Optimum Soil Water Content for Chickpea Emergence in Heavy‐Textured Soils of North‐West Bangladesh

Sowing of chickpea in the heavy‐textured soils of north‐west Bangladesh with minimum tillage technology aims to increase the timely planting of large areas during a relatively short sowing window before soil water deficit limits germination and emergence. However, the seedbed conditions into which chickpea is sown need to be better quantified, so that limiting factors which affect germination and emergence can be identified. Two of the soil physical characteristics of importance are soil water and aeration. Growth cabinet studies have identified the fastest germination and emergence of chickpea on representative soils for this area at gravimetric water contents of 17–18 %, whilst soil water contents above and below this delayed germination and emergence. Emergence was recorded at soil water potentials between field capacity (?10 kPa) and wilting point (?1500 kPa). Emergence was possible at lower soil water potentials in the finer textured soil, whilst in coarser textured soil, emergence was still possible at higher soil water potentials.     

Effect of Salinity Stress on Growth and Nutrient Composition of Three Soybean (Glycine max L. Merrill) Cultivars

Soil salinity is a major limitation to legume production in many areas of the world. The salinity sensitivity of soybean was studied to determine the effect of salinity on seed germination, shoot and root dry weights, and leaf mineral contents. Three soybean cultivars, Lee, Coquitt, and Clark 63, were planted in soils of different salinity levels. The electrical conductivity (EC) of the soils used in this experiment was 0.5 dS m^?1. The soil salinity treatments were 0.5, 2.5 4.5, 6.5 and 8.5 dS m^?1. Saline drainage water from a drainage canal with an EC of 15 dS m^?1 was used to treat the soil samples in order to obtain the desired salinity levels. Germination percentages were recorded 10 days after planting. Shoot and root dry weights of 45‐day‐old plants were measured. Nutrient concentrations for Na⁺, K⁺, Ca²⁺, Mg²⁺ and Cl^? were determined. Germination percentages were significantly reduced with increasing salinity levels. The cultivar Lee was less affected by salinity stress than Coquitt and Clark 63. At 8.5 dS m^?1 a significant reduction in plant height was found in all three cultivars. However, Lee plants were taller than plants of the other two cultivars. Salinity stress induced a significant increase in leaf sodium (Na⁺) and chloride (Cl^?) in all cultivars. However, the cultivar Lee maintained lower Na⁺ and Cl⁺ concentrations, a higher potassium (K⁺) concentration and a higher K⁺/Na⁺ ratio at higher salinity levels than Coquitt and Clark 63. Saline stress reduced the accumulation of K⁺, calcium (Ca²⁺) and magnesium (Mg²⁺) in the leaves of the cultivars studied. This study suggests that Lee is the most tolerant cultivar, and that there is a relationship between the salt tolerance of the cultivar and macronutrient accumulation in the leaves.     

不同肥料对甜瓜植株生长、果实品质及蔗糖代谢的影响

为评价不同比例肥料对甜瓜果实不同糖分含量及相关酶活性的影响,以甜瓜品种‘脆禧’为材料,在叶面喷施肥料条件下进行设施栽培试验。采用4种不同肥料（N-P₂O₅-K₂O比例含量不同,T1为15-15-15,T2为20-20-20,T3为15-10-17,T4为15-6-35）,以普通尿素为对照(T0),探讨不同肥料处理对甜瓜植株生长、SPAD、产量、品质及蔗糖代谢的影响,以筛选出最佳的肥料。与普通尿素(T0)相比,4种肥料处理下,植株生长量差异不明显,SPAD有所增加,其中T3和T4处理差异明显,在这2种肥料条件下,可溶性固形物、可溶性糖、氨基酸、葡萄糖、果糖和蔗糖及糖代谢相关的蔗糖磷酸合成酶(SPS)和蔗糖合成酶(SS)活性明显升高,硝酸盐含量显著降低。综合各指标比较,T3和T4处理下的甜瓜果实产量与对照T0相当,且综合品质有所提高。     

不同盐度胁迫对芦荟生长和离子吸收分配的影响

为探索芦荟对微咸水灌溉栽培的适应性,研究了不同盐浓度对其生长和离子吸收分配的影响。结果表明,长期（120天）以含盐溶液灌溉栽培,盐浓度达200 mmol/L NaCl显著抑制芦荟生长,100 mmol/L NaCl对芦荟生长的抑制作用显著减轻,50 mmol/L NaCl不抑制芦荟生长。同时,以50 mmol/L NaCl溶液灌溉对芦荟盐分离子吸收分配影响轻微,但盐浓度达100 mmol/L NaCl对芦荟影响显著：根、茎、叶中K+含量显著下降,Na+ 、Cl-含量显著增大,K+/Na+大幅减小。X-射线能谱分析结果进一步表明,叶片贮水组织是芦荟积累盐分离子的重要部位,但100 mmol/L NaCl胁迫下芦荟根尖和叶片细胞中的离子平衡受到显著干扰。结果说明,芦荟适于用微咸水灌溉栽培,叶片贮水组织在缓解其盐胁迫中可起重要作用。     

再生水灌溉对作物生长及土壤养分影响研究进展

水资源短缺是农业灌溉面临的重大挑战,在农业用水严重紧缺的现状下,以再生水为农业灌溉水源,将有效缓解农业用水紧缺形势。由于再生水中养分浓度与有机物含量较高,若使用不当会对作物生长及土壤环境带来不利影响,并可能导致农业面源污染问题。从再生水灌溉对作物生长、土壤养分及土壤酶活性的影响3个方面概括了再生水灌溉国内外研究现状与存在问题,并对下一步的研究重点提出了建议：加强再生水灌溉对作物不同关键生育期土壤供氮特征的影响研究,重视土壤酶活性对长期再生水灌溉响应特征研究,强化再生水灌溉土壤氮营养诊断与阈值范围研究以及拓宽再生水灌溉对农作物果实超微结构的影响研究等。     

Seed Size and Water Potential Effects on Water Uptake, Germination and Growth of Lentil

Seed size is an important parameter for plant growth and yield. The effects of seed size and water potential on seed water uptake, germination and early growth of lentil ( Lens culinaris Medik. cvs. Jor-1 and Jor-2) were investigated. Rate of water uptake by seed size (small, medium and large) from solutions containing different water potentials (0, –0.5 and –1.0 MPa, as polyethylene gly-col-8000) was higher in large than in medium or small seeds of both cultivars, regardless of water potential. Rate of water taken into seeds was higher in Jor-2 than in Jor-1. Decreasing water potential (more stress) had adverse effects on rate of water uptake by seeds in both cultivars. In another experiment, with lentils grown in a greenhouse at different soil metric potentials (–0.03, –0.15 and –0.30 MPa), seed size or cultivar had no effects on germination percentage (GP), but GP was reduced as soil water potential decreased (more stress), in greenhouse soil, shoot dry matter (SDM), root dry matter (RDM), plant height, total root length (TRL) and number of primary branches per plant of 35-day-old plants from large seeds were larger than those of plants from medium and small seeds of both cultivars. Increasing soil water deficit progressively decreased each of these traits. Plants from large seeds had higher SDM, RDM and TRL than those from small seeds at intermediate soil water potential (–0.15 MPa) in comparison with the control (–0.03 MPa) or severe (–0.30 MPa) soil water potentials. Larger seeds produced larger plants than smaller seeds, and this appeared to be more pronounced under intermediate than well-watered or more severe water-stressed conditions. Faster early growth of plants from larger seeds may be advantageous in establishing plants under semiarid conditions.     

不同覆盖物对夏黑葡萄关键生育期土壤温度和土壤水势的影响

覆盖是调节土壤温度、减少土壤水分无效蒸发的一种行之有效的手段,为探明不同覆盖物对夏黑葡萄开花期—成熟期内土壤温度和土壤水势的影响效果,本试验在夏黑葡萄园设置地布、黑棉毡、黑地膜覆盖和不覆盖(对照)4个处理,对各处理土壤温度和土壤水势的变化进行了比较研究.结果表明:与CK处理相比,T1、T2和T3处理均可以提高开花期土壤...     

有机无机-土壤改良剂对咸灌土壤理化环境调控及玉米产量影响

为了减轻和抑制咸水灌溉土壤盐分积累及对土壤理化环境的影响,研究3种有机无机-土壤改良剂配方进行咸灌土壤改良试验。试验结果表明：有机无机-土壤改良剂能够明显地改善土壤物理环境,施用土壤改良剂的土壤容重比咸灌土壤和对照降低8.55%~12.82%;土壤毛管孔隙增加5.68%~10.63%;土壤渗水速率提高22.41%~49.14%。土壤改良剂能够有效地调控咸灌土壤的化学离子组成,施用改良剂处理的土壤Na++K+、Cl-分别比对照减少了43.38%~64.88%和99.65%~122.69%;Ca2+增加了15.91%~67.21%。改良剂B和C降盐效果较改良剂A更为明显,比咸灌土壤分别下降了20.45%~57.35%,同时土壤pH降低了0.36%~1.84%。有机无机-土壤改良剂还为土壤、作物提供了充足的天然腐殖酸、活性有机物质以及Ca、S等营养物质,增加了玉米抗逆能力,提高产量,比对照增产20.63%~34.28%。     

不同灌水量对枸杞土壤水分动态及蒸散耗水规律的影响

为了充分利用有限的水资源,调节土壤水分状况,根据枸杞生育期内土壤水分的变化特点,利用时域反射仪,在非称重式蒸渗仪（测坑）中研究不同灌水量下枸杞土壤水分动态变化和耗水规律。结果表明：灌水是影响枸杞园内土壤水分变化重要因素,土壤水分的消耗主要依靠灌水来补充;枸杞耗水量显著受土壤水分的影响,土壤越湿润,耗水量也越大;受温度和枸杞生长的影响,不同水分条件下枸杞月耗水高峰在5-9月,最高月耗水量在7月;最高旬耗水量分别在5月下旬、6月中旬和7月下旬;阶段耗水量的趋势均表现为：盛果期＞盛花期＞营养生长期＞秋果生长期＞秋果采收期。     

梯度滨海盐土对费菜生长指标及Na+、K+分布的影响

为探明滨海盐土对费菜生长发育的影响,掌握其盐碱土壤栽植下的耐盐特性,通过3、5、7、9、 11 g/kg等5个梯度的滨海盐土处理,对费菜生长指标及Na⁺、K⁺分布等进行研究。结果表明,随着盐分升高,株高、分枝、鲜重、干重均减小,≥7 g/kg盐分对费菜生长具有较大抑制,但盐分达到11 g/kg植株仍能继续生长;≥9 g/kg高盐分显著抑制地上干物质积累,对地下部生物量影响明显小于地上部。随着盐分升高,根、茎、叶中Na⁺的含量有升高的趋势,从部位含量看,茎>叶>根;随着盐分含量升高,叶中的K⁺含量逐渐减少,根、茎有升高趋势,从部位看,茎、叶是根的3倍;随着盐分浓度升高,根、茎、叶的Na⁺/K⁺比值具升高趋势,≤9 g/kg盐分胁迫下,根保持高Na⁺/K⁺比值,是茎、叶的近4倍。低于7 g/kg盐土对费菜影响不大,其耐盐性可能与宿根特性及茎叶结构有关。费菜集食用、园林于一体,由于其耐盐性强,可在滨海盐碱区种植应用。     

胶东半湿润区滴灌制度对冬小麦农田土壤水分、作物生长及水分利用的影响

针对胶东地区冬小麦生育期内降雨和灌溉水资源明显不足问题,通过研究滴灌条件下灌溉制度对土壤水分、冬小麦生长及水分利用的影响,探究该地区冬小麦最优灌溉模式.试验实施从2016到2019年,共3季冬小麦,灌溉方式为滴灌,共设置4种处理:T1:不灌水;T2:拔节期灌水40 mm;T3:开花期灌水40 mm;T4:拔节期和开花期...     

土壤基质势对盐碱地设施番茄生长及光合指标的影响

为指导滨海盐碱地设施番茄中前期的合理灌溉,以春茬番茄为研究对象,采用滴灌方式灌溉,设置4个不同基质势处理(-10、-15、-20、-25 kPa),研究其对设施番茄中前期生长及光合指标的影响。随着滴头正下方0.2 m深度处土壤基质势的降低,灌溉水次数明显减少;株高、茎粗、叶长生长指标随着基质势降低逐渐减小,-10、-15 kPa处理间差异不显著;生物量随基质势下降逐渐减小,低于-15 kPa的基质势番茄植株鲜重降低明显,-10、-15 kPa间差异不显著;净光合速率、气孔导度、蒸腾速率、胞间CO₂浓度等光合指标随基质势降低呈减小趋势,-10、-15 kPa处理间各指标差异不显著,与其他2个处理达到显著水平;总根长、总根体积、总根表面积随基质势降低逐渐减小,-10、-15 kPa处理间指标差异不显著,而>4 mm的粗根系数量以-15 kPa基质势处理下最高,与其他3个处理均达到显著水平。在滨海盐碱区番茄中前期生长阶段,以控制滴头正下方0.2 m深度处土壤基质势下限-15 kPa指导灌溉为宜。     

土壤水分胁迫对冬小麦耗水规律及产量的影响

在温定盆栽和池栽防雨旱棚条件下，研究了土壤水胁迫对冬小麦耗水规律及产量的影响，结果表明，随土壤水分胁迫加剧，干物质积累减少，子粒千物质来自贮藏同化物的比例上升，产量下降，产量构成三因子中穗粒数，亩穗数下降均极显著，而千粒重下降较少，随水分胁迫加剧，拔节前耗水量占总耗水量的比率增高，从播种到拔节期，耗水量占总耗水量的比例愈高，拔节后植株衰老死亡愈早，产量降低就愈大，中度水分胁迫下，虽然水分生产率和经     

Influence of Soil Water Regimes on VA Mycorrhiza IV. Effect on Root Growth and Water Relations of Sorghum bicolor

In a greenhouse trial, non-mycorrhizal and mycorrhizal plants of Sorghum bicolor were grown at three water regimes. The root length and root morphology of Sorghum bicolor was monitored in two soils during 34 days. From 29 days on, total root length of mycorrhizal sorghum was greater than of non-mycorrhizal sorghum in moderate and high water stress conditions. In soil A, at all water regimes a lower percentage of coarse roots and smaller root length per leaf area were found with mycorrhizal plants; in soil B, this was only the case in well watered conditions. In general, all root and water relation parameters were less affected by water stress when plants were mycorrhizal; this less sensitivity of mycorrhizal sorghum may increase the tolerance of the plant to drought. However, water relations of plants were indirectly enhanced by mycorrhiza via increased P uptake.     

Influence of Soil Moisture on Growth, Water Use and Yield of Mustard

A field experiment was conducted to study the influence of soil moisture on growth, water use and yield of mustard ( Brassica juncea L. cv. Rai 5 ). Two soil moisture regimes were rainfed and irrigated at 10 days interval throughout the growing season. The total amount of water received as irrigation was 110 mm and as rainfall was 15 mm. Total dry matter per unit ground area, leaf area index (LAI), crop growth rate (CGR) and net assimilation rate (NAR) were increased and leaf area ratio (LAR) and specific leaf area (SLA) were decreased by irrigation. Chlorophyll content and relative leaf water content (RLWC) were increased by irrigation, but proline content was greater in the rainfed crop at both the flowering and pod-filling stages. Time taken to first flowering, duration of flowering, number of seeds/pod and harvest index were unaffected by irrigation. Plant height at harvest, number of pods/plant, seed yield and oil content of seeds were increased and 1000-seed weight was decreased by irrigation. The consumptive use of water increased with an increase in water supply, but the water use efficiency (WUE) was decreased.     

Effectiveness of Mulching vs. Incorporation of Composted Cattle Manure in Soil Water Conservation for Wheat Based on Eco-Physiological Parameters

Abstract The objective was to study soil water conservation and physiological growth of wheat (Triticum aestivum L.) using composted cattle manure applied either as mulch or incorporated with soil at 20 Mg ha^?1. Haruhikari, a relatively drought‐sensitive and Hongmangmai, a relatively drought‐tolerant wheat, were the cultivars studied under both adequate and deficit irrigation. Fourteen weeks after sowing (WAS), the number of tillers and leaves was significantly reduced by 19 % and 30 % respectively under deficit irrigation and Hongmangmai produced slightly (10 %) more tillers than Haruhikari. Unlike mulching, the incorporation of manure had favourable effects on plants in terms of shoot dry mass (SDM) by 36 % and number of tillers and leaves by 40 %. Haruhikari produced substantially (29 %) greater root mass under adequate irrigation but Hongmangmai produced slightly (2.7 %) more roots and responded much better to manure use whether under adequate or deficit irrigation. As a result, Hongmangmai suffered less severe reductions in tillers and biomass under water stress. In comparison, the mulched manure treatment saved 15 % and 64 % respectively more water than the control and the treatment incorporating manure, but this advantage in water‐saving did not translate to superior plant growth. Leaf water potential (ψ_l) under adequate irrigation significantly exceeded that under deficit irrigation by 27 % and the ψ_l of Haruhikari exceeded that of Hongmangmai by 15 %. However, Hongmangmai may be considered more tolerant of dehydration since it maintained much higher net photosynthetic rates (P_N) even with a lower leaf water potential. The reduction in the P_N and intracellular carbon dioxide concentration (C_i) of the cultivars under deficit irrigation was on account of decreasing stomatal conductance (g_s) and transpiration rate but on average, the g_s of Hongmangmai significantly exceeded that of Haruhikari by as much as 0.53 under adequate irrigation and 0.22 under deficit irrigation. In conclusion, we suggest that the drought tolerance of Hongmangmai was related to its superior root growth and greater ability than Haruhikari, to efficiently utilize incorporated manure for growth under water stress.     

分根交替灌水对棉花生长、光合与水分利用效率的影响

应用部分根区干燥(PRD)技术,研究分根交替灌水(APRI)、分根固定灌水(FPRI)与全根系均匀灌水(BPRI)对盆栽棉花的生长、光合和水分利用效率的影响。结果表明:APRI黎明前与正午的叶水势均明显高于FPRI,而与BPRI无显著差异。APRI在叶片水分状况未变化时,显著降低了气孔导度,在维持光合作用不变的情况下,减少蒸腾量,瞬时水分利用效率与FPRI和BPRI相比分别提高了35.86%和63.51%。APRI处理的棉株在干旱复水后由于补偿效应,叶片生长速率和总叶面积较同等灌水量的FPRI分别提高了67.42%和27.16%。同时,干湿交替刺激APRI处理棉株的吸收根生长,其干重是FPRI的1.39倍。分根交替灌水在节水50%条件下,比同水量固定灌水处理的水分利用效率显著提高。     

温室微润灌溉对黄瓜生长和产量的影响

微润灌水器是一种新型的微灌设备,为了更好地推广应用这一新技术,对微润灌溉和沟灌灌溉条件下,温室黄瓜生长和产量差异进行对比分析。研究结果表明,微润灌溉条件下棚内空气温度、土壤温度和空气湿度分别较沟灌灌溉增加9.6%、9.6%和降低4.4%;微润灌溉有利于黄瓜株高和茎粗生长,并增产4.4%,而各生育期日均耗水量均低于沟灌灌溉,全生育期耗水量仅为沟灌的54.9%,水分利用效率提高130%,达到60.8 g/kg。因此,微润灌水器在大棚蔬菜灌溉应用中具有节水增产的效果,能够提高经济效益,是适合大棚经济作物灌溉的新技术。     

Effect of Benzyladenine on Transpiration, Water Potential and its Components in Genotypes of Wheat Contrasting in Drought Tolerance

Drought tolerant and susceptible cultivars of wheat, C-306 and Kalyan sona, growing under non-stressed and water-stressed conditions, were sprayed with benzyladenine (BA) at 70 days after sowing (DAS). Observations recorded at 5, 10, 15, 20 and 25 days after spraying revealed that BA increased the rate of transpiration (TR) in C-306 under non-stressed conditions. However, under water stress, the increase was significant only after 5 days of BA spraying. In Kalyan sona BA treatment either decreased TR or did not exhibit significant increase under non-stressed conditions, but caused significant increase in TR under water stress. The increase in TR was elicited through enhanced stomatal opening. Water potential, osmotic potential and pressure potential of both genotypes decreased on account of water stress. The effect of BA was not perceptible on restoration of leaf water potential (LWP) or its components. The effect of BA was possibly confined to stomatal behaviour and transpiration.     

土壤水分对冬小麦初生根、次生根生长发育的影响

１９９３－１９９４年冬小麦管栽水分试验结果表明,初生根与次生根生长量,数量及分枝能力基本与土体水量呈正相关,胁迫程度愈深,受抑程度愈大。初生根特别是一,二次根及其分枝数具有很强抗逆逆能力,水量愈大,三,四次根数愈多。次生根尤其是其数量对土水环境极为敏感。当土壤含水量你于田间持水量６０％时,受到严重抑制,胁迫后复水,使初生根三次根数量增加,根系活性延长对次生根的激励作用更大。前期胁迫愈严重,促进效果