• Authors:
    • Vanham, D.
    • Laghari, A. N.
    • Rauch, W.
  • Source: Hydrology and Earth System Sciences
  • Volume: 16
  • Issue: 4
  • Year: 2012
  • Summary: The Indus basin is one of the regions in the world that is faced with major challenges for its water sector, due to population growth, rapid urbanisation and industrialisation, environmental degradation, unregulated utilization of the resources, inefficient water use and poverty, all aggravated by climate change. The Indus Basin is shared by 4 countries - Pakistan, India, Afghanistan and China. With a current population of 237 million people which is projected to increase to 319 million in 2025 and 383 million in 2050, already today water resources are abstracted almost entirely (more than 95% for irrigation). Climate change will result in increased water availability in the short term. However in the long term water availability will decrease. Some current aspects in the basin need to be re-evaluated. During the past decades water abstractions - and especially groundwater extractions - have augmented continuously to support a rice-wheat system where rice is grown during the kharif (wet, summer) season (as well as sugar cane, cotton, maize and other crops) and wheat during the rabi (dry, winter) season. However, the sustainability of this system in its current form is questionable. Additional water for domestic and industrial purposes is required for the future and should be made available by a reduction in irrigation requirements. This paper gives a comprehensive listing and description of available options for current and future sustainable water resources management (WRM) within the basin. Sustainable WRM practices include both water supply management and water demand management options. Water supply management options include: (1) reservoir management as the basin is characterised by a strong seasonal behaviour in water availability (monsoon and meltwater) and water demands; (2) water quality conservation and investment in wastewater infrastructure; (3) the use of alternative water resources like the recycling of wastewater and desalination; (4) land use planning and soil conservation as well as flood management, with a focus on the reduction of erosion and resulting sedimentation as well as the restoration of ecosystem services like wetlands and natural floodplains. Water demand management options include: (1) the management of conjunctive use of surface and groundwater; as well as (2) the rehabilitation and modernization of existing infrastructure. Other demand management options are: (3) the increase of water productivity for agriculture; (4) crop planning and diversification including the critical assessment of agricultural export, especially (basmati) rice; (5) economic instruments and (6) changing food demand patterns and limiting post-harvest losses.
  • 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:
    • 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.
  • Authors:
    • Vadaria, K. N.
    • Nariya, J. N.
    • Solanki, R. M.
    • Modhvadia, J. M.
    • Rathod, A. D.
  • Source: Journal of Cotton Research and Development
  • Volume: 26
  • Issue: 1
  • Year: 2012
  • Summary: A field experiment was conducted at Junagadh Agricultural University, Junagadh during kharif 2006-2007 and 2007-2008 to evaluate the effect of different levels of nitrogen, phosphorus and potassium on growth, yield and quality of hybrid Bt cotton. The results indicated that significantly higher seed cotton and stalk yields, growth and yield attributes, quality parameters as well as total uptake of N, P, K were obtained with the application of N @ 240 kg/ha, P 2O 5 @ 50 kg/ha and K 2O @ 120 kg/ha. The seed cotton yield of Bt cotton increased to the tune of 20.51, 6.90 and 13.27 per cent with the application of 240 kg N/ha, 50 kg P 2O 2/ha and 120 kg K 2O/ha, respectively as compared to control.
  • Authors:
    • Dhaka, A. K.
    • Dahiya, S. S.
    • Pannu, R. K.
    • Singh, M.
  • Source: Crop Research
  • Volume: 43
  • Issue: 1/2/3
  • Year: 2012
  • Summary: The survey was conducted in Haryana state during rabi season of 2005-06 on 972 farmers in 54 villages of 16 districts with respective cropping system i. e. pearl millet-wheat, cotton-wheat and rice-wheat. The 18 farmers from each village were selected randomly covering small (4.0 ha) group of land holders. Only those farmers were selected, who had grown PBW 343 variety of wheat. The sample sizes for pearl millet-wheat, cotton-wheat and rice-wheat of all three small, medium and large farm size groups were 90, 108 and 126, respectively. Yield reported in rice-wheat system was higher than cotton-wheat and pearl millet-wheat system. Maximum yield was observed with the use of more than five bags urea/ha. Numbers of irrigations above 4 and seed rate above 100 kg/ha were also reported to increase in yield. Protein content of wheat in pearl millet-wheat system was the highest. Protein content in late sown wheat in pearl millet-wheat system was higher than cotton-wheat and rice-wheat systems. Seed rate of 100 kg/ha and nitrogen dose of five bags of urea/ha gave significantly higher protein content. Quantitative production of wheat in rice-wheat and cotton-wheat cropping systems was higher than pearl millet-wheat system but quality in terms of protein content was significantly superior to both the rice-wheat and cotton-wheat systems. Hence, export market should be developed in quality grain producing zone i. e. in pearl millet-wheat growing areas, where lower percentage of farmers use higher nitrogen doses and cultivation practices were numerically better than other cropping systems.