刈割对油莎豆碳氮积累以及产量和品质的影响

为明确刈割对油莎豆（Cyperus esculentus L.）地上部碳氮积累、生物量、地下部块茎产量和品质的影响,寻求适宜留茬高度,以新疆沙区油莎豆为研究对象,比较6个不同留茬高度（LC10、LC20、LC30、LC40、LC50和未刈割）下油莎豆地上部碳氮积累及产量和品质的差异。结果表明：刈割后第1天,LC50有利于叶片碳氮含量的积累,碳、氮含量分别达到 22.79%和1.65%;刈割后第5天至20天,LC10和LC20叶片碳氮含量急剧下降;刈割后第5天和第10天,LC40的全碳和全氮含量高于其他处理,分别为39.78%、38.39%和1.48%、2.12%。LC40地上部干草质量和干豆质量最大,分别为4 310.39 kg·hm^-2和8 208.90 kg·hm^-2,且LC40块茎淀粉、粗蛋白、粗脂肪含量以及含油量显著高于其他处理,增幅分别为38.6%、28.8%、6.0%、22.44%,此外,该留茬高度下油莎豆块茎中不饱和脂肪酸油酸含量高达74.10%,明显高于其他处理。LC10 块茎中总糖与粗灰分含量最高,分别达到44.4%和2.3%,且块茎中棕榈酸、硬脂酸、棕榈油酸、亚麻酸和亚油酸含量相对其他处理较高,分别为14.00%、2.99%、0.28%、0.42%、11.21%。综上所述,留茬高度40 cm为适宜刈割高度,利于提高新疆沙区油莎豆的产量和品质。     

科尔沁沙地人工黄柳林平茬复壮技术研究

针对科尔沁沙地人工黄柳林的生存现状和生长动态规律,分析不同预留盖度和留茬高度的平茬处理后黄柳和林间草本植被的恢复情况及其防风固沙效益,结果表明:1)平茬对黄柳及其林间草本的生长均有极大的促进作用;2)在平茬后的第一年内和现有的4个预留盖度下,不同预留盖度对黄柳生长无显著影响;留茬高度以0cm(齐地刈割)为佳;3)综合风速和风蚀量的测定分析发现,在全面围封、林间草本较好的情况下,留茬盖度在10%已经完全可以满足沙地人工灌木林的生态防护功能。     

塔里木沙漠公路防护林乔木状沙拐枣平茬复壮技术的研究

为了塔里木沙漠公路防护林持续稳定的发展,对防护林内衰退的乔木状沙拐枣进行不同留茬高度和不同灌水量的平茬实验,选取萌蘖条数、株高、冠幅、萌蘖条地径、地上生物量5项指标评价平茬效果。结果表明:1)平茬后乔木状沙拐枣的萌芽期推迟10天左右,但萌蘖株的生长势明显好于未平茬植株,合理的留茬处理更能促进这一优势的发挥。2)平茬当年,不同留茬高度处理萌蘖株月生长动态一致,即株高、冠幅和地径均呈"S"型增长,而萌条数呈对数增长,但留茬高度对萌蘖条生长状况和地上生物量积累及分配均有显著影响(P0.05),不同留茬高度平茬效果为:10cm20cm15cm5cm。3)灌水量引起的土壤水分状况的差异极大的影响着防护林内乔木沙拐枣的平茬效果,单次灌水量45L/株的平茬效果明显好于22.5L/株。     

沙漠边缘三种主要天然植物再生性能的观察

通过对骆驼刺、叉枝鸦葱、花花柴不同刈割时间和不同留茬高度处理对再生速度、分枝性能、再生强度及再生草产量的观察研究表明：以上三种植物齐地面刈割能刺激侧芽的发生和生长，增加分枝数，提高再生草产量。以骆驼刺为例：齐地面刈割再生草产量比地面以上１０ｃｍ、地面以下１０ｃｍ和地面以下２０ｃｍ留茬高度分别高６０．７３％、４８．９７％和１３２．０５％；春天刈割再生草生长旺盛、能正常开花结实。夏天刈割时，因气温和沙     

塔里木河中下游退耕还草植物种选择试验--苏丹草引种适宜性与主要农艺性状分析

20 0 2年在塔里木河中下游土地沙化、盐渍化较重、种植棉花长势不好的中、低产田退耕建植苏丹草 ,并对 8个农艺性状与单株重进行相关、回归分析 ,表明 :苏丹草适宜在 81°～ 89°E ,4 0°～ 4 5°N的塔河中下游地区种植 ;温度是影响出苗的重要因子 ;每茬刈割后及时追肥可显著提高产草量。叶宽、叶鞘长与苏丹草单株重相关性较显著 ,相关系数大小依次为叶宽 >叶鞘长 >节长 >节径 >穗长 >株高 >叶长 >叶数。     

陇东黄土高原春播紫花苜蓿不同茬次生物量动态研究

2003～2005年,在陇东黄土高原区进行的春播紫花苜蓿生物量观测试验表明,春播紫花苜蓿当年的株高,由缓慢增长转为快速增长的转变时段在分枝到现蕾期,由快速增长再次转为缓慢增长的时段在开花期后;生长二、三年紫花苜蓿,一年中适宜刈割三次,前二茬鲜草的平均日增长量明显高于第三茬,并且生长三年的各茬鲜草平均日增长量普遍高于生长二年的;最大地上生物量均出现在第一、二茬,其鲜草和干草重量分别占三茬总重量的76.9%～84.3%和79.1%～86.3%;各茬次紫花苜蓿鲜干比在现蕾期后明显降低,到开花期刈割前降至最低.年际和地域的气候条件差异直接反映在紫花苜蓿各茬次生物量和鲜干比的变化上,在水份满足的情况下,以气温日较差大的地域更有利于紫花苜蓿物质积累.     

割草对典型草原植物营养元素贮量及分配的影响Ⅱ．地上生物量的营养元素贮量

本文研究了内蒙古典型草原地区割草地9种营养元素的贮量及分配。研究结果表明：刈割对羊草、治草、其它草种和群落的营养元素贮量产生了一定影响,其贮量随刈割时间而逐渐增加的趋势。一年内,营养元素的高值期在8月30日前后。割草区的贮量一般低于对照区,羊草的留茬部分低于割取部分的贮量,治草则相反。在生物量高峰期8月30日前后,其割草区群落的营养元素贮量为：N3.3557g.m^-2,P0.1747g.m^_2,K2.620g.m^-2,Ca1.0795g.m^-2,Mg0.1278g.m^-2,Fe0.0324g.m^-2,Cu1669.66μg.m^-2,Mn10343.84μg.m^-2,Zn3303.51μg.m^-2。除Mn外,其它元素都是对照区高于割草区。上述9种营养元素贮量在割取部分中亦随刈割时间而逐渐增加,高峰期也在8月30日前后,但留茬部分相反。割草区营养元素的贮量多数低于对照区,割取部分多数高于留茬部分。在生物量高峰期8月30日前后,割草区群落的营养元素贮量分配在割取部分的为：N60.84％,P49．06％,K53．34％,Ca59．76％,Mg57．51％,Fe34．25％,Cu48．92％,Mn44．46％,Zn62．67％。洽草营养元素的贮量分配在割取部分的相对较少,而在留茬部分中相对较多。所以,刈割使洽草的生物量增加。     

春播紫花苜蓿生长期（刈割后）的杂草防除研究

选用7种不同的除草处理,探究不同茬次刈割后的单、混用除草技术对紫花苜蓿的安全性、产量及杂草防除效果的影响.结果表明：一茬刈割后施药,杂草鲜重防效最好的是烯草酮＋2,4-DB,最差的是2,4-DB;禾草鲜防最好的是烯草酮,其次分别是精稳杀得和精喹禾灵,效果一般;喷施精稳杀得＋2,4-DB和精稳杀得＋苯达松可显著提高二茬的产量.然而,二茬刈割后施药,杂草鲜重防效最好的却是精稳杀得＋苯达松;喷施烯草酮、精稳杀得和精喹禾灵防除禾草的效果非常好,防效在86.18％ ～ 100.00％.喷施2,4-DB的单、混用处理三茬产量显著减少.此外,喷施2,4-DB和苯达松的单、混用处理对阔叶草的鲜重防效和株防效都超过66.70％.     

巨菌草留茬沙障防风固沙效益及其适宜模式研究

基于对乌兰布和沙漠刘拐沙头黄河沿岸相近株距(10~15 cm)、不同行距(1 m,2 m)、不同留茬高度(10cm,30 cm)巨菌草的防风阻沙试验的观测数据分析。结果表明:(1)巨菌草留茬沙障的防风固沙效益与沙障的高度和行距有直接关系,高度一定,行数越多,带距越小,防护效果越好,但所需材料增加。(2)巨菌草留茬沙障内输沙量主要集中在地表15 cm以下,近地表0~5 cm处沙障对风沙流的阻碍能力较强。沙障行距为1 m、2 m时,高10 cm的沙障分别经9带、12带后风速降至起沙风速以下;高30 cm的沙障对风的阻碍能力增强,分别经7带、9带后地表无流沙运动。(3)沙障的设置应在保证高效的前提下降低成本。行距2 m、高30 cm的巨菌草留茬沙障,气流经过9个条带(18 m宽)后,风速可降至起沙风速以下,此设置模式宜在干旱地区推广。     

保护性耕作对风沙区农田土壤物理性状及玉米产量的影响

在科尔沁沙地东南部风沙区采用完全随机区组试验设计,在2013—2014年比较研究了4种保护性耕作措施(深松、留茬、免耕、秸秆覆盖)和传统翻耕(CK)平作种植玉米的土壤物理性状及产量。结果表明,与传统耕作相比,连续2 a保护性耕作以深松、留茬处理显著降低0~40 cm土层土壤容重(P0.05),降幅0.72%~7.12%。0~40 cm土层0.25 mm土壤团聚体含量各土层均以深松处理含量最高,2014年土壤团聚体含量较2013年增加4.11%,其中秸秆覆盖对0~10 cm团聚体含量影响较大,2014年较2013年提高5.54%。4种保护性耕作措施均提高了收获后0~100 cm土壤贮水量,表现为留茬秸秆覆盖深松免耕,较传统耕作提高12.22%~26.91%。进行保护性耕作的处理玉米子粒产量和水分利用率均比传统耕作高,其中以深松处理增产幅度最大,子粒产量平均较传统耕作提高14.57%,水分利用效率提高25.81%。由2 a数据显示,深松、留茬和秸秆覆盖等保护性耕作措施改善了风沙土耕层土壤结构,具有较好的保水性和增产效果。     

不同缓解处理对甲咪唑烟酸紫花苜蓿药害的缓解效果研究

为了评价不同缓解处理对甲咪唑烟酸引起的紫花苜蓿药害的缓解效果,于紫花苜蓿刈割后10 d喷施甲咪唑烟酸,分别在药后5 d和10 d喷施磷酸二氢钾、芸苔素内酯、赤·吲乙·芸苔、赤霉酸、复硝酚钠、吡唑醚菌酯、萘乙酸、氨基酸原液、奈安共9种缓解剂进行药害缓解,调查紫花苜蓿株高、鲜重并测定其产量、品质。结果表明,240 g/L甲咪唑烟酸水剂129.6 g/hm~2对紫花苜蓿药害明显,严重抑制其生长,株高下降25.45%,鲜重减少38.26%,最终减产13.28%;药后5 d赤·吲乙·芸苔、芸苔素内酯、氨基酸原液及药后10 d奈安处理的株高抑制率分别为-2.11%、-3.16%、-1.06%和-0.80%,株高均显著高于药害植株,缓解效果好。复硝酚钠、吡唑醚菌酯处理的株高、鲜重显著低于空白对照,抑制率均>10%,缓解效果差。药后5 d芸苔素内酯处理较甲咪唑烟酸对照、空白对照产量增加22.96%、6.64%,增产率最高,赤·吲乙·芸苔、氨基酸原液其次,且对品质均无不良影响。综合分析,在甲咪唑烟酸药后5 d喷施0.01%芸苔素内酯可溶液剂0.022 5 g/hm~2、0.136%赤·吲乙·芸苔可...     

西北黄土区主要作物茬口对土壤理化性质和冬油菜农艺性状的影响

为了探讨不同茬口对土壤肥力及后茬油菜产量的影响,以休闲田为对照,研究了西北黄土区冬油菜、马铃薯、玉米、冬小麦、春小麦、蚕豆等6种主要农作物茬口土壤耕作层肥力效应及其对后茬白菜型冬油菜产量和农艺性状的影响,结果表明：（1）不同作物茬口土壤养分含量总体表现为越冬作物>休闲田>春播作物,除固氮作物蚕豆茬口碱解氮含量较高外,冬油菜茬口土壤营养各项指标、土壤微生物种群结构及土壤物理性状均显著优于其它作物茬口,其有机质、全氮、全磷、全钾、碱解氮、速效磷、速效钾含量分别比休闲田增加32.6%、12.1%,5.9%、7.2%、11.6%、99.8%、44.2%,其次为蚕豆、冬小麦茬口和休闲田,玉米和春小麦茬口肥力状况较差;与休闲田相比,冬油菜、冬小麦和蚕豆茬口耕层（0~20 cm）土壤容重分别降低10.14%、5.80%和5.80%,而冬油菜茬口土壤总孔隙度、毛管孔隙度和田间持水量分别提高7.33%、4.12%和5.65%,马铃薯、玉米、春小麦茬口均有不同程度下降,冬小麦与蚕豆茬口无明显差异;（2）前茬对白菜型冬油菜农艺性状的影响主要表现在株高、根量、全株角果数、角果粒数及千粒重等指标,其中蚕豆茬口白菜型冬油菜比休闲田增产4.50%,冬小麦茬口与休闲田相当,而马铃薯、玉米、春小麦、冬油菜茬口分别较休闲田减产11.05%、15.04%、16.27%、21.14%。白菜型冬油菜的最佳前茬是豆类作物,休闲田和冬小麦茬口次之,但白菜型冬油菜连作可能会产生自毒作用或病害加重,从而造成显著减产。     

青海高原春小麦留茬高度对后茬绿肥生物量和水分利用效率的影响

采用裂区试验设计,以华北坝上及其周边寒旱区15个常规栽培品种为供试材料,设置不施氮与施氮两个水平,从块茎产量、氮吸收量、氮生物学效率、肥料氮农学效率、偏生产力、表观利用率等方面进行不同品种氮效率评价;在此基础上,采用隶属函数法对各品种进行综合氮效率鉴评与分类。结果表明：品种、施氮水平、品种×施氮水平等对马铃薯产量具有极显著的影响,在不施氮肥的条件下北方002的产量最高,为5 863 kg·hm^-2,冀张薯12号的氮素生物学效率最高,为92.10 kg·kg^-1;在施氮肥的条件下荷十五的产量最高,为8 284 kg·hm-2,V7的氮素生物学效率最高,为59.05 kg·kg^-1。15个品种在氮效率性状如地力产量、施氮肥后产量、块茎氮吸收量、肥料氮农学效率、肥料氮偏生产力、肥料氮表观利用率等方面存在宽幅变异,变幅范围为21%~58%。在未施氮肥条件下,马铃薯不同品种产量（Y）与块茎含氮量（X）呈极显著负相关,Y=-0.0019X+22.045（R²=0.6269^**）;在施氮条件下,产量与块茎含氮量无显著相关,而肥料氮表观利用率（Y）与肥料氮偏生产力（X）之间呈极显著正相关,Y=1.617X-21.784（R²=0.7465^**）。隶属函数分析表明,荷十五、希森6号与斯凡特（F8）具有较高的综合氮效率,可作为氮高效品种应用于生产或作为氮高效种质材料。     

辽西半干旱区秋后覆膜保墒对翌年春玉米生长发育的影响

针对辽西半干旱地区春旱严重、降雨资源年内分布不均的气候特点,在秋收后、霜冻之前进行灭茬覆膜处理,试验对旱地雨水资源跨时间调节。翌年春季土壤含水量、玉米生长状况及产量的试验结果表明,秋覆膜处理的耕层土壤含水量比未覆膜处理高出60%,播种15d后玉米出苗率达到85%,抽穗期玉米株高比未覆膜处理高33cm、径粗增加0.42cm,秋收时玉米穗重比未覆膜处理提高了49.62%。研究表明,春墒秋保、跨时间调控农田水分状况是北方干旱半干旱地区有效的农业节水措施。     

Effects of Irrigation and Verticillium dahliae on Cauliflower Root and Shoot Growth Dynamics

ABSTRACT Cauliflower root and plant growth and Verticillium wilt development were evaluated under different moisture regimes in the presence or absence of V. dahliae. Treatments included two main plots (V. dahliae-infested and fumigated), two subplots (furrow and subsurface drip irrigation), and three sub-subplots (deficit, moderate, and excessive regimes) that were arranged in a split-split-plot design in the field. Soil cores with roots were periodically sampled at 5 and 25 cm distance from plants. Total roots in each soil core were extracted with a hydropneumatic root elutriator, and root length from each sample was determined with a digital image analysis system. Incidence and severity of Verticillium wilt, plant height, number of leaves, and dry weights of leaves and roots were determined on 10 plants sampled at 7- to 10-day intervals 1 month after cauliflower transplanting and continued until harvest. To evaluate the effects of Verticillium wilt-induced stress on cauliflower plants, stomatal resistance was measured in upper healthy and lower (or diseased) leaves. Root length density at 5 and 25 cm from plant was significantly (P < 0.05) higher in subsurface drip than in furrow irrigation. Root length density was significantly higher in excessive irrigation regime than in the other regimes. Concomitantly, there was higher wilt incidence and severity in excessive and moderate regimes than deficit regime regardless of the irrigation method. Plant height was affected by irrigation methods and deficit regime. Neither the method of irrigation nor the quantity of water affected the other variables. Stomatal resistance in lower diseased leaves was significantly higher in infested than in fumigated plots but it was not in the upper healthy leaves. In this study, cauliflower yield was not affected by V. dahliae and irrigation method, but the deficit irrigation regime resulted in reduced yield even though it suppressed wilt in cauliflower. Thus, higher moisture levels resulted in higher root length density in V. dahliae-infested plots that in turn lead to greater incidence of Verticillium wilt and severity. The pathogen also affected physiological processes such as hydraulic conductance of cauliflower leaves, but not shoot growth or yield under these experimental conditions.     

干旱绿洲农田盐渍化对土壤理化特性和农艺特征的影响

在河西走廊西部大田试验条件下,通过一个生长季的观测,分析研究农田盐渍化对土壤理化特性和典型牧草(紫花苜蓿)和农作物(大麦)农艺性状、干物质积累和产量的影响。结果表明:(1)在0 ～ 20 cm土层,牧草土壤容重沿盐渍化梯度增加了3％,4.54％,8.62％,9.96％,农作物土壤容重没有明显变化规律;土壤有机质显著降低,且0～ 10 cm土层的降低速率快于10 ～ 20 cm土层;(2)盐渍化程度等于或高于中度盐渍化水平时,大麦植株的穗长、穗粒数和秸秆重受到显著影响;在开花、孕穗和灌浆期的盐度既会降低籽粒产量也降。低秸秆产量。与农作物相比,盐渍化程度等于或高于轻度盐渍化水平时,牧草植株的株高、主侧枝长和主根直径会受到影响,进而导致牧草产量的降低。因此,在农业生产中,可根据两种作物在不同盐渍化梯度各生育期的受害状况进行相应的水盐调控和耕作管理,以实现盐渍化农田作物产量的维持和增加。     

Large-scale assessment of agricultural practices affecting Fusarium root rot and common bean yield

The relationships between a number of agronomic practices, Fusarium root rot (FRR) measurements and yield variables were characterized at different growth stages in 122 commercial bean fields in Zanjan, Iran. Mean FRR incidence, severity and index differed among growth stages and years. A lower FRR index at growth stage R9 and higher yields were detected in Red beans compared to Pinto and White beans. FRR severity affected the number of pods and seeds per plant. Despite the lack of an impact of initial drought on FRR and yield factors, FRR levels were higher following frequent irrigations at 2–3 days intervals than at longer intervals at R6-7. The highest FRR index at R6-7 (51.9%) and incidence at R9 (69.1%) were associated with the densest category of plant populations. Yield components differed significantly between the levels of plant density at R9. FRR levels at V3 were lower for June plantings than for May-second-week plantings. Lower FRR ratings and higher yields were detected at a seeding depth of 0–5 cm in comparison to 10–20 cm. At R9, FRR levels on beans following maize were lower than those following barley, bean, tomato or wheat. At V3, FRR severity was greater in fields that received 50–500 kg/ha of urea compared to non-fertilized fields. Greater mean FRR index at R6-7 and lower yield levels were associated with the greatest weed density compared to weed-free fields. This new information benefits the systematic understanding of interactions between bean yield, FRR and various agronomic variables at large-scale.     

Effect of Weeding Regime and Plant Spacings on Weed Growth and Performance of Transplanted Rice

Abstract

Effect of weeding regime (unweeded control, hand weeding once, 4 weeks after transplanting (w.a.t.) and hand weeding twice, 4 and 7 w.a.t.) and different plant spacings (20 × 2.5 cm, 20 × 5 cm, 20 × 10 cm, 20 × 15 cm and 20 × 20 cm) on weed growth and performance of transplanted rice were tested in a split-plot design. Grain yield and number of panicles were not significantly different in both weeding treatments from the unweeded control at 20 × 2.5 to 20 × 10 cm spacings, showing that, at closer spacings weed control may not be necessary to increase grain yield. The number of weeds at harvest was significantly lower in the weeded plots than the unweeded control at all spacings used. Weed weight at harvest was significantly affected by weeding regime at all spacings except at 20 × 2.5 cm, where no significant difference was observed between the weeded and the unweeded plots. Plant spacings significantly affected the grain yield and weed weight, but did not affect the panicle number and weed counts of transplanted rice. At 20 × 2.5 cm, grain yield was significantly better than that at 20 × 15 cm or 20 × 20 cm. A simple trend of increase in grain yield along with the decrease in spacing between plants was observed in terms of actual grain yield.