relationship among rainfall, soil water supply, and total water supply during the whole growth stage of rain-fed spring wheat. PR is the practical rainfall during the whole growth stage of rain-fed spring wheat; TSWS the theoretical soil water supply; TWS the total water supply; UR the utilization of rainfall during the whole growth stage of rain-fed spring wheat; PSWS the practical soil water supply; PWS the practical water supply of rain-fed spring wheat; PSRH the practical soil rainwater harvesting; TSWS the theoretical soil water supply; LR the loss of rainfall; LSWS the loss of soil water supply; ISI the index of supplemental irrigation.
spring wheat was shown in Fig. 5. In simulated artificial experiment of the field cultivation of rainwater harvesting, the results suggested that the practical rainfall (PR) during the whole growth stage of rain-fed spring wheat was nearly 223 mm, the utilization of rainfall (UR) was 196 mm, and the theoretical soil water supply (TSWS) was about 85 mm. The total water supply (TWS) of rain-fed spring wheat was 307 mm, and then the yield would reach to 1250 kg ha1. The practical soil rainwater harvesting (PSRH) was about 59 mm and the practical soil water supply (PSWS) was 52 mm. The practical water supply (PWS) of rain-fed spring wheat was 248 mm. The total loss of water supply during the whole growth stage was about 34 mm. The total water deficit was 59 mm, which should be determined as a reference index of supplemental
irrigation (ISI) for rain-fed spring wheat production to realize 2250 kg ha1 in a semiarid region of China. 3.3. Rainwater harvesting with a sowing in the furrow between film-covered ridges Rain-fed spring wheat field cultivation of rainwater harvesting with a sowing in the furrow between filmcovered ridges has been practiced widely in semiarid areas of China. This cultivation technology reached not only the distribution of field rainwater harvesting in time and space, but also the transformation from the non-effective rainwater to effective rainwater use. Simultaneously, it could reduce the soil-dry-humidity ratio and the loss of soil moisture through evaporation. As a planting plot, the furrow combined with the
434
G. Xiao et al. / Soil & Tillage Research 93 (2007) 429–437
film-covered ridge was used as a rainwater-harvesting plot. This formed the typical cultivation technology of rainwater harvesting with the sowing in the furrow between film-covered ridges. The amount of rainwater harvesting in the planting plot was calculated by Dun ¼ S1 Rn v þ S2 Rn ðAE þ DÞn
(1)
where Dun is the amount of rainwater harvesting (mm), S1 the rainwater harvesting plot area of film-covered ridges (m2), S2 the rainwater harvesting plot area of furrows (m2), Rn the amount of rainfall and supplemental irrigation (mm), v the rainwater harvesting quotient, AE the actual evaporation (mm), and D is the loss of soil moisture through drainage (mm): v¼
Ra Rn
(2)
with v is the rainwater harvesting quotient, which is an experimental value and is measured in different rainwater harvesting plot, Ra the amount of rainwater harvesting in a rainwater harvesting plot or planting plot (mm), and Rn is the actual rainfall (mm). The efficiency of soil-dry-humidity of rain-fed spring wheat field cultivation was determined by the function of the saving water sowing machinery. The efficiency of water saving supplemental irrigation of rain-fed spring wheat field cultivation was calculated by W ¼ E n S n ; . . . ; Pn
(3)
where W is the efficiency of water saving supplemental irrigation (%), En the efficiency of rainwater harvesting (%), Sn the efficiency of water saving of supplemental irrigation (%), and Pn is the efficiency of soil-dryhumidity (%). 3.4. Rainwater harvesting with a sowing in the holes on film-covered ridges The sowing in the holes on film-covered ridges, as a part of the field cultivation of rainwater harvesting, could be carried out by the holes sowing machinery on filmcovered ridges. In adjacency of film-covered ridge and furrow, the film-covered ridges were not only the rainwater harvesting plots, but also the planting plots. To improve rainwater harvesting from the film-covered ridges, the line sowing on film-covered ridges was turned into the sowing in the holes on film-covered ridges. The efficiency of rainwater harvesting of the sowing in the holes on film-covered ridges was calculated by En ¼
S0 S1 v
(4)
where En is the efficiency of rainwater harvesting (%), S1 the rainwater harvesting plot area of film-covered ridges (m2), S0 the holes area on film-covered ridges (m2), and v is the rainwater harvesting quotient. The efficiency of soil-dry-humidity of the sowing in holes on film-covered ridges could be calculated according to Eq. (5). The efficiency of water saving supplemental irrigation of rain-fed spring wheat field cultivation could be calculated according to Eq. (3): Pn ¼
2S3 þ S4 2L1 L2
(5)
where Pn is the efficiency of soil-dry-humidity (%), L1 the space length of adjacent holes (m), L2 is the space length of adjacent line-hole (m), and S3 and S4 is the soil humidity area of the holes (m2). 3.5. Efficiency of water saving supplemental irrigation Experimental results showed that the efficiency of water saving supplemental irrigation of the field cultivation with a sowing in the holes on film-covered ridges was higher than that with a sowing in the furrow between film-covered ridges. Similarly, rain-fed spring wheat yield was also higher. The efficiency of water saving supplemental irrigation of the field cultivation with a sowing in the holes on film-covered ridges was improved by 40.4% in comparison with a sowing in the furrow between film-covered ridges (Tables 2 and 3). If supplemental irrigation was about 40 mm, or practical water supply was 400 mm during the whole growth stage of rain-fed spring wheat, the yield would reach over 2000 kg ha1. Moreover, to realize the 2250 kg ha1 yield, supplement irrigation would be about 59 mm or practical water supply was 430 mm. The study was supported by the outcome of regression analysis on the relationship between rainfed spring wheat yield and the efficiency of water saving supplemental irrigation. A close positive linear relationship was found between rain-fed spring wheat yield (Y (kg ha1)) and the efficiency of water saving supplemental irrigation (X (%)) for a rainwater harvesting system with the sowing in the furrow between filmcovered ridges (Y = 358.14X + 214.09, r = 0.72) (Fig. 6). A non-linear positive relationship existed between the yield (Y (kg ha1)) and the efficiency of water saving supplemental irrigation (X (%)) for a rainwater harvesting system with the sowing in the holes on film-covered ridges (Y = 2.93X2.96, r = 0.71) (Fig. 7), suggesting that the efficiency of water saving supplemental irrigation was associated not only with the
G. Xiao et al. / Soil & Tillage Research 93 (2007) 429–437
435
Table 2 The efficiency of water saving supplemental irrigation and water use efficiency for the field cultivation of rainwater harvesting with a sowing in the furrow between film-covered ridges and in the holes on film-covered ridges PR (mm)
UR (mm)
ISI (mm)
ARH (mm)
PSWS (mm)
PWS (mm)
En (%)
Pn (%)
Sn (%)
W (%)
WUE (kg ha1 mm1)
Yield (kg ha1) 1050 2104 2140 2254 2358
(A) Sowing in the furrow between 223 196 0 223 196 40 223 196 50 223 196 59 223 196 70
film-covered ridges 293 52 351 50 365 50 382 52 400 54
345 401 416 434 454
50.0 49.1 49.0 50.0 50.8
– 25.0 25.3 25.0 25.3
– 45.0 45.6 45.1 45.4
– 5.5 5.7 5.6 5.8
4.7 8.0 7.8 8.0 8.0
PR (mm)
ARH (mm)
PWS (mm)
En (%)
Pn (%)
Sn (%)
W (%)
WUE (kg ha1 mm1)
Yield (kg ha1)
366 429 443 463 472
60.7 59.9 59.8 61.0 60.6
– 28.5 28.7 28.4 28.6
– 55.0 55.4 55.1 55.6
– 9.4 9.5 9.5 9.6
5.5 8.9 8.7 8.5 8.6
1220 2351 2390 2409 2508
UR (mm)
ISI (mm)
PSWS (mm)
(B) Sowing in the holes on film-covered ridges 223 196 0 314 52 223 196 40 376 52 223 196 50 392 50 223 196 59 410 52 223 196 70 425 52
a b b b b
a b b b b
a b b b b
a b b b b
PR is the practical rainfall during the whole growth stage of rain-fed spring wheat; UR the utilization of rainfall during the whole growth stage of rain-fed spring wheat; ISI the index of supplemental irrigation; ARH the amount of rainwater harvesting in planting plots; PSWS the practical soil water supply; PWS the practical water supply of rain-fed spring wheat; En is the efficiency of rainwater harvesting; Pn the efficiency of soil-dryhumidity; Sn the efficiency of water saving of supplemental irrigation; W the efficiency of water saving supplemental irrigation; WUE water use efficiency. Means within columns followed by different letters are significantly different at p < 0.05.
is aggravating. In this case, the technologies of tillage and cultivation have achieved a great breakthrough from the flat to field cultivation of rainwater harvesting, which could improve water use efficiency of natural rainfall and limited supplemental irrigation (Wang et al., 2004). Rainwater harvesting can be achieved by using pretreated catchment and micro-catchment areas to increase the efficiency of runoff and maximize the amount of collected rainfall (Lindstrom, 1986; Tsiouris et al., 2002). Micro-catchment water harvesting (MCWH), which collects runoff from short slopes, is
index of supplemental irrigation, but also with patterns of field cultivation of rainwater harvesting. Therefore, the combination of supplemental irrigation and field cultivation of rainwater harvesting had a positive effect on the improvement of rain-fed spring wheat yield. 4. Discussion In the 1990s, the water saving agriculture was developed all over the world. At the same time, global temperatures have risen steadily, and the spring drought as well as continuous drought across spring and summer
Table 3 The efficiency of water saving supplemental irrigation and rain-fed spring wheat yields for the field cultivation of rainwater harvesting with a sowing in the furrow between film-covered ridges, and with a sowing in the holes on film-covered ridges Field cultivation
ISI (mm)
Mean
0
40
50
59
70
W (%) SFFCR SHFCR
– –
5.5 a 9.4 a
5.7 b 9.5 a b
5.6 b 9.5 a b
5.8 c 9.6 b
5.7 A 9.5 B
Yield (kg ha1) SFFCR SHFCR
1050 a 1220 a
2104 a 2351 a
2140 a 2390 a
2254 b 2409 b
2358 c 2508 c
1981 A 2176 B
ISI is the index of supplemental irrigation; W the efficiency of water saving supplemental irrigation; SFFCR the rainwater harvesting with a sowing in the furrow between film-covered ridges; SHFCR the rainwater harvesting with a sowing in the holes on film-covered ridges. Means within rows followed by different lowercase letters are significantly different at p < 0.05. Means within columns followed by different uppercase letters are significantly different at p < 0.05.
436
G. Xiao et al. / Soil & Tillage Research 93 (2007) 429–437
Fig. 6. A close positive linear relationship of rain-fed spring wheat yield and the efficiency of water saving supplemental irrigation for the rainwater harvesting with a sowing in the furrow between filmcovered ridges.
Fig. 7. A non-linear positive relationship of rain-fed spring wheat yield and the efficiency of water saving supplemental irrigation for the rainwater harvesting with a sowing in the holes on film-covered ridges.
especially useful in arid and semiarid regions (Bruins et al., 1986). The major advantages of MCWH are that it is simple, cheap, replicable, efficient and adaptable (Reiz et al., 1988). MCWH can improve soil moisture storage, prolong the period of moisture availability, and enhance the growth of agricultural, horticultural and forest crops (Carter and Miller, 1991; Gupta, 1995). The use of terraces, rippers, contour ridges, and microcatchments is widely recognized to increase soil water storage and agricultural production (Gupta et al., 1999). In semiarid areas of China, the field experiment of rainwater harvesting with the sowing in the furrow between film-covered ridges (SFFCR), and with the sowing in the holes on film-covered ridges (SHFCR) is applied widely in agronomic practices. This study has showed that SFFCR and SHFCR can improve soil moisture storage, reduce the loss of soil moisture through evaporation, and reach the transformation from the non-effective rainwater to effective rainwater use. Supplemental irrigation in smallholder farming systems can be achieved with water harvesting systems that collect local surface runoff in small storage structures (100–1000 m3). Rainfall is collected from areas specifically treated to increase precipitation runoff
and stored in tanks for supplemental irrigation (Mejed et al., 2000). In Burkina Faso, on shallow soil with low water holding capacity, supplemental irrigation alone improved water use efficiency (rainfall + irrigation) with 37% on average (from 0.9 to 1.2 kg ha1 mm1) compared to the control (traditional rain-fed practice with manure but no fertilizer). The highest improvement in the yield and water use efficiency was achieved by combining supplemental irrigation and fertilizer application (Johan et al., 2002). In semiarid areas of China, small 10–60 m3 (on average 30 m3) sub-surface storage tanks are widely promoted. These tanks collect surface runoff from small, often treated catchments (e.g., with asphalt or concrete). Research on using these sub-surface tanks for supplemental irrigation of wheat indicated a 20% increase in water use efficiency (rain amounting to 420 mm + supplemental irrigation ranging from 35 to 105 mm). Water use efficiency increased on average from 8.7 kg ha1 mm1 for rain-fed wheat to 10.3 kg ha1 mm1 because of receiving supplemental irrigation, meanwhile incremental water use efficiency ranged from 17 to 30 kg ha1 mm1, indicating the largely relative added value of supplemental irrigation. Similar results were observed on maize, with the yield increase of 20–88%, and incremental water use efficiency ranging from 15 to 60 kg ha1 mm1 of supplemental irrigation (Li et al., 2000). In this study, 40 and 59 mm of supplemental irrigation during the whole growth stage of rain-fed spring wheat can reach the yield of 2000 and 2250 kg ha1, respectively, in semiarid areas of China. Moreover, crop production using rainwater harvesting and supplemental irrigation is the best alternative for improving yields and water use efficiency in this region. 5. Conclusions The study concludes that supplemental irrigation during the whole growth stage of rain-fed spring wheat was divided into three different periods concerning the three-leaf stage (irrigated once), the elongation to flowering stage (irrigated twice), and the flowering to filling stage (irrigated once). To meet 2000 kg ha1 yield, the practical water supply of rain-fed spring wheat was about 400 mm, or supplemental irrigation was 40 mm. Also, to keep in line with the yield of 2250 kg ha1, the practical water supply and supplemental irrigation were 430 and 59 mm, respectively, in semiarid areas of China. The efficiency of water saving supplemental irrigation of the field cultivation with a sowing in the furrow between film-covered ridges was 5.5–5.8%, and with a sowing in the holes on film-covered ridges was 9.4–9.6%,
G. Xiao et al. / Soil & Tillage Research 93 (2007) 429–437
suggesting that the efficiency of water saving supplemental irrigation related not only to the index of supplemental irrigation, but also to patterns of field cultivation of rainwater harvesting. Acknowledgements This work was granted by the post-doctorate research project ‘‘The Effects of Global Climate Change on Crops Planting Pattern in the Semi-arid Region of China’’, and Development Planning Commission of Gansu Province (No. [2000] 736), and a subproject example of agricultural high efficiency water saving of China Science and Technology Promoting Agriculture Development Project. References Ali, R.T., Theib, Y.O., 2004. The role of supplemental irrigation and nitrogen in producing bead wheat in the highlands of Iran. Agric. Water Manage. 65, 225–236. Bruins, H.J., Evenari, M., Nessler, U., 1986. Rainwater harvesting agriculture for food production in arid zone: the challenge of the African famine. Appl. Geogr. 6, 13–32. Carter, D.C., Miller, S., 1991. Three years experience with on-farm water catchment water harvesting system in Botswana. Agric. Water Manage. 19, 191–203. Cook, S., Li, F., Wei, H., 2000. Rainwater harvesting agriculture in Gansu Province. People’s Republic of China. J. Soil Water Conserv. 55 (2), 112–114. Fox, P., Rockstro˝n, J., 2000. Water harvesting for supplemental irrigation of cereal crops to overcome imtra-seasonal dry-spells in the Sahel. Phys. Chem. Earth. Part B: Hydrol. Oecans Atmos. 25 (3), 289–296. Gupta, G.N., 1995. Rainwater management for tree planting in the India desert. J. Arid. Environ. 31, 219–235. Gupta, G.N., Limba, N.K., Mutha, S., 1999. Growth of prosopis cineraria on micro-catchments in an arid region. Ann. Arid. Zone 38 (1), 37–44. Herman, B., 2000. Integrated water management: emerging issues and challenges. Agric. Water Manage. 45, 217–228. Jo, L., Garry, J.O.L., 2003. Long-term comparison of rotation and fallow tillage system of wheat in Australia. Field Crops Res. 83, 111–222. Johan, R., Jennie, B., Patrick, F., 2002. Rainwater management for increased productively among small-holder farmers in drought prone environments. Phys. Chem. Earth 27, 949–959. Kang, S.Z., Zhao, L., Liang, Y.L., Hu, X.T., Cai, H.J., Gu, B.J., 2002. Effects of limited irrigation on yield and water use efficiency of winter wheat in the Loess Plateau of China. Agric. Water Manage. 55, 203–216. Li, F., Cook, S., Geballe, G.T., Burch Jr., W.R., 2000. Rainwater harvesting agriculture: An integrated system for water management on rainfed land in China’s semiarid areas. AMBIO 29 (8), 477–483.
437
Li, X.Y., Gong, J.D., 2002. Effects of different ridge:furrow ratios and supplement irrigation on crop production in ridge and furrow rainfall harvesting system with mulches. Agric. Water Manage. 54, 243–254. Li, X.Y., Gong, J.D., Gao, Q.Z., Li, F.R., 2001. Incorporation of ridge and furrow method of rainfall harvesting with mulching for crop production under semiarid conditions. Agric. Water Manage. 50, 173–183. Li, Y.L., Cui, J.Y., Zhang, T.H., Zhao, H.L., 2003. Measurement of evapotranspiration of irrigation spring wheat and maize in a semiarid region of north China. Agric. Water Manage. 61, 1–12. Lindstrom, M.J., 1986. Effects of residue harvesting on water runoff, soil-erosion and nutrient loss. Agric. Ecosyst. Environ. 16, 103– 112. Mejed, A.Z., Mousa, A., Nisreen, H., 2000. Rainfall harvesting using sand ditches in Jordan. Agric. Water Manage. 46, 183–192. Mintesinot, B., Verplancke, H., Ranst, E.V., Mitiku, H., 2004. Examine traditional irrigation methods, irrigation scheduling and alternate furrows irrigation on verticals in north Ethiopia. Agric. Water Manage. 64, 17–27. Pacey, A., Cullis, A., 1986. Rainwater Harvesting: The Collection of Rainfall and Runoff in Rural Areas. Intermediate Technology Publications, London, UK, p. 13. Pan, X.Y., Wang, G.X., Yang, H.M., Wer, X.P., 2003. Effect of water deficits on within-plot variability in growth and grain yield of spring wheat in northwest China. Field Crops Res. 80, 195–205. Patrick, G., Chales, G., Joseph, M., Edword, M., 2004. Effects of soil management practices and tillage system on surface soil water conservation and crust formation on a sandy loam in semi-arid Kenya. Soil Till. Res. 75, 99–186. Ramalan, A.A., Nwokeocha, C.U., 2000. Effects of furrow irrigation methods, mulching and soil water suction on the growth, yield and water use efficiency of tomato in the Nigerian Savanna. Agric. Water Manage. 45, 317–330. Reiz, C., Maulder, P., Begemann, L., 1988. Water harvesting for plant production. World Bank Technical Paper 91, Washington. DC, USA. SAS Institute Inc., 1989. SAS/STAT User’s Guide. Ver. 6, 4th ed., vol. 1. SAS Institute Inc., Cary, NC. Singandhape, R.B., Rao, G.G.S.N., Patil, N.G., Brahmanand, P.S., 2003. Fustigation studies and irrigation scheduling in drip irrigation system in tomato crop. Eur. J. Agron. 19, 327–340. Tsiouris, S.E., Mamolos, A.P., Kalburtji, K.L., Alifrangis, D., 2002. The quality of runoff water collected from a wheat field margin in Greece. Agric. Ecosyst. Environ. 89, 117–125. Wang, F.H., Wang, X.Q., Ken, S., 2004. Comparison of conventional, flood irrigation, flat planting with furrow irrigated, raised bed planting for winter wheat in China. Field Crops Res. 87, 35–42. Xiao, G.J., Wang, J., 2003. Research on progress of rainwater harvesting agriculture on loess plateau. Acta Ecol. Sin. (in Chinese with English abstract) 23 (5), 179–188. Xiao, G.J., Liu, W.X., Xu, Q., Sun, Z.J., Wang, J., 2005. Effects of temperature increase and elevated CO2 concentration, with supplemental irrigation, on rain-fed spring wheat yield in semiarid areas of China. Agric. Water Manage. 74, 243–255. Xu, D., Mermoud, A., 2003. Modeling the soil water balance based on time-dependent hydraulic conductivity under different tillage practices. Agric. Water Manage. 63, 139–151.
