• Authors:
    • Zuo, Y. M.
    • Zhang, F. S.
  • Source: Plant and Soil
  • Volume: 339
  • Issue: 1/2
  • Year: 2011
  • Summary: Plants and humans cannot easily acquire iron from their nutrient sources although it is abundant in nature. Thus, iron deficiency is one of the major limiting factors affecting crop yields, food quality and human nutrition. Therefore, approaches need to be developed to increase Fe uptake by roots, transfer to edible plant portions and absorption by humans from plant food sources. Integrated strategies for soil and crop management are attractive not only for improving growing conditions for crops but also for exploiting a plant's potential for Fe mobilization and utilization. Recent research progress in soil and crop management has provided the means to resolve complex plant Fe nutritional problems through manipulating the rhizosphere (e.g., rhizosphere fertilization and water regulation), and crop management (includes managing cropping systems and screening for Fe efficient species and varieties). Some simple and effective soil management practices, termed 'rhizosphere fertilization' (such as root feeding and bag fertilization) have been developed and widely used by local farmers in China to improve the Fe nutrition of fruit plants. Production practices for rice cultivation are shifting from paddy-rice to aerobic rice to make more efficient use of irrigation water. This shift has brought about increases in Fe deficiency in rice, a new challenge depressing iron availability in rice and reducing Fe supplies to humans. Current crop management strategies addressing Fe deficiency include Fe foliar application, trunk injection, plant breeding for enriched Fe crop species and varieties, and selection of cropping systems. Managing cropping systems, such as intercropping strategies may have numerous advantages in terms of increasing Fe availability to plants. Studies of intercropping systems on peanut/maize, wheat/chickpea and guava/sorghum or -maize increased Fe content of crops and their seed, which suggests that a reasonable intercropping system of iron-efficient species could prevent or mitigate Fe deficiency in Fe-inefficient plants. This review provides a comprehensive comparison of the strategies that have been developed to address Fe deficiency and discusses the most recent advance in soil and crop management to improve the Fe nutrition of crops. These proofs of concept studies will serve as the basis for future Fe research and for integrated and optimized management strategies to alleviate Fe deficiency in farmers' fields.
  • Authors:
    • You, L. Z.
    • Zhao, J. S.
    • Ringler, C.
    • Yang, Y. C. E.
    • Cai, X. M.
  • Source: Agricultural Water Management
  • Volume: 98
  • Issue: 8
  • Year: 2011
  • Summary: Agricultural water productivity (WP) has been recognized as an important indicator of agricultural water management. This study assesses the WP for irrigated (WPI) and rainfed (WPR) crops in the Yellow River Basin (YRB) in China. WPI and WPR are calculated for major crops (corn, wheat, rice, and soybean) using experimental, statistical and empirically estimated data. The spatial variability of WPI and WRR is analyzed with regard to water and energy factors. Results show that although irrigated corn and soybean yields are significantly higher than rainfed yields in different regions of the YRB, WPI is slightly lower than WPR for these two crops. This can be explained by the seasonal coincidence of precipitation and solar energy patterns in the YRB. However, as expected, irrigation stabilizes crop production per unit of water consumption over space. WPI and WPR vary spatially from upstream to downstream in the YRB as a result of varying climate and water supply conditions. The water factor has stronger effects on both crop yield and WP than the energy factor in the upper and middle basin, whereas energy matters more in the lower basin. Moreover, WP in terms of crop yield is compared to that in terms of agricultural GDP and the results are not consistent. This paper contributes to the WP studies by a basin context, a comparison between WPI and WPR, a comparison of WP in terms of crop yield and economic value, and insights on the water and energy factors on WP. Moreover, policy implications based on the WP analysis are provided.
  • 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:
    • Liang, Y.
    • Gao, S. R.
    • Bo, C. P.
    • Yang, Y.
    • Wang, S. W.
    • Pan, C. D.
    • Chen, G. A.
  • Source: Xinjiang Agricultural Sciences
  • Volume: 48
  • Issue: 5
  • Year: 2011
  • Summary: Objective: The Purpose of this article is to provide scientific basis for its water and fertilizer management in South of Xinjiang under the condition of oasis irrigation, through analysis of the spatial distribution characteristics of apricot tree absorbing roots in apricot-wheat intercropping systems. Method: With profile digging and layered sampling methods, the spatial distribution of absorbing roots of 15-year-old apricot trees in the intercropping systems is analyzed by using WinRHIZO Pro2009a analysis system. Result: In horizontal directions (0-300 cm), the length density of the absorbing roots in the rows is decreasing with increasing distance from the trees. The maximum root length density is in the 0-50 cm from the trees. The length density of the absorbing roots between the rows is slightly increasing first, and then decreasing with increasing distance from the trees. The maximum root length density is in the 50-100 cm from the trees. The total length of the absorbing roots in the rows is only less 1.11% than it is between the rows. In vertical directions (0-150 cm), the length density of the absorbing roots in the rows and between the rows is increasing first, and then decreasing with increase of soil depth. The maximum root length density in the rows is in the 20-30 cm soil layer, and between the rows is in the 30-40 cm soil layer. Conclusion: Under the condition of oasis irrigation, the spatial distributions of apricot tree absorbing roots are differences between intra-row and inter-row in the intercropping systems, but the differences of total length of the absorbing roots are small. The 0-60 cm soil layer in the 0-120 cm from the trees is important for water and fertilizer management in apricot-wheat intercropping systems. The position of fertilization in the rows and between the rows should be under the crown 2/3-4/5 site at the prosperous fruit stage of apricot trees. The fertilization depth between the rows (30-50 cm) should be deeper about 10-20 cm than in the rows (20-40 cm).
  • Authors:
    • Kumar, V.
    • Kumar, V.
    • Saharawat, Y. S.
    • Ladha, J. K.
    • Gathala, M. K.
    • Sharma, P. K.
  • Source: Soil Science Society of America Journal
  • Volume: 75
  • Issue: 5
  • Year: 2011
  • Summary: Rice-wheat (Oryza sativa L.-Triticum aestivum L.) rotation is the major production system in Asia, covering about 18 million ha. Conventional practice of growing rice (puddled transplanting) and wheat (conventional till, CT) deteriorate soil physical properties, and are input- and energy-intensive. Zero-tillage (ZT) along with drill-seeding have been promoted to overcome these problems. A 7-yr permanent plot study evaluated various tillage and crop establishment (CE) methods on soil physical properties with an aim to improve soil health and resource-use efficiency. Treatments included transplanting and direct-seeding of rice on flat and raised beds with or without tillage followed by wheat in CT and ZT soil. Bulk density (D(b)) of the 10- to 20-cm soil layer was highest under puddled treatments (1.74-1.77 Mg m(-3)) and lowest under ZT treatments (1.66-1.71 Mg m(-3)). Likewise, soil penetration resistance (SPR) was highest at the 20-cm depth in puddled treatments (3.46-3.72 MPa) and lowest in ZT treatments (2.51-2.82 MPa). Compared with conventional practice, on average, water-stable aggregates (WSAs) > 0.25 mm were 28% higher in ZT direct-seeding with positive time trend of 4.02% yr(-1). Infiltration was higher (0.29-0.40 cm h(-1)) in ZT treatments than puddled treatments (0.18 cm h(-1)). The least-limiting water range was about double in ZT direct-seeding than that of conventional practice. Gradual improvement in soil physical parameters in ZT system resulted in improvement in wheat yield and is expected to be superior in long-run on system (rice+wheat) basis. Further research is needed to understand mechanisms and requirements of two cereals with contrasting edaphic requirements in their new environment of ZT direct-seeding.
  • 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:
    • Lu, X.
    • Gong, J.
    • Hou, Z. A.
    • Cui, J.
    • Wang, H. J.
  • Source: Xinjiang Agricultural Sciences
  • Volume: 47
  • Issue: 9
  • Year: 2011
  • Summary: Method: The experiment selected the major local cotton varieties Biaoza A 1 and Xinluzao33 as test materials and designed different irrigation water quantity and nitrogen (N) fertilizer quantity. Objective: Dry matter accumulation and differences between varieties were analyzed. Result: Result indicated that the total dry matter accumulation showed the change pattern of "slow-fast-slow" in two cotton varieties during the whole growing stage. The total dry matter accumulation were increased with the increase of irrigation water quantity and nitrogen fertilizer quantity, the maximum increasing rates augmented, and fast rising periods were delayed. But over-irrigation would lead to decrease of the total dry matter accumulation. Conclusion: Biaoza A 1 was higher in dry matter accumulation than Xinluzao33 at different treatments; the difference was not significant between varieties between varieties in low irrigation, but significant in medium and high irrigation.
  • Authors:
    • Yan, J. H.
    • Shi, L. S.
    • Hou, Z. A.
    • Cui, J.
    • Wang, H. J.
    • Lu, X.
  • Source: Xinjiang Agricultural Sciences
  • Volume: 47
  • Issue: 10
  • Year: 2011
  • Summary: The field experiment was conducted to research the effects and differences of different quantity of water and nitrogen application on cotton yield in two cotton varieties. The results show that the yields of two cotton varieties were increased significantly with the increase of water and nitrogen, but reduced with excessive irrigation water, the maximum cotton yield were obtained with treatment N 2W 2 (N 2: 360 kg/hm 2; W2: 4500 m 3/hm 2). The cotton yield of Biaoza A 1 is significantly higher than that of Xinluzao33, there was no significant difference between in treatment N 1W 1 and N 1W 3, other treatments showed significant difference in cotton yield between the two varieties. These results suggested that the yield and water and fertilizer use efficiency can be enhanced evidently by adopting suitable measures of water and fertilize application based on different cotton varieties.
  • 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.