• Authors:
    • Hussain, A.
    • Chattha, T.
    • Ahmad, Sh.
    • Tariq, N.
    • Ali, H.
  • Source: Journal of Food Agriculture & Environment
  • Volume: 10
  • Issue: 2
  • Year: 2012
  • Summary: A field study was conducted during 2006-2007 and 2007-2008 at Central Cotton Research Institute, Multan, Pakistan, on silt loam soils to evaluate the effect of irrigation at different growth stages and phosphorus application methods on agronomic traits of wheat. The field experiments were laid out in a split plot design with three replications. The irrigation treatments, i.e. control - no irrigation (I-1), two irrigations at crown root and booting stage (I-2), three irrigations at crown root, booting and grain development (I-3), four irrigations at crown root, booting, anthesis and grain development (I-4) and live irrigations at crown root, booting, caring, anthesis and grain development (I-5) were kept in main plots. The subplots were allocated to three phosphorus application methods viz. side dressed, 3 inches aside seed (I-1), broadcasting at the time of seedbed preparation (P-2), and top dressing alter first irrigation (P-3). Data on yield components such as tiller number m(-2), spikelet number spike(-1), number of grains spike(-1) and 1000-grain weight as well as grain and total dry matter (TDM) yields were collected. Full irrigation (I-4, I-5) treatments significantly affected yield and yield components. A reduction in all studied characters of wheat crop was subjected to water stress at low or greater degree (e.g. I-1, I-2, and I-3). Phosphorus application as side dressed (P-1), 3 inches aside seed, was more beneficial for increasing yield and yield components of wheat compared to other methods of P application.
  • Authors:
    • Li, Y.
    • Cao, W.
    • Lei, X.
    • Chen, D.
  • Source: Sensor Letters
  • Volume: 10
  • Issue: 1-2
  • Year: 2012
  • Summary: CIDSS, an irrigation decision support system (DSS), was developed to satisfy the need for drip irrigation under plastic film of cotton yield management in Xinjiang, China. It is compartmentalized into four main modules: database management, real-time moisture diagnosis, real-time irrigation decision making, and production management decisions. The present study used the Kriging interpolation method to estimate soil moisture caused by spatial variability. The Least Squares Support Vector Machines (LSSVM) model and an empirical model based on the exponential depletion relation of soil moisture were also employed to predict soil moisture. A cotton production management expert system was realized by embedding C Language Integrated Production System. By integrating the interfaces of the moisture sensor, the automatic meteorological station in the field, and the solenoid valve control system, the present study solved the problem of the data for real-time decision making. Finally, the use of CIDSS was demonstrated through characteristic case studies on cotton areas in Xinjiang Uygur Autonomous Region, China.
  • Authors:
    • Lamers, J.
    • Djanibekov, N.
    • Khamzina, A.
    • Djanibekov, U.
  • Source: Forest Policy and Economics
  • Volume: 21
  • Year: 2012
  • Summary: This study analyzed the financial attractiveness of Clean Development Mechanism Afforestation and Reforestation (CDM A/R) in irrigated agricultural settings. The Net Present Value (NPV) and Internal Rate of Return (IRR) of CDM A/R were estimated by analyzing the case of Khorezm region in Uzbekistan, where a mixed-species tree plantation was established on marginal cropland. The dual purposes of carbon sequestration and production of fruits, leaves as fodder, and fuelwood were studied over a seven-year rotation period. We compared the opportunity costs of land in marginal agricultural areas between this short-rotation plantation forestry and the annual cultivation of the major crops in the region, i.e., cotton, winter wheat, rice, and maize. The analyses were performed considering different levels of irrigation water availability, from 0 to 30,000 m(3)/ha, to reflect the reality of a high variability of water supply in the region. The NPV of CDM A/R ranged between 724 and 5794 USD/ha over seven years, depending on the tree species. Among the latter, Elaeagnus angustifolia L had the highest profits due to the annually recurring cash flows generated from fruit production. Temporary Certified Emission Reductions (tCER) ranged within 399-702 USD/ha after the assumed 7-year crediting period and would not suffice to cover initial investments and management costs of tree plantations. IRR peaked at 65% with E. angustifolia under the conventional afforestation and measured - 10% and 61% when considering only the tCER and the CDM A/R, respectively. In contrast, other species had higher IRRs in case of the CDM A/R. The total profits from tree plantations exceeded those of both cotton and winter wheat, even with the assumption that there was an optimal irrigation supply for these crops. Rice production was overall the most profitable land use option but required water input of 26,500 m(3)/ha/year, which is not consistently available for marginal croplands. We argue that the current global average price of 4.76 USD/tCER is insufficient to initiate forestry-based CDM projects but, in the absence of other incentives, can still motivate forestation of degraded croplands for land rehabilitation and the provisioning of non-timber products. Given the low irrigation needs of trees, 3-30% of the crop water demand, a conversion of degraded cropland to forested areas could save up to 15,300 m3/ha/year at the current tCER price. Combining the monetary value of water and carbon would enlarge the scope for CDM A/R in irrigated drylands, thus enhancing the investments in marginal land rehabilitation and strengthening the resilience of rural populations to the repercussions of climate change. (C) 2012 Elsevier B.V. All rights reserved.
  • Authors:
    • Frisvold, G. B.
    • Konyar, K.
  • Source: Water Resources Research
  • Volume: 48
  • Issue: 5
  • Year: 2012
  • Summary: This study examined how agriculture in six southwestern states might adapt to large reductions in water supplies, using the U.S. Agricultural Resource Model (USARM), a multiregion, multicommodity agricultural sector model. In the simulation, irrigation water supplies were reduced 25% in five Southern Mountain (SM) states and by 5% in California. USARM results were compared to those from a "rationing" model, which assumes no input substitution or changes in water use intensity, relying on land fallowing as the only means of adapting to water scarcity. The rationing model also ignores changes in output prices. Results quantify the importance of economic adjustment mechanisms and changes in output prices. Under the rationing model, SM irrigators lose $65 in net income. Compared to this price exogenous, "land-fallowing only" response, allowing irrigators to change cropping patterns, practice deficit irrigation, and adjust use of other inputs reduced irrigator costs of water shortages to $22 million. Allowing irrigators to pass on price increases to purchasers reduced income losses further, to $15 million. Higher crop prices from reduced production imposed direct losses of $130 million on first purchasers of crops, which include livestock and dairy producers, and cotton gins. SM agriculture, as a whole, was resilient to the water supply shock, with production of high value specialty crops along the Lower Colorado River little affected. Particular crops were vulnerable however. Cotton production and net returns fell substantially, while reductions in water devoted to alfalfa accounted for 57% of regional water reduction.
  • Authors:
    • Arriaga-Sevilla, J.
    • Durán-Zuazo, V. H.
    • García-Tejero, I.
    • Muriel-Fernández, J. L.
  • Source: Agronomy for Sustainable Development
  • Volume: 32
  • Issue: 3
  • Year: 2012
  • Summary: Water shortage is becoming a severe problem in arid and semi-arid regions worldwide, reducing the availability of agricultural land and water resources. Deficit irrigation strategies can improve water-use efficiency and the sustainability of agro-ecosystems, although it is important to model the effects on yield loss due to irrigation water restrictions. This work estimates the water production function in citrus trees, determining the relationship between plant water stress and yield depression, as well as establishing a mathematical model for each phenological stage considered (flowering, fruit growth and ripening), and for the entire productive process. For three consecutive years (2006-2008), four regulated deficit irrigation treatments plus a control (100% crop water evapotranspiration (ET C)) were implemented in 13-year-old citrus trees ( Citrus sinensis L. Osb. cv. Navelina). Different water production functions were determined for each phenological stage, establishing the relationship between the irrigation water stress and crop yield. Our results show that the fruit growth and flowering stages were the most sensitive periods in relation to irrigation water deficit and yield loss. Water stress close to 50% of ET C during the flowering stage would impose a yield loss of up to 20%, whereas this same water stress level during the fruit growth or ripening stages would result in yield losses of nearly 10% and 6%, respectively. The adjustment with cross terms ( r2=0.87) estimated the yield loss with good accuracy, being very similar to data measured in each study season. Consequently, the combined effect of deficit irrigation in different stages would be an additive-multiplicative model, considering that the effect of water stress in previous periods determined the crop yield response. Our model indicated that the crop water production function under deficit irrigation programmes would have a quasi-linear relation for water deficits below to 40% ET C. The previous model functions did not enable us to establish an accurate relationship when the water stress was applied in different phenological stages. Thus, this new interpretation is valuable to improve our knowledge and predict the impact of regulated deficit irrigation and have potential application in precision water stress and sustainable irrigation scheduling for citrus.
  • Authors:
    • Wang, G.
    • Thorp, K. R.
    • Norton, R.
    • Gutierrez, M.
  • Source: Crop Science
  • Volume: 52
  • Issue: 2
  • Year: 2012
  • Summary: Canopy reflectance plays an increasingly important role in crop management and yield prediction at large scale. The relationship of four spectral reflectance indices with cotton (Gossypium hirsutum L.) biomass, leaf area index (LAI), and crop yield were investigated using three cotton varieties and five N rates in the irrigated low desert in Arizona during the 2009 and 2010 growing seasons. Biomass, LAI, and canopy reflectance indices (normalized difference vegetation index [NDVI], simple ratio [SR], near-infrared index [NIR] and ratio vegetation index [RVI]) were determined at different growth stages. The commonly used NDVI and the other three canopy reflectance indices explained over 87% variation in cotton biomass (all R-2 > 0.87) and LAI (R-2 > 0.93). Indices SR, NIR, and RVI all had higher coefficients of determination (R-2) compared to NDVI because these indices were not saturated at late growth stages. There was no significant relationship between lint yield and the spectral indices measured at early growth stages. However, the spectral indices determined at peak bloom showed significant correlations with lint yield. Indices SR, NIR, and RVI explained 56, 60, and 58% of variations in cotton lint yield, respectively, while NDVI only explained 47% of variation in lint yield. This study suggests canopy reflectance indices can be used to predict cotton lint yield at peak bloom and the accuracy of yield prediction can be significantly improved when SR, NIR, and RVI are used.
  • Authors:
    • Abid, H.
    • Shakeel, A.
    • Nadeem, T.
    • Chattha,T. H.
    • Hakoomat, A.
  • Source: Food, Agriculture and Environment
  • Volume: 10
  • Issue: 2
  • Year: 2012
  • Summary: A field study was conducted during 2006-2007 and 2007-2008 at Central Cotton Research Institute, Multan, Pakistan, on silt loam soils to evaluate the effect of irrigation at different growth stages and phosphorus application methods on agronomic traits of wheat. The field experiments were laid out in a split plot design with three replications. The irrigation treatments, i.e. control - no irrigation (I 1), two irrigations at crown root and booting stage (I 2), three irrigations at crown root, booting and grain development (I 3), four irrigations at crown root, booting, anthesis and grain development (I 4) and five irrigations at crown root, booting, earing, anthesis and grain development (I 5) were kept in main plots. The subplots were allocated to three phosphorus application methods viz. side dressed, 3 inches aside seed (I 1), broadcasting at the time of seedbed preparation (P 2), and top dressing after first irrigation (P 3). Data on yield components such as tiller number m -2, spikelet number spike -1, number of grains spike -1and 1000-grain weight as well as grain and total dry matter (TDM) yields were collected. Full irrigation (I 4, I 5) treatments significantly affected yield and yield components. A reduction in all studied characters of wheat crop was subjected to water stress at low or greater degree (e.g. I 1, I 2, and I 3). Phosphorus application as side dressed (P 1), 3 inches aside seed, was more beneficial for increasing yield and yield components of wheat compared to other methods of P application.
  • Authors:
    • Yasir, I.
    • Ghazanfar, M. U.
    • Zafar, I.
    • Khan, M. A.
    • Hamid, M. I.
    • Naeem, A.
  • Source: Pakistan Journal of Phytopathology
  • Volume: 24
  • Issue: 1
  • Year: 2012
  • Summary: Bacterial blight (BL), caused by Xanthomonas campestris pv. malvacearum (Smith) Dye, is a common disease affecting the growth, development and yield of cotton ( Gossypium hirsutum L.) in Pakistan. Field trial was conducted for a season to determine the influence of environmental conditions representing heavy and low rainfall periods, wind speed and direction on disease incidence by growing 101 commercial varieties. However, out of 101 varieties, a total of 68 varieties were moderately susceptible response while 8 were susceptible to bacterial blight disease. A total of 25 varieties were moderately resistant to bacterial blight disease. No variety was resistant to bacterial blight disease. Except radiation and wind speed, overall correlation of maximum and minimum air temperature, relative humidity, rainfall and pan evaporation with bacterial blight disease severity was statistically significant. The poor correlation of wind speed with disease severity may also be due to frequency and amount of air currents received in a certain adjoining areas of Faisalabad district of Pakistan and its indirect role to create humid conditions. Similarly relative humidity is different at different levels of crop canopy and largely depends upon the amount of moisture resulted due to rain showers and irrigation.
  • Authors:
    • Houdret, A.
  • Source: Water Alternatives
  • Volume: 5
  • Issue: 2
  • Year: 2012
  • Summary: Water and land grabbing is often an indication of growing control by an elite group over natural resources for agricultural production, marginalising their previous users. It may drive and exacerbate social, economic and political disparities and so increase the potential for conflict. In Southern Morocco's Souss valley, the overuse of water resources is causing aquifer levels to sink and agricultural land to be abandoned. At the same time, irrigated agriculture is still expanding, often permitting the lucrative growing of citrus fruits. This export-oriented agriculture mostly benefits the economic elite, increasing their political influence. Small farmers, on the other hand, face growing threats to their livelihoods. A public-private partnership (PPP) project reallocating water through a 90 km pipeline from a mountain region to plantations in the valley has been implemented to enhance water supply and save dying citrus plantations. However, it is accentuating disparities between farmers. We trace the dynamics of marginalisation linked to this PPP and use emerging water conflicts as a lens to analyse the appropriation of water resources and the underlying political and economic relationships and strategies. On the basis of the case study, we show that water conflicts are as much struggles over political influence as over the resource itself and, consequently, that the related phenomenon of 'water grabbing' is not only driven by economic interests but also determined by a political agenda of regime stability and economic control. However, we also point to the opportunities presented by recent social and political changes in Morocco, including the influence of the 'Arab Spring', and argue that such processes as increasing transparency, decentralisation and the empowerment of local civil society support the re-appropriation of water, livelihoods and power. We conclude by examining the limits of this PPP model, which has been internationally praised by financial institutions, and calling for a careful evaluation of its ecological and social impacts before such experience is replicated elsewhere.
  • Authors:
    • Ma, Y. G.
    • Chen, X.
    • Li, Y. P.
    • Huang, Y.
  • Source: Agricultural Water Management
  • Volume: 107
  • Year: 2012
  • Summary: An integrated optimization method is developed for supporting agriculture water management and planning in Tarim River Basin, Northwest China. The developed method couples two-stage stochastic programming (TSP) with inexact quadratic program (IQP). The hydrological model is provided for forecasting the available irrigation water. The simulation system is then embedded into an optimization framework, where the objective is to maximize the system benefit for water resources management. The developed method can not only deal with nonlinearities in the cost/benefit objective and uncertainties expressed as probabilities and intervals, but also support the analysis of policy scenarios that are associated with economic penalties when the promised water-allocation targets are violated. A case study is conducted for Kaidu-kongque watershed in Tarim River Basin. The results obtained can help generate desired policies for water resources management with maximized economic benefit and minimized system-failure risk. (C) 2012 Elsevier B.V. All rights reserved.