密度、施肥对旱地春小麦产量、水分利用效率和籽粒养分含量的补偿效应

为了探明旱作条件下无机营养对作物产量和水分利用效率的补偿效应,我们在宁南黄土高原半干旱地区开展了为期两年的春小麦密度与肥料试验。通过4种播种密度和5种肥力水平的综合研究结果表明,在不同处理的籽粒产量和水分利用效率排序中,播种密度为500粒／m^2时,以施肥量90kg／hm^2N和135kg／hm^2P2O5处理的产量和水分利用效率为最大。与不施肥的对照相比,增施肥料与籽粒产量和水分利用效率的提高成显著的正相关关系,相关系数分别达到0．959和0．894,而播种密度则与产量和水分利用效率的相关性不显著。增施肥料虽然能够提高可育小花数,但随着播种密度的增大,穗粒数和千粒重反而呈下降趋势,表明可育小花数对肥料水平反应敏感,而穗粒数和千粒重主要受播种密度的影响。施肥能够促进春小麦根系的生长发育,特别是促进浅层根量的增加,增强了作物的水分养分吸收。另外,不同种类肥料配施的结果表明,单施P肥或者N、P、K配合施用,可使春小麦产量分别提高44．6％和55．4％。N、P、K配合施肥还能够提高品质,使籽粒中的P、N、K含量分别提高18．5％、18．4％和8．1％。上述研究结果说明,控制播种密度、改善土壤肥力对于促进旱地春小麦高效利用有限水分具有明显的补偿效应。     

Heritability of,and relationships between phosphorus and nitrogen concentration in shoot,stolon and root of white clover (Trifolium repens L.)

Ninety eight white clover genotypes were cloned and grown in pots at two levels of phosphorus (P) supply in soil. After harvest the nitrogen (N) and P content of shoot (leaf, petiole and unrooted stolon), stolon and root tissue was determined. Broad sense heritabilities for %N, %P, and proportion of total N or P in each tissue type were calculated. Heritabilities ranged from 0.22 to 0.68. They were generally higher for %P than %N; and higher in shoot and stolon tissue than root tissue for %P, %N, and proportion of N or P. Level of P in which plants were grown had little effect on heritability values. Genotypes from bred cultivars differed from those collected from hill country pastures for plant size, and partitioning of N and P to shoot, stolon and root. Relationships between plant characters were examined to determine the consequences of selection.     

Response of potatoes to N fertilizer: Dynamic model

Summary A simulation model is described to interpret N fertilizer experiments on potatoes. It calculates the total growth of dry matter, the N uptake, the partition of dry matter and of N between tuber and foliage and the distribution of inorganic N down the profile for each day during the growing season.The validity of the model was tested against measurements of these parameters made at approximately fortnightly intervals on plots that received N fertilizer and those that received none in 4 experiments on a sand, 4 on a sandy loam and 3 on a clay soil.Simulated values were in reasonably good agreement with the measured values in all experiments. Overall the sums of squares of the differences between the simulated and measured values of the %N in the total plant, and the total amount of inorganic N in the top metre of soil and the logarithms of the total weight of dry matter, tuber dry weight, N uptake in the entire plant and N uptake in the tubers were each less than 25% of the sum of squares of the measured values about the mean.Only 9 inputs were required for the model. It was found essential to take account of differences in spring and summer leaching but not of inter-site differences in mineralization rate.     

长期不同施肥方式对麦田杂草群落的影响

以太湖地区农业科学研究所31a的长期肥料定位试验田为材料,分别于2011—2012年小麦苗期、拔节期和收获期进行了杂草群落调查,研究杂草类型与密度的分布、杂草多样性指数的变化,并对杂草种群分布与土壤养分因子进行冗余分析。结果表明:小飞蓬、看麦娘、大巢菜、稻槎菜、通泉草是本地区小麦生长期的主要杂草类型;随着小麦的生长以及氮肥、有机肥的施入,杂草密度呈下降趋势;施入有机肥降低了麦季杂草的群落多样性指数,在小麦生长的不同时期均衡施肥的CNPK处理以及不施肥的C0处理的群落各项多样性指数能维持在一个较高的水平。RDA分析显示土壤氮含量以及有机质含量与第一排序轴相关性大,是对杂草分布影响最大的两个土壤养分因子。太湖地区稻麦两熟制条件下,长期有机无机肥料单一或配合投入可显著影响麦田杂草的群落组成,其中氮肥和有机肥的施入能显著降低杂草密度;土壤养分的差异影响田面杂草密度和优势种群,均衡施肥能降低优势杂草种群的优势地位,抑制其发生危害程度,提高农田生态系统的生产力及稳定性。     

Use of plant residues for improving soil fertility, pod nutrients, root growth and pod weight of okra (Abelmoschus esculentum L)

The effect of wood ash, sawdust, ground cocoa husk, spent grain and rice bran upon root development, ash content, pod yield and nutrient status and soil fertility for okra (Abelmoschus esculentum L NHAe 47 variety) was studied. The five organic fertilizer treatments were compared to chemical fertilizer (400kg/ha/crop NPK 15-15-15) and unfertilized controls in four field experiments replicated four times in a randomized complete block design. The results showed that the application of 6tha(-1) of plant residues increased (P<0.05) the soil N, P, K, Ca, Mg, pH, and SOM; pod N, P, K, Ca, Mg and ash; root length; and pod yield of okra in all four experiments relative to the control treatment. For instance, spent grain treatment increased the okra pod yield by 99%, 33%, 50%, 49%, 65% and 67% compared to control, NPK, wood ash, cocoa husk, rice bran and sawdust treatments respectively. In the stepwise regression, out of the total R(2) value of 0.83 for the soil nutrients to the pod yield of okra; soil N accounted for 50% of the soil fertility improvement and yield of okra. Spent grain, wood ash and cocoa husk were the most effective in improving okra pod weight, pod nutrients, ash content, root length and soil fertility whereas the rice bran and sawdust were the least effective. This was because the spent grain, wood ash and cocoa husk had lower C/N ratio and higher nutrient composition than rice bran and sawdust, thus, the former enhanced an increase in pod nutrients, composition for better human dietary intake, increased the root length, pod weight of okra and improved soil fertility and plant nutrition crop. The significance of the increases in okra mineral nutrition concentration by plant residues is that consumers will consume more of these minerals in their meals and monetarily spend less for purchasing vitamins and mineral supplement drugs to meet health requirements. In addition, the increase in plant nutrition and soil fertility would help to reduce the high cost of buying synthetic inorganic fertilizers and maintain the long term productivity of soils for sustainable cultivation of okra.     

Evaluation of sewage sludge, septic waste and sludge compost applications to corn and forage: yields and N, P and K content of crops and soils

This paper presents the data from two years of experiments concerned with the application of aerobically-digested sewage sludge, anaerobic lagoon septic sludge, sewage sludge compost or fertilizer to soils for grass forage and feed corn (Zea mays L.) production at two different sites 45 km from Truro, Nova Scotia. Crop yields, plant tissue and Mehlich-1 extractable soil nutrients were evaluated; 15 elements were analyzed in the plant tissue and nine elements in the soil extracts. This paper describes the results of crop yields, plant N, P and K content and Mehlich-1 extractable P and K. The research demonstrated the fertilizer produced higher yields of grass forage than the sludge and the compost but equivalent to the sludge in corn yields. Forage and corn N, P and K contents, however, varied with treatment, crop and year, while the compost-amended soils were highest in extractable nutrients. Both sludges and the compost, therefore, could be effective sources of N, P and K for crop production. Compared to the conventional fertilizer, the nutrient availability from the organic amendments (especially N and P) was considerably lower than the 50% assumed at the start of the experiment; the sludges however, provided higher nutrient availability than the compost.     

Synchronizing N release from organic residues: opportunities for integrated management of N

In intensive cropping systems, mineral nitrogen (N) fertilizers represent the largest component of the N cycle because the indigenous N supply is not adequate. The requirement for mineral fertilizer may be reduced with the use of organic nutrient sources. A more realistic use of organic matter, particularly in sub-Saharan Africa due to limited amounts and availability, is the combined use of organic nutrient sources and mineral fertilizers. The beneficial effects of integrated use of inorganic fertilizers and organic manures on improved nutrient recoveries, soil moisture retention, cation exchange capacity, and erosion control have been reported. However, there are as many reports indicating negligible benefits or even disadvantages of combining nutrient sources on crop production. This is not surprising given the combination of organic residue sources, soils, climatic, crops, and management factors that influence nutrient dynamics. The most widely accepted function of organic materials is improving the nutrient availability to crops by supplying N. The key to both improving efficiency of N use and reducing N losses is synchronization of N supply from soil, biological N2 fixation, organic residues, and inorganic fertilizers with the crop N demand. Organic materials are not magic; N losses also result from their use. Controlling N release from organic sources depends on their nutrient content and quality, soil properties, and the environmental and management factors. This paper will synthesize the information generated from integrated nutrient management trials in sub-Saharan Africa and the Philippines. Management strategies based on an organic resources database and a dynamic soil-crop simulation model are used to identify organic sources as N fertilizers or soil amendments. The decision support tools are also used to attain optimum synchrony between release from organic sources and soils with crop N demand.     

Field-specific potassium and phosphorus balances and fertilizer requirements for irrigated rice-based cropping systems

Fertilizer K and P requirements for rice (Oryza sativa L.) can be determined with site-specific nutrient management (SSNM) using estimated target yield, nutrient balances, and yield gains from added nutrient. We used the QUEFTS (QUantitative Evaluation of the Fertility of Tropical Soils) model with >8000 plot-level observations to estimate the relationship between grain yield and nutrient accumulation in above-ground dry matter of irrigated rice with harvest index?≥?0.4. Predicted reciprocal internal efficiencies (RIEs) at 60–70% of yield potential corresponded to plant accumulation of 14.6 kg N, 2.7 kg P, and 15.9 kg K per tonne of grain yield. These RIEs enable determination of plant requirements for K and P and net output of K and P in harvested grain and removed crop residues at a target yield. Yield gains for nutrient applied to irrigated rice averaged 12% for K and 9% for P for 525 to 531 observations. For fields without certain yield gain, fertilizer K and P requirements can be determined by a partial maintenance approach (i.e., fertilizer input?<?output in nutrient balance), which considers nutrient supply mediated through soil processes and balances trade-offs between financial loss with full maintenance rates and risk of excessive nutrient depletion without nutrient application. When yield gains to an added nutrient are certain, partial maintenance plus yield gain can be used to determine fertilizer requirements. The SSNM-based approach and algorithms enable rapid development of field-specific K and P management.     

长期施肥对红壤旱地作物产量和土壤肥力的影响

历时14年的田间定位试验表明,红壤旱地磷素最为缺乏,施用磷肥对提高作物产量效果最好;施用石灰和微量元素对作物产量没有明显增产作用．施肥可以提高花生植株磷、钾的浓度,表明作物的养分含量受土壤养分供应水平的影响．土壤中赢余(亏损)的养分在养分库重建中的作用可以用速效养分库重建效率来表示．研究表明,当红壤旱地N、P2O5、K2O养分赢余1kg·hm^-2时,可分别使土壤中水解氮、有效磷、交换性钾含量提高0．6～6．26、0．20～0．28和1．1～8．5mg·kg^-1．红壤旱地氮和磷通过径流等损失较大,不同处理之间的变化幅度也较大．红壤每年可固定磷43．5kg·hm^-2,通过自身风化作用每年可提供氮48．1kg·hm^-2和钾40．5kg·hm^-2,以满足作物生长所需．     

Does the combined application of organic and mineral nutrient sources influence maize productivity? A meta-analysis

The combined application of organic resources (ORs) and mineral fertilizers is increasingly gaining recognition as a viable approach to address soil fertility decline in sub-Saharan Africa (SSA). We conducted a meta-analysis to provide a comprehensive and quantitative synthesis of conditions under which ORs, N fertilizers, and combined ORs with N fertilizers positively or negatively influence Zea mays (maize) yields, agronomic N use efficiency and soil organic C (SOC) in SSA. Four OR quality classes were assessed; classes I (high quality) and II (intermediate quality) had >2.5% N while classes III (intermediate quality) and IV (low quality) had <2.5% N and classes I and III had <4% polyphenol and <15% lignin. On the average, yield responses over the control were 60%, 84% and 114% following the addition of ORs, N fertilizers and ORs + N fertilizers, respectively. There was a general increase in yield responses with increasing OR quality and OR-N quantity, both when ORs were added alone or with N fertilizers. Surprisingly, greater OR residual effects were observed with high quality ORs and declined with decreasing OR quality. The greater yield responses with ORs + N fertilizers than either resource alone were mostly due to extra N added and not improved N utilization efficiency because negative interactive effects were, most often, observed when combining ORs with N fertilizers. Additionally, their agronomic N use efficiency was not different from sole added ORs but lower than N fertilizers added alone. Nevertheless, positive interactive effects were observed in sandy soils with low quality ORs whereas agronomic use efficiency was greater when smaller quantities of N were added in all soils. Compared to sole added ORs, yield responses for the combined treatment increased with decreasing OR quality and greater yield increases were observed in sandy (68%) than clayey soils (25%). While ORs and ORs + N fertilizer additions increased SOC by at least 12% compared to the control, N fertilizer additions were not different from control suggesting that ORs are needed to increase SOC. Thus, the addition of ORs will likely improve nutrient storage while crop yields are increased and more so for high quality ORs. Furthermore, interactive effects are seldom occurring, but agronomic N use efficiency of ORs + N fertilizers were greater with low quantities of N added, offering potential for increasing crop productivity.     

果粮间作模式优化调控研究Ⅳ:系统养分管理及其优化对策探讨

我国农林复合经营(Ａｇｒｏｆｏｒｅｓｔｒｙ)历史悠久,有许多实践已证明的成功模式类型,果农间作就是分布面积最大的代表类型[1～3,8]。目前,已有的研究主要集中于类型划分[1,2,8]生态和经济效益定量观测和评价[1～10]、模式的建立[3,4,8]、资源的经营利用特点[1,2,5～10]等方面,基本上都是针对现状而进行,尚缺乏对进一步提高果农间作模式效益的优化调控研究。果粮间作条件下最大的矛盾是果与粮相互竞争可利用资源(光、热、水和土壤养分等)而导致粮食的减产和土壤的过渡利用[1,6,7]。如何优化调控,以进一步提高生态和经济效益,达到提高土地…     

中国土壤和植物养分管理现状与改进策略

针对当前我国农业生产面临增肥不增产、土壤养分过量累积、化肥施用过量和养分利用效率下降等重大问题, 本文综述了中国土壤养分与植物营养状况的历史演变和研究进展, 提出中国植物营养科学研究应在跟踪国际科学前沿的同时, 紧密结合中国农业生产实际, 通过大幅度提高养分效率和作物产量为农业可持续发展做出应有的贡献。     

中国土壤和植物养分管理现状与改进策略

针对当前我国农业生产面临增肥不增产、土壤养分过量累积、化肥施用过量和养分利用效率下降等重大问题,本文综述了中国土壤养分与植物营养状况的历史演变和研究进展,提出中国植物营养科学研究应在跟踪国际科学前沿的同时,紧密结合中国农业生产实际,通过大幅度提高养分效率和作物产量为农业可持续发展做出应有的贡献。     

Simple models and concepts as tools for the study of sustained soil productivity in long-term experiments. II. Crop nutrient equivalents, balanced supplies of available nutrients, and NPK triangles

Two NPK factorial trials, one in Vietnam and one in The Netherlands were (re-)analyzed to find causes of success or failure with regard to sustained soil productivity, using the concept of crop nutrient equivalents (CNE). A (k)CNE is the quantity of a nutrient that, under conditions of balanced nutrition, has the same effect on yield as 1 (k)g of nitrogen. The percentages the nutrients take in the (k)CNE sum of N, P and K are plotted along the sides of a triangle. Soil, crop and input NPK are indicated in the triangle. Balanced crop NPK is found in the centre of the triangle, and required NPK inputs are on a straight line in the extension of the line trough the point of soil NPK and the centre. Experimental inputs were compared with inputs required for balanced NPK. In Vietnam, responses to P and soil available N:P:K pointed to severe shortage of P. Rice yields increased over time in dry but not in wet seasons. The lower yields in wet seasons were ascribed to insufficiently long periods between the dry and the next wet seasons for replenishment of labile soil P. In the Netherlands, four crops were grown in rotation on a former sea bottom. Only N had a strong effect on yield. Soil available N:P:K revealed low N, very high K and medium P. Recovery of fertilizer N was high because of capillary rise of groundwater and absence of leaching. In both trials, first-season chemical crop analysis would directly have detected disproportions of soil available N, P and K. This knowledge could have improved the experimental designs, optimized nutrient use efficiency and minimized losses of N and K to the environment.     

Prediction and Measurement of the Decline in the Critical-K, the Maximum-K and Total Cation Plant Concentrations during the Growth of Field Vegetable Crops

The declines in maximum and critical K concentrations in plantdry matter of 16 different vegetable species were predictedfrom emergence to maturity by assuming that both were proportionalto the critical %N calculated in terms of plant dry matter perunit area using previously-described equations. Values of theproportionality constants were obtained from published measurementsmade, at commercial maturity, of crops grown in multi-levelfertilizer experiments. Predictions were tested: (a) againstmeasurements made at intervals during growth in experimentsreceiving a single level of fertilizer; (b) against measurementsmade of the highest K concentrations measured at the seedlingstage in soil-K gradient experiments; and (c) against the resultsof a K-fertilizer-response experiment in which harvests werecarried out at intervals during growth. Results were consistentwith the predictions and, thus, with the view that both criticaland maximum K concentrations are proportional to critical %Nthroughout growth. K concentrations in plant tissue water fluctuatedwidely during the growing season and values, averaged over theentire growing period for each of ten crops, varied by a factorof 3. These values were proportional to the mean cation concentrations(meq l^-1) calculated by assuming that all the ions were in solution.Total cation concentration (meq 100 g^-1) of dry matter was linearlyrelated to critical N concentration. Evidence was also obtainedthat maximum K concentration, critical K concentration and totalcation concentration (meq 100 g^-1) during growth were linearlyrelated to relative growth rate, provided that crop weightswere greater than 2 t ha^-1dry matter. A hypothesis was developedto co-ordinate these findings.Copyright 1998 Annals of BotanyCompany. Vegetable crops, cation, plant potassium, plant nitrogen, critical concentration, relative growth rate, plant weight.     

Plant nutrition in the 20th and perspectives for the 21st century

This paper briefly presents the knowledge of plant nutrition in 1900 and its expansion since then in two areas - the discovery of the micronutrients and the absorption of nutrients from soils.Application of macro- and micronutrient fertilizers has contributed substantially to the huge increase in world food production experienced this century. In developed countries, excessive fertilizer use has led to serious problems of nutrient pollution; here, plant nutritionists will be concerned with monitoring nutrient status of crops and soils to maintain crop production with minimum loss of nutrients to the environment, and development of cultivars with high nutrient efficiency in soils with luxury supplies of nutrients.In many developing countries, soil infertility limits productivity; here, plant nutritional research can raise productivity by diagnosis of nutrient deficiencies and toxicities of crops on previously unfertilized soils, their correction with minimal fertilizer and treatment costs, and development of cultivars with high nutrient efficiency in deficient soils and high tolerance of natural toxicities.The pre-occupation of developed countries with pollution is blinding them to the urgent needs of developing countries for fertilizers and fertilizer research to increase crop production ha-1 as an alternative to clearing more land.     

不同施肥模式对下辽河平原水稻生态系统生产力及养分收支的影响

采用田间肥料试验,研究了不同施肥模式对稻田生态系统的生产力和养分收支的影响。结果表明:随养分配施均衡程度的增加,系统的生产力逐渐提高,其中氮磷钾处理的生产力最高;氮肥对水稻生产力的贡献最大(对生物量的贡献约20%,对籽实产量的贡献约34%),磷肥和钾肥的贡献相当;在水稻各部位对氮、磷、钾养分的吸收中,氮的吸收主要集中在籽实和秸秆中,磷的吸收则主要集中在籽实中,钾的吸收主要集中在秸秆中;在各施肥处理中,土壤全量养分和有机质的变化不大,而速效养分的变化较大,特别是速效磷库和速效氮库;单施化肥处理的土壤,其速效养分含量不高,而施有机肥处理土壤的速效养分含量较高,表明有机肥较有利于土壤养分的积累。     

Cultivation of Miscanthus under West European conditions: Seasonal changes in dry matter production,nutrient uptake and remobilization

There is increasing interest in cultivation of Miscanthus as a source of renewable energy in Europe, but there is little information on its nutrient requirements. Our aim was to determine the nutrient requirement of an established Miscanthus crop through a detailed study of nutrient uptake and nutrient remobilization between plant parts during growth and senescence. Therefore dry matter of rhizomes and shoots as well as N, P, K and Mg concentration under three N fertilizer rates (0, 90, and 180 kg N ha-1) were measured in field trials in 1992/93 and at one rate of 100 kg N h-1 in 1994/95.Maximum aboveground biomass in an established Miscanthus crop ranged between 25-30 t dry matter ha-1 in the September of both trial years. Due to senescence and leaf fall there was a 30% loss in dry matter between September and harvest in March. N fertilization had no effect on crop yield at harvest. Concentrations of N, P, K and Mg in shoots were at a maximum at the beginning of the growing period in May and decreased thereafter while concentrations in rhizomes stayed fairly constant throughout the year and were not affected by N fertilization.Nutrient mobilization from rhizomes to shoots - defined as the maximum change in nutrient content in rhizomes from the beginning of the growth period measured in 1992/93 was 55 kg N ha-1, 8 kg P ha-1, 39 kg K ha-1 and 11 kg Mg ha-1. This is equivalent to 21 N, 36 P, 14 K and 27 Mg of the maximum nutrient content of the shoots. Nutrient remobilization from shoots to rhizomes defined as the increase in nutrient content of rhizomes between September and March measured in 1994/95 was 101 kg N ha-1, 9 kg P ha-1, 81 kg K ha-1 and 8 kg Mg ha-1 equivalent to 46 N, 50 P, 30 K and 27 Mg of nutrient content of shoots in September. Results showed that nutrient remobilization within the plant needs to be considered when calculating nutrient balances and fertilizer recommendations.     

Dynamic Model for the Effects of Soil P and Fertilizer P on Crop Growth, P Uptake and Soil P in Arable Cropping: Experimental Test of the Model for Field Vegetables

In a previous paper (Greenwood et al. Annals of Botany88: 279–291,2001), we described a mechanistic model that calculates theeffects of extractable soil P and fertilizer P on daily incrementsin dry matter yield and P uptake of field crops. This paperdescribes the calibration of that model for six different speciesand subsequent tests of the calibrated model against resultsof independent experiments on the same soil type. Calibrationsfor lettuce, carrot and turnip were obtained by altering onlyone parameter, the effective root radius, while for onion, leekand spinach, both this and one of the parameters linking growthrate to % P in the plant were altered. The validity of the calibratedmodel was tested against results of field experiments that wereharvested at the seedling stage and at commercial maturity.The model predictions of the shapes of the responses of dryweight and of % P to both extractable soil P and fertilizerP were generally not significantly different from those measured.The model also gave satisfactory predictions of the time courseof dry weight and plant % P from emergence to commercial harvestof two crops grown with optimum levels of P fertilizer. In anotherexperiment, reasonably good agreement was obtained between simulatedresponses of plant dry weight yield and % P in the dry matterof carrot at commercial maturity and mid-way through the growingseason. Values of the effective root radius and various rootparameters, and calculations of P fluxes through the soil tothe root surfaces during the course of the simulation were,with few exceptions, consistent with information in the literature.Simulated P responsiveness is very sensitive to changes in thevalues of plant parameters affecting the dependence of P uptakeon plant % P as well as those concerned with the ability ofroots to exploit the soil's reserves of P. Reasons for inter-speciesdifferences in P response are elucidated and weaknesses in themodel identified. The model could form the basis of a short-cutapproach to forecasting optimal fertilizer P practices for differentcrops on different soils. It runs interactively on the Internetat: www.qpais.co.uk/phosmod/phos.htm Copyright 2001 Annals ofBotany Company Vegetable crops, model, simulation, plant phosphate, phosphate fertilizer, soil phosphate, crop response, root radius, species comparison     

施用纳米碳对烤烟氮素吸收和利用的影响

为明确纳米碳在提高烤烟氮素吸收利用方面的效果,在盆栽条件下,研究了纳米碳不同用量对烤烟根系生长发育、干物质积累和氮素吸收利用的影响。结果表明,在常规肥料中添加纳米碳能够促进烤烟根系生长发育,明显提高烟株根系活力和单株根系生物量,增加植株干物质积累量。施用纳米碳增加了烤烟植株成熟期各器官氮素含量和积累量,而未明显影响氮素在植株不同器官的分配。施用纳米碳不仅增加了植株对肥料氮的吸收量,还增加了对土壤氮的吸收量,这与其促进烤烟根系生长发育、提高根系吸收能力有密切关系。纳米碳无论做基肥还是做追肥,均显著提高了氮肥利用率,提高幅度分别达到14.44%和9.62%,有效降低了氮素土壤残留和损失。