Effects of mixed fertilizers formed by the compounding of two targeted controlled-release nitrogen fertilizers on yield,nitrogen use efficiency,and ammonia volatilization in double-cropping rice

One-time application of mixed fertilizer formed by the compounding of two controlled-release nitrogen fertilizers(CRUs)with targeted N supply during the periods from transplantation(TS)to panicle initiation(PI)and from PI to heading(HS)is expected to synchronize the double-peak N demand of rice.However,its effects on the yield and N use efficiency(NUE)of labor-intensive double-cropping rice were unknown.Two targeted CRU(CRU_(A)and CRU_(B))were compounded in five ratios(CRU_(A):CRU_(B)=10:0,7:3,5:5,3:7,and 0:10)to form five mixed fertilizers(BBFs):BBF1-5.A field experiment was performed to investigate the characteristics of N supply in early and late seasons under different BBFs and their effects on N uptake,yield,and ammonia volatilization(AV)loss from paddy fields of double-cropping rice.Conventional high-yield fertilization(CK,three split applications of urea)and zero-N treatments were established as controls.The N supply dropped significantly with the increased compound ratio of CRU_(B)during the period from TS to PI,but increased during the period from PI to HS.With the exception of the period from TS to PI in the late rice season,the N uptake of early and late rice maintained close synchronicity with the N supply of BBFs during the double-peak periods.Excessive N supply(BBF1 and BBF2)in the late rice season during the period from TS to PI increased N loss by AV.The effect of BBF on grain yield increase varied widely between seasons,irrespective of year.Among the BBFs,the BBF2 treatment of early rice not only stabilized the spikelets per panicle but also ensured a high number of effective panicles by promoting N uptake during the period from TS to PI and a high grain-filling percentage by appropriately reducing the N supply at the later PI stage,resulting in the highest rice yield.While stabilizing the effective panicle number,the BBF4 treatment of late rice increased the number of spikelets per panicle by promoting N uptake during the period from PI to HS,resulting in the highest rice yield.The two-year average yield and apparent N recovery efficiency of the BBF2 treatment during the early rice season were 9.6 t ha 1 and 45.3%,while those of late rice in BBF4 were 9.6 t ha 1 and 43.0%,respectively.The yield and NUE indexes of BBF2 in early rice and BBF4 in late rice showed no significant difference from those of CK.The AVs of BBF2 during the early rice season and of BBF4 during the late rice season were 50.0%and 76.8%lower,respectively,than those of CK.BBF2 and BBF4 could effectively replace conventional urea split fertilization in early and late rice seasons,ensuring rice yield and NUE and reducing AV loss in paddy fields.

Studies on the Mechanism of Single Basal Application of Controlled-Release Fertilizers for Increasing Yield of Rice (Oryza sativa L.)

This paper was to explore the mechanism of single basal application of controlled-release fertilizers for increasing yield of rice （Oryza sativa L.）. Pot trials and cylinder trials were carried out from 2002 to 2005 to study the influences of single basal application of 3 controlled-release fertilizers on the changes of soil available N, root development, senescence and lodging resistance at late growth stages. Results showed that at 30 days after fertilization, single basal application of controlled-release fertilizers coated with vegetal-substance （CRF1） and polymer materials （CRF3） increased soil available N to 12.0 and 147.9%, respectively, in comparison to split fertilization of rice-specific fertilizer （RSF1）. Treatments of the two CRFs obviously benefited the development of root system, resulting in greater rice root weights with extensive distribution and higher root activity. In addition, the two CRF treatments, in comparison to RSF1, enhanced chlorophyll consents of the flag leaves to 9.5 and 15.5%, and soluble protein up to 89.7 and 108.0% respectively. Application of the two CRFs also made the base of rice stems strong and large, declined the proportion of shoot and root, increased root depth index. Though relatively low K rate, single basal application of the CRF3 coated with NH4MgPO4 could also promote the development of root system, enhance root activity and some physiological functions of flag leaves. Based on these results, it was concluded that major mechanisms for increasing rice yield by single basal application of the CRFs should be attributed to grater soil available N supply, superior development of root systems, better nutrient absorption capacity, slower senescence and enhancement of lodging resistance at late stages.

Controlled-release fertilizer(CRF): A green fertilizer for controlling non-point contamination in agriculture

Fertilizers contribute greatly to high yields but also result in environmental non-point contamination, including the emission of greenhouse gas(N 2O) and eutrophication of water bodies. How to solve this problem has become a serious challenge, especially for China as its high ecological pressure. Controlled-release fertilizer(CRF) has been developed to minimize the contamination while keeping high yield and has become a green fertilizer for agriculture. Several CRFs made with special coating technology were used for testing the fertilizer effects in yield and environment through pot experiment and field trial. The result indicated that the CRFs had higher N use efficiency, thus reducing N loss through leaching and volatilization while keeping higher yields. Comparing with imported standard CRFs, the test on CRFs showed similar fertilizer effect but with much lower cost. CRFs application is becoming a new approach for minimizing non-point contamination in agriculture.

Release Characteristics of Different N Forms in an Uncoated Slow/Controlled Release Compound Fertilizer

This study examined the release characteristics of different N forms in an uncoated slow/controlled-release compound fertilizer （UCRF） and the N uptake and N-use efficiency by rice plants. Water dissolution, soil leaching, and pot experiments were employed. The dynamics of N release from the UCRF could be quantitatively described by three equations： the first-order kinetics equation [N1=N0 （1-e^-kt）], Elovich equation （N1=a ＋ blnt）, and parabola equation （N1=a ＋ bt^0.5）, with the best fitting by the first-order kinetics equation for different N （r= 0.9569^＊＊-0.9999^＊＊）. The release potentials （No values estimated by the first-order kinetics equation） of different N in the UCRF decreased in the order of total N 〉 DON 〉 urea-N 〉 NH4^＋-N 〉 NO3^-N in water, and total N 〉 NH4^＋-N 〉 DON 〉 urea-N 〉 NO3^--N in soil, respectively, being in accordance with cumulative amounts of N release. The constants of N release rate （k values and b values） for different N forms were in decreasing order of total N 〉 DON 〉 NH4^＋-N 〉 NO3^--N in water, whereas the k values were urea- N 〉DON 〉 NH4^＋-N 〉 total N 〉 NO3^--N, and the b values were total N 〉 NH4^＋-N 〉 DON 〉 NO3^--N 〉 urea-N in soil. Compared with a common compound fertilizer, the N-use efficiency, N-agronomy efficiency, and N-physiological efficiency of the UCRF were increased by 11.4%, 8.32 kg kg^-1, and 5.17 kg kg^-1, respectively. The ratios of different N to total N in the UCRF showed significant correlation with N uptake by rice plants. The findings showed that the first-order kinetics equation [Nt=N0 （l-e^kt）] could be used to describe the release characteristics of different N forms in the fertilizer. The UCRF containing different N forms was more effective in facilitating N uptake by rice compared with the common compound fertilizer containing single urea-N form.

Shifts in soil bacterial communities induced by the controlled-release fertilizer coatings

Coated controlled-release fertilizers （CRFs） have been widely applied in agriculture due to their increased efficiency. However, the widespread and a lot of coated CRFs application may leave undesired coating residues in the soil due to their slow degradation. Limited information is available on the effects of substantial residual coatings on the soil bacterial community. By adding 0, 5, 10, 20, and 50 times quantities of residual coating from conventional application amount of resin and water-soluble coated CRFs, we studied the responses of soil properties and bacterial community composition to these two residual coatings in black soil. The results showed that the resin and water-soluble coatings did not essentially alter the properties of black soil or cause dramatic changes to bacterial diversity within the test concentration range. The residual resin and water-soluble coatings also did not distinctly alter the relative abundance of the top ten bacteria at phylum level. Heatmap results suggested that the treatments were basically clustered into two groups by concentration rather than types of coating material. Pearson correlation analysis showed that the Simpson＇s diversity index of the bacterial community was significantly correlated with microbial biomass carbon （MBC, r=0.394, P〈0.05）, and the richness index abundance-based coverage estimator （ACE） of the bacterial community was significantly correlated with microbial biomass nitrogen （MBN, t=0.407, P〈0.05）. Overall, results of this study suggested that substantial residual resin and water-soluble coatings with 0-50 times quantities of residual coating from conventional application amount of coated CRFs did not generate obviously negative impacts on the bacterial community in black soil.

Physiological Basis of Photosynthetic Function and Senescence of Rice Leaves as Regulated by Controlled-Release Nitrogen Fertilizer

The physiological mechanism of photosynthetic function and senescence of rice leaves was studied by using early rice variety Baliangyou 100 and late rice variety Weiyou 46, treated with controlled-release nitrogen fertilizer （CRNF）, urea and no nitrogen fertilizer. CRNF showed obvious effects on delaying the senescence and prolonging photosynthetic function duration of rice leaves. Compared with urea, CRNF could significantly increase the chlorophyll content of functional leaves in both early and late rice varieties, and this difference between the treatments became larger as rice growth progressed; CRNF increased the activities of active oxygen scavenging enzymes super oxide dismutase （SOD） and peroxidase （POD）, and decreased the accumulation amount of malondialdehyde （MDA） in functional leaves during leaf aging; Photosynthetic rate of functional leaves in CRNF treatment was significantly higher than that in urea treatment. The result also indicated that CRNF could effectively regulate the contents of indole-3-acetic acid （IAA） and abscisic acid （ABA） in functional leaves; IAA content was higher and ABA content was lower in CRNF treatment than those in urea treatment. Therefore, application of CRNF could increase the rice yield significantly due to these physiological changes in the functional leaves.

In situ polymerization coating and characteristics of coated NPK compound fertilizer

Controlled release NPK compound fertilizers were prepared by means of in situ polymerization of monomers on the surface of fertilizer granules at room temperature. Methacrylate, α-methyl acrylic acid, and ethylene dimethylacrylate were used as monomers, Dibenzoyl peroxide as initiator, and cobalt naphthenate, and triethyl amine as promoters. The structures of coating materials were characterized by IR spectra. The thermogravimetric analysis result indicated that the coating materials were of good thermal stability. The mean thickness of single coating measured with screw gauge was ca. 140 μm. The morphologies of uncoated and coated fertilizer granules analyzed by using scanning electron microscopy were changed from porosities and gullies to hills and plain. The release rate of coated compound fertilizers in water could be controlled by the hydrophicity and thickness of coating. The increase in coating hydrophicity caused the increase in release rate of fertilizer. The increase in thickness of coating slowed the release rate.

Effects of different types of slow-and controlled-release fertilizers on rice yield

This experiment explored the effects of single application of seven types of slow-and controlled-release fertilizers on rice yield and various population characteristics.Based on a study of the nitrogen(N)release characteristics of these fertilizers,pot experiments were conducted in 2018 and 2019 with split fertilization(CK,urea applied split equally at basal and panicle initiation stages,respectively)as control,which assessed the effects on SPAD value,yield and yield components,dynamic changes of rice tillers and dry matter accumulation.The results showed that the N release characteristics of different types of slow-and controlled-release fertilizers were significantly different.Polymer-coated urea(PCU)showed a controlledrelease mode and provided sustained release throughout the whole growth stages.Sulfur-coated urea(SCU)exhibited a slow-release mode,providing insufficient release at the middle and late stages.Urease inhibitor urea(AHA)and ureaformaldehyde(UF)yielded a rapid-release mode,with an explosive N release at the early stage and no release at the middle and late stages.These results showed that PCU delayed the peak seedling stage.Compared with CK,dry matter accumulation and SPAD showed no significant differences,and due to the continuous release of N throughout the growth stages,rice yield,spikelets per panicle,seed setting rate,and 1000-grain weight were all increased.Owing to the lack of N supply at the late stage and the low number of spikelets,SCU led to a reduction of rice yield,which is nevertheless not statistically significant.AHA and UF were susceptible to environmental factors and had varying effects on rice yield.The results of this experiment indicated that given a fixed amount of N applied in a pot,the stronger the N supply capacity and the longer the effective duration time of the fertilizer,the higher the dry matter accumulation at the late growth stage,and the higher the rice yield.

Effects of Magnesium Compound with Fertilizer on Daylily (Hemerocallis citrina Baroni) Growth and Soil Nutrients

Effects of two kinds of magnesium compound with fertilizer on Daylily （Hemerocallis citrina Baroni） growth, yield, and soil nutrients in red soil were studied. The results indicated that significant effects of magnesium applied to soils were observed in increasing Daylily （Hemerocallis citrina Baroni） yield, improving its growth, and strengthening its antivirus property as well as increasing the amount of exchangeable Mg, N, P, and K in red soil. In particular, the effects of magnesium compound fertilizer Ⅱ （MCF2） with higher Mg content were better than that of the others, which increased Daylily （Hemerocallis citrina Baroni） yield by 57.4, 32.8, and 14.5% compared to that of control treatment （CK）, chemical fertilizer with nitrogen, phosphorus, potassium treatment （CF）, and magnesium compound fertilizer Ⅰ treatment （MCF1） with lower Mg content. It increased soil Alkali N, available P, exchangeable K, and exchangeable Mg by 94.9, 46.5, 31.1, and 35.3%, respectively, compared with that of CK treatment. Therefore, the application of magnesium compound with fertilizer is an optimum method for improving red soil quality.

The Application of Fertilizer and AMF Promotes Growth and Reduces the Cadmium and Lead Contents of Ryegrass (Lolium multiflorum L.) in a Copper Mining Area

Heavy metal-polluted soil was collected from the Pulang copper mine in Shangri-La City,Yunnan Province,Southwest China.The effects of fertilizer(organic and inorganic)and arbuscular mycorrhizal fungi(AMF)on ryegrass(Lolium multiflorum L.)growth,root morphology,mineral nutrition and cadmium(Cd)and lead(Pb)contents were investigated by pot experiments.The results showed that both fertilizer and AMF significantly ameliorated the root morphology and mineral nutrition,reduced the Cd and Pb contents,and promoted the growth of ryegrass.Among all treatments,the combined application of organic–inorganic compound fertilizer with AMF had the highest effect,resulting in increases in root length,surface area and branch number by 2.3,1.1,and 3.9 times,respectively;an 88%increase in plant biomass;a nitrogen content increase of 2.3 and 1.2 times,and phosphorus content increase of 62%and 68%in shoots and roots,respectively was also recorded as well as decreases in Cd content by 34%and 62%and Pb content by 47%and 34%in shoots and roots,respectively.Twofactor analysis showed that both fertilizer and AMF significantly promoted ryegrass growth(plant height,biomass,chlorophyll content,root length,nitrogen and phosphorus content)and reduced the Cd and Pb contents in roots,and there was a synergistic effect between them.Moreover,the nitrogen and phosphorus contents were very significantly positively correlated with the shoot and root biomasses but very significantly negatively correlated with the Cd and Pb contents of ryegrass.Thus,the application of fertilizer and AMF synergistically improved ryegrass growth on polluted soils in the copper mining area.

Effects of Different Application Rates of Pesticides and Chemical Fertilizers on Wheat Stripe Rust and Wheat Yield

[Objectives]The paper was to investigate the effects of different application rates of pesticides and fertilizers on wheat stripe rust and wheat yield.[Methods]Two-factor split block design was adopted.[Results]Different application rates of pesticides and chemical fertilizers would affect the incidence of wheat stripe rust,and further affect the yield of wheat.Triadimefon had no significant effect on wheat yield,and potassium sulfate compound fertilizer had significant effect on wheat yield,while their interaction had no significant effect on wheat yield.There were significant differences in wheat yield among the 15 treatment combinations,which may be due to the fact that the application rate of potassium sulfate compound fertilizer had extremely significant effect on wheat yield.[Conclusions]Under the wheat/green manure/maize zonal rotation system in Bijie,the sowing width of wheat is guaranteed to be 0.5 m under the 1.65 m zonal cropping system,and the sowing rate of wheat is arranged according to the basic seedling of 1.2 million plants/hm^(2).In the early stage of wheat stripe rust,15%triadimefon WP can be sprayed evenly at the dose of 1050 g/hm^(2)by a high-power sprayer in a sunny day.

Effects of Controlled-Release Fertilizers and Their Application Methods on Germination and Seedling Growth of Dent and Sweet Corns

Effects of controlled-release fertilizers (CRFs) (C-AS, polyolefin coated ammonium sulfate, 50-day-type; Dd-LP, polyolefincoated urea with dicyandiamide, 40-day-type; C-ANP, polyolefin coated ammonium nitrate phosphate, 40-day-type; andC-DAP, polyolefin coated diammonium acid phosphate, 40-day-type), ammonium sulphate and no fertilizer control, andtheir application methods (spot, band, surface and mixed) on germination and seedling development of sweet corn (Zeamays L.var. saccharata Sturt.) and dent corn (Zea mays L.var. indentata Sturt.) were investigated in a greenhouse. Underco-situs application (band and spot) of CRFs, there were no obvious differences in the germination speed and rate for bothdent corn and sweet corn relative to control. Mortality rates of sweet corn seedlings under co-situs application were highin experiment 1, but were very low in experiment 2, because the environmental conditions were different in the twoexperiments. That is, under lower temperature and weaker sunlight, young seedlings easily die due to high soil nutrientconcentration and slow growth speed of corn. Shoot weight of both dent and sweet corn did not greatly decrease inexperiment 1. In experiment 2, there were no significant differences in shoot and root weight of both corns between co-situs and surface or mixed application methods. However, with spot and band application of ammonium sulfate, shoot androot weight were significantly reduced. Soil EC and pH were considerably affected by co-situs application, especially atthe fertilizer application site. For both dent and sweet corn, EC in the 0-3 cm soil was significantly higher under co-situsapplication and surface application than that under mixed application, whereas in the 3-6 cm soil depth the situation wasreversed. Compared with control, mixed application of CRFs decreased soil pH slightly (0-3 cm depth) or greatly (3-6 cmdepth).

Yield and quality responses of citrus (Citrus reticulate) and tea (Podocarpus fleuryi Hickel.) to compound fertilizers

Experiments were carried out with citrus (Citrus reticulate) and tea (Podocarpus fleuryi Hickel.) to study the effects of compound fertilizers on their yields and quality. In the citrus experiment, application of compound fertilizers increased available P, K and Mg contents in soil but decreased alkali-hydrolyzable N contents in soil and N, P and K contents in leaves. In the tea ex- periment, application of compound fertilizers increased available P, K and Mg contents in soil and N, P, K and Mg contents in leaves but decreased alkali-hydrolyzable N in soil compared with the urea treatment. Application of compound fertilizers could improve the quality of citrus and tea, increase their yields and enhance their economical profits significantly. Compared with the control, application of compound fertilizers increased citrus yields by 6.31, 12.94 and 17.69 t/ha, and those of tea by 0.51, 0.86 and 1.30 t/ha, respectively. Correspondingly, profits were increased by 21.4% to 61.1% for citrus and by 10.0% to 15.7% for tea. Optimal rates of compound fertilizers were recommended for both crops.

Production of Potash and N-Mg Compound Fertilizer via Mineral Shoenite from Kunteyi Salt Lake:Phase Diagrams of Quaternary System(NH_(4))_(2)SO_(4)-MgSO_(4)-K_(2)SO_(4)-H_(2)O in the Isothermal Evaporation and Crystallization Process

Based on the requirement of the new technology for producing potassium sulfate and N-Mg compound fertilizer,boussingaultite,by the reaction of the mineral shoenite from Kunteyi Salt Lake,Qinghai province,and the industrial by-product ammonium sulfate,the solubilities of the quaternary system(NH_(4))_(2)SO_(4)-MgSO_(4)-K_(2)SO_(4)-H_(2)O at 25.0℃in the isothermal evaporation and crystallization process were measured using the isothermal evaporation method,and the corresponding phase diagrams were plotted.According to the diagram,this system contains six saturation points and six solid phase fields of crystallization,which correspond to(K1-m,(NH_(4))m)_(2)SO_(4),(NH_(4))_(2)SO_(4)·MgSO_(4)·6H_(2)O,K_(2)SO_(4)·MgSO_(4)·6H_(2)O,MgSO_(4)·6H_(2)O,(K1-n,(NH_(4))n)_(2)SO_(4)·MgSO_(4)·6H_(2)O and MgSO_(4)·7H_(2)O,respectively.By analyzing and calculating the isothermal evaporation and dissolution phase diagram of this quaternary system at 25.0℃,K_(2)SO_(4)and(NH_(4))_(2)SO_(4)·MgSO_(4)·6H_(2)O can be separated via K_(2)SO_(4)·MgSO_(4)·6H_(2)O and(NH_(4))_(2)SO_(4)as raw materials.Theoretical calculations about the proposed process were carried out and verified by experiment,which indicated that the yield of potassium sulfate was improved and the magnesium resources were fully utilized.

Effects of Different Compound Fertilizers on Growth and Quality of Ginger(Zingiber officinale Roscoe)

[Objectives] This study was conducted to screen compound fertilizers suitable for ginger( Zingiber officinale Roscoe). [Methods]The effects of several different compound fertilizers on the growth,development,yield,and quality of ginger were compared under field test conditions. [Results] Treatment T2( 17-9-19) could effectively promote the growth and development of ginger plants and increase the yield of ginger. The content of soluble sugars in ginger was the highest in T2;the content of vitamin C in ginger was the highest in treatment T1( 15-15-15);treatment T2 showed the highest content of free amino acids in ginger;the content of proteins in ginger treated by T3( 22-8-10) was the highest;T3 also showed the highest content of gingerol;and treatment T2 had the lowest nitrate content. Comprehensive from the growth,yield and quality effect of ginger plants,treatment T2 was the best. [Conclusions]This study provides scientific basis for the rational fertilization and high-yield and efficient cultivation of ginger.

Effects of Organic Compound Fertilizers on Soil Water Infiltration Characteristics

In order to study the effects of organic compound fertilizers on soil water infiltration characteristics,an indoor one-dimensional soil column water infiltration test was carried out.Six soil sample treatment groups were set,namely marshy solonchak(control check,CK for short),bamboo charcoal-mixed marshy solonchak,Difuyuan-mixed marshy solonchak,salined flavo-aquic soil(CK),bamboo charcoal-mixed salined flavo-aquic soil and Difuyuan-mixed salined flavo-aquic soil.After 120 min of infiltration,compared with the CK groups of marshy solonchak and salined flavo-aquic soil,the cumulative infiltration volumes of the bamboo charcoal and difuyuan treatment groups increased by -18.78%,-3.93% and 25.77%,6.53%,respectively;and the displacement increased by -18.93%,1.64% and 22.6%,12.5%,respectively.The relationship between the wetting front displacement and time conformed to a linear function.The effects of organic compound fertilizers on the initial infiltration rates of marshy solonchak and salined flavo-aquic soil were significant,and the relationship between infiltration rate and time conformed to a power function.The vertical distribution of soil moisture under the application of organic compound fertilizers showed that the moisture content changed relatively small within 5 cm of the surface soil layer,then decreased slowly within 5-10 cm of the soil layer,and decreased drastically below 10 cm of soil layer;and relative to the CK group,the application of organic compound fertilizers was beneficial to increase the moisture content of salined flavo-aquic soil.The organic compound fertilizers reduced the water infiltration capacity of marshy solonchak and improved the water infiltration capacity of salined flavo-aquic soil.Compared with Difuyuan,bamboo charcoal reduced the water infiltration capacity of marshy solonchak better and improved the water permeability of salined flavo-aquic soil more significantly.

Application of Aisi Si/TE Compound Bacterial Fertilizer in Rice

[Objectives]To investigate the application effect of compound microbial fertilizer on crops.[Methods]Livestock and poultry breeding waste,rapeseed cake and peanut straw were fully decomposed,and then added with compound functional microbial inoculum to produce Aisi Si/TE(active chelated silicon/trace element)compound microbial fertilizer,which was used to conduct 10%nitrogen reduction alternative fertilization experiment on rice.[Results]The yield of rice applied with 225 kg/ha Aisi Si/TE compound bacterial fertilizer was 7203 kg/ha,increased by 5.4%,6.9%and 46.9%,respectively compared to those of rice applied with 225 kg/ha inactivated Aisi Si/TE compound microbial fertilizer,conventional fertilization and blank control(P<0.01).Application of Aisi Si/TE compound microbial fertilizer to rice improved soil organic matter and effective nutrient content and showed obvious effect of saving nitrogen and increasing yield and income.In addition,it provided a good micro-ecological environment,passivated and solidified heavy metals,effectively reduced the biological mobility of heavy metals,and greatly reduced the cadmium content in rice.[Conclusions]Application of Aisi Si/TE compound microbial fertilizer is beneficial to improving the quality of agricultural products.

Highly-Effective Nitrogen-phosphate Compound Fertilizer.

The Tianji brand highly effective nitrogen-phosphate compound fertilizer is produced by the Shanxi Cheyenne Fertilizer Plant, one of the main compound fertilizer producers in the country. The fertilizer is made through the chemical reaction between the nitric acid and the fine phosphate ore and a series of purifying and condensing processes. It contains nitrogen, phosphate, calcium, magnesium, zinc, copper and iron. It has high and lasting fertility

Advances in controlled-release fertilizer encapsulated by organic-inorganic composite membranes

Heavy use of conventional fertilizers can lead to negative environmental concerns.Controlled-release fertilizers(CRFs)can effectively reduce the amounts of fertilizers used,improve the availability of fer-tilizers,and which is conducive to the protection of the ecological environment and sustainable devel-opment of agriculture.Therefore,it is imperative to develop and use CRFs as an alternative to traditional fertilizers.This review aims to present the classification,raw material composition,benefits,release process,release mode,and manufacturing methods of fertilizers coated with organic-inorganic com-posite membranes(OICMs)in order to provide an overall update and summarize CRFs encapsulated by OICMs and provide an insight for future trends in the field of fertilizers.It is expected that utilizing CRFs encapsulated by OICMs and their characteristics for agricultural applications can provide innovative ideas and suggestions for developing novel CRFs suitable for modern and sustainable agriculture.

Biochar-compost-based controlled-release nitrogen fertilizer intended for an active microbial community

Nitrogen(N) fertilizers in agriculture suffer losses by volatilization of N to the air, surface runoff and leaching into the soil, resulting in low N use efficiency(NUE)( 50%) and raising severe environmental pollutions. Controlledrelease nitrogen fertilizers(CRNFs) can control the release of N nutrients to NUE in crop production. Different methods were used to develop new CRNFs.However, different CRNF technologies are still underdeveloped due to inadequate controlling on N releasing time and/or unsustainable diffusion. The study on the influences of CRNF processing parameters on microbial conditions are lacking when the CRNFs composed of various bio-ingredients such as biochar, composts, and biowaste. The complexity of processing methods, material biodegradability, and other physical properties make current CRNFs of questionable value in agricultural production. This research aims to develop a novel biochar-compost-based controlled-release urea fertilizer(BCRUF) to preserve microbial properties carried by the compost. The BCRUF was synthesized by pelletizing the 50:50(dry, wt/wt) mixture of biochar and compost. BCRUF was loaded with urea and then spray-coated with polylactic acid(PLA). The releasing time of two types of BCRUFs, coated and uncoated with PLA, for 80% of N release in water was up to 6 h at three different temperatures(4, 23, and 40 °C), compared to conventional urea fertilizer and commercial environmentally smart N(ESN) fertilizer. The releasing time of coated BCRUF for 80% N release in soil was up to 192 h(8 days). Fourier-transform infrared spectroscopy(FTIR) analysis revealed that no new functional groups were found in the release solution, indicating no new chemical hazards generated. The differential scanning calorimetry(DSC)tests also verified that its thermal stability could be up to 160 °C. The microbe populations in the BCRUF pellets were reduced after the pelleting and drying processes in BCRUF fabrication, but a few bacteria can endure in the air-drying process. BCRUF pellets soaked in water for 4 days retained some bacteria. The BCRUF showed very promising characteristics to improve NUE and sustainability in agricultural production.