• 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:
    • 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:
    • Ya, T.
    • Ma, X. W.
    • Ji, H. Y.
    • Li, P.
  • Source: Xinjiang Agricultural Sciences
  • Volume: 48
  • Issue: 7
  • Year: 2011
  • Summary: Objective: This study researched the effects of the optimal proportion of Nitrogen, Phosphorus and Potassium to cotton yield under the same irrigation condition in arid area. Method: The experiment adopted orthogonal saturated designs, design of different N, P fertilization level and their combination treatment, and the total experimental plots were 27. Result: According to the experiment results, the polynomial regression was established, that is, the cotton (ginned cotton) yield (Y) and nitrogen (N) and phosphorus (P) quantity of regression equation: Y=206.58+3.21 XN +9.83 XP -0.003 5 XN2+0.029 XP2-0.011 XNXP . The optimum formulation of fertilizer was: nitrogen fertilizer was 260.74 kg/hm 2; phosphorus fertilizer was 120.07 kg/hm 2. At this time cotton (ginned cotton) can get the highest yield: Y=1 214.98 kg/hm 2. Conclusion: Different levels of nitrogen and phosphorous fertilizers decide different cotton yields. Interaction between Nitrogen and Phosphorus is very significant.
  • 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.
  • Authors:
    • Chen, D. L.
    • Qin, X. B.
    • Gao, Q. Z.
    • Wan, Y. .F.
    • Li, Y. E.
    • Liu, Y. T.
  • Source: see: http://www.findanexpert.unimelb.edu.au/display/publication195094
  • Volume: 30
  • Issue: 7
  • Year: 2011
  • Summary: Excessive fertilizer application to cropland results in high N 2O emissions; thus cropland becomes an important source of greenhouse gas (GHG) emissions. To reduce N 2O emissions, an experiment was conducted to investigate the effects of fertilizer types on N 2O emissions in spring maize fields in northern China, which was monitored continuously by automatic measurement system. The responses of grain yield, in addition to N 2O emissions, were examined to explore feasible strategies to reduce N 2O emission. Four fertilizer application treatments including no fertilizer application treatment (control), urea treatment (U), urea and phosphorus treatment (NP), and nitric phosphate treatment (NOP) were designed in field experiment. Results showed that the total N 2O fluxes in each treatment were 0.21 kg N/ha in the control, 1.19 kg N/ha in U, 0.93 kg N/ha in NP, and 0.69 kg N/ha in NOP treatments, respectively. The N 2O emissions were mainly influenced by fertilizer application, irrigation, precipitation and soil temperature. Soil N 2O uptake was observed during the late growth stage of spring maize when soil mineral N was lower than 7 mg N/kg. The N 2O emission factor (EF) of each fertilizer treatment was lower than 1% which was suggested by the Intergovernmental Panel on Climate Change (IPCC). This means that the default EF should not be used for estimation of the regional N 2O fluxes in spring maize fields in northern China. Phosphorus fertilizer not only could reduce the N 2O emission but also increase maize grain yield, whereas nitric phosphate was significantly more effective than urea in reducing N 2O emissions. Evaluation based on crop yield and N 2O emissions showed that NOP treatment was a better management practice in the sense that, when compared to U and NP treatments, it reduced not only N 2O emission by 42% and 26%, respectively, but also the farmers' expenditure reduced by 15% and 30%, while crop yield was maintained.