Plant Growth Promoting Rhizobacteria Enhance the Efficiency of the Combination of Organic and Chemical Fertilisers in Sugarcane

Modern agricultural practices involve the extensive use of chemical fertilisers to increase productivity. However less than half of the applied chemical fertiliser nitrogen is used by the target crops, and much of the remaining pollutes air and waterways. Farming systems that sustain productivity while reducing the negative effect on the environment are crucially needed. One avenue is to use plant growth promoting rhizobacteria (PGPR) as bio-fertiliser to reduce the dependency on chemical fertiliser. The potential of PGPR to improve the efficiency of the combination of organic and chemical fertilisers has recently been proposed. Here, we demonstrate that this combination benefits sugarcane grown in field conditions.

Phosphorus fractions of fertiliser-derived P in an allophanic soil under Pinus radiata seedlings grown with broom and ryegrass

Changes in phosphorus （P） fractions in a P deficient allophanic soil under P. radiata seedlings grown with broom （Cytisus scoparius L.） and ryegrass （Lolium multiflorum） in pots were studied 14 months after the application of triple superphosphate at the rates of 0, 50, and 100 pg.g^-1, to determine the fate of fertiliser-derived P in the rhizosphere soils. Application of P fertiliser increased NaOH-Pi, NaOH-Po, and H2SO4-Pi concentrations in the soil, but decreased the residual-P concentration. The resin-Pi concentration, which is ex- tremely low in this soil （1 to μgg^-1 ）, remained the same. The majority of the added fertiliser P was however recovered in the NaOH-Pi fraction （40%-49%）. This is due to the high P fixation in this soil （92%）. The second highest P recovery was in NaOH-Po fraction （7%-19%）. Under P deficient condition or addition at the rate of 0 μg.g^-6, the NaOH-Pi concentration in the radiata rhizosphere soil was lower than that in the bulk soil and broom and grass rhizosphere soils. This may be due to higher oxalate production by the roots and mycorrhiza under P deficient conditions which released some ＆the P fixed to the soils in the rhizosphere, which needs to be tested in future studies.

The current status of nitrogen fertiliser use efficiency and future research directions for the Australian cotton industry

Fifty years of sustained investment in research and development has left the Australian cotton industry well placed to manage nitrogen(N) fertiliser. The average production in the Australian cotton industry today is greater than two tonnes of lint per hectare due to improved plant genetics and crop management. However, this average yield is well below the yield that would be expected from the amount of N fertiliser used. It is clear from the recent studies that across all growing regions, conversion of fertiliser N into lint is not uniformly occurring at application rates greater than 200-240 kg·hm^(-2) of N. This indicates that factors other than N availability are limiting yield, and that the observed nitrogen fertiliser use efficiency(NFUE) values may be caused by subsoil constraints such as sodicity and compaction. There is a need to investigate the impact of subsoil constraints on yield and NFUE.Gains in NFUE will be made through improved N fertiliser application timing, better targeting the amount of fertiliser applied for the expected yield, and improved soil N management. There is also a need to improve the ability and confidence of growers to estimate the contribution of soil N mineralisation to the crop N budget. Many Australian studies including data that could theoretically be collated in a meta-analysis suggest relative NFUE values as a function of irrigation technique; however, with the extensive list of uncontrolled variables and few studies using non-furrow irrigation, this would be a poor substitute for a single field-based study directly measuring their efficacies. In irrigated cotton, a re-examination of optimal NFUE is due because of the availability of new varieties and the potential management and long-term soil resilience implications of the continued removal of mineralised soil N suggested by high NFUE values. NFUE critical limits still need to be derived for dryland systems.

Application of Nejayote as a Foliar and Edaphic Fertiliser to Native Blue Maize (Zea mays L.) Crops

Raw and treated “nejayote” were assessed as foliar and edaphic fertilisers for native blue maize (Zea mays L.) crops in the municipality of Amozoc de Mota, Puebla, Mexico, during the 2015 agricultural cycle. Treated nejayote refers to raw nejayote subjected to a coagulation-flocculation process. Two states of nejayote were established (raw and treated nejayote) with different physicochemical properties. Foliar bio-fertilisers were prepared from raw and treated nejayote and mixed with organic matter (OM) to promote a fermentation process. The foliar treatments used were: BNC5, BNC15, BNC30 (raw nejayote-based bio-fertiliser at 5%, 15%, and 30%), BNCQ5, and NCQ30 (nejayote treated by chemical coagulation at 5% and 30%), with BT as a control (traditional bio-fertiliser). The edaphic treatments used were: NC50, NC75, and NC100 (raw nejayote at 50%, 75%, 100%), with AP as a control (drinking water), thus giving rise to 10 treatments in terms of content of raw or treated nejayote. Foliar and edaphic field treatments applied to native blue maize crops were statistically assessed using the following response variables: plant height, stem diameter, number of leaves, and grain yield. The experiment was laid out in a randomised complete block design (RCBD) with five replications of each treatment. The results obtained showed, that foliar or edaphic application at the different stages of development did not produce statistically significant differences, at P ≤ 0.05, in terms of response variables. The most significant effects occurred at the early stage of plant development and were mainly reflected in the stem diameter with foliar treatment NCQ30 and in the number of leaves with foliar treatment BNC5. At the final stage of crop development, the highest yield (0.639 ± 0.121 t·ha-1) was obtained with treatment BNC5, which produced a statistically significant difference (b) in relation to the rest of the foliar and edaphic treatments (Tukey P ≤ 0.05).

Analysis of the simultaneous adsorption mechanism of ammonium and phosphate on magnesium-modified biochar and the slow release effect of fertiliser

To decrease the eutrophication caused by nitrogen(N)and phosphorus(P)in water,magnesium-modified corn stalk biochar(MgB)was prepared under the synergistic impact of the multi-pyrolysis temperatures and Mg^(2+)contents for the co-adsorption of ammonium(NH_(4)^(+)-N)and phosphate(PO_(4)^(3−)).The co-adsorption mechanism,slow-release performance and plant application of MgB were systematically studied.The results showed that pyrolysis temperatures(350-650℃)and Mg^(2+)(0-3.6 g/L)contents not only altered the physicochemical properties of biochar,but also significantly affected the adsorption efficacy of MgB.The adsorption of NH_(4)^(+)-N and PO_(4)^(3−)was in accordance with Langmuir-Freundlich and pseudo-second-order kinetic models(Q_(max)=37.72 and 73.29 mg/g,respectively).Based on the characteristics,adsorption kinetics and isotherms results,the adsorption mechanism was determined and found to mainly involve struvite precipitation,ion exchange,and surface precipitation or electrostatic attraction.Compared with the leaching performance of chemical fertilizers(CF),after adsorption of NH_(4)^(+)-N and PO_(4)^(3−)(MgB-A),MgB had a more stable pH and lower conductivity.Leaching of NH_(4)^(+)-N and PO_(4)^(3−)by MgB-A was controlled by both the diffusion mechanism and the dissolution rate of struvite and Mg-P.The excel-lent long-term slow-release performance and abundant Mg^(2+)of MgB-A promoted the growth of Zea mays L.and Lolium perenne L.Overall,this study suggested that MgB could realize a win-win outcome of struvite biochar-based fertiliser production and wastewater treatment.

Potential Use of a Poultry Manure Digestate as a Biofertiliser:Evaluation of Soil Properties and Lactuca sativa Growth

Anaerobic digestion is a process that is widely used for the treatment of organic wastes. The digestate can be used as a soil amendment or crop fertiliser. The aims of our work were to evaluate 1) the physicochemical composition and pathogen content in a digestate from poultry manure, according to international regulations, and 2) the effect of its soil application on the major chemical and biological soil properties and on the growth of Lactuca sativa. The experiment consisted of two groups of pots(with and without crop). Treatments applied to each group were as follows: low and high doses of digestate and inorganic fertiliser, and no application(control)(low dose: 70 kg nitrogen(N) ha^(-1) and 21 kg phosphorus(P) ha^(-1); high dose: 210 kg N ha^(-1) and 63 kg P ha^(-1)). Soil samples were taken 7 and 34 d(harvest) after treatment applications. Heavy metal and pathogen contents in the digestate were below the upper limit values. Despite the high pH and electrical conductivity values of the digestate, both soil parameters presented acceptable values for crop growth. Although there were no initial increases in total inorganic N and available P in soil with digestate application, an increase in the fresh weight of crop was observed with the high dose application. This is probably associated with the slow nutrient release from the digestate during the development of the crop. Changes in the microbial community were temporary and occurred at the initial sampling stage of the experiment.

Can Bacteria Help Crops Cut Down on Fertilisers?

Ever since the nitrogen-fixing properties of legumes were discovered more than a century ago, scientists have dreamt of transferring the same trait to cereals. Now they might finally have succeeded. A team of scientists from Britain, Australia, China and Mexico has

Maize response to nitrogen and phosphorus starter fertilisation in mineral-fertilised or manured systems

Phosphorus(P)is an essential nutrient for maize production,but in temperate areas the P uptake during early growing stages can be limited due to low soil temperature,even though the soil was tested high in P.The objective of this study was to assess the effects of nitrogen and phosphorous(NP)starter fertilisation during early growth stages and its carryover until maize harvest,in mineral-fertilised or manured systems.A field experiment was carried out in north-west Italy during the 2019 and 2020 growing seasons.The trial compared sub-surface placement of NP(diammonium phosphate)or N alone(ammonium nitrate)in bands close to the maize seed furrows,in differing long-term(LT)fertilisation managements:two doses of urea(Min-L and Min-H),two doses of bovine slurry(Slu-L and Slu-H)or two doses of farmyard manure(Fym-L and Fym-H).The two rates,low(L)and high(H),corresponded to 170 and250 kg N ha^(-1)year^(-1) respectively.Compared to N fertilisation,NP starter fertilisation improved early maize growth assessed by leaf area index(LAI)and shoot dry weight(SDW)in all systems.The effects differed between the two years(2019:LAI+63%,SDW+67%;2020:LAI+36%,SDW+38%),as 2019was cool during the first growth.Higher LAI and SDW values were confirmed at crop flowering in the mineral-fertilised systems only.As shoot growth was enhanced by NP starter fertilisation,anthesis occurred 1 day earlier in all systems.However,a response to NP starter fertilisation at harvest was recorded in mineral-fertilised systems only(+1.3 and+3.2 t ha^(-1) in Min-L and Min-H,respectively).The uptake of P,used as a true indicator of soil nutrient availability,increased with increasing soil Olsen P until 39 mg kg^(-1).These results suggest that soil test thresholds should be revised for points above which P fertilisation should be suspended.

Russian Collaborative Development of Reproduction Technologies for the Sustainable Management of Amphibian Biodiversity

Reproduction technologies(RTs)can provide for the reliable reproduction of amphibians,as well as perpetuation of species genetic variation with the use of biobanks.In 1982,in anticipation of the biodiversity conservation crisis,major Russian institutions collaborated in a dynamic program to develop and implement RTs for the sustainable management of amphibian biodiversity.An initial primary focus was the captive breeding of threatened Russian endemic anuran and caudate species,using RTs that varied from environmental manipulation to the use of exogenous gonadotropic hormones to stimulate reproduction.These species were mostly from Palearctic or cool mountain regions,but also included a wide range of species from warm regions.Other early achievements included the successful cryopreservation of anuran spermatozoa and anuran diploid pluripotent cell nuclei,in order to store both the matrilineal and patrilineal genomes in biobanks,with their subsequent development to the blastula stage after implantation into enucleated oocytes.After the turn of the 21st Century,in support of the priorities of the Amphibian Conservation Action Plan(2007),we developed RTs for the refrigerated storage of testicular or urinary spermatozoa for days to weeks at 4℃,the cryopreservation of urinary spermatozoa using anovel cryoprotectant,the in vitro fertilisation of hormonally induced oocytes either fresh or after refrigerated ex situ or in situ storage,and the artificial insemination of salamanders with fresh spermatozoa.In this article,we describe previously unpublished techniques and techniques from obscure Russian sources.

Closing the nitrogen use efficiency gap and reducing the environmental impact of wheat-maize cropping on smallholder farms in the Guanzhong Plain,Northwest China

A high crop yield with the minimum possible cost to the environment is generally desirable.However,the complicated relationships among crop production,nitrogen(N) use efficiency and environmental impacts must be clearly assessed.We conducted a series of on-farm N application rate experiments to establish the linkage between crop yield and N_2 O emissions in the Guanzhong Plain in Northwest China.We also examined crop yield,partial factor productivity of applied N(PFPN) and reactive N(Nr) losses through a survey of 1 529 and 1 497 smallholder farms that grow wheat and maize,respectively,in the region.The optimum N rates were 175 and 214 kg ha^(-1) for winter wheat and summer maize,respectively,thereby achieving the yields of 6 799 and 7 518 kg ha^(-1),correspondingly,with low N_2 O emissions based on on-farm N rate experiments.Among the smallholder farms,the average N application rates were 215 and 294 kg ha^(-1) season^(-1),thus producing 6 490 and 6 220 kg ha^(-1) of wheat and maize,respectively.The corresponding PFPN values for the two crops were 36.8 and 21.2 kg N kg^(-1),and the total N_2 O emissions were 1.50 and 3.88 kg ha^(-1),respectively.High N balance,large Nr losses and elevated N_2 O emissions could be explained by the overdoses of N application and low grain yields under the current farming practice.The crop yields,N application rates,PFPN and total N_2 O for wheat and maize were 18 and 24% higher,42 and 37% less,75 and 116% higher,and 42 and 47% less,correspondingly,in the high-yield and high-PFPN group than in the average smallholder farms.In conclusion,closing the PFPN gap between the current average and the value for the high-yield and high-PFPN group would increase crop production and reduce Nr losses or the total N_2 O emissions for the investigated cropping system in Northwest China.

Growth response of broom (Cytisus scoparius) growing with and without radiata pine (Pinus radiata) seedlings to different P levels in soils

A study was carried out to test the effects of three rates of TSP （triple superphosphate） （0, 50, and 100 mg·kg^-1 P） on growth of broom with and without radiata pine seedlings and to determine the relationships between P concentrations in the broom shoot and dry matter yields with soil plant-available P （Bray-2 P）. A bulk sample of soil was collected from Kaweka forest at soil depth of 0-10 cm, in New Zealand on March 11, 2001. The forest area was not supplied with fertiliser at least 30 years. The results show that TSP application increased P avail- ability in the soil. The P availability concentration in soil of broom with radiata pine seedlings was higher than that in soil of broom alone. Bray-2 P concentrations had a significant logarithmic relationship with Pcon- centrations of broom shoot and an exponential relationship with dry matter weight of whole broom plant.

The Effect of Organo-Mineral Fertilizer Applications on the Yield of Winter Wheat, Spring Barley, Forage Maize and Grass Cut for Silage

Biosolids were applied with urea to produce a granulated organo-mineral fertiliser (OMF) for application by farm fertiliser equipment to a range of agricultural crops. The recommended rates of nitrogen, phosphate and potash were calculated for the test crops using “The Fertiliser Manual”, which assesses the nutrient requirement based on previous cropping, rainfall and soil index. The OMF produced similar crop yields compared to ammonium nitrate fertiliser when applied as a top-dressing to winter wheat, forage maize and grass cut for silage in the cropping years 2010 to 2014. In 2012 the grain yield of spring barley top-dressed with OMF was significantly lower than the conventional fertiliser treatment, due to dry conditions following application. For this reason it is recommended that OMF is incorporated into the seedbed for spring sown crops and The Safe Sludge Matrix guidelines followed. The experimental work presented shows that OMF can be used in sustainable crop production systems as a source of nitrogen and phosphorus for a range of agricultural crops.

伴生有金雀花、黑麦草的辐射松幼苗Allophanic土壤磷肥驱动的各磷形态变化

Changes in phosphorus (P) fractions in a P deficient allophanic soil under P. radiata seedlings grown with broom (Cytisus scoparius L.) and ryegrass (Lolium multiflorum) in pots were studied 14 months after the application of triple superphosphate at the rates of 0, 50, and 100 μg·g-1, to determine the fate of fertiliser-derived P in the rhizosphere soils. Application of P fertiliser increased NaOH-Pi, NaOH-Po, and H2SO4-Pi concentrations in the soil, but decreased the residual-P concentration. The resin-Pi concentration, which is extremely low in this soil (1 to 3 μg·g-1 ), remained the same. The majority of the added fertiliser P was however recovered in the NaOH-Pi fraction (40%?49%). This is due to the high P fixation in this soil (92%). The second highest P recovery was in NaOH-Po fraction (7%?19%). Under P deficient condition or addition at the rate of 0 μg·g-1, the NaOH-Pi concentration in the radiata rhizosphere soil was lower than that in the bulk soil and broom and grass rhizosphere soils. This may be due to higher oxalate production by the roots and mycorrhiza under P deficient conditions which released some of the P fixed to the soils in the rhizosphere, which needs to be tested in future studies.

Integrating Source and Transport Factors with Best Management Practices to Derive an Index for Assessing Phosphorus Mobilization Risks from Mauritius Sugarcane Fields

Application of phosphorus (P) fertilisers to sugarcane fields in Mauritius increased almost four-fold per unit area over the past 60 years. Some of the applied P accumulated in the soils and can therefore be transported eventually to surface waters resulting in the eutrophication thereof. Precaution measures such as an appropriate P index as a management tool is required. Source factors (dissolved P, particulate P, P application rates, methods and timing), transport factors (soil erosion, runoff potential and precipitation factor) and a best management practices multiplier were integrated to derive an index for assessing risks of P mobilisation from the island’s sugarcane fields. Farmers and their advisors can use the proposed P index during the planning process before sugarcane fields are planted and will be applicable for the whole crop cycle of 6 - 7 years if factors in the index do not change. The index can be also valuable in the selection of alternative management practices that could reduce the risks of P losses from sugarcane fields where the potential of P movement is initially high. Sensitivity analyses and edge-to-plot field tests showed that the P index needs further improvement, especially the estimation of soil erosion rates. The P index can, however, be applied by farmers and their advisors if they are well informed about the index’s capability.

Acrosome reaction： relevance of zona pellucida glycoproteins

During mammalian fertilisation, the zona pellucida （ZP） matrix surrounding the oocyte is responsible for the binding of the spermatozoa to the oocyte and induction of the acrosome reaction （AR） in the ZP-bound spermatozoon. The AR is crucial for the penetration of the ZP matrix by spermatozoa. The ZP matrix in mice is composed of three glycoproteins designated ZP1, ZP2 and ZP3, whereas in humans, it is composed of four （ZP1, ZP2, ZP3 and ZP4）. ZP3 acts as the putative primary sperm receptor and is responsible for AR induction in mice, whereas in humans （in addition to ZP3）, ZP1 and ZP4 also induce the AR. The ability of ZP3 to induce the AR resides in its C-terminal fragment. O-linked glycans are critical for the murine ZP3-mediated AR. However, N-linked glycans of human ZP1, ZP3 and ZP4 have important roles in the induction of the AR. Studies with pharmacological inhibitors showed that the ZP3-induced AR involves the activation of the Gi-coupled receptor pathway, whereas ZP1- and ZP4-mediated ARs are independent of this pathway. The ZP3-induced AR involves the activation of T-type voltage-operated calcium channels （VOCCs）, whereas ZP1- and ZP4-induced ARs involve both T- and L-type VOCCs. To conclude, in mice, ZP3 is primarily responsible for the binding of capacitated spermatozoa to the ZP matrix and induction of the AR, whereas in humans （in addition to ZP3）, ZP1 and ZP4 also participate in these stages of fertilisation.

Heat shock protein family D member 1 in boar spermatozoa is strongly related to the litter size of inseminated sows

Background:Sperm quality evaluation is the logical first step in increasing field fertility.Spermatozoa contain cytoplasmic organelles and biomolecules known as sperm-intrinsic factors,which play key roles in sperm maturation,sperm-oocyte fusion,and embryo development.In particular,sperm membrane proteins[e.g.,arginine vasopressin receptor 2,beta-actin,prohibitin,and heat shock protein family D member 1(HSPD1)]and RNA could be used as functional indicators of male fertility.We sought to clarify the effects of differential mRNA expression of selected genes on several fertilisation parameters,including sperm motility,motion kinematics,capacitation,and litter size,in a porcine model.Results:Our results demonstrated that HSPD1 expression was significantly correlated with male fertility,as measured by the litter size of inseminated sows.The expression of HSPD1 mRNA was linked to sperm motility and other motion kinematic characteristics.Furthermore,HSPD1 had a 66.7%overall accuracy in detecting male fertility,and the high-litter size group which was selected with the HSPD1 marker had a 1.34 greater litter size than the lowlitter size group.Conclusions:Our findings indicate that HSPD1 might be a helpful biomarker for superior boar selection for artificial insemination,which could boost field fertility.

A delayed diagnosis of unsuspected retinoblastoma in an in vitro fertilisation infant with retinopathy of prematurity

Dear Editor,I am Dr.Tian Tian,from the Department of Ophthalmology,Xin Hua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine,Shanghai,China.I write to present a rare case report of a delayed diagnosis of unsuspected retinoblastoma（RB）in an in vitro fertilisation（IVF）infant with retinopathy of prematurity.

Effects of acut and chronic doses of methoxy acetic acid on hamster sperm fertilising ability

Aim: To evaluate the effects of acute and chronic doses of methoxy acetic acid (MAA) on in vitro fertilisation byhamster sperm and to correlate the data with the testicular damage. Methods: Adult male hamsters were gavagedwith 3 single doses (0, 80, 160 and 650 mg/kg) and 3 chronic doses (0, 8, 32 and 64 mg/kg daily for 5 weeks) ofMAA in distilled water. After treatment hamsters were killed at weekly intervals and spermatozoa recovered from thedistal cauda epididymides were used to assess the fertilising capacity in vitro. The testes were processed for histologicalexamination. Results; Acute doses showed a significant reduction in sperm fertilising ability from week 3 and 4 af-ter treatment and with the chronic doses, the effects were more extensive and persistent. The results were in correpon-dence with the testicular damages observed. Conclusion: It is evident that both acute and chronic doses of MAAcan impair the sperm function by damaging one or more cell populations in the testis.(Asian J Androl 2001 Sep; 3: 209- 216)

Context dependent song-flight performance and timing in the Black-headed Bunting(Emberiza melanocephala)

Many songbirds produce song-flights;however,the function,vocal and motor characteristics,as well as the diel and seasonal variation of song-flight in songbirds remain not well understood.Here,we studied two types of song-flight in male Black-headed Buntings(Emberiza melanocephala),the Moth—a standard,i.e.,perch song produced during a horizontal flight,and the Towering—a specifically structured song produced during a complex ascending and descending flight.While perch song,used during Moth flight,has already been described,here we provide the first description and sonogram representation of the more elaborate and less stereotyped Towering song.While males started to perform Moth song-flights as soon as they arrived at the breeding site,Towering did not start before the female arrival.Males usually delivered spontaneous Moth song-flights before chasing rivals or undertaking aerial fights,suggesting Moth is directed towards conspecific males and serves as a threat display.Furthermore,playback of conspecific perch songs triggered males to approach the loudspeaker with Moth song-flights.The Towering started after females arrived at the breeding site,suggesting the Towering is directed towards conspecific females.We detected a seasonal difference in the peak Towering rate between forenoon and afternoon,suggesting that Towerings performed at different times of the day have different functions.Forenoon Towerings were strongly positively related to the number of fertile females at the breeding site,while afternoon Towerings peaked very early in the breeding season and coincided with the number of females at the breeding site before the onset of nest-building.These results provide evidence that birds can direct different types of song-flight towards different receivers and suggest the possibility that time of the day determines the context of the display,namely to attract social mates or solicit copulation.Further work is needed to account for the effect of between male variability in song-flight rate,as well as in height/steepness of flight or song quality.

Relationship between Endometriosis and Subfertility

An association between minor endometriosis and subfertility is shown by prevalence studies but a clear causal relationship has not yet been demonstrated. This review presents the evidence for pituitary-ovarian dysfunction as a cause for subfertility in women with minor endometriosis. Using tubal infertility cases as controls, group comparison has shown effects on the following: follicular growth (impaired) , preovulatory circulating oestradiol levels (reduced) and early luteal phase oestradiol and progesterone (reduced) , and LH surge patterns (disordered), preovulatory follicular fluid LH concentration (reduced) , and granulosa cell steroidogenic capacity (impaired) . However, these findings are not consistent in the literature. Compared with controls, reduced oocyte fertilisation and implantation rates are reported in natural and go-nadotrophin stimulated cycles. An inherent disorder of follicular function is possible as a cause, with LH surge impairment probably a secondary phenomenon. Natural sub-fertility is substantially disordered as a result of oocyte fertilisation impairment. However, as excess numbers of oocytes are available in bitrofertility in vitro fertility (IVF) is still successful.