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Benefits of Supplemental Irrigation of Wheat Crop under Rainfed Farming Systems
Shahid Ahmad,Muhammad Yasin,Asif Ali Bhatti,Mohammad Aslam
Pakistan Journal of Biological Sciences , 1999,
Abstract: Field experiments were conducted at the Field Station of the Water Resources Research Institute (WRRI), National Agricultural Research Centre (NARC), Islamabad and farmers fields at Hittar, Tehsil Fatehjang, district Attock of the Punjab province to study the benefits of supplemental irrigation on wheat crop under rainfed farming systems. Three irrigation strategies, namely 10 mm application at pre-sowing (Rauni), 10 mm application at 50 percent management allowed deficit (MAD) and 25 mm application at 75 percent MAD were employed. The supplemental irrigations were applied using locally developed raingun sprinkler irrigation systems. The yields of wheat grain and straw were increased with the application of supplemental irrigation at all the three selected strategies. Highest water use efficiency of 20.55 and 24.07 kg/mm of water was obtained at NARC, Islamabad and Fatehjang locations during the driest years of 1993-94 and 1992-93, respectively. The highest net benefits of around Rs. 9000 were obtained with irrigation strategy of 25 mm application at 75 percent MAD at both the locations. However, the economic irrigation strategy was a pre-sowing irrigation of 10 mm only, where highest benefit-cost ratio was observed. Therefore, scheduling programme must be designed in a way to apply deficit irrigations to plant crop at optimal planting time and to avoid effects of dry spells on reduction in yield or crop failures. The depth of irrigation application must be in accordance with the stage of growth. Furthermore, economic priority must be linked with the irrigation priority for developing management strategies.
Impacts of Improved Supplemental Irrigation on Farm Income, Productive Efficiency and Risk Management in Dry Areas  [PDF]
Tamer El-Shater, Yigezu A. Yigezu, Kamil Shideed, Aden Aw-Hassan
Journal of Water Resource and Protection (JWARP) , 2017, DOI: 10.4236/jwarp.2017.913106
Abstract: This paper provides empirical evidence that improved supplemental irrigation (ISI) can be justified on both environmental and economic grounds. Results of a stochastic frontier model which explicitly and simultaneously accounts for technical inefficiency and production risk applied to data collected from 513 wheat farms in the rainfed areas of Syria show that the typical adopter farmer obtained yield and productive efficiency gains of 6% and 7% respectively. A stochastic dominance criterion also showed that the adopter farmers got 10% and 13% reductions in risk of obtaining yield levels below 4 tons/ha and 3 tons/ha respectively. Given its adoption level of 22.3% in 2010, ISI led to the production of 52 thousand metric tons (6%), more wheat and conservation of 120 million cubic meters of water (10%). ISI has the potential to reduce total irrigation water use by upto 45% and for further increases in yield if accompanied with sprinklers and other improved agronomic practices, thereby enhancing food security and environmental sustainability in the country. An important policy implication of these findings is that wider dissemination of ISI along with other complementary agronomic practices in postwar Syria could be a viable option to be considered by national and international efforts for the restoration and rehabilitation of agriculture in the country.
Effects of limited supplemental irrigation with catchment rainfall on potato growth in rainfed areas of western Loess Plateau
黄土高原西部旱农区不同品种马铃薯集雨限灌效应

秦舒浩,张俊莲,王蒂,蒲玉林
应用生态学报 , 2009,
Abstract: Field experiments were conducted to study the effects of limited supplemental irrigation with catchment rainfall on the growth of potato cultivars Dax iyang and Tongshu 23 in rainfed areas of western Loess Plateau. Supplemental irrigation with catchment rainfall at seedling stage increased the potato yield significantly, and the increment was higher for Daxiyang than for Tongshu No.23. Supplemental irrigation at tuber expanding stage increased the yield of Tongshu 23, but decreased the yield of Daxiyang. Low amount of supplemental irrigation (45 mm) increased the water use efficiency (WUE) and irrigation water use efficiency (IWUE) of Tongshu 23. For Daxiyang, its WUE and IWUE were higher when the supplemental irrigation was made at seedling stage than at tuber expanding stage. Supplemental irrigation increased the tuber yield and the percentages of bigger and medium tubers of Tongshu 23, but the percentages of green and blet tubers were also increased. As for Daxiyang, supplemental irrigation increased the percentages of bigger and smaller tubers, as well as the percentage of blet tuber.
Effect of supplemental irrigation on nitrogen translation and high-yield wheat yield in drylands
不同补灌次数对旱地高产小麦氮素运转及产量的影响

HUANG Ling-Feng,LIU Yi-Guo,LIN Qi,LI Jing-Tao,
黄令峰
,刘义国,林 琪,李京涛

中国生态农业学报 , 2009,
Abstract: The effects of different supplemental irrigation schemes on nitrogen translation and high-yield wheat yield in the drylands of Qingdao were investigated via field experiments. The results reveal that increasing supplemental irrigation negatively influences grain protein content, while grain protein content is highest under CK (dry land treatment). Grain protein accumulation under CK is lower than those under treatments with only one or two irrigations, however, obviously higher than those with four or five irrigations. Appropriate supplemental irrigation enhances grain yield and nitrogen utilization efficiency, while nitrogen transfer rates and amounts reduce under excessive irrigation. There is an insignificant yield difference between W4 (a three-time irrigation treatment at wintering, jointing and filling stages) and W3 (a two-time irrigation treatment at jointing and filling stages). With increasing frequency and volume of irrigation, wheat yield, 1000-grain weight and per-spike grain decrease accordingly. Based on yield, water use efficiency and grain protein accumulation under W2 at 120 mm irrigation at jointing and filling stages are optimum.
Supplemental irrigation potential and impact on downstream flow of Karkheh River Basin of Iran
B. Hessari,A. Bruggeman,A. Akhoond-Ali,T. Oweis
Hydrology and Earth System Sciences Discussions , 2012, DOI: 10.5194/hessd-9-13519-2012
Abstract: Supplemental irrigation of rainfed winter crops improves and stabilizes crop yield and water productivity. Although yield increases by supplemental irrigation are well established at the field level, its potential extent and impact on water resources at the basin level are less researched. This work presents a GIS-based methodology for identifying areas that are potentially suitable for supplemental irrigation and a computer routine for allocating stream flow for supplemental irrigation in different subbasins. A case study is presented for the 42 908 km2 upper Karkheh River Basin (KRB) in Iran, which has 15 840 km2 of rainfed crop areas. Rainfed crop areas within 1 km from the streams, with slope classes 0–5%, 0–8%, 0–12% and 0–20%, were assumed to be suitable for supplemental irrigation. Four stream flow conditions (normal, normal with environmental flow requirements, drought and drought with environmental flow) were considered for the allocation of water resources. Thirty-seven percent (5801 km2) of the rainfed croplands had slopes less than 5%. Sixty-one percent (3559 km2) of this land was suitable for supplemental irrigation, but only 22% (1278 km2) could be served with irrigation in both fall (75 mm) and spring (100 mm), under normal flow conditions. If irrigation would be allocated to all suitable land with slopes up to 20%, 2057 km2 could be irrigated. This would reduce the average annual outflow of the upper KRB by 9%. If environmental flow requirements are considered, a maximum (0–20% slopes) of 1444 km2 could receive supplemental irrigation. Under drought conditions a maximum of 1013 km2 could be irrigated, while the outflow would again be reduced by 9%. Thus, the withdrawal of steam flow for supplemental irrigation has relatively little effect on the outflow of the upper KRB. However, if the main policy goal would be to improve rainfed areas throughout the upper KRB, options for storing surface water need to be developed.
Regional simulation of wheat yield in China under the climatic change conditions
气候变化下我国小麦产量变化区域模拟研究

XIONG Wei,JU Hui,XU Yin-Long,LIN Er-Da,
熊 伟
,居 辉,许吟隆,林而达

中国生态农业学报 , 2006,
Abstract: In this research,we applied the(newest) emission scenarios of the sulfur and greenhouse gases,i.e.(Intergovernmental) Panel on Climate Change(IPCC) Special Report on Emission Scenarios((SRES)) A2 and B2 scenarios,combined with the RCM ((Regional) Climate Model) model and(CERES)-Wheat model to (investigate) the change of wheat(yield) in 2080s.The results show(that) under the two emission scenarios,in 2080s,the yield of rainfed wheat decreases(dramatically;) irrigation can offset the decrease,but can not stop it;the yield increases for both irrigated wheat and rainfed wheat if the direct effect of CO_2 is considered in the simulation.
Modeling crop land soil moisture and impacts of supplimental irrigaiton in a rainfed region of Bangladesh  [PDF]
Pramod K. Pandey, Sagor Biswas
Journal of Agricultural Chemistry and Environment (JACEN) , 2014, DOI: 10.4236/jacen.2014.31B004
Abstract:

A robust water balance model has been tested for predicting soil moisture levels and supplemental irrigation requirement of a rainfed region of Bangladesh. The predictions were used for improving the understanding of the impacts of rainwater harvesting on rainfed agriculture. The climate data (i.e., rainfall, temperature, evaporation, and evapotranspiration) were used as inputs for predicting the variations in soil moisture. Soil moisture levels under rainfed and supplementary irrigation conditions were compared. Results showed that rainwater harvesting i.e., rain water storage tanks during rainy seasons can be potentially useful for storing rainwater, which can be utilized for enhancing crop land soil moisture during dry seasons for enhancing crop yield. The study presented here will be useful for improving and disseminating rainwater harvesting approaches for enhancing water availability in rainfed regions.

Relationships between Grain Yield and Yield Components in Bread Wheat under Different Water Availability (Dryland and Supplemental Irrigation Conditions)
Mohtasham MOHAMMADI,Peyman SHARIFI,Rahmatollah KARIMIZADEH,Mohammad Kazem SHEFAZADEH
Notulae Botanicae Horti Agrobotanici Cluj-Napoca , 2012,
Abstract: Path and correlation analysis were executed to investigate the relationships between grain yield and other important yield components in bread wheat (Triticum aestivum L.) genotypes during two years (2009-2011) under supplemental irrigation and dryland conditions. Field experiments were performed in a randomized complete block design with four replications. Grain yield showed positive correlation with plant height and test weight under supplemental irrigation condition. The similar results were also revealed between grain yield and plant height, spike length, days to maturity, agronomic score and test weight in dryland environment. The grain yield of bread wheat in dryland condition depended on the effect of plant height, days to maturity, agronomic score and 1000 kernel weight, whereas in supplemental irrigation was mainly related to plant height, spike length, 1000 kernel weight and test weight. The influence of 1000 kernel weight on grain yield in both environments seems to cause from the fact that grain yield in wheat is frequently the sink limited, and for this reason, the 1000 kernel weight has been reported as a promising trait for increasing grain yield in wheat under different conditions. The nearly equal value of correlation and path coefficients of plant height and grain yield showed plant height had positive and direct effect on grain yield, in both conditions and suggesting a criteria trait for improving of grain yield. The results showed that genotype 12 (CS/TH.SC//3*PVN/3/MIRLO/BUC/4/MILAN/5/ TILHI) is a high yielding potential genotype in moisture limited conditions.
Yield Performance and Grain Quality of Wheat Varieties Grown under Rainfed and Irrigated Conditions  [PDF]
A.M.A. Kamal,M.R. Islam,B.L.D. Chowdhury,M.A. Maleque Talukder
Asian Journal of Plant Sciences , 2003,
Abstract: A study was undertaken to evaluate the growth performance and grain quality of eight modern wheat varieties grown under rainfed and irrigated conditions. Wheat varieties used in the experiment were aghrani, akbar, ananda, balaka, barkat, kanchan, pavon and sonalika. In irrigated condition, one flood irrigation was applied at 28 days of sowing to saturate the soil up to 15 cm depth. The wheat varieties differed significantly (P<0.05) with respect to plant height and 1000-grains weight, grain and straw yields, protein, amylose, ash and K contents in grains. The highest grain yield obtained in aghrani (2.16 t ha-1) was statistically identical to those found in kanchan (2.08 t ha-1), akbar (2.06 t ha-1) and barkat (2.02 t ha-1). The highest protein content was found in barkat (13.75%), which was followed by ananda (12.65%), akbar (12.55%), sonalika (12.5%), aghrani (12.35%) and kanchan (12.25%). Balaka had the lowest grain protein content (11.55%). The highest amylose content were found in barkat (24.4%) and was followed by balaka (24.25%), aghrani (23.6%), akbar (23.2%), ananda (23.05%) and kanchan (21.75%). Application of irrigation improved the plant characteristics like grain and straw yields, protein, amylose, P, K and S contents in grains compared to wheat grown under rainfed conditions. Among the eight varieties of wheat barkat, aghrani, akbar and kanchan are the promising varieties than the others with respect to grain and protein yields.
Yield and Yield Components of Faba Bean Genotypes Under Rainfed and Irrigation Conditions  [PDF]
Iyad W. Musallam,Ghazi Al-Karaki,Khalil Ereifej,Abdel Rahman Al-Tawaha
Asian Journal of Plant Sciences , 2004,
Abstract: In this study, thirteen faba bean genotypes were investigated for yield and yield components under rainfed (Maru) and irrigation (JUST) conditions. The results showed that irrigation resulted in a substantial yield increase, more than double that produced under rainfed conditions. The highest seed yield was obtained from genotypes Reina Blanca, L82007-11-3-1, FLIP83-24FB and 80S4387 under both rainfed and irrigation conditions. Higher pods per plant, taller plants, greater hundred seed weight, biological yield, nodule number and nodule dry weight per plant were obtained under irrigation than under rainfed conditions.
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