【Objectives】Si and microbial application could relieve the crop replanting problems(CRPs).We further studied the change of key microorganisms that are related to the beneficial effects,aiming at provide reference fo...【Objectives】Si and microbial application could relieve the crop replanting problems(CRPs).We further studied the change of key microorganisms that are related to the beneficial effects,aiming at provide reference for the manufacture and application of both microbial agents and Si fertilizer in food lily production.【Methods】A field experiment was conducted over a three-year period,from March 2019 to March 2022.The experimental field had been continuously cultivated with lily for 9 years.Three treatments were established:silicon fertilizer(SF),microbial agents(“Special 8^(TM)”,MF),and combined application of silicon fertilizer and microbial agents(SMF).A control group with blank soil(CK)was also included.At seedling stage of Lanzhou lilies in 2020 and 2021,the shoot and bulb dry weight,and the plant height and stem diameter of Lanzhou lilies were investigated for calculation of seedling index.In July 2020,20 plants were selected in each plot,and root zone soils were sampled at a depth of 20 cm,10 cm away from the roots,and then mixed to form a composite sample.The soil available Si and organic matter content were analyzed,and the fungal community structure and some specific microbial groups in soils were determined with high-throughput sequencing of ITS.【Results】All the three treatments significantly enhanced the lily plant growth and the seedling index,compared to CK.Besides,SF and MF treatments increased the relative abundances(RA)and diversity of fungal communities,and altered the community structures.The RA of some specific groups were found to be significantly correlated with the seedling index and/or soil available Si.Of them,the RA of the genera Fusarium,Dactylonectria,Humicola,Stilbella,and the species Humicola_grisea showed a positive correlation,while that of the genera Mortierella,Stilbella,Holtermanniella,and the species Mortierella_fatshederae showed a negative correlation with seedling index.The genera Fusarium,Stilbella,the species Humicola_grisea,and Dactylonectria_estremocensis showed a positive correlation,while the genura Stilbella,and the species Mortierella fatshederae showed a negative correlation with available Si content.In the co-occurence network of top twenty fungal genera and top sixteen bacterial genera(RA>0.2%),Holtermanniella was the only genus that interacted with the bacteria and negatively correlated with bacterial genus Blastococcus.Holtermanniella was also the most densely connected genera,followed by the genus Fusarium,Didymella and Humicola.In addition,the genus Holtermanniella was the key species connecting fungal and bacterial community in soil.Fungal functional prediction revealed that SF,MF and SMF treatments decreased plant pathogens guilds and increased the beneficial guilds Ectomycorrhizal,plant saprophyte,leaf saprophyte,and arbuscular mycorrhizal compared to CK.【Conclusions】Combined application of silicon fertilizer and microbial agents can alleviate continuous replanting problems of Lanzhou lilies through restoring the fungal community diversity,and promoting plant residue depredation,thus reducing soil born disease incidence.The beneficial genus Humicola and its one species H.grisea acts as bioconversion,and the genus Acremonium acts as plant pathogen inhibitor.展开更多
【Objectives】Rose(Rosa hybrida L.)is a beautiful and widely cultivated flowering plant around the world whose quality is of great commercial importance.The objective of this study was to investigate the impact of fol...【Objectives】Rose(Rosa hybrida L.)is a beautiful and widely cultivated flowering plant around the world whose quality is of great commercial importance.The objective of this study was to investigate the impact of foliar application of calcium nitrate on the quality and postharvest life of two rose varieties(cvs.Samurai,and Jumilia)in a soilless culture system.【Methods】The research used a hydroponic culture method,the roses plants were grown in Hoagland nutrient solution containing 50%less Ca for a total span of 4 months.One month was dedicated to plant acclimatization,and 3 months for spray treatment.Two rose varieties(Rosa hybrida L.),cvs.Samurai and Jumilia plants were used as test materials and planted in pots containing 100%perlite(3-5 mm).After one month of culture,160 mg/kg CaNO3 solution was sprayed,and each treatment corresponded to the first,second,and third harvests,respectively.The plant and flower growth indicators and flower vase life were investigated after each harvesting immediately.【Results】A positive impact of foliar-applied Ca on stem characteristics,pedicel dimensions,corolla size,flower attributes,and vase life was found.Furthermore,a general trend was observed,wherein an increase in the number of harvesting stages led to improved traits.Notably,Jumilia rose consistently exhibited lower values for all studied traits,except for flower vase life,in comparison to the Samurai rose.While there were no significant differences in length values between Samurai and Jumilia roses due to calcium foliar application across the three harvesting stages.Duncan’s grouping revealed a specific effect on Jumilia roses during the third harvest stage.Calcium fertilizer significantly increased photosynthesis rates of of rose leaves in the calcium treatments compared with the control treatment.【Conclusions】Foliar spraying of calcium nitrate is an effective measure to promote the growth of roses and improve the yield,quality and bottle life of fresh cut flowers.展开更多
To determine appropriate quantities of water and fertilizer required for early growth of hybrid poplar cuttings,we recorded the growth traits of four clones grown under four factors(irrigation and nitrogen,phosphorus,...To determine appropriate quantities of water and fertilizer required for early growth of hybrid poplar cuttings,we recorded the growth traits of four clones grown under four factors(irrigation and nitrogen,phosphorus,and potassium fertilizers),each with four levels,using an orthogonal experimental design.A logistic model was used to estimate growth in height.The growth curves for tree height were sigmoid,and the model R^2 values were greater than 0.9,which indicated that the fit was highly significant.ANOVA results for tree height and basal diameter indicated that all sources of variance showed significant differences(p<0.001).The average tree height and basal diameter for all the four clones under the different treatments ranged from 155.39 to 235.04 cm,and from 13.71 to 17.42 mm,respectively.A highly positive correlation between the extreme k value and tree height was observed,suggesting that the k value was an accurate estimation of tree height.For model parameters,the earliest average time point for the onset of the rapid growth period of poplar clones was 131 d,and the highest average increment in tree height during the rapid growth period was 138.78 cm.The highest average tree height for all clones under each factor was 219,210.51,200,and 201 cm when treated with either 1200 mL of water applied every third day,3 g of nitrogen,0 g of phosphorus,or 0 g of potassium,respectively.The most suitable treatment for the early growth of hybrid poplar cuttings,as suggested by the developed logistic model,was 1200 mL of water applied every third day and three applications of 1 g nitrogen(in the form of CH4N2O).展开更多
This paper puts forward a valuation model for the flexibility of revamping urea plants based on the substitutability of switching between the internationally accepted fertilizer feedstock fuel oil and natural gas. The...This paper puts forward a valuation model for the flexibility of revamping urea plants based on the substitutability of switching between the internationally accepted fertilizer feedstock fuel oil and natural gas. The paper first builds a stochastic mean-reversion model for fuel oil prices and natural gas prices respectively, then estimates and tests the parameters using the fuel oil and natural gas prices data from the U.S. market. This paper also conducts a sensitivity analysis with important parameters. The results show that the real option method can be applied successfully to evaluate the flexibility in decision- making for revamping installations in fertilizer plants or other similar plants.展开更多
How to improve the water use efficiency of rice in black soil regions was studied. The black soil region in paddy fields was chosen as the research object. The research showed the fertilizer coupling mathematical mode...How to improve the water use efficiency of rice in black soil regions was studied. The black soil region in paddy fields was chosen as the research object. The research showed the fertilizer coupling mathematical model with N,P,K,irrigation water( W) and water use efficiency( WUE),which was set up under the condition of controlled irrigation with quadratic D- 416 optimized saturation design. The results show that the decending order of single factor' s influence on the WUE was N,K,P and W. All the interactions between N&P,N&K,N&W,K&P,P&W and K&W on the WUE were raised initially,and when reached a certain value,they began to decline. The decending order of each interaction on the WUE was K&P,K&W,N&K,N&P,P&W and N&W. When the WUE was targeted within 1. 8- 2. 5 kg / km^3,an optimized proportion plan was obtained in the 95% confidence interval,i. e. N 87. 76- 103. 32 kg / hm^2,K_2 O 52. 37- 66. 53 kg / hm^2 and P_2O_536. 80- 46. 71 kg / hm^2. Furthermore,the late tillering of the soil moisture content was 70. 07%- 72. 57% of the saturated moisture content.展开更多
Triple Super Phosphate, TSP fertilizer, was applied @ 80 kg·ha^-1 as the source of phosphorous on six months old polybag seed- lings of Albizia chinensis, Albizia saman and Pongamia pinnta in nursery beds in Bang...Triple Super Phosphate, TSP fertilizer, was applied @ 80 kg·ha^-1 as the source of phosphorous on six months old polybag seed- lings of Albizia chinensis, Albizia saman and Pongamia pinnta in nursery beds in Bangladesh. The effects of P-fertilizer on seedling growth and nodulation were comparcd to that of seedlings grown in unfertilized soil or in control at different harvesting intervals. The study revealed that, seedling growth was enhanced significantly with the application of P-fertilizer. The growth was found more pronounced in cases of A. saman and P. pinnata, whereas it was not noticeable and showed depressed growth in case of A. chinensis. The study also suggests that nodulation in terms of nodule number and size was also increased significantly with P-fertilization except in case ofP. pinnata, where higher harvesting intervals lowered the nodulation performance of that species展开更多
To explore fertilization methods for wine bamboo cultivation in southwestern semi-arid areas of China, this study analyzed annual changes in sap yield and nutrient composition from May 2013 to March 2015 by using bamb...To explore fertilization methods for wine bamboo cultivation in southwestern semi-arid areas of China, this study analyzed annual changes in sap yield and nutrient composition from May 2013 to March 2015 by using bamboo charcoal-based bio-fertilizer （ZT） and organic fertilizer treatments （CK）. The study also provided basic data for functional beverage preparation and for application of ZT. The results of the two experimental cycles revealed that under the ZT treatment, sap was available for collection from May, the beginning of the rainy season, to November, the beginning of the dry season. The period of abundance was July to October with the highest yield of sap of 3.18 L stalk-1 in September, 2014, still lower than the moso bamboo sap, which was likely due to the scale of sap production of monopodial bamboos being different from that of sympodial bamboos. In January, trace amounts of sap were still detected, suggesting that the effect of the treatment was significant. Moreover,in the dry season, soil water content and soil temperatures at 10-15 cm depths indicated that the fertilizer had the ability to maintain soil temperatures and moisture. In both fertilizer treatments, the correlation between the collected sap and environmental parameters was significant. In the ZT treatment for the entire 2 years, the effectual environ- mental factors were soil water at 10-15 cm, air tempera- tures, and wind speeds. The same determining factors were observed for the rainy season. In the CK treatments, the effectual environmental factors for the entire year and the rainy season were soil water at 0-5 cm and air moisture. The bamboo charcoal-based bio-fertilizer elevated the potassium, calcium, iron, manganese, copper, and total phosphorus content, simultaneously increasing the sap yield, protein and reducing sugar contents, and with a relative increase in sap pH. The wine bamboo sap con- tained 18 amino acids. Glutamic acid, alanine and proline were the most abundant. Compared to the controls, the treatment showed higher levels of all amino acids. Thus, the ZT treatment could be more beneficial to the development of root systems because the function of heat preservation and moisture retention prolong the sap collection period, increase sap yields, and elevate mineral element, conventional nutrients, and amino acid contents with evident fertilization effects and broader application prospects.展开更多
Allocation of biomass and nutrient elements including Nitrogen to above and belowground compartments of beech seedlings （Fagus sylvatica L.） treated by labeled nitrogen fertilizer in the form of 15NH4 and 15NO3 were...Allocation of biomass and nutrient elements including Nitrogen to above and belowground compartments of beech seedlings （Fagus sylvatica L.） treated by labeled nitrogen fertilizer in the form of 15NH4 and 15NO3 were investigated at the end of two successive growing seasons. Pot cultured beech seedlings were grown at a green house on intact soil cores sampled from three adjacent stands including beech, Norway spruce and mixed beech-spruce cultures of Soiling forest, Germany. Comparing biomass allocation and nutrients concentrations of the seedlings between the control and 15N-fertilized treatments revealed no significant effect of N fertilization on nutrients uptake by seedlings over the experiment. The form of N input influenced its movement into plant pools. It was demonstrated that beech seedlings take up nitrogen mainly in the form of nitrate, which is then reduced in the leaves, although the differences between the retention of NO3^--N and NH4^＋-N in plants were not statistically significant. Percent recoveries of 15N in trees were typically greater after 15NO3 than after 15NH4 additions. It was indicated that immobilization of ~SN tracer in fine roots was a slower process comparing other plant compartments such as stem and coarse roots, but a powerful sink for N during the course of study.展开更多
The present study was undertaken to determine the effects of different levels of urea-N fertilizer in addition to ipil-ipil tree litter on yield of rice and insect prevalence. The field study was conducted at the Agro...The present study was undertaken to determine the effects of different levels of urea-N fertilizer in addition to ipil-ipil tree litter on yield of rice and insect prevalence. The field study was conducted at the Agroforestry Field Laboratory, Bangladesh Agricultural University, Mymensingh during July-December 2004. The treatments included 0, 90, 180, and 270 kg urea per hectare. All four treatments received five tons ipil-ipil tree litter per hectare. The experiment was laid out in a randomized complete block design （RCBD） with four replications. The results showed that the different treatments significantly influenced the yield and yield component viz. total tillers/hill, effective tillers/hill, filled grains and unfilled grains/panicle. The highest yield of 4.62 t·h^m-2 with an increase of 21.57% over the control was recorded in treatment 180 kg urea·h^m-2, which was statistically similar to treatment 90 kg urea·h^m-2. The prevalence of insects viz. green leafhopper, brown plant hopper, rice bugs, leaf folder and stem borers were mostly correlated with N-levels. The prevalence of insects in general gradu- ally increased with the increase of N. Therefore, this study suggests that the combined application of organic materials （tree litter of ipil-ipil） and N-fertilizer of 90 kg·h^m-2 may oroduce good yield while minimizine insect arevalence in the rice field.展开更多
The effects of long-day photoperiod on growth,photo synthetic fluorescence,carbon and nitrogen metabolism,and yield of Dendrocalamopsis oldhami and the compensation effects of fertilization were investigated.A complet...The effects of long-day photoperiod on growth,photo synthetic fluorescence,carbon and nitrogen metabolism,and yield of Dendrocalamopsis oldhami and the compensation effects of fertilization were investigated.A completely randomized design was used with two light factors(bamboo culms cultivated in solar greenhouse under long-day[Ls]and short-day[Ln]treatments);two organic nitrogen fertilizer levels(application of organic fertilizer[OF]and no organic fertilizer[NF]);and three nitrogen fertilizer levels(Low[N0],medium[N1]and high nitrogen[N2]).Leaf chlorophyll and fluorescence parameters(φPo,PIABS,and ETo/CSm)decreased and DIo/CSmincreased in Ls compared to Ln.Indole acetic acid(IAA)and gibberellic acid(GA3)levels decreased,whereas abscisic acid(ABA)increased.Leaf area decreased and leaf dry mass increased.The contents of carbon and nitrogen metabolism-related enzymes(nitrate reductase,glutamine synthetase,amylase,and sucrose synthase)and products(total nitrogen,organic carbon,soluble sugar,and starch)increased.Single bamboo shoot weight and diameter at breast height decreased,whereas shoot quantity and total yield increased.Fertilizer application significantly affected physiological growth and yield in the two light treatments,thus promoting carbon and nitrogen metabolism.TheφPo,PIABS,IAA,and GA3contents increased slightly,whereas ABA levels decreased.Shoot quantity,individual weight,and total yield improved.IA A,soluble sugar,and total yield to organic manure and light were lower than those of nitrogen levels(FN>FL,FO).Other indicators showed lower responses to different fertilization treatments than the light factor(FL>FN,FO).The ability of D.oldhami to alter its morphological and physiobiochemical traits and yield in response to variations in light applications may translate into high phenotypic plasticity.Fertilization significantly improved photoplasticity of D.oldhami.Under Ls,D.oldhami had high metabolic rates.was easily inhibited by light,and showed accelerated leaf senescence,and shoot quantity and total output increased.However,the quality of individual shoots decreased.Different fertilization treatments affected D.oldhami differently under the two light intensities.Ls sensitivity to nitrogen was higher.Fertilization could delay leaf dormancy and senescence under Ls treatment.Organic fertilizer addition could improve yield more effectively,with OFN1being the optimal fertilization level.展开更多
A study was carried out to investigate changes in the soil plant-available P,the P nutrition and the growth of Pinus radiata seedlings grown in association with understory,broom（Cytisus scoparius L.） or ryegrass（Lo...A study was carried out to investigate changes in the soil plant-available P,the P nutrition and the growth of Pinus radiata seedlings grown in association with understory,broom（Cytisus scoparius L.） or ryegrass（Lolium multiflorum） on Orthic Allophanic Soil,following the application of three rates of triple superphosphate（TSP）（0,50,and 100 mg·kg^-1P） under a glasshouse condition.The application of P fertilizer enhanced P availability in the rhizospheric of radiata seedlings and the bulk soils in a P-deficient site.P availability in the rhizospheric soils of ryegrass and broom,grown in association with radiata,were also increased by the presence of radiata roots.P concentrations in new shoot needles,old shoot needles,stem and roots of radiata pine increased with increase rates of TSP application,but the effects of ryegrass and broom on P nutrition of radiata seedlings depended on the soil P status.In the absence of P fertilizer addition（control treatment）,P concentrations in new shoot needles,old shoot needles,stem,and roots of radiata grown in association with broom were higher than those with ryegrass,whereas,when P fertilizer was added（50 and 100 mg·kg^-1） the P concentration was lower.This is probably related to the growth of broom that may have removed much of the plant-available P in the soil as indicated by the consistently lower Bray-2 P concentration in the rhizosphere soil of radiata in association with broom than that in the rhizosphere soil of radiata in association with grass at the two high P rates.Furthermore,in the high P fertile soil（application rate of 100 mg·kg^-1）,the dry matter yield of radiata was lower when it was grown with broom than with ryegrass.This result suggests that in moderate to high P fertile soils,P.radiata seedlings grow better with ryegrass than with broom,because broom grows vigorously in high P fertile soil and competes with P.radiata for P and perhaps for other nutrients as well.展开更多
The effects of different inorganic fertilizers （Urea and Triple Super Phosphate （TSP）） on seedling growth and nodulation capabilities of four agroforestry tree species （Albizia chinensis, A. saman, Acacia nilotic...The effects of different inorganic fertilizers （Urea and Triple Super Phosphate （TSP）） on seedling growth and nodulation capabilities of four agroforestry tree species （Albizia chinensis, A. saman, Acacia nilotica and Sesbania sesban） were compared. The nodulation of these seedlings were treated with different fertilizer treatments （at the rate of urea 40 kg·hm^-2, urea 80 kg·hm^-2 TSP 40 kg·hm^-2, TSP 80 kg·hm^-2, （urea＋TSP） 40 kghm 2 and （urea＋TSP） 80 kg·hm^-2） after one month of seed germination. The results revealed that the seedling growth was enhanced significantly with moderate fertilizer treatment. In some cases, the higher levels of fertilizers reduced the seedling growth. The study also revealed that the nodulation in nodule number and size was significantly inhibited by the application of N fertilizer （Urea）, while it was increased significantly with the application of P fertilizer （TSP）. This study improved our understanding and provided insights that would be useful to the farmers in their efforts to amend the soil with inorganic fertilizers in order to enhance plant growth and biological nitrogen fixation.展开更多
Wood from three tree species was used for making slow-releasing woodchip fertilizer. Fertilizer made from Populus tomentiglandulosa retained the highest amounts of N （29.04%）, P205 （26.03%） and K20 （16.93%）. On ...Wood from three tree species was used for making slow-releasing woodchip fertilizer. Fertilizer made from Populus tomentiglandulosa retained the highest amounts of N （29.04%）, P205 （26.03%） and K20 （16.93%）. On the other band, woodchip fertilizer made from Pinus koraiensis retained the lowest amounts of N （26.22%）, P205 （21.80%） and I（20 （14.49%）. A field experiment was performed in a 50 m^2 experimental plot at Gangwon Agricultural Research and Extension Services, Chuncheon, Korea from August to November 1999. The effects of a general fertilizer along with compost and slow releasing woodchip fertilizer without compost on the cabbage production were observed. Cabbage production parameters, such as top height, head weight, head height, head width, number of outer and inner leaves, leaf width and head length, increased in the field where Larix kaempferi woodchip fertilizer was added as a basal dose. The result showed that the woodchip fertilizer made from Pinus koraiensis had faster releasing properties compared to other woodchip fertilizers. Without adding any compost in the woodchip fertilized field, woodchip fertilizer showed a superior outcome over a general chemical fertilizer. Although the amount of woodchip fertilizer was larger compared to that of a chemical fertilizer, it increased cabbage production.展开更多
Low nitrogen （N） availability often results in reduced productivity of Eucalyptus plantations. We studied the response of four eucalyptus plantations （two plantations of E. tereticornis on the coastal lowlands, and...Low nitrogen （N） availability often results in reduced productivity of Eucalyptus plantations. We studied the response of four eucalyptus plantations （two plantations of E. tereticornis on the coastal lowlands, and two plantations of E. grandis in the upland region of the Western Ghats, Kerala, India） to N addition and related this response to seasonal N mineralization as well as other indices of N availability, in order to examine the utility of soil based indicators of N mineralization for predicting the response of eucalyptus growth to added N ferti- lizer. Several biochemical indicators were examined for their capacity to predict response to N fertilizer, including total soil N, soil C：N ratio, and N released during anaerobic and aerobic incubation. Results show that nitrogen fertilizer addition increased productivity across the 4 sites from 7% to 70%, N released during an aerobic incubation had the highest correlation with fertilizer response across the 4 sites （R^2=0.92/ p〈0.01）, and that Modelled seasonal soil N mineralisation was a poorer predictor of fertilizer response than N released during an aerobic incubation. Whilst some of these indicators are promising, they need wider validation and testing before they could be routinely applied.展开更多
Low nitrogen (N) availability often results in reduced productivity of Eucalyptus plantations. We studied the response of four eucalyptus plantations (two plantations of E. tereticornis on the coastal lowlands, and tw...Low nitrogen (N) availability often results in reduced productivity of Eucalyptus plantations. We studied the response of four eucalyptus plantations (two plantations of E. tereticornis on the coastal lowlands, and two plantations of E. grandis in the upland region of the Western Ghats, Kerala, India) to N addition and related this response to seasonal N mineralization as well as other indices of N availability, in order to examine the utility of soil based indicators of N mineralization for predicting the response of eucalyptus growth to added N fertilizer. Several biochemical indicators were examined for their capacity to predict response to N fertilizer, including total soil N, soil C:N ratio, and N released during anaerobic and aerobic incubation. Results show that nitrogen fertilizer addition increased productivity across the 4 sites from 7% to 70%, N released during an aerobic incubation had the highest correlation with fertilizer response across the 4 sites (R2=0.92, p<0.01), and that Modelled seasonal soil N mineralisation was a poorer predictor of fertilizer response than N released during an aerobic incubation. Whilst some of these indicators are promising, they need wider validation and testing before they could be routinely applied.展开更多
The Brazil nut tree（Bertholletia excelsa） is a frequent component of agroforestry systems in the Amazon because of its adaptation to nutrient-poor upland soils and multiple uses.We investigated the aboveground bioma...The Brazil nut tree（Bertholletia excelsa） is a frequent component of agroforestry systems in the Amazon because of its adaptation to nutrient-poor upland soils and multiple uses.We investigated the aboveground biomass production（kg dry weight）,nutrient uptake and requirements（N,P,Ca,Mg,K） of Brazil nut trees of different sizes grown under agroforestry conditions and fertilized at different levels.Eight of 70 experimental trees with different size were harvested and stem,branches and leaves were separated.Nutrient contents were determined for three trees of varying size.Average tree growth was fast,but variability was high,suggesting considerable potential for the improvement of this economically important species.The trees responded to increased levels of fertilizer and lime with significantly increased foliar nutrient contents and growth,probably because of the improved availability of Mg and Ca for which the species seems to have a relatively high demand.In contrast to Brazil nut trees grown in forest or dense plantations,the agroforestry trees invested a substantial part of their biomass and nutrients in large branches and developed spreading crowns.To improve stem form,reduce competition with associated crops for light and recycle nutrients,regular pruning of lower branches or planting arrangements that favor self-pruning are recommended.These measures would also increase the recycling of Ca and Mg,large quantities of which are contained in the branches.展开更多
The application of phosphorus(P)to soil can increase its availability to plants and alter P fractions in annual and perennial organs of Cordia trichotoma.If a portion of P accumulates in perennial organs in organic fr...The application of phosphorus(P)to soil can increase its availability to plants and alter P fractions in annual and perennial organs of Cordia trichotoma.If a portion of P accumulates in perennial organs in organic fractions it can be used in the next growth season,possibly decreasing plant dependence on P derived from soil fertilization.However,if P is preferentially accumulated in inorganic fractions in annual organs,plants will be more dependent on phosphate fertilization.This study aimed to evaluate the distribution of P fractions in organs of C.trichotoma grown on sandy soil treated with 120 and 360 kg P2O5 ha^(−1).The control was a zero application.After 24 months following fertilization,C.trichotoma seedlings were cut and separated into leaves,branches,stems and roots,dried,ground and subjected to chemical fractionation of P,which estimates fractions of total soluble P,soluble inorganic and organic P,lipid P,P associated ribonucleic acid and deoxyribonucleic acid,and residual P.P in annual organs,as leaves,accumulated preferentially in the soluble inorganic fraction in both treatments.In perennial organs such as stems and branches,P accumulated preferentially in the soluble organic fraction.The application of 300%of the recommended dosage(360 kg P2O5 ha^(−1))promoted the accumulation of P in soluble organic fractions which may contribute to annual growth the following season and be a strategy to reduce the dependence of 2-year-old stands on soil-derived P and on fertilizers.展开更多
An experiment was conducted to assess the effect of Phosphorous （P） fertilizer （i.e. TSP or triple super phosphate @ 80 kg/hm^2） on seedling growth and nodulation capabilities of three potentially important agrofo...An experiment was conducted to assess the effect of Phosphorous （P） fertilizer （i.e. TSP or triple super phosphate @ 80 kg/hm^2） on seedling growth and nodulation capabilities of three potentially important agroforestry tree species （Acacia auriculiformis, Albizia lebbeck and Albizia procera） of Bangladesh. The study was conducted in nursery beds with six-month-old polybag seedlings ofA. auriculiformis, A. lebbeck and A. procera. The effects of P fertilizer on seedling growth and nodulation were compared with that of the seedlings grown in control （i.e. unfertilized soil）. The observations revealed that the seedling growth was enhanced significantly with the application of P fertilizer. The growth was found more pronounced in A. auriculiformis, whereas it was not apparent and shows depressed growth in case ofA. lebbeck. The study also suggests that the nodulation in terms of nodule number and size was also increased significantly with the application of P fertilizer.展开更多
Based on the experimental data,this study investigated the effect of sand content of muddy water on water and nitrogen transport characteristics of the single-line interference infiltration under film hole irrigation ...Based on the experimental data,this study investigated the effect of sand content of muddy water on water and nitrogen transport characteristics of the single-line interference infiltration under film hole irrigation with muddy water and fertilizer.The relationship between the single-line interference infiltration parameters,the sand content,the wetting front movement distances,and the sand content were all established.The model of the cumulative infiltration volume of per unit film pore area,the vertical and horizontal wetting front movement distance of the free surface,and the wetting front movement distance of the interference center with sand content and infiltration time were proposed.Reveal the law of the change of soil water content and the distribution of NO_(3)^(-)-N content based on different muddy water sand content.The results indicate that at the same infiltration time,as the muddy water sand content increases,the cumulative infiltration volume per unit pore area decreases.The infiltration index of the free infiltration and the single-line interference vary little when the sand content increases,mainly are around 0.64 and 0.58.The relationship between infiltration parameters a,b and the sand content is linear function.At the same location,the more the sand content,the smaller the wetting front movement distance in free surface and the single-line interference surface,the less the NO_(3)^(-)-N content.展开更多
基金Key Research project of Gansu Province of China(22YF7NA108)National Natural Science Foundation of China(31860549)+1 种基金Industry Supporting Project from Education Department of Gansu Province(2023CYZC-49)Major Science and Technology project of Gansu province(24ZDNA006)。
文摘【Objectives】Si and microbial application could relieve the crop replanting problems(CRPs).We further studied the change of key microorganisms that are related to the beneficial effects,aiming at provide reference for the manufacture and application of both microbial agents and Si fertilizer in food lily production.【Methods】A field experiment was conducted over a three-year period,from March 2019 to March 2022.The experimental field had been continuously cultivated with lily for 9 years.Three treatments were established:silicon fertilizer(SF),microbial agents(“Special 8^(TM)”,MF),and combined application of silicon fertilizer and microbial agents(SMF).A control group with blank soil(CK)was also included.At seedling stage of Lanzhou lilies in 2020 and 2021,the shoot and bulb dry weight,and the plant height and stem diameter of Lanzhou lilies were investigated for calculation of seedling index.In July 2020,20 plants were selected in each plot,and root zone soils were sampled at a depth of 20 cm,10 cm away from the roots,and then mixed to form a composite sample.The soil available Si and organic matter content were analyzed,and the fungal community structure and some specific microbial groups in soils were determined with high-throughput sequencing of ITS.【Results】All the three treatments significantly enhanced the lily plant growth and the seedling index,compared to CK.Besides,SF and MF treatments increased the relative abundances(RA)and diversity of fungal communities,and altered the community structures.The RA of some specific groups were found to be significantly correlated with the seedling index and/or soil available Si.Of them,the RA of the genera Fusarium,Dactylonectria,Humicola,Stilbella,and the species Humicola_grisea showed a positive correlation,while that of the genera Mortierella,Stilbella,Holtermanniella,and the species Mortierella_fatshederae showed a negative correlation with seedling index.The genera Fusarium,Stilbella,the species Humicola_grisea,and Dactylonectria_estremocensis showed a positive correlation,while the genura Stilbella,and the species Mortierella fatshederae showed a negative correlation with available Si content.In the co-occurence network of top twenty fungal genera and top sixteen bacterial genera(RA>0.2%),Holtermanniella was the only genus that interacted with the bacteria and negatively correlated with bacterial genus Blastococcus.Holtermanniella was also the most densely connected genera,followed by the genus Fusarium,Didymella and Humicola.In addition,the genus Holtermanniella was the key species connecting fungal and bacterial community in soil.Fungal functional prediction revealed that SF,MF and SMF treatments decreased plant pathogens guilds and increased the beneficial guilds Ectomycorrhizal,plant saprophyte,leaf saprophyte,and arbuscular mycorrhizal compared to CK.【Conclusions】Combined application of silicon fertilizer and microbial agents can alleviate continuous replanting problems of Lanzhou lilies through restoring the fungal community diversity,and promoting plant residue depredation,thus reducing soil born disease incidence.The beneficial genus Humicola and its one species H.grisea acts as bioconversion,and the genus Acremonium acts as plant pathogen inhibitor.
文摘【Objectives】Rose(Rosa hybrida L.)is a beautiful and widely cultivated flowering plant around the world whose quality is of great commercial importance.The objective of this study was to investigate the impact of foliar application of calcium nitrate on the quality and postharvest life of two rose varieties(cvs.Samurai,and Jumilia)in a soilless culture system.【Methods】The research used a hydroponic culture method,the roses plants were grown in Hoagland nutrient solution containing 50%less Ca for a total span of 4 months.One month was dedicated to plant acclimatization,and 3 months for spray treatment.Two rose varieties(Rosa hybrida L.),cvs.Samurai and Jumilia plants were used as test materials and planted in pots containing 100%perlite(3-5 mm).After one month of culture,160 mg/kg CaNO3 solution was sprayed,and each treatment corresponded to the first,second,and third harvests,respectively.The plant and flower growth indicators and flower vase life were investigated after each harvesting immediately.【Results】A positive impact of foliar-applied Ca on stem characteristics,pedicel dimensions,corolla size,flower attributes,and vase life was found.Furthermore,a general trend was observed,wherein an increase in the number of harvesting stages led to improved traits.Notably,Jumilia rose consistently exhibited lower values for all studied traits,except for flower vase life,in comparison to the Samurai rose.While there were no significant differences in length values between Samurai and Jumilia roses due to calcium foliar application across the three harvesting stages.Duncan’s grouping revealed a specific effect on Jumilia roses during the third harvest stage.Calcium fertilizer significantly increased photosynthesis rates of of rose leaves in the calcium treatments compared with the control treatment.【Conclusions】Foliar spraying of calcium nitrate is an effective measure to promote the growth of roses and improve the yield,quality and bottle life of fresh cut flowers.
基金financially supported by the National Key Research and Development Program of China(Grant No.2016YFD0600404)the Fundamental Research Funds for the Central Universities(2572017DA02)
文摘To determine appropriate quantities of water and fertilizer required for early growth of hybrid poplar cuttings,we recorded the growth traits of four clones grown under four factors(irrigation and nitrogen,phosphorus,and potassium fertilizers),each with four levels,using an orthogonal experimental design.A logistic model was used to estimate growth in height.The growth curves for tree height were sigmoid,and the model R^2 values were greater than 0.9,which indicated that the fit was highly significant.ANOVA results for tree height and basal diameter indicated that all sources of variance showed significant differences(p<0.001).The average tree height and basal diameter for all the four clones under the different treatments ranged from 155.39 to 235.04 cm,and from 13.71 to 17.42 mm,respectively.A highly positive correlation between the extreme k value and tree height was observed,suggesting that the k value was an accurate estimation of tree height.For model parameters,the earliest average time point for the onset of the rapid growth period of poplar clones was 131 d,and the highest average increment in tree height during the rapid growth period was 138.78 cm.The highest average tree height for all clones under each factor was 219,210.51,200,and 201 cm when treated with either 1200 mL of water applied every third day,3 g of nitrogen,0 g of phosphorus,or 0 g of potassium,respectively.The most suitable treatment for the early growth of hybrid poplar cuttings,as suggested by the developed logistic model,was 1200 mL of water applied every third day and three applications of 1 g nitrogen(in the form of CH4N2O).
文摘This paper puts forward a valuation model for the flexibility of revamping urea plants based on the substitutability of switching between the internationally accepted fertilizer feedstock fuel oil and natural gas. The paper first builds a stochastic mean-reversion model for fuel oil prices and natural gas prices respectively, then estimates and tests the parameters using the fuel oil and natural gas prices data from the U.S. market. This paper also conducts a sensitivity analysis with important parameters. The results show that the real option method can be applied successfully to evaluate the flexibility in decision- making for revamping installations in fertilizer plants or other similar plants.
文摘How to improve the water use efficiency of rice in black soil regions was studied. The black soil region in paddy fields was chosen as the research object. The research showed the fertilizer coupling mathematical model with N,P,K,irrigation water( W) and water use efficiency( WUE),which was set up under the condition of controlled irrigation with quadratic D- 416 optimized saturation design. The results show that the decending order of single factor' s influence on the WUE was N,K,P and W. All the interactions between N&P,N&K,N&W,K&P,P&W and K&W on the WUE were raised initially,and when reached a certain value,they began to decline. The decending order of each interaction on the WUE was K&P,K&W,N&K,N&P,P&W and N&W. When the WUE was targeted within 1. 8- 2. 5 kg / km^3,an optimized proportion plan was obtained in the 95% confidence interval,i. e. N 87. 76- 103. 32 kg / hm^2,K_2 O 52. 37- 66. 53 kg / hm^2 and P_2O_536. 80- 46. 71 kg / hm^2. Furthermore,the late tillering of the soil moisture content was 70. 07%- 72. 57% of the saturated moisture content.
文摘Triple Super Phosphate, TSP fertilizer, was applied @ 80 kg·ha^-1 as the source of phosphorous on six months old polybag seed- lings of Albizia chinensis, Albizia saman and Pongamia pinnta in nursery beds in Bangladesh. The effects of P-fertilizer on seedling growth and nodulation were comparcd to that of seedlings grown in unfertilized soil or in control at different harvesting intervals. The study revealed that, seedling growth was enhanced significantly with the application of P-fertilizer. The growth was found more pronounced in cases of A. saman and P. pinnata, whereas it was not noticeable and showed depressed growth in case of A. chinensis. The study also suggests that nodulation in terms of nodule number and size was also increased significantly with P-fertilization except in case ofP. pinnata, where higher harvesting intervals lowered the nodulation performance of that species
基金supported by Zhejiang Provincial Natural Science Foundation of China(LY14C030008)Forestry Industry Standard Project of China(2015LY-080)
文摘To explore fertilization methods for wine bamboo cultivation in southwestern semi-arid areas of China, this study analyzed annual changes in sap yield and nutrient composition from May 2013 to March 2015 by using bamboo charcoal-based bio-fertilizer （ZT） and organic fertilizer treatments （CK）. The study also provided basic data for functional beverage preparation and for application of ZT. The results of the two experimental cycles revealed that under the ZT treatment, sap was available for collection from May, the beginning of the rainy season, to November, the beginning of the dry season. The period of abundance was July to October with the highest yield of sap of 3.18 L stalk-1 in September, 2014, still lower than the moso bamboo sap, which was likely due to the scale of sap production of monopodial bamboos being different from that of sympodial bamboos. In January, trace amounts of sap were still detected, suggesting that the effect of the treatment was significant. Moreover,in the dry season, soil water content and soil temperatures at 10-15 cm depths indicated that the fertilizer had the ability to maintain soil temperatures and moisture. In both fertilizer treatments, the correlation between the collected sap and environmental parameters was significant. In the ZT treatment for the entire 2 years, the effectual environ- mental factors were soil water at 10-15 cm, air tempera- tures, and wind speeds. The same determining factors were observed for the rainy season. In the CK treatments, the effectual environmental factors for the entire year and the rainy season were soil water at 0-5 cm and air moisture. The bamboo charcoal-based bio-fertilizer elevated the potassium, calcium, iron, manganese, copper, and total phosphorus content, simultaneously increasing the sap yield, protein and reducing sugar contents, and with a relative increase in sap pH. The wine bamboo sap con- tained 18 amino acids. Glutamic acid, alanine and proline were the most abundant. Compared to the controls, the treatment showed higher levels of all amino acids. Thus, the ZT treatment could be more beneficial to the development of root systems because the function of heat preservation and moisture retention prolong the sap collection period, increase sap yields, and elevate mineral element, conventional nutrients, and amino acid contents with evident fertilization effects and broader application prospects.
基金supported by Institut für Bodenkunde und Waldernhrung,Georg-August-Universitt,Gttingen,Germany.
文摘Allocation of biomass and nutrient elements including Nitrogen to above and belowground compartments of beech seedlings （Fagus sylvatica L.） treated by labeled nitrogen fertilizer in the form of 15NH4 and 15NO3 were investigated at the end of two successive growing seasons. Pot cultured beech seedlings were grown at a green house on intact soil cores sampled from three adjacent stands including beech, Norway spruce and mixed beech-spruce cultures of Soiling forest, Germany. Comparing biomass allocation and nutrients concentrations of the seedlings between the control and 15N-fertilized treatments revealed no significant effect of N fertilization on nutrients uptake by seedlings over the experiment. The form of N input influenced its movement into plant pools. It was demonstrated that beech seedlings take up nitrogen mainly in the form of nitrate, which is then reduced in the leaves, although the differences between the retention of NO3^--N and NH4^＋-N in plants were not statistically significant. Percent recoveries of 15N in trees were typically greater after 15NO3 than after 15NH4 additions. It was indicated that immobilization of ~SN tracer in fine roots was a slower process comparing other plant compartments such as stem and coarse roots, but a powerful sink for N during the course of study.
文摘The present study was undertaken to determine the effects of different levels of urea-N fertilizer in addition to ipil-ipil tree litter on yield of rice and insect prevalence. The field study was conducted at the Agroforestry Field Laboratory, Bangladesh Agricultural University, Mymensingh during July-December 2004. The treatments included 0, 90, 180, and 270 kg urea per hectare. All four treatments received five tons ipil-ipil tree litter per hectare. The experiment was laid out in a randomized complete block design （RCBD） with four replications. The results showed that the different treatments significantly influenced the yield and yield component viz. total tillers/hill, effective tillers/hill, filled grains and unfilled grains/panicle. The highest yield of 4.62 t·h^m-2 with an increase of 21.57% over the control was recorded in treatment 180 kg urea·h^m-2, which was statistically similar to treatment 90 kg urea·h^m-2. The prevalence of insects viz. green leafhopper, brown plant hopper, rice bugs, leaf folder and stem borers were mostly correlated with N-levels. The prevalence of insects in general gradu- ally increased with the increase of N. Therefore, this study suggests that the combined application of organic materials （tree litter of ipil-ipil） and N-fertilizer of 90 kg·h^m-2 may oroduce good yield while minimizine insect arevalence in the rice field.
基金Basic Scientific Research Funding of the International Center for Bamboo and Rattan(1632020023)。
文摘The effects of long-day photoperiod on growth,photo synthetic fluorescence,carbon and nitrogen metabolism,and yield of Dendrocalamopsis oldhami and the compensation effects of fertilization were investigated.A completely randomized design was used with two light factors(bamboo culms cultivated in solar greenhouse under long-day[Ls]and short-day[Ln]treatments);two organic nitrogen fertilizer levels(application of organic fertilizer[OF]and no organic fertilizer[NF]);and three nitrogen fertilizer levels(Low[N0],medium[N1]and high nitrogen[N2]).Leaf chlorophyll and fluorescence parameters(φPo,PIABS,and ETo/CSm)decreased and DIo/CSmincreased in Ls compared to Ln.Indole acetic acid(IAA)and gibberellic acid(GA3)levels decreased,whereas abscisic acid(ABA)increased.Leaf area decreased and leaf dry mass increased.The contents of carbon and nitrogen metabolism-related enzymes(nitrate reductase,glutamine synthetase,amylase,and sucrose synthase)and products(total nitrogen,organic carbon,soluble sugar,and starch)increased.Single bamboo shoot weight and diameter at breast height decreased,whereas shoot quantity and total yield increased.Fertilizer application significantly affected physiological growth and yield in the two light treatments,thus promoting carbon and nitrogen metabolism.TheφPo,PIABS,IAA,and GA3contents increased slightly,whereas ABA levels decreased.Shoot quantity,individual weight,and total yield improved.IA A,soluble sugar,and total yield to organic manure and light were lower than those of nitrogen levels(FN>FL,FO).Other indicators showed lower responses to different fertilization treatments than the light factor(FL>FN,FO).The ability of D.oldhami to alter its morphological and physiobiochemical traits and yield in response to variations in light applications may translate into high phenotypic plasticity.Fertilization significantly improved photoplasticity of D.oldhami.Under Ls,D.oldhami had high metabolic rates.was easily inhibited by light,and showed accelerated leaf senescence,and shoot quantity and total output increased.However,the quality of individual shoots decreased.Different fertilization treatments affected D.oldhami differently under the two light intensities.Ls sensitivity to nitrogen was higher.Fertilization could delay leaf dormancy and senescence under Ls treatment.Organic fertilizer addition could improve yield more effectively,with OFN1being the optimal fertilization level.
基金supported by Massey University and the Centre for Sustainable Forest Management at Forest Research Institute, New Zealand
文摘A study was carried out to investigate changes in the soil plant-available P,the P nutrition and the growth of Pinus radiata seedlings grown in association with understory,broom（Cytisus scoparius L.） or ryegrass（Lolium multiflorum） on Orthic Allophanic Soil,following the application of three rates of triple superphosphate（TSP）（0,50,and 100 mg·kg^-1P） under a glasshouse condition.The application of P fertilizer enhanced P availability in the rhizospheric of radiata seedlings and the bulk soils in a P-deficient site.P availability in the rhizospheric soils of ryegrass and broom,grown in association with radiata,were also increased by the presence of radiata roots.P concentrations in new shoot needles,old shoot needles,stem and roots of radiata pine increased with increase rates of TSP application,but the effects of ryegrass and broom on P nutrition of radiata seedlings depended on the soil P status.In the absence of P fertilizer addition（control treatment）,P concentrations in new shoot needles,old shoot needles,stem,and roots of radiata grown in association with broom were higher than those with ryegrass,whereas,when P fertilizer was added（50 and 100 mg·kg^-1） the P concentration was lower.This is probably related to the growth of broom that may have removed much of the plant-available P in the soil as indicated by the consistently lower Bray-2 P concentration in the rhizosphere soil of radiata in association with broom than that in the rhizosphere soil of radiata in association with grass at the two high P rates.Furthermore,in the high P fertile soil（application rate of 100 mg·kg^-1）,the dry matter yield of radiata was lower when it was grown with broom than with ryegrass.This result suggests that in moderate to high P fertile soils,P.radiata seedlings grow better with ryegrass than with broom,because broom grows vigorously in high P fertile soil and competes with P.radiata for P and perhaps for other nutrients as well.
文摘The effects of different inorganic fertilizers （Urea and Triple Super Phosphate （TSP）） on seedling growth and nodulation capabilities of four agroforestry tree species （Albizia chinensis, A. saman, Acacia nilotica and Sesbania sesban） were compared. The nodulation of these seedlings were treated with different fertilizer treatments （at the rate of urea 40 kg·hm^-2, urea 80 kg·hm^-2 TSP 40 kg·hm^-2, TSP 80 kg·hm^-2, （urea＋TSP） 40 kghm 2 and （urea＋TSP） 80 kg·hm^-2） after one month of seed germination. The results revealed that the seedling growth was enhanced significantly with moderate fertilizer treatment. In some cases, the higher levels of fertilizers reduced the seedling growth. The study also revealed that the nodulation in nodule number and size was significantly inhibited by the application of N fertilizer （Urea）, while it was increased significantly with the application of P fertilizer （TSP）. This study improved our understanding and provided insights that would be useful to the farmers in their efforts to amend the soil with inorganic fertilizers in order to enhance plant growth and biological nitrogen fixation.
文摘Wood from three tree species was used for making slow-releasing woodchip fertilizer. Fertilizer made from Populus tomentiglandulosa retained the highest amounts of N （29.04%）, P205 （26.03%） and K20 （16.93%）. On the other band, woodchip fertilizer made from Pinus koraiensis retained the lowest amounts of N （26.22%）, P205 （21.80%） and I（20 （14.49%）. A field experiment was performed in a 50 m^2 experimental plot at Gangwon Agricultural Research and Extension Services, Chuncheon, Korea from August to November 1999. The effects of a general fertilizer along with compost and slow releasing woodchip fertilizer without compost on the cabbage production were observed. Cabbage production parameters, such as top height, head weight, head height, head width, number of outer and inner leaves, leaf width and head length, increased in the field where Larix kaempferi woodchip fertilizer was added as a basal dose. The result showed that the woodchip fertilizer made from Pinus koraiensis had faster releasing properties compared to other woodchip fertilizers. Without adding any compost in the woodchip fertilized field, woodchip fertilizer showed a superior outcome over a general chemical fertilizer. Although the amount of woodchip fertilizer was larger compared to that of a chemical fertilizer, it increased cabbage production.
文摘Low nitrogen （N） availability often results in reduced productivity of Eucalyptus plantations. We studied the response of four eucalyptus plantations （two plantations of E. tereticornis on the coastal lowlands, and two plantations of E. grandis in the upland region of the Western Ghats, Kerala, India） to N addition and related this response to seasonal N mineralization as well as other indices of N availability, in order to examine the utility of soil based indicators of N mineralization for predicting the response of eucalyptus growth to added N ferti- lizer. Several biochemical indicators were examined for their capacity to predict response to N fertilizer, including total soil N, soil C：N ratio, and N released during anaerobic and aerobic incubation. Results show that nitrogen fertilizer addition increased productivity across the 4 sites from 7% to 70%, N released during an aerobic incubation had the highest correlation with fertilizer response across the 4 sites （R^2=0.92/ p〈0.01）, and that Modelled seasonal soil N mineralisation was a poorer predictor of fertilizer response than N released during an aerobic incubation. Whilst some of these indicators are promising, they need wider validation and testing before they could be routinely applied.
基金supported by the Australian Centrefor International Agricultural Research
文摘Low nitrogen (N) availability often results in reduced productivity of Eucalyptus plantations. We studied the response of four eucalyptus plantations (two plantations of E. tereticornis on the coastal lowlands, and two plantations of E. grandis in the upland region of the Western Ghats, Kerala, India) to N addition and related this response to seasonal N mineralization as well as other indices of N availability, in order to examine the utility of soil based indicators of N mineralization for predicting the response of eucalyptus growth to added N fertilizer. Several biochemical indicators were examined for their capacity to predict response to N fertilizer, including total soil N, soil C:N ratio, and N released during anaerobic and aerobic incubation. Results show that nitrogen fertilizer addition increased productivity across the 4 sites from 7% to 70%, N released during an aerobic incubation had the highest correlation with fertilizer response across the 4 sites (R2=0.92, p<0.01), and that Modelled seasonal soil N mineralisation was a poorer predictor of fertilizer response than N released during an aerobic incubation. Whilst some of these indicators are promising, they need wider validation and testing before they could be routinely applied.
基金funded by the German Ministry of Education and Research(BMBF)the Brazilian Conselho National de Desenvolvimento Científico e Tecnológico(CNPq)
文摘The Brazil nut tree（Bertholletia excelsa） is a frequent component of agroforestry systems in the Amazon because of its adaptation to nutrient-poor upland soils and multiple uses.We investigated the aboveground biomass production（kg dry weight）,nutrient uptake and requirements（N,P,Ca,Mg,K） of Brazil nut trees of different sizes grown under agroforestry conditions and fertilized at different levels.Eight of 70 experimental trees with different size were harvested and stem,branches and leaves were separated.Nutrient contents were determined for three trees of varying size.Average tree growth was fast,but variability was high,suggesting considerable potential for the improvement of this economically important species.The trees responded to increased levels of fertilizer and lime with significantly increased foliar nutrient contents and growth,probably because of the improved availability of Mg and Ca for which the species seems to have a relatively high demand.In contrast to Brazil nut trees grown in forest or dense plantations,the agroforestry trees invested a substantial part of their biomass and nutrients in large branches and developed spreading crowns.To improve stem form,reduce competition with associated crops for light and recycle nutrients,regular pruning of lower branches or planting arrangements that favor self-pruning are recommended.These measures would also increase the recycling of Ca and Mg,large quantities of which are contained in the branches.
基金financed in part by the Conselho Nacional de Desenvolvimento Cientifico e Tecnologico(CNPq)the Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior-Brasil(CAPES)。
文摘The application of phosphorus(P)to soil can increase its availability to plants and alter P fractions in annual and perennial organs of Cordia trichotoma.If a portion of P accumulates in perennial organs in organic fractions it can be used in the next growth season,possibly decreasing plant dependence on P derived from soil fertilization.However,if P is preferentially accumulated in inorganic fractions in annual organs,plants will be more dependent on phosphate fertilization.This study aimed to evaluate the distribution of P fractions in organs of C.trichotoma grown on sandy soil treated with 120 and 360 kg P2O5 ha^(−1).The control was a zero application.After 24 months following fertilization,C.trichotoma seedlings were cut and separated into leaves,branches,stems and roots,dried,ground and subjected to chemical fractionation of P,which estimates fractions of total soluble P,soluble inorganic and organic P,lipid P,P associated ribonucleic acid and deoxyribonucleic acid,and residual P.P in annual organs,as leaves,accumulated preferentially in the soluble inorganic fraction in both treatments.In perennial organs such as stems and branches,P accumulated preferentially in the soluble organic fraction.The application of 300%of the recommended dosage(360 kg P2O5 ha^(−1))promoted the accumulation of P in soluble organic fractions which may contribute to annual growth the following season and be a strategy to reduce the dependence of 2-year-old stands on soil-derived P and on fertilizers.
文摘An experiment was conducted to assess the effect of Phosphorous （P） fertilizer （i.e. TSP or triple super phosphate @ 80 kg/hm^2） on seedling growth and nodulation capabilities of three potentially important agroforestry tree species （Acacia auriculiformis, Albizia lebbeck and Albizia procera） of Bangladesh. The study was conducted in nursery beds with six-month-old polybag seedlings ofA. auriculiformis, A. lebbeck and A. procera. The effects of P fertilizer on seedling growth and nodulation were compared with that of the seedlings grown in control （i.e. unfertilized soil）. The observations revealed that the seedling growth was enhanced significantly with the application of P fertilizer. The growth was found more pronounced in A. auriculiformis, whereas it was not apparent and shows depressed growth in case ofA. lebbeck. The study also suggests that the nodulation in terms of nodule number and size was also increased significantly with the application of P fertilizer.
基金National Key R&D Program of China(2016YFC0400204)National Natural Science Foundation of China(51479161,51279157,51779205)。
文摘Based on the experimental data,this study investigated the effect of sand content of muddy water on water and nitrogen transport characteristics of the single-line interference infiltration under film hole irrigation with muddy water and fertilizer.The relationship between the single-line interference infiltration parameters,the sand content,the wetting front movement distances,and the sand content were all established.The model of the cumulative infiltration volume of per unit film pore area,the vertical and horizontal wetting front movement distance of the free surface,and the wetting front movement distance of the interference center with sand content and infiltration time were proposed.Reveal the law of the change of soil water content and the distribution of NO_(3)^(-)-N content based on different muddy water sand content.The results indicate that at the same infiltration time,as the muddy water sand content increases,the cumulative infiltration volume per unit pore area decreases.The infiltration index of the free infiltration and the single-line interference vary little when the sand content increases,mainly are around 0.64 and 0.58.The relationship between infiltration parameters a,b and the sand content is linear function.At the same location,the more the sand content,the smaller the wetting front movement distance in free surface and the single-line interference surface,the less the NO_(3)^(-)-N content.
