• Authors:
    • Munkhtsetseg, E.
    • Kimura, R.
    • Şaylan, L.
    • Kamichika, M.
  • Source: Theoretical and Applied Climatology
  • Volume: 105
  • Issue: 1/2
  • Year: 2011
  • Summary: In this study, variations in carbon dioxide (CO 2) fluxes resulting from gross primary production (GPP), net ecosystem exchange (NEE), and respiration ( Re) of soybean ( Glycine max L.) were investigated by the Eddy Covariance method during the growing period from June to November 2005 on an irrigated sand field at the Arid Land Research Center, Tottori University in Tottori, Japan. Although climatic conditions were humid and temperate, the soybeans required frequent irrigation because of the low water holding capacity of the sandy soil at the field site. Finally, it has been found that the accumulated NEE, GPP, and Re fluxes of soybean over 126 days amount to -93, 319, and 226 gC m -2, respectively. Furthermore, the average ratio of GPP to Re was 1.4 and the average ratio of NEE to GPP was about -0.29 for the growth period of soybean. Daily maximum NEE of -3.8 gC m -2 occurred when LAI was 1.1.
  • Authors:
    • Chai, Q.
    • Huang, G. B.
    • Yang, C. H.
    • Luo, Z. X.
  • Source: Field Crops Research
  • Volume: 124
  • Issue: 3
  • Year: 2011
  • Summary: A field experiment was carried out to investigate the effects of alternate irrigation (AI) on the yield, water use and water use efficiency (WUE) of wheat (Triticum aestivum L.)/maize (Zea mays L.) intercropping system in an oasis region of northwest China in 2006-2008. Three planting patterns, i.e., sole wheat, sole maize and wheat/maize intercropping. Three irrigation levels were applied for each treatment during 3 years. Results showed that land use efficiency of wheat and maize was significantly enhanced by intercropping system; land equivalent ratio (LER) of wheat/maize intercropping system in different treatments was all greater than 1.0. Moreover, significant difference in grain yield was observed between intercropping treatment and sole cropping treatment, in which the yield of intercropped wheat was 55.37-74.88% of sole wheat, and intercropped maize was 66.63-78.87% of sole maize. Wheat/maize intercropping treatments increased water use by 1.8-16.4% than half of the total water use of sole-cropping wheat and maize. Compared to sole cropping wheat treatments, wheat/maize intercropping with alternate irrigation significantly improved water use efficiency (WUE) by 30.5-57.7%, 55.5-71.4% and 12.0-19.8%, and increased by 32.7-37.8%, 9.5-15.8% and 4.0-20.8% than sole cropping maize treatments in 2006-2008, respectively. Our results suggest that AI should be a useful water-saving irrigation method on wheat/maize intercropping in arid oasis field where intercropping planting is decreased because of limited water resource.
  • Authors:
    • Huang, G. B.
    • Yang, C. H.
    • Chai, Q.
  • Source: ACTA AGRONOMICA SINICA
  • Volume: 37
  • Issue: 9
  • Year: 2011
  • Summary: In oasis irrigation region of northwestern China, the decreasing of multiple cropping areas may lead to significant reduction of land and light use efficiencies due to serious water shortage. Therefore, water-saving irrigation is a priority in the research on theory and technology for intercropping system. Alternate irrigation is a technique to save water and enhance water use efficiency (WUE) simultaneously in common cropping systems. However, its effect is not clear on intercropping system. In 2006-2008 cropping years, we carried out a field experiment in oasis region of Hexi Corridor, Gansu province, China under wheat/maize intercropping to disclose the effects of alternate irrigation on crop yields, water consumption, and WUE. The results showed that, compared to sole cropping treatments, there was a significant increase of land equivalent ratio (LER) in the alternately irrigated wheat/maize intercropping treatment with the LER values ranging from 1.22 to 1.52 under different irrigation levels of the intercropping treatments. However, the difference of LERs between conventionally irrigated and alternately irrigated intercropping systems was not significant at the same irrigation quota. Compared to the conventionally irrigated intercropping treatment, there was no significant change of wheat yield in the alternately irrigated intercropping treatment, but significant increase by 11.4-36.4% in maize yield. Therefore, the total yield of wheat and maize in the alternately irrigated intercropping treatment was increased by 12.9 averagely. The water consumption in the alternately irrigated intercropping treatment had no significant increase compared to that of the conventionally irrigated intercropping treatment, with 1.2-19.4% higher than the weighted average of monoculture of both crops. The WUE of alternately irrigated intercropping treatment was 0.9-22.5% higher than that of the conventionally irrigated intercropping treatment, and 12.0-71.4% and 10.6-37.8% higher than that of wheat and maize monoculture, respectively. These results suggest that alternate irrigation is feasible in intercropping systems in arid oasis regions with the purpose of saving water and increasing WUE.
  • Authors:
    • Yudong, S.
    • Tumaerbai, H.
    • Shalamu, A
    • Litan, S.
  • Source: ACTA PEDOLOGICA SINICA
  • Volume: 48
  • Issue: 4
  • Year: 2011
  • Summary: Soil salinization has become more and more severe in arid regions. Make an appropriate irrigation regimes to leaching soil salinity is a key scientific issue under drip irrigation in the silt loam soil in arid region. A 3-year field experiment was carried out to investigate the effects of different drip irrigation regimes on soil salinity distribution and cotton yield at Akesu agricultural ecosystem national scientific research station, Chinese Academy of Sciences. Throughout cotton growing season, the peak cure of soil salt under mulch moved downward with the increases of DIA (drip irrigation amount). The quantity of drip irrigation increased from 3 000 m 3 hm -2 to 4 800 m 3 hm -2, peak value of soil salt moved downward from 35 cm to 65 cm. The results showed that the peak cure of soil salt under mulch decreased in the order 1.6 DIA > 1.4 DIA > 1.2 DIA > DIA after irrigation. At the same time, the peak cure of soil salt under mulch also moved downward with the increases of drip irrigation discharge rates for all treatments except 3.2 L h -1 treatments because of the capability of infiltration of porosity of soil less than the drip irrigation discharge rate. The peak cure of soil salt under mulch decreased in the order 2.6 L h -1 >2.2 L h -1 > 1.8 L h -1 > 3.2 L h -1 after irrigation. The soil salinity moved gradually from deep soil to surface soil and moved slowly from under mulch to inter-mulch simultaneously with elapse time. With the increasing of quantity of drip irrigation or drip irrigation discharge rates, seed yield presenting increased except 1.6 DIA and 3.2 L h -1 treatment. Both water deficit and heavy irrigation will decrease the cotton yield, as well as the high and law drip irrigation discharge rate. Therefore, quantity of drip irrigation of 1.4 DIA and appropriate drip irrigation discharge rate of 2. 6 L h -1 was the best drip irrigation regimes for the higher cotton yield in the silt loam soil in arid region.
  • Authors:
    • Trethowan, R.
    • Moeller, C.
    • Carrillo-Garcia, A.
    • Verhulst, N.
    • Sayre, K. D.
    • Govaerts, B.
  • Source: Plant and Soil
  • Volume: 340
  • Issue: 1/2
  • Year: 2011
  • Summary: A field experiment was conducted under furrow irrigation on a Vertisol in arid northwestern Mexico, to evaluate sustainable production alternatives for irrigated wheat systems. Treatments included: tillage (conventionally tilled raised beds where new beds are formed after disc ploughing before planting [CTB] and permanent raised beds [PB]) and irrigation regimes (full and reduced). Physical and chemical soil quality was compared among treatments. PB improved soil structure and direct infiltration, increased topsoil K concentrations (0-5 cm; 1.6 cmol kg -1 in PB vs. 1.0-1.1 cmol kg -1 in CTB) and reduced Na concentrations (0-5 cm; 1.3-1.4 cmol kg -1 in PB vs. 1.9-2.2 cmol kg -1 in CTB) compared to CTB. Crop growth dynamics were studied throughout the season with an optical handheld NDVI sensor. Crop growth was initially slower in PB compared to CTB, but this was compensated by increased crop growth in the later stages of the crop cycle which influenced final yield, especially under reduced irrigation. These results were reflected in the final grain yield: in the third year after conversion to PB, no difference in grain yield was found between tillage systems under full irrigation. However, under reduced irrigation the improved soil quality with PB resulted in a 19% and 26% increment in bread and durum wheat grain yields, respectively. As projected climatic scenarios forecast higher evapotranspiration, less reliable rainfall and increased drought, our results indicate that PB could contribute to maintaining and increasing wheat yields in a sustainable way.
  • Authors:
    • Wang, H. L.
    • Niu, J. Y.
    • Lv, X. D.
    • Wang, R. Y.
  • Source: Acta Prataculturae Sinica
  • Volume: 20
  • Issue: 5
  • Year: 2011
  • Summary: The crop water requirement is one of the most important factors in farmland water circulation system, study the effects of climate warming on water requirement of major crops in irrigated oasis in Hexi corridor when 1-4degreesC temperature rise in the future scenarios. The results show that climate change will have great impact on water requirement of cotton and corn, followed by spring wheat, when the temperature rises 1-4degreesC during the growth period, cotton, water requirement of cotton will increase by 2.17%-12.66%, equivalent to 15.00-83.00 mm; corn will increase by 1.90%-11.49%, equivalent to 14.60-82.50 mm; wheat will be increase by 1.80%-10.03%, equivalent to 9.70-50.70 mm. There are certain regional differences which the impact of climate change on crop water requirements. When the temperature increases 1degreesC, the crop water requirement of Wuwei in arid regions slightly larger than Dunhuang in extreme arid region; When increases 2degreesC, the demand almost equivalent. Dunhuang is greater than the Wuwei if increased 3 and 4degreesC. According to the current planting planning in Hexi Oasis, the given temperature scenario will cause an additional water requirement of 0.11, 0.21, 0.37, 0.62 million m 3 for cotton, 0.16, 0.33, 0.56, 0.93 million m 3 for corn; and 0.14, 0.26, 0.45, 0.71 million m 3 for spring wheat. The total irrigation water increase 0.41, 0.80, 1.38, 2.25 billion m 3. Climate warming will make the situation of water shortage more severe.
  • Authors:
    • Liu, S. H.
    • Liu, S. P.
    • Hu, W.
    • Wan, S. Q.
    • Kang, Y. H.
    • Wang, R. S.
  • Source: Agricultural Water Management
  • Volume: 100
  • Issue: 1
  • Year: 2011
  • Summary: A 3-year experiment was conducted in an extremely dry and saline wasteland to investigate the effects of the drip irrigation on salt distributions and the growth of cotton under different irrigation regimes in Xinjiang, Northwest China. The experiment included five treatments in which the soil matric potential (SMP) at 20 cm depth was controlled at -5, -10, -15, -20, and -25 kPa after cotton was established. The results indicated that a favorable low salinity zone existed in the root zone throughout the growing season when the SMP threshold was controlled below -25 kPa. When the SMP value decreased, the electrical conductivity of the saturation paste extract (EC e) in the root zone after the growing season decreased as well. After the 3-year experiment, the seed-cotton yield had reached 84% of the average yield level for non-saline soil in the study region and the emergence rate was 78.1% when the SMP target value was controlled below -5 kPa. The average pH of the soil decreased slightly after 3 years of cultivation. The highest irrigation water use efficiency (IWUE) values were recorded when the SMP was around -20 kPa. After years of reclamation and utilization, the saline soil gradually changed to a moderately saline soil. The SMP of -5 kPa at a depth of 20 cm immediately under a drip emitter can be used as an indicator for cotton drip irrigation scheduling in saline areas in Xinjiang, Northwest China.
  • Authors:
    • Ma, X. W.
    • Liu, H.
    • Xu, Y. M.
    • Chen, B. Y.
    • Niu, X. X.
    • Wang, B.
    • Yang, T.
    • Zhu, J. R.
  • Source: Xinjiang Agricultural Sciences
  • Volume: 48
  • Issue: 4
  • Year: 2011
  • Summary: Objective: To reveal how water affects fertilizer is important to make decision to regulate and control water and fertilizer use. Method: The paper described temporal-spatial character of soil N extracted by alkaline affected by different irrigation water usage in Awati County, Xinjiang. Result: Irrigation resulted in change of soil N content in depth from 0 cm to 100 cm obviously, especially from 0 cm to 40 cm; generally the more water irrigated, the more nitrogen dissolved and moved down. Conclusion: One reason that water promoted fertilizer use efficiency was to enlarge distribution area of nitrogen in soil profile, then more cotton roots could adsorb nutrients.
  • Authors:
    • Zhang, J.
    • Zhang, X.
    • Sun, J.
    • Kang, S.
    • Du, T.
  • Source: Agricultural Water Management
  • Volume: 97
  • Issue: 1
  • Year: 2010
  • Summary: Water shortage is the major bottleneck that limits sustainable development of agriculture in north China. Crop physiological water-saving irrigation methods such as temporal (regulated deficit irrigation) and spatial (partial root zone irrigation) deficit irrigation have been tested with much improved crop water use efficiency (WUE) without significant yield reduction. Field experiments were conducted to investigate the effect of (1) spatial deficit irrigation on spring maize in arid Inland River Basin of northwest China during 1997-2000; (2) temporal deficit irrigation on winter wheat in semi-arid Haihe River Basin during 2003-2007 and (3) temporal deficit irrigation on winter wheat and summer maize in Yellow River Basin during 2006-2007. Results showed that alternate furrow irrigation (AFI) maintained similar photosynthetic rate ( Pn) but reduced transpiration rate ( Tr), and thus increased leaf WUE of maize. It also showed that the improved WUE might only be gained for AFI under less water amount per irrigation. The feasible irrigation cycle is 7d in the extremely arid condition in Inner River Basin of northwest China and less water amount with more irrigation frequency is better for both grain yield and WUE in semi-arid Haihe River Basin of north China. Field experiment in Yellow River Basin of north China also suggests that mild water deficit at early seedling stage is beneficial for grain yield and WUE of summer maize, and the deficit timing and severity should be modulated according to the drought tolerance of different crop varieties. The economical evapotranspiration for winter wheat in Haihe River Basin, summer maize in Yellow River Basin of north China and spring maize in Inland River Basin of northwest China are 420.0 mm, 432.5 mm and 450.0 mm respectively. Our study in the three regions in recent decade also showed that AFI should be a useful water-saving irrigation method for wide-spaced cereals in arid region, but mild water deficit in earlier stage might be a practical irrigation strategy for close-planting cereals. Application of such temporal and spatial deficit irrigation in field-grown crops has greater potential in saving water, maintaining economic yield and improving WUE.
  • Authors:
    • Fine, P.
    • Clapp, C. E.
    • Zhang, Y.
    • Chen, D.
    • Venterea, R. T.
    • Bloom, P.
    • Tamir, G.
    • Bar-Tal, A.
    • Heller, H.
  • Source: Journal of Environmental Quality
  • Volume: 39
  • Issue: 2
  • Year: 2010
  • Summary: The use of organic residues as soil additives is increasing, but, depending on their composition and application methods, these organic amendments can stimulate the emissions of CO2 and N2O. The objective of this Study was to quantify the effects of management practices in irrigated sweet corn (Zea mays L.) on CO2 and N2O emissions and to relate emissions to environmental factors. In a 3-yr study, corn residues (CR) and pasteurized chicken manure (PCM) Were used as soil amendments compared with no residue (NR) under three management practices: shallow tillage (ST) and no tillage (NT) under consecutive corn crops and ST Without crop. Tillage significantly increased (P < 0.05) CO2 and N2O fluxes in residue-amended plots and in NR plots. Carbon dioxide and N2O fluxes were correlated with soil NH4 concentrations and with days since tillage and days since seeding, Fluxes of CO2 were correlated with soil water content, whereas N2O flux had higher correlation with air temperature. Annual CO2 emissions were higher with PCM than with CR and NR (9.7, 2.9, and 2.3 Mg C ha(-1), respectively). Fluxes of N2O were 34.4, 0.94, and 0.77 kg N ha(-1) yr(-1) with PCM, CR, and NR, respectively. Annual amounts of CO2-C and N2O-N emissions from the PCM treatments were 64 and 3% of the applied C and N, respectively. Regardless of cultivation practices, elevated N2O emissions were recorded in the PCM treatment. These emissions could negate some of the beneficial effects of PCM on soil properties.