陕西武功附近土壤之固氮作用

武功位於西北之黄土区,本区之土壤一般富含磷钾而缺乏氮素(1),肥料之施用在本区甚感不足,赵云梦曾以附农民之最高施吧量,每市亩施用堆吧四大车估计,其加入土壤氮质养分之量,仍不足抵偿每年種植小麥与玉蜀黍自土壤中吸收之量(2),而多数农民之施肥尚不足此数。关于土壤中氨质养分之补充,有一公认之事實,即土壤於适当之环境下,可因微生物活动之结果,而固定空气中之氮素。     

有机肥料对黄潮土有效磷库的影响

通过室内培养与田间长期定位试验，研究了有机肥料有机－无机肥料配合施用对土壤供磷的影响。结果表明，黄潮土经１５年连年施用有机肥料后，土壤速效磷大幅度提高，土壤中活性，中等活性和中稳性有机磷对提高土壤供磷水平有不同程度的作用；施用猪粪等有机肥料，土壤中磷酸酶和生物量磷活性提高，从而改善了作物的磷素营养。     

包膜控释肥料在旱地农田的应用研究进展与展望

就国内外控释肥料在旱地农田中的应用效果、田间养分释放,以及高效施用做了综述,重点总结了控释肥料在不同作物上的增产效果和当前应用研究中存在的问题。施用控释肥料可以提高肥料利用率,减少氮素淋溶损失,并具有增加作物产量和改善蔬菜品质的优点,但控释肥料应用中也存在着养分在土壤中的转化和去向不明,养分释放与作物生长对应性差,忽视环境条件对养分释放影响等问题。并对今后高效施用控释肥的技术研究进行了展望。     

硫对油菜产量和抗逆性的影响

通过田间小区试验 ,研究了施用硫肥对油菜的生长、产量构成因素和抗逆性的影响。结果表明 ,苏北建湖和大丰的潮土尽管土壤有效硫测定值超过临界值 ,但是 ,施用硫肥显著促进油菜的生长发育 ,提高油菜的株高、叶面积、绿叶数等生物学参数和产量。与对照相比 ,施用硫肥处理的分枝数、每株角果数、每角粒数均显著增加 ,但千粒重无显著差异。施用硫肥后植株对冻害和菌核病的抵抗力增强。本研究结果表明 ,对油菜这类需硫量大的作物 ,现有的土壤有效硫临界值不能准确反映其对硫肥的需要 ,其缺硫指标要进一步研究     

硫对油菜产量和抗逆性的影响

通过田间小区试验，研究了施用硫肥对油菜的生长、产量构成因素和抗逆性的影响。结果表明，苏北建湖和大丰的潮土尽管土壤有效硫测定值超过临界值，但是，施用硫肥显著促进油菜的生长发育，提高油菜的株高、叶面积、绿叶数等生物学参数和产量。与对照相比，施用硫肥处理的分枝数、每株角果数、每角粒数均显著增加，但千粒重无显著差异。施用硫肥后植株对冻害和菌核病的抵抗力增强。本研究结果表明，对油菜这类需硫量大的作物，现有的土壤有效硫临界值不能准确反映其对硫肥的需要，其缺硫指标要进一步研究。     

抑菌剂浇施与不均匀施肥对玉米马铃薯生长和产量的影响

农业生产中,肥料和抑菌性农药施用是两种重要的农业生产技术。在施肥过程中,点状和条状施肥是主要的施肥方式,易导致作物生长期内土壤养分以斑块状分布,因此根系趋肥性对农田中作物获取养分具有重要性。而在施用抑菌性农药时,药剂能够通过淋溶等过程进入土体中,对土壤生态环境和根-土过程产生直接或间接的影响。然而目前有关农药施用是否影响作物根系趋肥性,进而改变产量表现还不清楚。本研究选用旱地主要粮食作物玉米和马铃薯为研究对象,通过等量肥料下隔行施用的方式构建土壤养分斑块,在此基础上进行广谱性杀菌剂浇施土壤,研究抑菌性农药对作物利用异质性养分的影响。两年的大田试验数据表明,一定程度上,抑菌剂浇施和隔行施肥能够显著地影响作物的植株生物量、产量,根系生物量及分布,且对玉米生物量影响具显著交互效应,表现为隔行施肥对生物量的显著提高发生在抑菌剂浇施条件下,而抑菌剂对玉米生物量的提高则主要表现在隔行施肥条件下。同时,抑菌剂浇施能够提高作物的根系觅养精确度,其中在马铃薯上达到显著水平,表明抑菌剂浇施对作物适应土壤养分斑块具有一定的促进作用。当然,抑菌农药和养分斑块在影响作物生长过程中的显著性受作物类型和种植年份的影响,具有复杂性。因此,进一步针对不同作物、生态环境和栽培措施,探讨抑菌剂农药在作物适应养分斑块中的作用以及对作物根系趋肥的影响机制,对于了解农药施用对化肥利用的影响具有潜在的价值。     

不同施肥结构对茄子产量、养分吸收及土壤有效养分动态变化的影响

为了解湖南岳阳君山区蔬菜基地土壤肥力状况、不同施肥结构对茄子生长发育的影响。通过田间小区试验、室外采样和室内测定,研究了不同施肥结构对茄子产量、养分吸收和土壤有效养分动态变化的影响。结果表明:(1)有机肥与化肥配合施用较纯化肥处理(NPK),可以显著提高茄子产量,尤以牛粪+化肥(NPKM1)处理茄子产量最高。(2)有机肥与化肥配合施用较当地习惯施肥处理和化肥处理,可以提高茄子对N、P、K养分的吸收量和利用率;(3)在茄子生长的前期,化肥可迅速提高土壤有效养分的含量。在茄子生长的后期,有机肥对提高土壤有效养分的含量有重要作用。由以上结果,根据不同施肥结构茄子的产量和茄子对肥料养分的利用率、土壤养分状况及有效性,初步提出了在茄子生产中增施有机肥的优化施肥结构模式,以保证茄子的丰产优质。     

不同施肥处理对连续三季作物氮肥利用率及其分配与去向的影响

采用室外盆栽试验系统研究了不同施肥处理对连续3个生长季作物生长状况、标记^15N利用率及其分配与去向的影响。结果表明,高量氮肥的施用能显著提高作物的生长和产量,而化肥配施玉米秸秆在第1生长季表现为抑制,第2、第3生长季则相反。作物体内来自标记氮肥的含量和比例随生长季的增加显著下降,高量氮肥和玉米秸秆的施用能显著提高其含量和比例（P〈0.05）。标记氮肥在土壤中的残留率随作物生长季的增加而降低,而标记氮肥的累积作物利用率和总损失率随着生长季的增加而增加,经过连续3季作物的吸收利用,标记氮肥在土壤中的残留率、累积作物利用率和总损失率分别平均为15．82％、61．11％和23．07％。标记氮肥的作物利用率和损失率主要发生在第1生长季内,高量氮肥的施用降低了标记肥料氮在土壤中的残留率,增加了氮素损失率;与单施化肥处理相比,化肥配施玉米秸秆能明显增加标记肥料氮在土壤和作物中的回收率,降低氮素损失率,提高比例为21．74％,从而说明在施肥当季,通过施入高C/N比有机物料玉米秸秆合理调节土壤中C源和N素营养的施用比例,可以达到增加氮肥在土壤中的残留率,提高氮肥利用率的目的。     

腐殖酸生物活性肥料对冬小麦生长及土壤微生物活性的影响

施用腐殖酸生物活性肥料对冬小麦生长和土壤微生物活性的试验结果表明,于等量无机养分水平下,施用腐殖酸生物活性肥料冬小麦群体发育平稳,改善植株性状明显,增强抗逆性能。与施用无机复混肥和习惯施肥处理相比,施用腐殖酸生物活性肥料,冬小麦穗长分别增加0.4和0.5cm,旗叶面积分别增加0.7和1.1cm2,次生根条数分别增加1.3和2.2条。产量构成因素中有效穗数,穗粒数和千粒重施用生物活性肥处理也明显高于无机复混肥和习惯施肥,其产量分别增加9.0％和15.2％,差异达显著水平。同时腐殖酸生物活性肥料能够促进土壤有益微生物繁衍,使土壤微生物数量明显增加,提高土壤脲酶、蔗糖酶、磷酸酶和过氧化氢酶活性,对提高肥效,增强土壤肥力,改善作物营养环境有一定作用。     

黄山区茶叶有机肥替代化肥试验初报

作物的生长离不开肥料,但单纯施用化肥会使土壤板结,影响作物产量及品质。有机肥因为能够减少环境污染,调节土壤养分比例,正逐步取代化肥使用。本试验在茶叶生产上使用有机肥和化肥配比施用,探索茶叶生产过程中最合适的有机肥和化肥配比及正确的施肥方式。     

一株具有ACC脱氨酶活性固氮菌的筛选与鉴定

ACC（1-aminocyclopropane-1-carboxylate, 1-氨基环丙烷-1-羧酸）脱氨酶是近年来发现的许多植物促生细菌（Plant growth promoting bacteria, PGPB）共有的一个特征性酶,很多具有ACC脱氨酶活性的细菌能够增强植物抗逆性,缓解干旱、淹水、盐碱、高温、病虫害等对植物的危害。因此,ACC脱氨酶阳性细菌的筛选和研究对促进农业生产具有重要意义。本文从大量样品中分离、筛选到1株ACC脱氨酶阳性固氮菌,编号为7037,该菌株ACC脱氨酶活性为-丁酮酸2.530 mol /(hmg),protein,固氮酶活性为C2H410.068 nmol /(hmg), protein;具有较为广泛的碳源利用能力和很强的环境适应能力,被鉴定为节杆菌属（Arthrobacter sp.）的一个种。盆栽试验显示,小白菜接种7037菌株比对照组鲜重增加了139%,差异极显著。该菌株可望进一步研究开发成为微生物肥料的生产菌种。     

Macronutrient omission and the development and nutritional status of basil in nutritive solution

The correct nutrition of basil (Ocinum basilicum L.) is important to increase its production and quality; however, few papers have deal with this subject. The aim of this work was to evaluate the effects of omission of individual macronutrients on the growth and nutritional status of basil cultivated in nutritive solution. The treatments consisted of nutrient solutions with nitrogen, phosphorus, potassium, calcium, magnesium or sulfur (N, P, K, Ca, Mg, or S) omissions and a complete solution treatment. The plants were cultivated in 8 L plant pots. Plant height, number of leaves per plant, leaf area, relative chlorophyll index, net photosynthesis rate, stomatal conductance, plant dry matter, concentration levels of macronutrients in the aerial part and root system, and nutritional disorders were all evaluated. Nutrient omission was a limiting factor for plant development, substantially reducing its growth. There was also a considerable decrease in nutrient accumulation when compared to the control treatment.     

Advances in fungal-assisted phytoremediation of heavy metals: A review

Trace metals such as manganese (Mn), copper (Cu), zinc (Zn), and iron (Fe) are essential for many biological processes in plant life cycles. However, in excess, they can be toxic and disrupt plant growth processes, which is economically undesirable for crop production. For this reason, processes such as homeostasis and transport control of these trace metals are of constant interest to scientists studying heavily contaminated habitats. Phytoremediation is a promising cleanup technology for soils polluted with heavy metals. However, this technique has some disadvantages, such as the slow growth rate of metal-accumulating plant species, low bioavailability of heavy metals, and long duration of remediation. Microbial-assisted phytoremediation is a promising strategy for hyperaccumulating, detoxifying, or remediating soil contaminants. Arbuscular mycorrhizal fungi (AMF) are found in association with almost all plants, contributing to their healthy performance and providing resistance against environmental stresses. They colonize plant roots and extend their hyphae to the rhizosphere region, assisting in mineral nutrient uptake and regulation of heavy metal acquisition. Endophytic fungi exist in every healthy plant tissue and provide enormous services to their host plants, including growth enhancement by nutrient acquisition, detoxification of heavy metals, secondary metabolite regulation, and enhancement of abiotic/biotic stress tolerance. The aim of the present work is to review the recent literature regarding the role of AMF and endophytic fungi in plant heavy metal tolerance in terms of its regulation in highly contaminated conditions.     

K和Al对水稻生长和养分吸收的影响

The effects of K and Al in K-deficient and complete nutrient solutions on the growth and nutrient uptake of rice were studied in the work.The effect of Al on the growth of roots and above-ground part of rice was associated with the concentration of Al in solution .A low level(0.1 mmol L^-1) of Al promtoed but a high level(1 mmol L^-1)of Al inhibited the growth of both the root and the aerial part of rice,and the magnitude of K concentration in the nutrient solution also had an appreciable impact on this,Thus ,in the low-Al solution,the plant treated with K2(80 mg K L^-1)produced much longer roots,showing the presence of interaction between Al and K; in the high-Al solution the K-reated plant had more and longe roots and a considerably greater dry weigh of the above-ground part compared with the plant deficient in K, showing the alleviating effect of K^ on Al toxicity.The mechanism of the Al-K interaction affecting the rice aerial part growth is not yet known,but part of the reason might be that the excessive amount of Al inhibited the uptake of some nutrients such as Ca and Mg and reduced their transfer to the plant aerial organs,whereas K showed its compensating effect on this;therefore,K could relieve Al toxicity at a high level of Al and promoted rice growth at a low level of Al.     

The apoplast — its significance for the nutrition of higher plants

Since the fundamental work of the botanist Ernst Munch there has been a clear differentiation between a symplastic and an apoplastic compartment of plants, separated by the plasmalemma. In contrast to the symplast, the apoplast was considered as being dead and hence attracted little interest. It is not before the late seventies of this century that plant scientists realised that processes such as growth and differentiation as well as signal transduction may not be understood without accounting for apoplastic processes. Since then growing evidence has supported the view that apoplastic properties are of significance for such diverse processes as genotypic variation in nutrient efficiency and tolerance against adverse ion relations, for plant/microbe interaction, or for water and nutrient transport. In this contribution we review apoplastic properties and processes in relation to plant mineral nutrition. Examples are taken from work being conducted in the scope of the special research project of the German Research Foundation “The apoplast of higher plants: compartment for storage, transport and reactions” and especially from own work.     

温室番茄果实生长模型的建立与实现

为深入研究果实坐果机理,在现有模型基础上,以温室番茄为研究对象开展温室试验,结合温室环境的可控性和计算机软件设计,观察不同密度植株的动态坐果率,通过模型分析动态坐果率与植株内部动态同化物供给与需求比率（Q/D）之间的关系,建立反映果实从坐果到发育与全局生物量动态反馈的生长模型,并用独立数据进行了生长模拟,生物量和几何尺寸的模拟值与试验数据接近,验证了模型的有效性。模型的建立完善了GreenLab模型在果实方面的处理功能,实现了植株坐果的定量化研究。     

Non-rhizobial peanut nodule bacteria promote maize (Zea mays L.) and peanut (Arachis hypogaea L.) growth in a simulated crop rotation system

The term “Plant Growth Promoting Bacteria” or PGPB designates a diverse group of prokaryotic microorganisms that can increase plant growth by diverse mechanisms. Some PGPB are capable of colonizing root inner tissues and constitute endophytic populations. Incorporation of these microorganisms into agricultural practices may constitute a valid alternative to increase crop productivity in a sustainable and environmentally friendly production scheme, reducing the application of agrochemicals. In a previous work, we described the characterization of bacteria belonging to Pseudomonas, Enterobacter and Klebsiella obtained from surface sterilized peanut nodules. In addition, we showed that some of these isolates were able to promote several peanut growth and symbiotic parameters. Bounded to the results from this particular study, and considering their potential ability to interact with different plant species, in this work we assessed the effects of their inoculation in maize (Zea mays L.) under controlled conditions. Furthermore, we analyzed growth promotion in a simulated peanut–maize crop rotation system. Finally, we determined the plant growth promoting (PGP) properties present in the isolates. Results indicated that all bacteria are able to significantly promote maize and peanut growth, and that they also displayed plant growth promotion activity in maize growing in a peanut–maize crop rotation sequence.     

By-Plant Prediction of Corn (Zea mays L.) Grain Yield using Height and Stalk Diameter

Methods for determining midseason nitrogen (N) rates in corn have used the parameter normalized difference vegetation index (NDVI) and, in some cases, plant height. The objective of this study was to analyze the relationship of stalk diameter along with predictors of yield, including NDVI and plant height with grain yield. Five site-years of data were analyzed, where several rows of corn plants were selected, and yield from plants within the row was recorded individually. Measurements of stalk diameter, plant height, and NDVI were taken from growth stages V8–VT. Using a value of stalk diameter × plant height gave the best correlation with grain yield (r² = 0.34, 0.55, 0.67; V8, V10, V12, growth stages respectively). This work showed that stalk diameter × plant height was positively correlated with by-plant corn grain yields, and this parameter could be used for refining midseason fertilizer N rates for growth stages V8–V12.     

Effect of soil compaction on photosynthesis and carbon partitioning within a maize–soil system

Soil compaction is known to affect plant growth. However, most of the information regarding the effects of this factor on carbon partitioning has been obtained on young plants while little is known about the evolution of these effects with plant age. The objective of this work was to investigate how soil compaction affects carbon assimilation, photosynthate partitioning and morphology of maize plants during vegetative growth up to tassel initiation. A pressure was applied on moist soil to obtain a bulk density of 1.45 g cm⁻³ (compacted soil (CS) treatment) while the loose soil (LS) treatment (bulk density of 1.30 g cm⁻³) was obtained by gentle vibration of soil columns. Plants were grown in a growth chamber for 3–6 weeks and carbon partitioning in the plant–soil system was evaluated using ¹⁴C pulse-labelling techniques. Soil compaction greatly hampered root elongation and delayed leaf appearance rate, thereby decreasing plant height, shoot and root dry weights and leaf area. The increase in soil bulk density decreased carbon assimilation rate especially in early growth stages. The main effect of soil compaction on assimilate partitioning occurred on carbon exudation, which increased considerably to the detriment of root carbon. Furthermore, soil microbial biomass greatly increased in CS. Two hypotheses were formulated. The first was that increasing soil resistance to root penetration induced a sink limitation in roots and this increased carbon release into the soil and resulted in a root feedback that regulated carbon assimilation rate. The second hypothesis relies on soil–plant water relations since, due to compaction, the pore size distribution has to be considered. In a compacted soil, the peak of the pore size distribution curve is shifted towards the small pore size. The volume of small pores increases and the unsaturated conductivity decreases substantially, when compared to non-compacted soil. Due to small hydraulic conductivity, the inflow into the roots is well below optimum and the plant closes stomata thus reducing carbon assimilation rate. The effects of soil compaction persisted with plant age although the difference between the two treatments, in terms of percentage, decreased at advanced growth stages, especially in the case of root parameters.     

植物吸收转运硝态氮及其信号调控研究进展

硝态氮是植物吸收利用的主要氮源,其吸收利用是一个高度协调复杂的调控过程。植物为了在各种变化的环境中生存,进化出了适宜不同环境的硝态氮吸收利用机制。植物根系中存在不同类型的硝态氮受体,可以感受外界硝态氮浓度变化,并启用高亲和力或低亲和力硝态氮吸收系统,从而吸收硝态氮;硝态氮进入根系后,大部分被运输到地上部进行同化作用,合成大分子物质,以促进植物生长;如果地上部硝态氮含量过多,植物可把多余的硝态氮运送到液泡内储存,待需要时再从液泡转运至细胞质中利用。植物生长发育过程中,老叶和成熟叶片中的硝态氮可被转运到新生组织中,促进新生组织生长。硝态氮吸收利用过程中大量硝态氮吸收、转运、储存、同化和信号调控基因被有序激活并协调工作,促进植物高效吸收利用硝态氮。本文主要针对NRT1和NRT2硝态氮吸收转运相关基因及其功能,以及参与初级硝态氮反应的相关转录因子和小信号多肽在硝态氮信号传导和组织间的信号交流进行综述,以便深入理解植物吸收利用硝态氮的机理,为高效利用氮素的作物育种和栽培技术的创建提供新的思路。