模拟自然降雨条件下水稻的受旱试验研究

用模拟典型年降雨的方法，系统地分析了淠史杭灌区各降雨年型的水稻大田生长期缺水量、缺水率、缺水的主要生育阶段，水稻缺水受旱减产量、减产率，分别找出了水稻受旱减产率与生育期降雨量、大田生长期缺水量之间的相关关系     

模拟自然降雨条件下水稻的受旱试验研究

用模拟典型年降雨的方法，系统地分析了淠史杭灌区各降雨年型的大稻田生长期缺水量，缺水率，缺水的主要生育阶段，水稻缺水受旱减产量，减产率，分别找出了水稻受旱减产率与生育期降雨量、大田生长缺水量之间的相关关系。     

不同生育期干旱对棉花生长发育及产量的影响

在防雨棚隔绝降雨的条件下,通过在棉花的各生育阶段设置不同的干旱处理,分析了不同生育期干旱对棉花生长发育及产量的影响,并对桶栽棉花施加不同程度的水分胁迫,在花铃期测定了棉花的某些生理活动,以揭示光合速率,蒸腾速率,叶片水分利用效率在不同土壤水分条件下的变化规律。     

不同生育期干旱对棉花生长发育及产量的影响

在防雨棚隔绝降雨的条件下,通过在棉花的各生育阶段设置不同的干旱处理,分析了不同生育期干旱对棉花生长发育及产量的影响,并对桶栽棉花施加不同程度的水分胁迫,在花铃期测定了棉花的某些生理活动（如光合、蒸腾等）,以揭示光合速率、蒸腾速率、叶片水分利用效率在不同土壤水分条件下的变化规律     

水稻灌溉效益分摊系数试验研究

通过试验方法，选择不同的降雨年型，系统地分析了淠史杭灌区不同降雨年型的灌溉增产率，灌溉效益扮摊系数；找出了水稻灌溉效益分摊系数与水稻生育期降雨量，灌水量之间的经验公式，对本地区及气候条件相似地区具有一定的参考价值。     

辽宁西部地区不同生育期玉米穿透雨特征及其影响因素研究

穿透雨是农田土壤水分的重要来源，对于农业用水管理十分重要。然而，以往不同地区的研究结果差异较大，也缺乏对玉米各生育阶段穿透雨过程的深入研究。为量化辽西地区穿透雨特征，了解不同生育期玉米透雨率过程的差异性，通过开展天然降雨试验，系统测定降雨特征、玉米形态特征及玉米全生育期穿透雨，分析辽宁西部地区不同生育期玉米穿透雨及其影响因素。结果表明：穿透雨量随降雨量的增加而增加，降雨量相同的条件下，穿透雨量在不同生育阶段呈现拔节期>成熟期>抽雄期的规律。穿透雨率随玉米叶面积指数的增加而减小。拔节期穿透雨率随降雨强度的增加而增大，但在抽穗期和成熟期这种趋势并不显著。研究区的玉米穿透雨率均值为51.44%。拔节期、抽雄期和成熟期穿透雨率均值分别为64.30%、38.93%和44.80%，同一影响因素在玉米不同生育期对穿透雨的影响效果存在差异。     

地下滴灌对棉花生理性状及产量影响的研究

根据新疆生产建设兵团农五师90团在棉花上应用地下滴灌的实践，以膜下滴灌棉花为对照，研究分析了地下滴灌对新疆棉花生理性状及产量的影响，认为地下滴灌条件下的棉花生育期有所提前、株高较低、铃数较多、叶面积系数较大、根冠比较大、根系发达并有两个根系层，生物学产量和经济产量均比较高。     

降雨特征分析及其与旱涝关系的探讨

以河北省雄县试区为代表。进行了雨量资料的合理性检验和年雨量周期性变化趋势的分析，计算了丰、平、枯３种降雨状态的转移概率及最大１日和最大３日设计雨量，并对降雨的时空分布特性及其与旱涝的关系进行了初步探讨。     

微咸水造墒对棉花生长发育及产量的影响研究

采用小区对比试验方法,研究了河北低平原区旱地等雨播种（HD）、播前淡水造墒（S1）以及矿化度为2.2g/L（S2.2）和5g/L（S5）微咸水造墒等不同处理对棉花生长发育和产量的影响。结果表明,棉花生育期内HD处理0～100cm土壤含水率明显低于3种造墒处理;S5处理0～40cm土壤盐分含量最高,但降雨淋洗效果较为显著...     

灌区尺度作物水分利用效率指标研究

在对灌区来水、作物产量和作物需水量尺度分析的基础上,研究了灌区尺度作物水分利用效率指标,结果表明,冬小麦、夏玉米、棉花不同的生育期对采用哪种水分利用效率指标有直接影响;灌溉、降雨、地下水补给等资料较全时,3种作物都采用WUEET;无降雨资料时,冬小麦可选用WUEi近似代替WUEET;正常年份,夏玉米的WUEP0就是WUEET,干旱年份且需夏灌时,夏玉米WUEET由有效降雨量与灌溉量共同产生;棉花不能用WUEi或WUEP0中的任何一种指标反映其真实的水分利用效率,而只能用WUEET确定。     

Suitability of cotton cultivation in shrink–swell soils in central India

Rainfed cotton farming is a risky enterprise. It has always been a challenge to sustain cotton productivity under rainfed conditions not only in India but also in similar agro-environments elsewhere. The present study is an attempt to find out the most sustainable soil under varying rainfall through crop yield correlation with agro-environment factors, like soil physiographic conditions, growing period rainfall, crop ET and phasic rainfall, by conducting (farmers’) field experiment in a representative catena with four different soil types in central India. Cotton (hybrid-H4) was grown for 5 years; 3 years under normal rainfall, 1 year under excessive rainfall and 1 year under drought conditions. The investigation revealed that in the excess rainfall to drought years, yield fluctuation varied from 2% to 38% over the normal year in shallow soils occurring on a pediment plain to the very deep soils in a valley plain. However, the yield fluctuation in deep Vertisols occurring on lower Piedmont and narrow valley, representing Vertic Haplustepts (P3) and Typic Haplusterts (P4), was 25–38% and 6–25%, respectively. The low yield fluctuation and high yield correlation with agro-environmental factors, observed for P3 soils, suggests the suitability of Vertic Haplustepts (P3) for cotton production under varying rainfall conditions. Cultivating P3 soils for cotton could stabilize the income of cotton farmers and research relating to cotton genotype improvement under rainfed conditions should be carried out to minimize soil effects. The international land evaluation criteria suggested by FAO show that Vertisols (P3 and P4) qualify as a suitable category for cotton production under rainfed conditions. However, the present study indicates that this categorization may need revision in view of the adverse climatic conditions of central India. In order to improve the effectiveness of the FAO’s land evaluation criteria for sub-tropical Vertisols, the study suggests that more emphasis be given to rainfall in the critical growth phases related to crop yield and to soil hydraulic conductivity related to the Ca²⁺/Mg²⁺ ratio in computing land indices, rather than total quantum rainfall during the growing period. Also, too many soil properties are presently considered in the FAO method. A quantum of 250–325 mm rainfall at the square initiation to peak flowering stages was found to influence yield. Under climatic aberration, the high fluctuation of cotton productivity in deep Vertisol (P4) may be minimized by adoption of any soil management technology (e.g. ridges or broad-bed furrow system) that helps in improving internal drainage. It is, therefore, urgent that the Indian Government should enact special legislation or introduce incentives for the Vertisol farmers who mostly use old cultivation practices to adopt such technology on a large scale. A quadratic regression model developed in this study to compute the yield under varying rainfall may help in estimating the economic losses to the farmers and quantifying crop insurance compensation.     

Irrigation scheduling of cotton in a climate with uncertain rainfall

Summary An investigation was made of the irrigation requirements of cotton grown in a sub-humid environment with significant but highly variable rainfall. In the first year of the study, no additional yield benefits accrued to subsequent irrigations following a pre-emergent irrigation due to above average rainfall (550 mm) throughout the growing season. In the second year a similar rainfall amount (502 mm) fell but significant yield increases to irrigation resulted due to the uneven distribution of the rainfall. The main effect was associated with later rains which influenced the number of bolls set. The maximum amount of water extracted by cotton from a deep grey cracking clay was 178 mm. It was found that 70% of this amount could be depleted before irrigation without loss of yield. Crop evapotranspiration varied from 607 mm with no irrigation after emergence to 775 mm following three irrigations. Irrigation was associated with significant losses from rainfall runoff. Too frequent irrigation creates a risk that soil will be too wet to permit utilisation of natural rainfall. Therefore, the use of soil water information to maximise the interval between irrigation is proposed as a necessary basis for efficient irrigation management.     

几种作物不同生育阶段对持续受渍的敏感性研究

以减产幅度作为作物各生育阶段对持续受渍的敏感性评价指标 ,进行了棉花、大豆、油菜 3种作物不同生育阶段持续受渍试验。初步研究表明 ,持续受渍对作物产量影响最大的时段棉花在蕾玲期 (减产 2 9.98%～ 31 .2 9% ) ,大豆在初花期和花荚期 (减产 31 .1 9%～ 34 .4 9% ) ,油菜在花期 (减产 39.5 9% )。需要指出的是 ,棉花的吐絮初期、大豆的结荚期、油菜的苔期和花果期等排水管理也不容忽视 ,这些阶段较长时间持续受渍也会引起较为严重的减产 ,减产幅度达 1 8.38%～ 2 8.6 2 %。     

Agronomic and economic response to furrow diking tillage in irrigated and non-irrigated cotton (Gossypium hirsutum L.)

The Southeast U.S. receives an average of 1300 mm annual rainfall, however poor seasonal distribution of rainfall often limits production. Irrigation is used during the growing season to supplement rainfall to sustain profitable crop production. Increased water capture would improve water use efficiency and reduce irrigation requirements. Furrow diking has been proposed as a cost effective management practice that is designed to create a series of storage basins in the furrow between crop rows to catch and retain rainfall and irrigation water. Furrow diking has received much attention in arid and semi-arid regions with mixed results, yet has not been adapted for cotton production in the Southeast U.S. Our objectives were to evaluate the agronomic response and economic feasibility of producing cotton with and without furrow diking in conventional tillage over a range of irrigation rates including no irrigation. Studies were conducted at two research sites each year from 2005 to 2007. Irrigation scheduling was based on Irrigator Pro for Cotton software. The use of furrow diking in these studies periodically reduced water consumption and improved yield and net returns. In 2006 and 2007, when irrigation scheduling was based on soil water status, an average of 76 mm ha⁻¹ of irrigation water was saved by furrow diking, producing similar cotton yield and net returns. Furrow diking improved cotton yield an average of 171 kg ha⁻¹ and net return by $245 ha⁻¹ over multiple irrigation rates, in 1 of 3 years. We conclude that furrow diking has the capability to reduce irrigation requirements and the costs associated with irrigation when rainfall is periodic and drought is not severe.     

咸水灌溉对棉花耗水特性和水分利用效率的影响

采用田间对比试验,连续3 a研究了1、3、5、7 g/L 4个矿化度咸水(记作S1、S2、S3、S4)灌溉对棉田土壤水盐、土壤蒸发、棉花阶段耗水量、籽棉产量和水分利用效率的影响。结果表明,棉花生育期内根系层土壤含水率和电导率有随灌溉水矿化度的增加而增大的趋势,土壤电导率增加尤为明显;年际间,各处理土壤含水率和电导率差异非常大,经过连续3 a灌溉,根系层土壤电导率均未逐年增加。S3和S4处理的平均土壤蒸发强度大于S1处理,S2与S1处理间的差异很小;7 g/L以下咸水灌溉对棉花耗水过程产生了一定影响,但对总耗水量影响并不明显。3 a的平均籽棉产量和水分利用效率由大到小顺序均为:S2、S1、S3、S4,S2比S1处理增产2.43%,水分利用效率增加1.15%,S3和S4比S1处理减产1.67%和8.88%,水分利用效率降低0.25%和7.31%,其中,S2和S3与S1处理间差异不显著,S4处理产量和水分利用效率降低显著。     

咸淡轮灌棉花耐盐指标及耐盐特征值研究

采用筒栽精确控制试验,模拟初始土壤含盐量较低,且降雨不足以对土壤进行淋洗的生产情况,通过分析不同生育期、不同程度盐分胁迫与棉花生长及生理指标的响应关系,得出不同生育期咸淡轮灌条件下棉花的耐盐指标及相应土壤含盐量的耐盐特征值。结果显示,株高相对增长量可以作为蕾期轮灌（AL）和花铃期轮灌（AH）的阶段耐盐指标,叶面积相对增长量可以作为AL、AH和吐絮期轮灌（AT）的阶段耐盐指标;相对铃数可以作为AL和AH的全生育期耐盐指标,相对叶面积可以作为AT的全生育期耐盐指标。在允许减产10%的情况下,AL与AH处理阶段土壤含盐量最好分别控制在0.277%和0.584%以下,全生育期土壤含盐量分别控制在0.486%和0.754%以下。AH较之AL和AT可以利用更多的微咸水。     

灌水模式及下限对滴灌棉花产量和品质的影响

为探索滴灌条件下棉花优质高效灌溉指标,在新疆石河子研究了地下滴灌(SSDI)和膜下滴灌(SDI)条件下不同灌水控制下限对棉花耗水量、品质以及水分利用率的影响.结果表明,相同滴灌模式,棉花蕾期耗水量随灌水控制下限的提高而增加,花铃期水分胁迫处理的棉花阶段耗水量普遍低于对照处理;蕾期适度水分胁迫(灌水控制下限为60% FC)花铃期充分供水(灌水控制下限为75% FC)处理(SDI-7和SSDI-7)有利于籽棉产量的提高,与对照处理相比,籽棉产量提高了14.48%(SDI-7)和11.60%(SSDI-7);水分处理对棉花衣分、棉纤维整齐度的影响不明显,蕾期和花铃期水分胁迫对棉纤维上半部平均长度的影响随水分胁迫程度的加重而加剧,蕾期适度水分胁迫(灌水控制下限为60% FC)有利于棉纤维断裂比强度的提高.相同水分处理,地下滴灌棉花产量和灌溉水利用率均高于膜下滴灌棉花.与对照处理相比,蕾期和花铃期灌水控制下限分别为60% FC和75% FC,灌水定额为30 mm处理在节约灌溉水的同时提高了籽棉产量并改善了棉纤维品质,可作为石河子垦区滴灌棉花适宜的灌水指标.     

咸水灌溉对土壤水热盐变化及棉花产量和品质的影响

为了充分利用咸水资源,采用田间对比试验,研究了1、3、5、7 g/L等4个矿化度咸水(分别用S1、S2、S3、S4表示)灌溉对棉田土壤水热盐变化特征及棉花长势、产量和纤维品质的影响。结果表明,棉花生育期内各处理0~40 cm土层土壤含水率及地下5 cm处土壤温度总体上都随着灌溉水矿化度的增加而增大,但差异不大;处理间土壤电导率差异明显,灌溉水矿化度愈高,土壤电导率愈大,棉花生育期结束后,降雨对各处理盐分的淋洗率介于29.40%~40.40%。土壤水分和盐分剖面分布受制于土壤质地、降雨和棉花蒸发蒸腾耗水;干旱时期,土壤干燥,盐分表聚,湿润时期与之相反。棉花成苗率、株高、单株最大叶面积和霜前花率均随着灌溉水矿化度的增加而降低,籽棉产量从大到小依次为S2、S1、S3和S4,其中,S4与S1处理间的差异达显著水平。咸水灌溉通过改变马克隆值对纤维品质产生了负面影响,尤其是S4处理。研究结果可为丰富棉花咸水灌溉技术体系提供理论支撑。