• Authors:
    • Shakir, A. S.
    • Rehman, H. U.
    • Sharif, M. B.
    • Hameed, A.
    • Qazi, A. U.
    • Khan, N. M.
    • Afzal, M.
  • Source: Pakistan Journal of Science
  • Volume: 63
  • Issue: 3
  • Year: 2011
  • Summary: Global demands for food & fiber are increasing, necessitating efficient management of the irrigated water. Vast-uncultivated but otherwise fertile lands in Baluchistan, Pakistan attract the authorities to develop the land for agriculture through irrigation. Kachhi plains are one of such areas that will be provided canal water through a gravity canal system off-taking from Indus river at Taunsa Barrage. Efficient use of water especially in arid climates requires good estimates of crop water requirements (CWR). Physical based methods of estimating crop water requirement including the Radiation-Resistance based methods take into account the energy radiated from various sources and the atmospheric resistance depending on air circulation and humidity. This study employs a radiation-resistance based Penman Monteith Equation (Allen et al., 1998) through a spread sheet based tool and CROPWAT software to estimate the crop water requirements in Kachhi Plains, the study area. The study compares the reference crop evapotranspiration with four other well known methods. Meteorological data namely rainfall, temperature, humidity, actual sunshine hours of the closest meteorological station i.e. Jacobabad station is used for the study. Crop coefficients are calculated using FAO guidelines. Total water requirement for Wheat is estimated as 380 mm, while that for Cotton is 928 mm. Crop water requirement calculated by the spreadsheet matches well with that from CROPWAT. The result differs by 3% from the crop water requirements estimated/used by the feasibility report of the Kachhi Canal. Staggering of major crops (wheat, cotton) have been incorporated while computing the CWR. The study can be used for optimization of the cropping pattern and can further be extended by estimation of crop water requirement using lysimeter in the study area. It can also be used to study the impact analysis of meteorological data on the crop water requirement.
  • Authors:
    • Kugbei, S.
  • Source: Journal of Crop Improvement
  • Volume: 25
  • Issue: 3
  • Year: 2011
  • Summary: Production figures in 2008 showed that new private seed enterprises in Afghanistan produced and sold about 12,000 tons of certified wheat seed, which accounted for 95% of the total certified seed produced in the country. At a retail price of about US$1,200 per ton, the enterprises earned an average margin of 20%. When interviewed, the farmers ranked high yield as by far the most important characteristic they sought in improved varieties. Besides yield, the next important attributes were earliness, disease resistance, grain color, and bread making quality. Estimates of on-farm productivity showed that use of improved wheat varieties alone could contribute up to 33% incremental yield under irrigated conditions, whereas the use of quality seed could enhance yield further by 28%. These estimates were obtained under recommended fertilizer rates, in the absence of which yield levels would have declined substantially. Apart from wheat, other major crops the farmers grew varied by regions but in broad terms included rice, vegetables, maize, potato, cotton, barley, watermelon, and alfalfa.
  • Authors:
    • Bacalan, G. E.
    • Kaman, H.
    • Uz, I.
    • Sonmez, N. K.
    • Uz, B. Y.
    • Ersahin, S.
    • Kurunc, A.
    • Emekli, Y.
  • Source: Agricultural Water Management
  • Volume: 98
  • Issue: 6
  • Year: 2011
  • Summary: Identification of nitrate (NO 3) leaching hot spots is important in mitigating environmental effect of NO 3. Once identified, the hot spots can be further analyzed in detail for evaluating appropriate alternative management techniques to reduce impact of nitrate on groundwater. This study was conducted to identify NO 3 leaching hot spots in an approximately 36,000 ha area in Serik plain, which is used intensively for agriculture in the Antalya region of Southern Turkey. Geo-referenced water samples were taken from 161 wells and from the representative soils around the wells during the period from late May to early June of 2009. The data were analyzed by classical statistics and geostatistics. Both soil and groundwater NO 3-N concentrations demonstrated a considerably high variation, with a mean of 10.2 mg kg -1 and 2.1 mg L -1 NO 3-N for soil and groundwater, respectively. The NO 3-N concentrations ranged from 0.01 to 102.5 mg L -1 in well waters and from 1.89 to 106.4 mg kg -1 in soils. Nitrate leaching was spatially dependent in the study area. Six hot spots were identified in the plain, and in general, the hot spots coincided with high water table, high sand content, and irrigated wheat and cotton. The adverse effects of NO 3 can be mitigated by switching the surface and furrow irrigation methods to sprinkler irrigation, which results in a more efficient N and water use. Computer models such as NLEAP can be used to analyze alternative management practices together with soil, aquifer, and climate characteristics to determine a set of management alternatives to mitigate NO 3 effect in these hot spot areas.
  • Authors:
    • Theodossiou, N.
    • Latinopoulos, D.
    • Latinopoulos, P.
  • Source: Spanish Journal of Agricultural Research
  • Volume: 9
  • Issue: 4
  • Year: 2011
  • Summary: In arid and semiarid areas in the world, including the Mediterranean region, groundwater has been widely and intensively used for irrigation over the last few decades. Practical as well as economic reasons make its use much more preferable, as compared to surface water, especially to individual farmers. Yet, this rapid and largely uncontrolled expansion in groundwater exploitation, which stimulated the socioeconomic development of numerous rural communities, has produced many negative impacts on aquifer degradation and environmental deterioration. The most common remedy to such problems is the application of specific groundwater management policies that can simultaneously meet socioeconomic and environmental protection goals. In this sense, the paper introduces a methodology for an optimal management of irrigation water, by specifically exploring the socioeconomic and environmental impacts of spatially allocated water conservation measures at the watershed level. The analysis is conducted by developing a multi-criteria decision-making framework, consisting of three distinct models: a hydrogeological, an optimization, and a multi-criteria one, which appraises the results of the other two. The proposed methodology is presented through a case study at a rural Greek watershed, in which groundwater is the sole water source for an intensively practiced agriculture. A system of water use quotas is the resource conservation policy instrument that is examined under a decision-making approach. Results show that some specifically designed and spatially non-uniform quota allocation schemes can meet in an optimum way the relevant criteria.
  • Authors:
    • Cao, G. D.
    • Xia, J.
    • Zhu, H. W.
    • Tu, J. N.
    • Wang, S. M.
    • Yang, Y.
    • Li, B.
  • Source: Xinjiang Agricultural Sciences
  • Volume: 48
  • Issue: 3
  • Year: 2011
  • Summary: Objective: To study the regularities of the distribution of water, temperature and salinity in drip irrigation cotton field during freeze-thaw season. Method: Based on the data of field survey and laboratory test, this experiment analyzed water, temperature and salinity of each layer of the soil in arid drip irrigation cotton field within the freeze-thaw season. Result: The result showed that the surface soil begins to freeze in late November, and reaches maximum freezing depth in early February, the soil is completely melted in early April. The amplitude of soil temperature is respectively 19.95degreesC and 10.25degreesC at 5 cm and 170 cm depth. In the process of soil freezing, the soil water and salinity show ascendant trend within 0-60 cm depth from November 29th, 2009 to February 11th, 2010. In melting process (February 11th, 2010 April 21th, 2010), the vertical change of soil water and salinity is complicated. Water-salinity vertical distribution have little change within 60-200 cm. The features of temporal variability coefficient of soil water and salinity showed as follow: the variability coefficient of surface soil salinity is greater than bottom during the freeze-thaw period, the change of soil water is greater than soil salinity within 0-80 cm, the temporal variability coefficient of the soil water and salinity have low variability within 80-200 cm. Conclusion: The present study provided useful data for further research on soil water, temperature and salinity distribution during freeze-thaw period, and have certain reference value on soil improvement, agricultural irrigation and other related issues.
  • Authors:
    • Zhang, C. G.
    • Zheng, C. L.
    • Cao, C. Y.
    • Ma, J. Y.
    • Li, K. J.
    • Niu, Y. J.
  • Source: Zhongguo Shengtai Nongye Xuebao / Chinese Journal of Eco-Agriculture
  • Volume: 19
  • Issue: 2
  • Year: 2011
  • Summary: A split-plot design was adopted in an irrigation experiment before cotton sowing with irrigation water amount as the main treatment and water mineral salinity as sub-treatments. The experiment results showed that the rate of cotton emergence decreased with increased irrigation water salt content. The rate of cotton emergence was over 90% at 4 g.L -1 of irrigation water salinity. At 6 g.L -1 of irrigation water salinity, cotton emergence was 85%, but delayed. The optimum irrigation range was 22.5-34.0 mm. Inhibitory actions of water salt on cotton growth and development at early stage was more obvious than at late stage. There was no significant difference in cotton yield between the fresh water and salt water (3.38 g.L -1, cotton yield linearly dropped. Yield was, however, much higher at irrigation water salinity
  • Authors:
    • Zhang, F. C.
    • Li, P. L.
  • Source: Transactions of the Chinese Society of Agricultural Engineering
  • Volume: 27
  • Issue: 2
  • Year: 2011
  • Summary: To explore the regulation effects of water and nitrogen on cotton population growth and development under the furrow irrigation, a cotton field furrow irrigation experiment was conducted. In the experiments, three kinds of furrow irrigation patterns and three irrigation and nitrogen fertilization levels were designed. The change trends of the cotton population physiological indices were simulated using single peak Gaussian distribution model. The results showed that the model simulation accuracy was relatively high. Compared with the peak values of leaf area duration (LAD) under conventional furrow irrigations (CFI), it decreased by 39.3% under alternative furrow irrigations (AFI) and low nitrogen treatments. Under medium nitrogen treatments, there was no significant difference in all indices. Under high nitrogen treatments, the LAD peak value increased by 17.26%, while the net assimilation rate (NAR) decreased by 21.69%. Meanwhile, under fixed furrow irrigations (FFI) and different nitrogen treatments, the peak value of each indices decreased by 35.1%-44.0%. Compared with the CFI, the LAD peak value decreased by 23.94% under AFI low water treatments. LAD peak value increased by 13.63% and leaf area index (LAI) decreased by 14.2% under AFI medium water treatments. Under AFI high water treatments, there was no significant difference in all indices. Under the FFI and different irrigation treatments, each index decreased by 20.7%-47.22%. Compared with the changes of cotton biomass and yield, the changes of ground dry weight and yield were insignificant under AFI and all water and nitrogen treatments. The FFI ground dry weight decreased by 9.8%-19.3% and the cotton yield decreased by 7.6%-8.9%. The experimental results show that AFI has obvious advantage of regulation effects of water and nitrogen on the performance of cotton population and it can be used to control the population growth and development of cotton effectively. Thus, AFI is recommended in practical applications of cotton water and fertilizer managements.
  • Authors:
    • Liu, G. M.
    • Yang, J. S.
    • Li, X. M.
  • Source: Chinese Journal of Eco-Agriculture
  • Volume: 19
  • Issue: 2
  • Year: 2011
  • Summary: Specific field sites in cotton field were selected for different film-mulched irrigation techniques, including one-mulch/one-pipe/four-row irrigation mode (114 mode), one-mulch/two-pipe/four-row irrigation mode (124 mode) and flooding irrigation mode (FIM). Then apparent electrical conductivities ( ECa ) were measured at different heights and locations of the sites, including wide-row with mulch, narrow-row with mulch and inter mulch. Soil profile salinity interpretation models were established to evaluate the horizontal and vertical distribution characteristics of soil salt. The study showed that, in horizontal direction, soil salt content in narrow-row with mulch was more than that in wide-row with mulch in 114 mode in the 0-10 cm soil layer. Under 124 mode, soil salt content in narrow-row with mulch was less than that in wide-row with mulch. There was no obvious difference at different locations under FIM. In vertical direction, surface accumulation occurred in all three modes (114 mode, 124 mode and FIM). The maximum accumulation occurred in the 10-20 cm soil layer, and soil salt content tended to be stable in layers below 80 cm. Soil profile salinity interpretation models were not only precise in results, but also convenient in use. The models could therefore be used to accurately predict soil salt distribution of cotton field under different film-mulched irrigation techniques. This was significant for improving agricultural production.
  • Authors:
    • Liu, T.
    • Liang, Y. C.
    • Liu, H. L.
    • Chu, G. X.
  • Source: Xinjiang Agricultural Sciences
  • Volume: 47
  • Issue: 11
  • Year: 2011
  • Summary: Objective: This paper focuses on exploring the effect of two chlorinated pyridine nitrification inhibitors under drip irrigation on soil nitrogen transformation and the yield of cotton. Method: A field experiment was conducted on nitrification inhibitor in cotton drip irrigation in the Agricultural Center. Result: The two types of tested nitrification inhibitor showed significant inhibitory effect on nitrification six days after they are applied with water drops, the content of soil NH 4+-N increased 3.82%-211.25%, NO 3--N decreased 56.2%-77.12%, the rate of apparent nitrification decreased 2.66%-52.83% compared with control treatment, the nitrogen validity increased by 1.54-4.15 percent, the increase of seed cotton yield per hectare is 202.5-247.5 kg, which showed 3.43%-4.3% increase rate, the newly increased economic benefit is 1 059-1 306.5 RMB. Conclusion: Under drip irrigation, the nitrification inhibitors apply with water drops, which is easy to operate and can effectively improve the N nutrition level of the cotton plants, therefore, the yield increase is significant.
  • Authors:
    • Zhang, J. H.
    • Fan, J. H.
    • Liu, M.
    • Liu, J. H.
  • Source: Xinjiang Agricultural Sciences
  • Volume: 48
  • Issue: 3
  • Year: 2011
  • Summary: Objective: The growth and development, assimilates accumulation and distribution of organs and its correlation with LAI, LAD and leaf SPAD value of YX-193 and XH-28 during output formative period were studied. Both of them were the improved lines of two major cultivated sea island cotton ( Gossypium barbadense L.) varieties Xinhai 21-Priority system 193, and Xinhai 28 (formerly-code-named TH 45). Method: Indexes such as the growth and development, assimilates accumulation and distribution of Sea Island cotton YX-193 and XH-28 were observed by mulched drip irrigation, using SPAD-502 chlorophyll meter the SPAD values were measured, correlation analysis and regression analysis were used to analyze data. Result: The results showed that stem diameter, leaf area index, photosynthetic potential, leaf area ratio, specific leaf area, relative growth rate, net assimilation rate, maximum LAI, and assimilates accumulation of YX-193 are slightly higher than that of XH-28 except plant height, the most rapid rate of assimilates accumulation is in between 60-90 d after seedling emergence; rules of assimilates distribution rate of different organs are different, their common characteristics are genital organs > vegetative organs > root; assimilates accumulation showed linear correlation with the leaf SPAD value, and meet the quadratic regression model with LAI, LAD. Conclusion: Under the same conditions, the assimilates accumulation of YX-193 are higher than XH-28's during yield formative period; assimilates accumulation of vegetative organs showed a parabolic type, assimilates accumulation of reproductive organs and single plant are close to "S" type. The vegetative organs/total dry weight, leaf dry weight ratio and root to shoot ratio of the two varieties (lines) showed decreasing trend, genital organs/total dry weight showed an increasing trend.