The effect of integrative crop management on root growth and methane emission of paddy rice

In previous studies, integrative crop management (ICM) improved shoot growth and grain yield of rice (Oryza sativa L.). However, little is known about the effect of ICM on root growth and methane (CH4) emission of paddy rice. In this study, two rice varieties, Wuyunjing 24 and Yongyou 2640, were grown. A field experiment was conducted with three crop management treatments including zero nitrogen fertilization (0N), local farmer practice (LFP), and ICM. Root morphophysiological traits and CH4 emission from the paddy field were investigated. ICM significantly increased mean grain yield by 29.9%, with the effect attributed mainly to an increase in mean total number of spikelets by 26.4% compared to LFP. ICM increased root and shoot biomass, root length, number of roots, root oxidation activity (ROA), root bleeding rate, and root total and active absorbing surface area by respectively 24.4%, 25.7%, 17.1%, 9.3%, 18.7%, 29.5%, 12.1%, and 24.7%. The concentrations of malic, succinic, and acetic acids in root exudates were respectively 5.8%, 6.0%, and 10.5% higher in ICM than in LFP. Compared to LFP, ICM significantly decreased the rate of CH4 emission during emission peak stages and reduced total CH4 emission by 17.1%. The root morphophysiological traits were positively and significantly correlated with grain yield, whereas root length, specific root length, ROA, and root total and active absorbing surface area were negatively and significantly correlated with total CH4 emission. These results suggest that ICM could achieve the dual goals of increasing grain yield and reducing the greenhouse gas effect by improving the root morphology and physiological traits of paddy rice.

Adaptation of Root Crop Farming System to Climate Change in Ikwerre Local Government Area of Rivers State, Nigeria

This study examined adaptation of root crop farming system to climate change in Ikwerre Local Government Area of Rivers state, Nigeria. Seven towns were selected based on a population of five thousand and above from which one hundred and ninety-one respondents were randomly chosen. Sixty-six years’ data on climatic variables of rainfall, temperature and relative humidity were obtained from Nigeria Meteorological Agency between 1950-2015. Analyses were carried out using simple proportion for qualitative variables while mean and standard deviation were used in analyzing the qualitative variable. Similarly, the triangulation method involving qualitative and quantitative components in data generation was used. Results showed that, there had been a steady but gradual increase in the mean annual minimum and maximum temperatures over the study period of thirty years. The overall mean rainfall computed was 191.1 mm. In general, there was a shift increase in both rainfall and temperature during the period under study. The respondents attributed crop failure (100%), reduced crop yield (100%), increase incidence of pest and diseases (100%) and delay in planting period (100%) as direct effects of climate change. A steady trend in relative humidity of (84.3%) was recorded and the mean annual wind speed computed was 67.9 knots. The adapted strategies include delay planting period, crop diversification 100%, cultivation of early maturing crops such as maize, vegetables, intercropped with the root crops and changes in the time of farm operations (99.4%) as well as a change in the planting period and changing farm location (98.9%). The latter will in addition to other benefits reduce the incidences of pest and diseases that may be attracted to the same field if continuously cultivated with the same crops. An implementable policy of accessibility of finance to the real farmers is seriously advocated.

Root zone soil moisture redistribution in maize (<i>Zea mays</i>L.) under different water application regimes

Soil moisture availability to plant roots is very important for crop growth. When soil moisture is not available in the root zone, plants wilt and yield is reduced. Adequate knowledge of the distribution of soil moisture within crop’s root zone and its linkage to the amount of water applied is very important as it assists in optimising the efficient use of water and reducing yield losses. The study aimed at evaluating the spatial redistribution of soil moisture within maize roots zone under different irrigation water application regimes. The study was conducted during two irrigatation seasons of 2012 at Nkango Irrigation Scheme, Malawi. The trials consisted of factorial arrangement in a Randomised Complete Block Design (RCBD). The factors were water and nitrogen and both were at four levels. The Triscan Sensor was used to measure volumetric soil moisture contents at different vertical and lateral points. The study inferred that the degree of soil moisture loss depends on the amount of water present in the soil. The rate of soil moisture loss in 100% of full water requirement regime (100% FWRR) treatment was higher than that in 40% FWRR treatment. This was particularly noticed when maize leaves were dry. In 100% FWRR treatment, the attraction between water and the surfaces of soil particles was not tight and as such “free” water was lost through evaporation and deep percolation, while in 40% FWRR, water was strongly attracted to and held on the soil particles surfaces and as such its potential of losing water was reduced.

异源双根缓解咖啡连作障碍及其机制初探

为明确异源双根是否能缓解咖啡连作障碍及其可能机制,本研究以大粒种咖啡1号(Caffealiberica,No.1)和中粒种咖啡热研1号(Caffea canephora, Reyan No. 1)靠接形成大粒种-中粒种异源双根咖啡,通过咖啡连作障碍园土壤培养幼苗,评价植株苗木质量,明确异源双根对咖啡连作障碍的缓解作用。通过双根无分隔、尼龙网分隔、双盆分隔等不同分根方式试验,明确异源双根缓解咖啡连作障碍机制,并探讨双根间在缓解连作障碍上的差异及协同作用。结果表明:较连作障碍咖啡园非根际土,异源双根咖啡或同源双根咖啡经根际土培养后苗木质量指数、总的植株生物量均显著下降,连作逆境抑制咖啡生物量积累,使苗木质量变差;非根际土培养后,异源双根咖啡、同源双根咖啡的苗木质量指数和总的植株生物量差异均不显著;而根际土培养后,异源双根咖啡较同源双根咖啡的苗木质量指数、大粒种根系生物量、中粒种根系生物量及总的植株生物量均显著提高。因此,连作逆境虽抑制咖啡生长,但对同源双根咖啡影响更大,异源双根通过其大粒种根系缓解连作逆境咖啡生长障碍。为进一步明确异源双根尤其是大粒种根系缓解咖啡连作障碍的可能机制,以不同分根方式培养异源双根咖啡,发现较无分隔、双盆分隔处理,连作逆境下双根尼龙网分隔后植株苗木质量佳,并且尼龙网分隔后植株的中粒种根系长势最好,说明大粒种根系化感物质促进中粒种根系生长。双根无分隔、双盆分隔后植株的苗木质量差异不显著,无分隔较双盆分隔后植株的大粒种根系长势差,即双根系在能够彼此接触的自然生长状态下,中粒种根系抑制大粒种根系生长,但这种抑制作用与中粒种根际化感物质无关,尼龙网分隔、双盆分隔后大粒种根系长势差异不显著,说明大粒种根际有无中粒种根际化感物质,对大粒种根系生长均无影响。综上所述,异源双根通过其大粒种根系减少自身在连作逆境中的化感抑制,利用其根际化感物质促进中粒种根系生长,实现根壮苗壮,达到缓解咖啡连作障碍的目的。研究结论为异源双根靠接在大田的推广应用提供理论依据。

Under-Winter Sowings of Red Beetroot in Uzbekistan

The results of the three-year researches which had the purpose to establish an optimum depth of seeding at sowing and rational norm of seeding of red beetroot seeds at under-winter sowing in conditions of mid-loamy typical grey soils of the central climatic zone of Uzbekistan are stated in article. The researches were spent at statement of field experiences in quadruple frequency with the area of a registration allotment 10 M^-1. Crops were carried out in the first decade of December against mulching surfaces of ridges by humus and without mulching. Crops were carried out on ridges in width of 70 sm tape-two-lined with distance between tapes of 50 sm, between lines-20 sm and distance between plants in a line of 12-13 sm, at density of standing of 228-230 thousand plants/hectares. Experiences were spent with zoned in Uzbekistan multi-seedling grade of a red beetroot ＂Bordo 237＂. Experiences were accompanied by phenological supervision, biometric accounts, the account of field germination of seeds, density of standing of plants and definition of size and quality of a crop. Results of researches were exposed to the statistical analysis by a dispersive method. It has been revealed that at under-winter sowing of a red beetroot the effective way providing acceleration of shoots occurrence, formations of high-grade density of standing and increase of productivity of root crops is mulching the surfaces of ridges by humus. It is defined that optimum depth of seeding at sowing both at application of mulching and without it is the depth of seeding 4 sm. It is established that the most rational norm of seeding of the seeds, providing high-grade density of standing, is at cultivation with application of mulching 8 kg/ha, and at cultivation without mulching 8-10 kg/ha. Application of mulching the surfaces of ridges by humus, depths of seeding of 4 sm and norms of seeding of seeds of 8-10 kg/ha in conditions of under-winter sowing in comparison with cultivation without mulching and depth of seeding 2 sm and norms of seeding of 6 kg/ha provides an acceleration of receipt of fresh production of a red beetroot for 12-14 days and considerably raises root crops productivity. Application of agro receptions improved by us is the important reserve of acceleration of receipt of red beetroot early production and increase of its manufacture.

基于根区温度和肥料浓度耦合的草莓生长调控

为探索草莓根区加热的最适温度及施肥浓度,该研究设置3个根区温度水平(不加温(8℃)、16、22℃)和3个肥料浓度水平(0.5、1.5、2.5 g/L),共计9个处理。分析了根区温度和肥料浓度协同作用对草莓产量、品质、肥料偏生产力、水分利用率的影响。结合层次分析法和CRITIC客观赋权法,运用优劣解距离法对各处理进行基于草莓产量、品质、肥料偏生产力、水分利用率的综合评价。结果表明:1)采用根区加温对设施草莓生长有促进作用。在采摘第3茬果实时,加温到16℃和22℃的处理下可以采摘的草莓植株数量相较于不加温处理明显增加。2)肥料浓度对草莓生长综合评分的影响大于根区温度。高肥料浓度(2.5 g/L)会降低草莓产量,中肥料浓度(1.5 g/L)不仅能增加单果质量,还能提高肥料偏生产力和水分利用率,具有更好的经济效益。3)基于TOPSIS综合评价建立了设施草莓生长综合评价体系,得出评分最高的处理为T5处理(16℃,1.5 g/L)。通过寻找最优区间,结果发现根区温度在13.10~18.47℃,肥料浓度在1.43~1.87g/L时,设施草莓生长效果较好。该研究结果可为设施草莓冬季及早春的温度和肥水管理提供理论依据。

连作烟草根系分泌物鉴定及潜在化感物质的筛选研究

为探索长期连作状态下烟草根系分泌物内含有的化感物质组成成分,设置石英砂栽培和连作土壤栽培2种烟草培养处理,对2种烟草不同生长时期的根系分泌物进行提取,利用超高效液相色谱串联质谱(ultra-high performance liquid chromatography tandem mass spectrometry,UHPLC-MS/MS)对提取的根系分泌物进行分析,通过数据库比对、差异分析和时间聚类分析等方法筛选连作烟草根系分泌物中潜在的化感物质。结果表明,共筛选出11类潜在化感物质,分别为生物碱、萜类、胺类、有机酸、苯酸及其衍生物、脂肪酸、酚类、氨基酸和多肽、香豆素、肉桂酸及其衍生物和其他。生物碱、萜类、胺类和有机酸4类化合物相对含量占所有化合物的73.3%。L-烟碱、熊果酸、β-氨基丙腈、5-羟基吲哚乙酸、早熟素Ⅱ、单乙基己基邻苯二甲酸、己内酰胺、姜酚、L-乳酸、邻苯二甲酸二乙酯和2,3-二氢-3,5-二羟基-2-氧代-3-吲哚乙酸甲酯是连作烟草根系分泌物中相对含量较高的潜在化感物质。研究结果为烟草根系化感物质的化感作用研究及缓解烟草连作障碍方法研究提供理论基础。

羊粪对土壤性状及植物生长影响的研究进展

羊粪作为一种常见的热性肥料,富含氮、磷、钾等元素,可以改善土壤理化性状,并且通过土壤微生物与植物根际营养之间的互作促进作物生长,提高农作物品质,从而实现农业绿色可持续发展和循环经济,最终形成种养结合型生态循环农业模式的长效机制。该文概述了施羊粪改善土壤理化性质,提高土壤酶活性和微生物多样性,进而促进植物根系生长发育与农作物品质方面的研究进展,并展望了羊粪在未来农业发展中的应用趋势,旨在为农业绿色发展提供施肥依据。

草莓连作根腐病原菌及根际真菌群落变化多样性研究

草莓是一种兼具营养和经济价值的水果,草莓连年栽培导致连作障碍发生严重,发病率逐渐增加,严重影响了草莓的产量。从连作3年且患有根腐病的草莓根际土壤中分离出病原菌,经鉴定分别为Fusarium pseudocircinatum、Fusarium solani、Fusarium luffae、Aspergillus westerdijkiae、Cladosporium oxysporum、Ectophoma multirostrata、Neopestalotiopsis rosae和Neocosmospora rubicola。进一步对连作前后草莓根际土壤真菌变化进行分析,结果表明,连作后真菌总数量下降,在属水平上,Pulvinula、Aspergillus、Acremonium、Funneliformis、unclassified_Cercozoa和unclassified_Pezizaceae等真菌的相对丰度均显著或极显著增加,unclassified_Hypocreales、Mortierella和Rhizophlyctis等真菌的相对丰度均显著或极显著降低。对连作后土壤的理化性质进行检测,结果表明,有机质含量极显著降低,全磷、硝态氮含量极显著增加,pH值显著增加。这说明土壤理化性质的改变和优势菌种的更替都是导致草莓连作障碍发生的原因,可为防治草莓根腐病和连作障碍提供科学依据。

添加生物炭对连作辣椒生长及根系生理代谢和产量的影响

旨在研究添加生物炭对宁南连作辣椒生长、根系生理代谢和产量的作用效果,为使用生物炭缓解宁南拱棚辣椒的连作障碍以及生物炭合理用量提供理论依据。2021年4月-2021年9月在宁夏回族自治区固原市彭阳县连作7 a的拱棚辣椒上开展生物炭添加试验,以彭阳县当地主栽的辣椒品种‘方兴大将军’为试验材料,以拱棚内垄上25 cm土层每千克土壤干质量的百分比等比递增设置5种生物炭梯度:0%(T0)、0.5%(T1)、1%(T2)、2%(T3)、4%(T4)。在2021年的幼苗期和盛果期测定并分析各处理辣椒的农艺性状、叶绿素含量以及盛果期的根系生长指标、根系生理指标以及果实维生素C含量和产量。结果表明:首先,施加生物炭显著提高了连作辣椒的茎粗,但对辣椒的株高、分枝数和叶面开展度无影响;施加生物炭优化了辣椒叶片的光合性能;增加了根长、根表面积和根体积,根系活力明显增强。其次,施加生物炭处理下,辣椒根系超氧化物歧化酶(SOD)、过氧化氢酶(CAT)和抗坏血酸过氧化物酶(APX)的活性显著增强,从而减少了根系中丙二醛(MDA)、过氧化氢(H_(2)O_(2))的积累;生物炭的添加降低了植株受胁迫的程度,从而维持了根系中脯氨酸(Pro)、可溶性糖等渗透调节物质含量的较低水平。最后,施加生物炭增加了辣椒果实中维生素C含量,提高了果实总产量。此外,生物炭对辣椒连作障碍的改良有一定的阈值,过多的生物炭添加量会对连作辣椒的生长产生不利影响。施加生物炭降低了由连作带来的逆境胁迫的伤害,有效地缓解了辣椒的连作障碍。根据本试验结果,宁南连作拱棚辣椒的生物炭推荐使用量为2%。

地下滴灌关键技术参数对砂土地区苜蓿根系与产量的影响

为研究地下滴灌条件下,适宜于紫花苜蓿根系生长和高产的滴头流量、滴灌带埋深以及灌水定额,采用田间试验,设3个滴灌带滴头流量(1.38、2.00、3.00 L/h),3个滴灌带埋深(10、20、30 cm)和3个地下滴灌灌水定额(15.0、22.5、30.0 mm),研究了不同地下滴灌关键技术参数对苜蓿根系与产量的单因素影响。结果表明:滴头流量为2.00 L/h时更有利于苜蓿根系的生长,滴灌带埋深对苜蓿侧根的影响显著;灌水定额对苜蓿的根系比表面积、根尖数、侧根发生数、侧根位置影响显著;小滴头流量处理的苜蓿产量总体上高于大滴头流量处理;滴灌带埋深对苜蓿产量的影响不显著;在一定范围内,随着灌水定额的增大,苜蓿产量增加。综合节水与产量因素,建议鄂尔多斯市鄂托克前旗地区紫花苜蓿地下滴灌关键技术参数:滴头流量为2.00 L/h、滴灌带埋深为20 cm、灌水定额为22.5 mm。

节水灌溉对块根作物和土壤微生物影响的研究进展

我国是人均水资源匮乏的国家,节水灌溉对于绿色农业和经济社会的可持续发展具有重要现实意义。本文围绕节水灌溉对块根作物产量与品质、农田土壤微生物的影响,阐述当前研究进展,并提出亟待解决的关键问题,以期为块根作物增产提质和水资源高效利用提供理论依据。

连作根系分泌物加剧土传病害的机制和缓解措施研究进展

基于植物-土壤反馈理论,连作体系中的根系分泌物必然在加剧土传病害发生中起重要作用,但相关研究证据尚缺少系统总结。本文梳理了连作加剧土传病害发生的现象以及连作累积典型根系分泌物组分的案例。从有利于土传病原菌由土体向根际迁移、增殖和致病(“利病”)、破坏根际有益微生物群落防线(“压益”)和毒害根系免疫系统(“自毒”)等三个方面,阐述连作根系分泌物中某些物质促进土传病原菌入侵的机制。从根系分泌物的角度阐述轮作、间作、套作、伴生和嫁接等多样性种植方式缓解连作土传病害的发生机制。提出鉴定“利病”、“压益”和“自毒”物质以及构建对应的消减技术途径,可为土传病害绿色高效综合防控提供科学支撑。

种植方式与施氮量对杂交籼稻养分吸收特性及根系活力的影响

为探明不同种植方式与施氮量对杂交籼稻养分吸收特性、产量及根系活力的影响,以杂交籼稻F优498为试验材料,采用二因素裂区设计,主区为3种种植方式(毯苗机插、湿润精量穴直播和人工移栽),副区为4个施氮量(0 kg hm^(-2)、90 kg hm^(-2)、135 kg hm^(–2)和180 kg hm^(–2)),探究F优498在不同处理下对养分积累、根系活力、产量及其构成因子的影响。结果表明,水稻抽穗期及成熟期的氮积累量均为人工移栽>机插>直播,拔节期磷积累总量和抽穗期钾积累总量均为人工移栽最大,拔节前直播稻的氮、磷和钾积累速率最高,分别比机插和人工移栽高40.68%~63.64%和19.42%~71.43%,不同种植方式下均在拔节至抽穗期养分积累速率达到最大;人工移栽和机插方式下水稻产量差异不显著,直播与人工移栽相比,减产8.09%~15.00%,人工移栽的水稻千粒重、穗粒数和结实率均高于机插和直播,但有效穗数显著降低,分别比机插和直播低15.99%~41.77%和23.19%~29.60%,施氮后产量的显著提高是由于提高了单位面积有效穗数和每穗粒数;各种植方式的地上部和根系干物重分别在成熟期和抽穗期达到最大,就不同施氮量而言,施氮处理的群体根系干物重显著高于不施氮处理;水稻抽穗后单茎和群体伤流强度降低,机插的单茎及群体根系活力显著高于人工移栽和直播。机插稻施氮量在中低氮水平(90~135 kg hm^(-2))较适宜,直播稻和人工移栽稻施氮量在中高氮水平(135~180 kg hm^(-2))较适宜。

不同类型作物根系对黑土物理特性和根际土壤性质的影响

为研究不同类型作物根系对黑土物理特性和根际土壤性质的影响,本研究以油菜、大葱、辣椒、小麦、玉米和大豆6种不同作物为研究对象,通过盆栽试验,测定各种作物不同生长阶段根际土壤的物理属性、养分状况和微生物量碳含量,并分析各种作物的根系特征,解析作物根系特征对根际土壤性质的影响。结果表明,6种作物在生长过程中均不同程度提高了根际土壤的饱和含水量和最大田间持水量,改善了土壤三相结构,其中大葱改善土壤三相结构的效果最好。与起始相比,6种作物种植51 d后的土壤有机碳和全氮含量分别提高了0.9%~3.2%和1.0%~15.0%,大豆处理全氮含量提升最显著。相关性分析发现作物生物量与土壤全氮、土壤微生物量碳呈显著正相关关系,与土壤C∶N、饱和含水量和最大田间持水量呈显著负相关关系。主成分分析表明:PC1和PC2分别解释根际土壤性质变化26.0%和22.9%的影响;作物的地上与地下生物量在不同作物种类间差异显著;土壤的物理指标主要受作物不同生长时期影响,土壤饱和含水量与最大田间持水量随生长时间变化显著。综合分析,种植大葱对根际土壤物理属性改良效果最好,种植大豆更有利于根际土壤有机碳和全氮含量的提升。

作物耐低磷机制研究进展

磷是作物生长发育必需的营养元素之一,在作物的生命过程中发挥重要作用。作物在长期进化过程中形成了一系列低磷适应机制,主要涉及土壤磷的活化、吸收、转运和内部磷的循环、再利用等过程。从作物低磷胁迫下的根系形态、根系分泌物、与微生物共生体系、分子机制4个方面综述了作物耐低磷机制的最新研究进展,旨在为作物栽培调控及耐低磷作物品种的改良与选育提供借鉴。

硅对连作花生根系生长发育·土壤酶活性·产量和品质的影响

为探明硅缓解障碍机理及最佳施用量,研究了5种施硅肥量(0、15、30、45、60 kg/hm^(2))对连作条件下根系的干物质积累、形态、土壤酶活性、产量和品质的影响。结果表明,与对照相比,F3、F4、F5处理显著促进根系干物质量的积累及长度、直径、表面积、体积的增加,并减少生育后期的衰退;F4、F5处理显著提高了根系土壤中α-葡萄糖苷酶、β-葡萄糖苷酶、过氧化氢酶、纤维素酶、酸性磷酸单酯酶的活性和花生的脂肪、油酸含量及产量,其中F4处理花生荚果产量最高,达4763.05 kg/hm^(2)。综上,硅肥能提高根系土壤酶活性,促进根系生长和干物质积累,提升连作花生产量和品质,在该研究条件下,45 kg/hm^(2)为最佳硅肥施用量。

复合菌剂施用方式对连作土栽培菜心生长、根系构型及光合特性的影响

【目的】考察复合菌剂施用方式对菜心幼苗生长、根系形态及光合特性的影响,为应用复合菌剂缓解菜心连作障碍提供理论依据。【方法】以菜心品种‘尖叶-70’、连作9年菜心土壤及微生物菌剂为试材,设置不施(对照)、叶面喷施、土施及叶面喷施+土施复合菌剂4个处理的盆栽试验,播种30d后观测植株生长、根系构型和叶片光合指标。【结果】各复合菌剂施用方式均能提高幼苗生长指标、根系构型指标以及净光合速率(Pn)、实际光化学效率(ΦPSⅡ)、光化学淬灭系数(qp)等光合指标,降低蒸腾速率(Tr)、胞间CO_(2)浓度(Ci)、非光化学淬灭系数(NPQ)等指标,并以叶面喷施处理效果最优,其地上干重、地下干重、根长分别比对照显著增加了128.57%、85.71%、91.81%,Pn、qp、ΦPSⅡ分别显著增加了24.55%、22.68%、23.93%,而Tr、Ci、NPQ分别显著降低72.73%、20.01%、39.78%。【结论】叶面喷施复合菌剂能有效促进连作菜心幼苗生长,改善根系构型,提高植株光合作用效率,是复合菌剂的最佳施用方式。

有机肥部分替代化肥对不同土壤连作棉花根系的影响

[目的]研究有机肥部分替代化肥对新疆不同连作棉田土壤及棉花根系生长的影响,筛选有机肥部分替代化肥的最佳比例,为新疆连作棉田的科学高效施肥提供参考依据。[方法]在新疆常见的棉田灰漠土和风沙土中种植棉花,采用腐熟的农家鸡粪作为有机肥,设置3个有机肥部分替代化肥处理:T1处理:100%化肥;T2:80%化肥+20%有机肥(有机肥2 250 kg·hm^(-2));T3:60%化肥+40%有机肥(有机肥4 500 kg·hm^(-2))。采用聚氯乙烯管开展试验,研究有机肥部分替代化肥对蕾期和吐絮期棉田土壤理化性质,棉花根系的形态特征、生理特征,以及棉花生物量和产量等的影响。并利用综合隶属函数法对所有指标进行主成分分析和回归分析,综合评价不同比例的有机肥和化肥组合对土壤-棉花系统的整体影响。[结果]有机肥替代化肥的T2处理和T3处理均显著提高灰漠土和风沙土中土壤全氮和有效磷含量。在灰漠土中与T1相比,T2处理的土壤全磷含量在蕾期和吐絮期分别增加14.7%和30.3%、有效磷含量分别增加138.7%和202.6%;T3处理的土壤全氮含量在蕾期增加39.2%、土壤全磷含量在吐絮期增加46.2%。T2处理和T3处理均使灰漠土中棉花根系的总根长、比根长、比根表面积、根系可溶性糖含量、硝酸还原酶活性显著增加,而根系组织密度、地上部生物量显著下降。在风沙土中棉花蕾期,T2处理和T3处理下比根长分别显著增加11.9%和9.6%。在风沙土中棉花吐絮期,与T1相比,T2处理和T3处理下土壤碱解氮含量分别显著增加51.3%和97.9%、总根长分别显著减少26.9%和21.0%;比根长显著减少33.4%和36.5%。对于风沙土中种植的棉花,T2处理下棉花蕾期和吐絮期比根表面积分别显著减少18.8%和19.3%;T3处理显著增加棉花吐絮期根系平均直径(65.3%)和地上部生物量(27.6%)。[结论]有机肥部分替代化肥可以通过改善灰漠土和风沙土土壤理化特征,提高土壤养分含量,促进棉花根系生理活性和优化根系构型,使根系投入更少的生物量以获得更高的养分吸收效益,优化对生物量的分配,最终缓解连作障碍。在灰漠土中,有机肥替代40%化肥处理效果最佳。在风沙土中,有机肥部分替代化肥的影响因有机肥添加比例和生育时期而不同。

不同栽培模式下人参根际土壤代谢物的差异研究

本研究旨在比较仿野生林下栽培人参(PSM)与农田栽培人参(NPSM)根际土壤代谢物的差异,以期为提升林下栽培人参的品质提供科学依据。通过采用气相色谱-串联质谱(GC-MS/MS)检测技术和分子生物学方法,分析了仿野生林下栽培人参和农田栽培人参根际土壤代谢物的差异。结果显示,仿野生林下栽培人参和农田栽培人参根际土壤代谢物具有差异,在检测到的68种差异代谢物中,有17种代谢物表现出显著差异,其中14种上调,3种下调。这些差异代谢物主要包括糖类、脂质类、有机酸类、酯类等物质。其中糖类占总显著差异代谢物的47%,是差异代谢物的主要部分;这些根际土壤差异代谢物直接或间接的影响了林下人参的品质。本研究不仅揭示了林下栽培人参和农田栽培人参根际土壤代谢物的差异,而且为提高林下栽培人参品质、探索克服林下人参栽培连作障碍的新途径以及提升林下人参药用价值和食用价值提供了科学参考。并为中国东北地区林下人参产业发展及乡村振兴战略的实施提供了新思路和方法。