调亏灌溉对棉花生长、生理及产量的影响

通过盆栽试验在棉花不同生育时期进行不同程度的调亏灌溉试验。结果表明,调亏灌溉对棉花株高、蕾铃脱落、成桃数等影响较显著;苗期和吐絮期重度水分亏缺、蕾铃期中度水分亏缺均有利于棉花产量的形成。棉花的光合速率和气孔阻力随土壤含水量变化的阈值约在14％土壤含水量水平,该阈值相当于田间持水量的60％～65％。合理的棉花调亏灌溉制度是苗期控制水分供应,土壤含水量维持在田间持水量的55％～60％;蕾期和花铃期是棉花的需水关键期,土壤含水量应分别保持在田间持水量的65％和70％左右;吐絮期应控制水分供应,土壤含水量维持在田间持水量的50％～55％。     

调亏灌溉对棉花生长,生理及产量的影响

通过盆栽试验在棉花不同生育时期进行不同程度的调亏灌溉试验。结果表明,调亏灌溉对棉花株高、蕾铃脱落、成桃数等影响较显著;苗期和吐絮期重度水分亏缺、蕾铃期中度水分亏缺均有利有棉花产量的形成。棉花的光合速率和气孔阻力随土壤含水量变化的阈值约在１４％土壤含水量水平,该阈值相当于田间持水量的６０％～６５％。合理的棉花调亏灌溉制度是苗期控制水分供应,土壤含水量维持在田间持水量的５５％～６０％;蕾期和花铃期是棉     

冬小麦调亏灌溉制度田间试验研究初报

大田试验结果表明,拔节期为冬小麦水分最敏感的生育时期,其次为孕穗期和抽穗～开花期,而返青～起身期充分供水则造成冬小麦明显减产。拔节期最大调亏程度为0～50cm土层土壤含水量≥田间持水量的65%,过小则导致明显减产;孕穗～抽穗期、抽穗～灌浆前期最大调亏程度为0～80cm和0～100cm土层土壤含水量≥田间持水量的60%;灌浆后期最大调亏程度为0～100cm土层土壤含水量≥田间持水量的50%,由此建立了冬小麦调亏灌溉制度。     

土壤调理剂对旱、盐条件下草种萌发的影响

利用田间和盆栽试验研究了不同材料土壤调理剂对草的生长影响,并探讨其使用条件和使用方法。结果表明,干旱条件下,应用调理剂可减轻干旱土壤盐碱的危害,提高出苗率在75%以上。土壤调理剂作种子包衣有较好的抗旱保苗效果,包衣处理的草籽出苗率较对照提高约19%;包衣处理的苗期土壤水分较对照高5%～11%;包衣处理的苗期耗水量较对照降低5%～12%。播期土壤水分为田间持水量的40%(土壤含水量约11%)和20%(土壤含水量约5%)的土壤上,土壤调理剂处理的出苗数分别较对照提高11%～14%和14%～24%;0～20cm土层含水量较对照增加4%～15%。当土壤水分为田间持水量的40%时,土壤调理剂处理的苗期生物量较对照增加3%～42%,单位耗水量较对照降低9%～34%;土壤水分在田间持水量的20%时,调理剂处理的苗期生物量和单位耗水量较对照亦分别表现为增加和降低趋势。     

硅钾肥配施对小麦抗条锈病及产量的影响

本文研究了不同土壤水分条件下 ,施用硅肥、钾肥及硅钾肥对冬小麦产量和小麦抗条锈病的影响 ,结果表明 :施用硅肥可减轻小麦病害 ,增强其抗病性 ,硅钾肥配施次之。低水分条件下 (土壤含水量为田间持水量的 35 %～ 4 0 % )施硅钾、硅肥对冬小麦抗条锈的影响优于充足水分条件下 (土壤含水量为田间持水量的 70 %～ 75 % )。施用硅、钾肥能明显增加冬小麦产量。     

温度和水分对典型香型烟区植烟土壤氮素矿化的影响

为探究典型香型烟区植烟土壤氮素矿化特征及其与温度和水分的关系,采用室内培养试验研究了土壤温度(15、28、37℃)和土壤相对含水量(50%、65%、80%田间持水量)对云南大理、贵州毕节、河南许昌3个典型香型产区植烟土壤氮素矿化的影响。结果表明:不同地区植烟土壤矿质氮和矿化速率变化规律与温度和水分密切相关。3个产区植烟土壤的矿质氮含量和矿化速率均随着温度的升高而升高,在同一温度条件下,以土壤有机质含量较高的云南大理土壤矿化量较大,有机质含量较低的河南许昌土壤矿化量较小。不同地区植烟土壤含水量与氮素矿化的关系不尽相同,土壤相对黏重的贵州毕节土壤以50%田间持水量处理土壤氮素矿化量和矿化速率最大,以80%田间持水量处理最不利于氮素矿化;而质地相对较轻的河南许昌土壤和云南大理土壤均为在65%田间持水量条件下最有利于氮素矿化,以50%田间持水量处理氮素矿化量较小。基于一级动力学方程的模拟,3个植烟土壤的潜在矿化氮库(N0)都随温度的增加而提高,总体以28～37℃的培养温度较为适宜,低于15℃不利于土壤有机氮的矿化,3个植烟土壤的N0以云南大理最高,河南许昌最低;土壤矿化速率常数(K)以云南大理最大。土壤相对含水量也对N0有一定影响,且土壤温度和含水量对不同土壤氮素矿化量和矿化速率均存在显著的互作影响,合理调控土壤温度和土壤相对含水量,可以有效调节不同生态烟区土壤氮素矿化动态变化。     

滴灌甜菜对糖分积累期水分亏缺的生理响应

滴灌条件下,于甜菜糖分积累期设置0~40 cm土层含水量下限分别为70%、50%、30%田间持水量的3种土壤水分处理,从叶片光合特性、水分胁迫指数、恢复度、产量及产糖量方面分析复水前后甜菜的生理响应,明确甜菜糖分积累期可忍受最大程度的水分亏缺下限。结果表明:30%田间持水量处理甜菜产量及产糖量都显著高于70%田间持水量和50%田间持水量,分别比70%田间持水量提高51.34%和51.47%,比50%田间持水量提高36.72%和39.48%。复水前30%田间持水量处理的甜菜叶片净光合速率显著低于其他处理,复水后处理间的叶片净光合速率的差异随时间推移减小,胞间CO2浓度表现出相反的趋势。当土壤水分下降到既定下限时,叶片脯氨酸和可溶性糖含量变化最为灵敏,且与缺水程度呈正相关;复水后叶片的细胞膜透性、抗氧化防御体系以及渗透调节物质均产生了正补偿效应,表现为丙二醛含量降低,抗氧化性酶活性增强,控制渗透调节的脯氨酸和可溶性糖含量增加。因此,在糖分积累期,土壤含水量下降至田间持水量的30%时进行补充灌溉,在一定程度上补偿水分亏缺对甜菜产生的负面影响,实现干旱区滴灌甜菜节水高产优质的目的。     

土壤水分对棉花蕾铃脱落和纤维品质的影响

１９９１￣１９９５年在人工控制水分的条件下,研究不同生育阶段土壤对棉花蕾铃脱落与纤维品质的影响。研究发现,土壤水分不足或过大,均易造成雷铃脱落增加和品质下降。有利于增蕾保铃和提高纤维品质的土壤湿度,约相当于田间持水量的５５％￣７５％。不同生育阶段的棉花蕾铃脱落率和对水分的敏感系数不同。蕾铃脱落对水分的敏感系数以开花盛期－吐絮期最大,蕾期相对较小。脱落率以开花盛期－吐絮期最大,开花－开花盛期次之,吐     

干旱胁迫对小叶杨幼苗生长的影响

[目的]了解小叶杨的抗旱机理,为山西省北部半干旱风沙区小叶杨防护林建设提供科学依据。[方法]通过在山西省苗圃基地盆栽模拟干旱试验,以小叶杨生长过程中的苗木株高和地径,根、茎、叶生物量,叶片相对含水量和水势,净光合速率、蒸腾速率等为生长和生理指标,研究干旱胁迫对小叶杨幼苗生长的影响。[结果]干旱胁迫抑制了小叶杨幼苗的生长,包括地上部分和根系的生长;叶片相对含水量和水势随土壤相对含水量降低而下降;各干旱梯度下CK,T1,T2,T3,T4,T5的净光合速率、蒸腾速率也随干旱梯度加深而降低,但从CK(田间持水量,土壤含水量20.3%)到T3(田间持水量的40%,土壤含水量8.12%)净光合速率和蒸腾速率随干旱梯度加深降幅逐渐较小,并且干旱时也能保持较大的光合速率和蒸腾速率,表明小叶杨具有明显抗旱特性;当土壤水分进一步减少,T4(田间持水量的30%,土壤含水量为6.09%)时小叶杨开始出现干枯现象,T5(田间持水量量的20%,土壤含水量为4.06%)时小叶杨全部死亡。[结论]山西省西南部及其周边地区进行小叶杨造林时,土壤水分应尽量要保持在6.09%(T4)以上。     

植被恢复对高速公路工程堆积体土壤性质的影响

以红壤区植被恢复5 a的昌栗高速工程堆积体为研究对象,研究植被恢复对工程堆积体土壤理化性质的影响。沿线选择6个工程堆积体,在堆积平台设置标准样方,采集土样,分析土壤的理化性质。研究结果表明:(1)0～10 cm土壤密度及含水量都最小,田间持水量、毛管孔隙度及非毛管孔隙度都最大; 20～40 cm土壤密度及含水量都最大,田间持水量、毛管孔隙度及非毛管孔隙度都最小。随着土层的增加,土壤密度、含水量逐渐增加,田间持水量、毛管孔隙度及非毛管孔隙度逐渐降低;(2)0～10 cm土层有机质、速效氮含量都最大,速效钾、速效磷含量最小,10～20 cm的速效钾、速效磷都最大。随着土层的深入,不同的化学性质呈现出不同的变化趋势,有机质逐渐降低,而速效钾、速效磷呈现先增加后降低的趋势,而速效氮含量逐渐降低。由此可见,植被恢复5 a后,土壤的理化性质得到不同程度的改善。     

农用地分等中最高单产和最高产量-成本指数确定方法

为提高农用地分等中最高单产和最高产量-成本指数确定方法的科学性和合理性,该文以土地报酬递减理论为基础,应用河南省农用地分等的小麦投入产出调查数据,将样点小麦单位面积产量(kg/hm~2)作为土地报酬递减曲线中的总产量(纵坐标),将样点小麦单位面积投入(元/hm~2)作为土地报酬递减曲线中的总投入(横坐标),从而使土地报酬递减理论中的平均产量(kg/元)与产量-成本指数具有相同的内涵。依据边际产量曲线的变化,分2种情况最高单产的确定:1)边际产量曲线表现为下降趋势,但没有与横坐标轴相交即边际产量仍大于0,这时单产曲线最右端的产量为最高单产;2)边际产量曲线向下与横坐标轴相交即边际产量递减为0时,边际产量曲线与横坐标轴相交点对应的产量为最高单产。依据产量-成本指数和边际产量2条曲线间的关系可以确定最高产量-成本指数:产量-成本指数曲线向上与边际产量曲线相交点的产量-成本指数为最高产量-成本指数,并建立了异常产量-成本指数的修正方法。采用研究数据和验证数据确定的最高单产和最高产量-成本指数分别相差0.12%、0.50%,表明该研究方法确定的区域最高单产和最高产量-成本指数具有相对稳定性。该研究为确定最高单产和最高产量-成本指数提供了理论依据,丰富了土地利用系数和土地经济系数的内涵。     

镉胁迫对不同基因型小麦产量及构成因子的影响

盆栽试验以筛选出的6份子粒镉（Cd）高积累和5份子粒Cd低积累小麦为试材,研究不同基因型小麦在028 （对照CK）、5、10和 20 mg/kg 4个Cd浓度胁迫下小麦子粒产量及其构成因子的变化。结果表明,不同基因型小麦产量及其构成因子对土壤Cd浓度的变化响应差异很大。产量对Cd胁迫很敏感,随着Cd浓度的提高极显著降低; 小穗数、穗粒数和千粒重随Cd浓度的增加逐渐降低,响应显著的浓度分别为5、5和10 mg/kg; 而有效分蘖随着Cd浓度的提高先在5 mg/kg显著增加,然后极显著降低,响应强烈的浓度为10 mg/kg。相关性和通径分析表明,Cd浓度与小麦产量及构成因子呈负相关,影响程度为: 产量＞千粒重＞穗粒数＞有效分蘖＞小穗数。由此可知,产量随着Cd浓度的提高极显著降低的直接原因是瘪粒和空粒的增加; 同时还看出,Cd胁迫下子粒Cd高积累小麦的产量、小穗数和穗粒数显著低于Cd低积累品种,千粒重两者相差不大,有效分蘖是前者高于后者。     

Effect of sulphur fertilization on grain yield and yield components of winter wheat

Abstract

The effect of sulphur application on winter wheat yield and yield components on two different soils in northern Estonia and southern Estonia during 2004–2009 was investigated. Sulphur was applied with NS-fertilizer Axan or Axan Super at the rate of S 10 or 13.6 kg ha^?1 accompanied with nitrogen background of N 100 kg ha^?1, which effect was compared to effect of ammonium nitrate at the same rate of N. The rates of fertilizers were divided into two portions and applied at the growth stages 21–22 and 25–30. The effect of sulphur fertilization on the formation of wheat yield varied on a quite large scale depending on soil and weather conditions of trial locations. The yield components were closely related: when one component was changed, the other components sometimes compensated for grain yield.

Sulphur deficiency symptoms appeared on the break-stony soil at Saku in a somewhat stronger form than on the pseudopodzolic soil at Auksi. The results of field trials conducted at Saku during the four years can be summarized as follows: the application of sulphur increased the number of ears per unit area by an average of 14.0% and the number of grains per ear by an average of 18.6%. At the same time, sulphur decreased the 1000-grain weight. As a final result, sulphur application on break-stony soil increased the wheat yield by 1.16 t ha^?1 on average, i.e. by 23.0%. Sulphur application in trials conducted on pseudopodzolic soil at Auksi during years with different weather conditions in growing season proved highly effective in three of five trials. As an average of all trials in Auksi, the sulphur application increased the number of ears per unit area and the number of grains per ear by 23.9% and 7.7%, respectively. The grain yield increased under the influence of sulphur on the average of all trials conducted on pseudopodzolic soil by 1.25 t ha^?1, i.e. by 22.4%.     

三大粮食作物产量潜力与产量差研究进展

产量潜力和产量差的研究对揭示未来粮食增产潜力,有针对性地制定提高作物产量的措施具有重要意义。通过总结近年发表的64篇经典文献,本文总结了世界三大粮食作物小麦、水稻和玉米的产量潜力和产量差的研究进展,并对定量产量潜力和产量差的4种常用方法进行了比较分析。研究表明:1)当前全世界小麦、水稻、玉米的平均产量潜力分别为6.7 t-hm-2、8.1 t-hm-2、11.2 t-hm-2,农户产量分别实现了产量潜力的60%、60%、53%。2)模型模拟是目前定量评估产量潜力最为有效的方法之一,综合使用模型模拟和高产纪录两种方法进行比较分析产量潜力结果会更加可靠;试验产量和高产农户产量一般会低于模型模拟产量潜力,对探索农户短期内增产潜力具有重要意义。3)优化栽培管理措施比如应用土壤-作物综合管理系统等方法是缩小产量差的有效途径。因此,当前三大粮食作物具有较大增产潜力,如何有效缩小产量差、提高作物产量、保证粮食安全是未来需要关注的重点。     

Influence of phosphorus application on yield,yield components,and quality of linseed

Abstract

Soil fertility depletion coupled with improper fertilization is one of the major constraints limiting linseed production in Ethiopia. Experiment was conducted in 2014/2015 on Nitisol in southeastern Ethiopian highlands to study the effect of phosphorus (P) fertilizer rate on yield, yield components, and oil content of linseed. It comprised of six levels of P fertilizer (0, 5, 10, 15, 20, and 25?kg?P?ha^?1) arranged in randomized complete block design with three replications. Results revealed that P fertilization brought significant effect on biomass yield, harvest index, plant height, number of capsules per plant, and kernel size. However, it didn’t significantly increase seed yield and oil content on linseed. Considering its influence on increasing biomass yield and improving yield components, application of 5?kg?P?ha^?1 has been recommended for replenishing the extracted P, maintaining soil fertility and improving linseed production on Nitisols of southeastern Ethiopian highlands and other similar agro-ecologies.     

适宜氮肥可提高人工羊草的抽穗数和种子产量

【目的】 施用氮肥是禾本科牧草种子高产的关键管理措施之一。为提高羊草种子产量,在人工羊草地上探讨施用氮肥对羊草种子产量及其构成因子的影响,以期为羊草种子生产提供理论和实践依据。 【方法】 试验于 2013～2015 年进行,以中科 2 号羊草 [Leymus chinensis (Trin.) Tzvel ‘Zhongke No.2’] 为材料,设置 5 个氮肥处理水平,分别为 N 0、60、120、180、240 kg/hm2,氮肥在返青期 (4 月上旬) 和种子完熟后 (7 月下旬) 施入,两个时期各施 1/2,羊草种子完熟时测定种子产量和产量构成因子。 【结果】 施氮量和年际对种子产量影响显著。随生长年限延长,羊草种子产量逐年增加。2013 年和 2014 年种子产量随施氮量增加呈先增加后降低的趋势,2013 年施用氮肥 104.9 kg/hm2 时羊草产量最高,为 395.2 kg/hm2,但氮肥对种子产量影响不显著,2014 年施用氮肥 173.5 kg/hm2 时产量最高,为 857.8 kg/hm2,较不施氮肥显著增加 56.0%。2015 年种子产量随施氮量增加而增加,施用氮肥 180 kg/hm2 时种子产量达较高水平为 1865.0 kg/hm2,与施用氮肥 240 kg/hm2 差异不显著,较不施氮肥显著增加 206.5%。通径分析结果表明,种子产量与抽穗数呈极显著正相关 ( r = 0.883, P < 0.01),抽穗数对种子产量的直接作用最大为 0.717,分蘖数对种子产量的间接作用最大为 0.689,且主要是通过抽穗数产生,抽穗数对种子产量的贡献最大。2013 年施用氮肥羊草抽穗数差异不显著,其后两年随氮肥施用量增加抽穗数的变化趋势与产量相同。三年连续施用氮肥使 2014 年和 2015 年抽穗数显著增加,对种子生产有利。施用氮肥显著增加羊草植株穗长、小穗花数、结实粒数/穗和结实率,而对千粒重和小穗数影响不显著。抽穗数与穗长、千粒重和小花数/小穗呈显著负相关。 【结论】 随生长年限增加,羊草种子高产所需施氮量增大,羊草适宜施氮量为 104.9～180.0 kg/hm2,2013 年以施氮 104.9 kg/hm2 为宜,而 2014 年和 2015 年则以 180 kg/hm2 左右为宜。抽穗数是影响种子产量的最关键因子,不受当年施用氮肥的影响,而与前一年种子完熟后施氮量和 8～10 月降雨量相关。抽穗数增加导致的穗长、千粒重和每小穗花数减少,可以通过添加氮素来给予补偿。      

Effects of the timing of sulphur application on grain yield and yield components of wheat

Pot experiments were conducted to examine the response of wheat to the timing of sulphur (S) application. Plants were fertilized at different Stages from sowing to the end of flowering. Plants grown without a basal S supply (severe deficiency), which showed deficiency symptoms at ear emergence, required fertilization with S at the tillering stage if yield losses were to be completely avoided. Moderate and slight S deficiency, which did not result in symptoms until after ear emergence, required rectification at the second node stage for full yield to be obtained. Treatment effects on yield were closely associated with effects on the number of kernels per ear. The results show that where S deficiency occurs, fertilization is required before symptoms become evident if yield reductions are to be avoided.     

Effects of desert dust on yield and yield components of cowpea (Vigna unguiculata L.)

In order to study the effects of desert dust on yield and yield components of cowpea, two field experiments were conducted in the factorial layout based on randomized complete block design with three replicates in Dezful and Mashhad, Iran in 2015. The experimental treatments were combinations of desert dust in three levels (0, 500 and 1500 µg m^?3), numbers of desert dust application (once, twice and thrice) and two types of desert dust. The desert-dust particles were collected during dust storms occurred in Dezful and Zabol, which are the main sources of dust in Iran. The results showed that the biological yield and the grain yield were significantly decreased in both studied sites (Dezful and Mashhad) when the plants exposed to 500 µg m^?3 desert dust treatment compared to normal conditions. Total soluble sugar and proline contents in plant leaf tissues increased significantly when they affected by 1500 µg m^?3 of desert dust, while the plant height was significantly decreased by increasing the desert-dust concentrations at both sites. Biological yield, grain yield, and 100-seed weight were also significantly affected by the desert dust. Overall, the desert dust has adverse effects on yield of cowpea.     

谷物联合收割机测产数据中的误差分析与处理

产量分布图作为实施精细农业的起点与农业生产管理决策的基础，其精度至关重要，而产量数据误差分析与处理则是提高产量分布图精度的关键。通过连续两年使用带有测产系统的联合收割机进行收获试验，并对得到的产量数据进行分析，发现产量数据中主要存在三类误差，即割幅宽度设置误差、填充时间误差和延迟时间误差。讨论了这三类误差的产生原因、识别和处理方法，并对小麦和玉米在不同收获条件下的误差进行了比较。分析结果表明，割幅宽度设置误差数据所占的比例一般小于6%，填充时间误差数据大于10%，延迟时间误差数据小于1%。     

Effect of sulfur source and rates on yield and yield components of soybean in subtropical soils

Abstract

The supply of sulfur (S) fertilizers, such as phosphogypsum, to new agricultural frontiers has been hindered by the high cost of freight. However, this problem could be resolved by utilizing deposits of rock in the affected regions. Accordingly, a greenhouse study was designed to evaluate the effect of S source and rate on soybean yield. Five S rates (0, 50, 100, and 200?mg kg^?1) and five S sources (S-phosphogypsum, S-Niquelândia rock, S-Araripina rock, S-Grajaú rock, and S-Sulfurgran [90% S0?+?10% bentonite]) were applied to soybean grown in two soil types (Typic Ultisol and Typic Oxisol), which differ in clay content. Regardless of soil type, the application of P-phosphogypsum resulted in a higher grain yield. However, application of the other S sources also improved grain yield as well as total dry weight; S application, in general, improved soybean yield components (number of grains per pod, number of pods per pot, and weight of pods per pot), photosynthetic rate, chlorophyll content, and the S levels of leaves and grains as well as the available sulfate (SO₄^2-) levels in the soil. Therefore, for soybean grown in Typic Ultisol and Typic Oxisol, different S sources effectively improve a variety of variables that ultimately improve grain yield.