• Authors:
    • Vervoort, W.
    • Ancev,T.
    • Lee, L. Y.
  • Source: Agricultural Water Management
  • Volume: 109
  • Year: 2012
  • Summary: An integrated biophysical and economic model is used to determine the effects of using more water efficient irrigation systems and trade in water rights on the environmental performance of irrigation enterprises in the Mooki catchment within the Murray-Darling Basin, Australia. We find that improved water use efficiency increased profit in the presence of modern irrigation technologies and water trading. Salinity risk downstream is reduced due to the fall in saline discharge from the catchment, and irrigation water is traded away from ecologically significant regions. It is important that the institutional setup gives confidence in the security of water supplies. When irrigators can be assured about the security of their water entitlements in the context of water reform policies, incentives emerge for them to invest in water efficient irrigation technologies and to participate in the water market. Environmental performance can thereby be improved without the need for financial support from the government. Further, minimal government intervention is required to address salinity; given the conjunctive nature of secondary salinity and water use it can be cost-efficient to address both environmental flow and salinity mitigation with a single policy instrument. (C) 2012 Elsevier BM. All rights reserved.
  • Authors:
    • Chen, S.
    • Yue, X. J.
    • Feng, R. J.
    • Hong, T. S.
    • Li, J. N.
  • Source: Transactions of the Chinese Society of Agricultural Engineering
  • Volume: 28
  • Issue: 10
  • Year: 2012
  • Summary: To realize automatic control of integral control of water and fertilization under drip irrigation for citrus with independent water tank and liquid fertilizer tank, a timing control device powered with battery for controlling drip irrigation and fertigation was developed. The device was composed of two solenoid valves which were used to control the order and time of water or liquid fertilizer flowing into the drip irrigation pipe network respectively. To extend battery life, sleep mechanism and power management technology were used with the quiescent current of the device less than 11.2 A. The device was tested in actual application for six consecutive months, and the results showed that the controller was stable and reliable, and the battery voltage dropped only from the initial value of 9.35 to 8.50 V. The device was simple to use, and it can control not only the drip irrigation integration of water and fertilizer, but water drip irrigation. In addition, the rotation irrigation can be carried out by combining multiple devices, and then can control a larger irrigation area. So the device developed in this research is practical and has good promotion prospects.
  • Authors:
    • Jiang, L.
    • Yan, Z. Y.
    • Lai, D. M.
    • Zhang, R. H.
    • Li, Z. G.
    • Tian, C. Y.
  • Source: Ying Yong Sheng Tai Xue Bao
  • Volume: 23
  • Issue: 4
  • Year: 2012
  • Summary: In April-October, 2009, a field experiment was conducted to study the effects of drip irrigation with plastic mulching (MD) on the net primary productivity (NPP), soil heterotrophic respiration (Rh) , and net CO2 exchange flux (NEF(CO2)) of cotton field ecosystem in Xinjiang, taking the traditional flood irrigation with no mulching (NF) as the control. With the increasing time, the NPP, Rh, and NEF(CO2) in treatments MD and NF all presented a trend of increasing first and decreased then. As compared with NF, MD increased the aboveground and belowground biomass and the NPP of cotton, and decreased the Rh. Over the whole growth period, the Rh in treatment MD (214 g C x m(-2)) was smaller than that in treatment NF (317 g C x m(-2)), but the NEF(CO2) in treatment MD (1030 g C x m(-2)) was higher than that in treatment NF (649 g C x m(-2)). Treatment MD could fix the atmospheric CO2 approximately 479 g C x m(-2) higher than treatment NF. Drip irrigation with plastic mulching could promote crop productivity while decreasing soil CO2 emission, being an important agricultural measure for the carbon sequestration and emission reduction of cropland ecosystems in arid area.
  • Authors:
    • Zhang, L. Q.
    • Ma, Z. M.
    • Lian, C. Y.
  • Source: Journal of Triticeae Crops
  • Volume: 32
  • Issue: 1
  • Year: 2012
  • Summary: A field experiment was carried out from March to July, 2007 in Zhangye oasis irrigation region of Gansu province to investigate the effects of a system of bed planting and furrow irrigation on the yield and water use efficiency of beer barley. Under conditions of a bed planting system, grain yield and soil temperature were increased. Compared with conventional flat planting, soil temperature of the 5 cm soil layer in bed planting treatment was raised by 1.27°C and 1.39°C in April and May, respectively. Beer barley plants grew more vigorously in the system of bed planting and furrow irrigation and consumed more water than in conventional flat planting, but the contribution of water to grain yield was greater, and thus bed planting and furrow irrigation showed a significant yield-improving and water saving effect. With the same irrigation quota, 1000-grain-weight increased by 2.10-5.37 g, grains/spike increased by 0.7-7.2, grain yield increased by 480.5-1 983.6 kg/ha and water use efficiency (WUE) was improved by 0.65-4.52 kg/mm/ha in bed planting and furrow irrigation, compared with conventional flat planting.
  • Authors:
    • Shen, X. J.
    • Zhang, J. P.
    • Zhang, J. Y.
    • Sun, J. S.
    • Liu, H.
  • Source: Ying Yong Sheng Tai Xue Bao
  • Volume: 23
  • Issue: 2
  • Year: 2012
  • Summary: To develop a suitable tillage mode and irrigation schedule of transplanted cotton following wheat harvest under sprinkler irrigation, a field experiment was conducted to study the effects of different tillage modes (conventional tillage and no-tillage) and different irrigation schedules (45 and 22.5 mm of irrigating water quota) on the water consumption, seed yield, water use efficiency, and fiber quality of cotton. Comparing with conventional tillage, no-tillage decreased the soil evaporation among cotton plants by 20.3%. Whether with conventional tillage or with no-tillage, deficit irrigation (22.5 mm of irrigating water quota) did not affect seed yield and fiber quality, while decreased the water consumption and improved the water use efficiency. No-tillage with 22.5 mm of irrigating water quota under sprinkler irrigation not only decreased the soil evaporation effectively, but also achieved water-saving, high quality and high yield of transplanted cotton following wheat harvest.
  • Authors:
    • Soriano, M. A.
    • Santos, C.
    • Carmona, M. A.
    • Garcia-Vila, M.
    • Lorite, I. J.
  • Source: Water Resources Management
  • Volume: 26
  • Issue: 8
  • Year: 2012
  • Summary: The Local Irrigation Advisory Services (LIAS) carry out essential work to achieve an efficient use of irrigation water at field and irrigation scheme level, which is crucial in Mediterranean irrigation systems. However, it is unusual to find agronomic and economic assessments of LIAS advice. In this work, the LIAS operating in the Genil-Cabra Irrigation Scheme (southern Spain) was evaluated during the first 5 years of its advice. Acceptance by farmers of the LIAS recommendations was evaluated by using agronomic indicators, such as ARIS (Annual Relative Irrigation Supply). ARIS(LIAS) (actual irrigation applied v. recommendation of LIAS) with values ranging from about 0.23 for wheat and sunflower, and 0.94 for maize, also detecting a high variability between farmers, which indicated a scant acceptance of the LIAS recommendations. The economic evaluation of irrigation was made through two economic indicators, Irrigation Water Productivity (IWP) and Irrigation Water Benefit (IWB). IWP values varied significantly between different crops: around 0.23 a,not sign m(-3) in wheat, sunflower and maize, about 0.53 a,not sign m(-3) in cotton and sugar beet, and values higher than 2.0 a,not sign m(-3) in garlic, for optimal irrigation schedules. For IWB, trends were similar, emphasizing the low IWB values in wheat and sunflower (average values of 0.06 and 0.13 a,not sign m(-3), respectively). Consideration of these economic indicators by LIAS could not only help to obtain more suitable and economically profitable irrigation schedules, but also contribute towards a greater acceptance of advisory services by farmers, by shifting the emphasis from maximizing production to maximizing irrigation profitability.
  • Authors:
    • Zhang, Y. L.
    • Zhang, H. Z.
    • Luo, H. H.
    • Zhang, W. F.
  • Source: Ying Yong Sheng Tai Xue Bao
  • Volume: 23
  • Issue: 2
  • Year: 2012
  • Summary: Taking cotton cultivar Xinluzao 13 as test material, a soil column culture expenment was conducted to study the effects of water storage in deeper (> 60 cm) soil layer on the root growth and its relations with the aboveground growth of the cultivar in arid area with drip irrigation under mulch. Two levels of water storage in 60-120 cm soil layer were installed, i. e., well-watered and no watering, and for each, the moisture content in 0-40 cm soil layer during growth period was controlled at two levels, i.e., 70% and 55% of field capacity. It was observed that the total root mass density of the cultivar and its root length density and root activity in 40-120 cm soil layer had significant positive correlations with the aboveground dry mass. When the moisture content in 0-40 cm soil layer during growth season was controlled at 70% of field capacity, the total root mass density under well-watered and no watering had less difference, but the root length density and root activity in 40-120 cm soil layer under well-watered condition increased, which enhanced the water consumption in deeper soil layer, increased the aboveground dry mass, and finally, led to an increased economic yield and higher water use efficiency. When the moisture content in 0-40 cm soil layer during growth season was controlled at 55% of field capacity and the deeper soil layer was well-watered, the root/shoot ratio and root length density in 40-120 cm soil layer and the root activity in 80-120 cm soil layer were higher, the water consumption in deeper soil layer increased, but it was still failed to adequately compensate for the negative effects of water deficit during growth season on the impaired growth of roots and aboveground parts, leading to a significant decrease in the economic yield, as compared with that at 70% of field capacity. Overall, sufficient water storage in deeper soil layer and a sustained soil moisture level of 65% -75% of field capacity during growth period could promote the downward growth of cotton roots, which was essential for achieving water-saving and high-yielding cultivation of cotton with drip irrigation under mulch.
  • Authors:
    • Payton, P.
    • Young, A. W.
    • Mahan, J. R.
  • Source: Irrigation Science
  • Volume: 30
  • Issue: 2
  • Year: 2012
  • Summary: Water available for agricultural use is declining worldwide as a result of both declining water resources and increasing application costs. Managing crop irrigation under conditions where the water need cannot be fully met represents the future of irrigation in many areas. On the southern high plains of Texas there is interest among producers to reduce the amount of water applied to cotton. In this study, a producer's efforts to reduce water application to a cotton crop were assessed in terms of a comparison between evapotranspiration, rainfall, and irrigation that is widely used in the region. The producer was able to reduce water application to meet intended reductions relative to the evapotranspiration estimates but, depending on the method used for calculating the crop water need, he tended to over water the crop in two out of three intended deficit irrigation regimes. Analysis of continuously monitored canopy temperatures provided verification of over-irrigation. Continuously monitored canopy temperature is proposed as a useful adjunct to evapotranspiration approaches to deficit irrigation management.
  • Authors:
    • Li, C. J.
    • Tian, C. Y.
    • Mai, W. X.
  • Source: Australian Journal of Crop Science
  • Volume: 6
  • Issue: 5
  • Year: 2012
  • Summary: Long-term use of drip irrigation technology may lead to root degradation and affect shoot growth and yield. A field experiment was conducted to investigate above- and belowground growth responses to drip irrigation under mulch film (DI) in comparison to flood irrigation under mulch film (FI) in cotton. The monolith method was used to harvest roots at seven timepoints in the growth periods, and the root length, and shoot and root dry weight were measured. The total root length per plant in the 0-10 cm soil layer was higher under DI, whereas in the 30-60 cm soil layer roots were longer under FI. From 65 to 96 days after sowing (DAS), the rate of increase in root length was lower under DI than FI. Total root length decreased after 125 DAS under DI, and was mainly centered in the 0-40 cm soil layer and at distances of 30-70 cm from drip-lines. The shoot:root ratio at 125 DAS was higher under DI than FI, but at 160 DAS the shoot:root ratio abruptly declined under DI. The decline in root length under DI during advanced growth stages may be attributable to the higher root density in shallow soil layers and the increase in the shoot:root ratio. These results suggest that, it are important to increase yield of cotton plants under DI early development of a deep root system and initial control of shoot growth by regulation of water and fertilizer supply.
  • Authors:
    • Tian, C. Y.
    • Mai, W. X.
  • Source: (Journal of) Plant Nutrition and Fertilizer Science AND Acta Metallurgica Sinica
  • Volume: 18
  • Issue: 1
  • Year: 2012
  • Summary: Premature senescence of cotton under drip irrigation below mulch film (DI) is much more widespread than under flooding irrigation (FI), and the change of plant nutrients under DI has been regarded as a possible influencing factor. In this study, a field experiment was conducted to investigate the cotton growth and nutrient status under DI in comparison to FI. Severe symptoms of premature senescence occurred at the later growth stages of cotton under DI, while no such symptoms were observed under FI. At 125 DAS (late bolling stage), shoot biomass under DI was significantly higher than that under FI, while root biomasses showed an opposite trend, and the shoot/root ratio under DI was significantly higher than that under FI. The shoot dry weight of plants grown under DI dropped abruptly from 125 DAS (late bolling stage) to 160 DAS (boll opening stage). Field observations indicated that the main reason for the decrease was the shedding of a large number of leaves, squares and bolls. The shoot to root ratio under DI also decreased to the same level as that of the FI treatment. An analysis of leaf nutrition revealed that the nitrogen and phosphorus concentrations of old leaves were lower than those of young leaves under both of DI and FI at the later growth stages, whereas the potassium concentration presented an opposite picture. The K concentration of young leaves under DI was lower than that under FI, and the K concentration of cotton shoots showed a similar trend. The above results suggested that premature senescence of cotton under DI may result from the fact that the requirement of the vigorously growing shoots for K exceeds the K amount that the poorly developed roots are able to supply.