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.

A Rapid Technique for Prediction of Nutrient Release from Polymer Coated Controlled Release Fertilizers

Controlled release fertilizers (CRF) are produced with different rates and durations of nutrient release to cater to different crops with wide ranges of nutrient requirements. A rapid technique is needed to verify the label specifications of nutrient release rate and duration. Polymer-coated urea (PCU) (43% nitrogen [N]) and polymer-coated N, phosphorus (P), potassium (K) (PC_NPK;14-14-14) fertilizer products were used in this study. Soil incubation of the above CRF products at 25℃ showed that 63.6% to 70.8% of total N was released over 220 days (d). At 100℃ in water 100% of N release occurred in about 168 to 216 hours (h). Regression equations were developed for cumulative nutrient release as a function of release time separately at 25℃ and 100℃. Using the above regressions, the release duration for a given percent nutrient release at each temperature was calculated. These values were then used to establish a relationship between the release duration at 25℃ as a function of that at 100℃. This relationship is useful to predict the release duration at 25℃ of an unknown CRF product by conducting a rapid release test in water at 100℃. This study demonstrated that a rapid nutrient release test at 100℃ successfully predicted nutrient release rate and duration at 25℃, for polymer coated fertilizers. Therefore, this rapid test can be used to verify the label release rate and duration of most CRF products.

Synthesis and Performance of Polyurethane Coated Urea as Slow/controlled Release Fertilizer

Polyurethane coated urea slow/controlled release fertilizer was prepared based on urea granules, isocyanate, polyols and paraffin. Isocyanate reacted with polyols to synthesize the polyurethane skin layer on urea granules surface. Paraffin serves as a lubricant during syntheses of polyurethane skin layers. The structure and nutrient release characteristics of the polyurethane skin layers were investigated by FTIR, SEM and TG. Urea nitrogen slow-release behavior of the polyurethane coated urea was tested. The experimental results indicated that compact and dense polyurethane skin layers with a thickness of 10-15 lam were formed on urea surface, the urea nitrogen slow-release time can reach 40-50 days. Paraffin proves to play a key role in inhibiting water to penetrate into urea, but excessive addition would decrease the polyurethane crosslinking density.

Study on the Rapid Method to Predict Longevity of Controlled Release Fertilizer Coated by Water Soluble Resin

The study discussed the rapid method to test and predict the longevity of controlled release fertilizers （CRFs） coated by water soluble resin by using the short-term leaching under higher temperature. Pure water dissolving incubation and higher temperature leaching were used to study the patterns of the nutrient release of the CRFs. The correlation analysis between the days at 25℃ and the hours at 80℃ of Trincote 1 and Trincote 2 for the same cumulative release rates were conducted. Patterns of cumulative nutrient release curve followed one factor quadratic regression equation at each given temperatures, and each of relative coefficient was bigger than 0.995. As the temperature increased, nutrients release of the CRFs increased. The longevity of resin coated CRFs were predicted by use of both the cumulative nutrients release equation at 80℃ and the regression equation of release time needed for the same cumulative release rates between 25 and 80℃. There were only 0.3-6.9% relative errors between the tested longevity and predicted one. In conclusion, the longevity of resin coated CRFs could be predicted more quickly and precisely by use of the higher temperature short-term leaching method than that of the traditional differential release rate. The longevity of resin coated CRF could be rapidly and precisely predicted in a few hours by application of the higher temperature shortterm leaching method.

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.

Preparation and characterization of controlled-release fertilizers coated with marine polysaccharide derivatives

Encapsulation of water-soluble nitrogen fertilizers by membranes can be used to control the release of nutrients to maximize the fertilization ef fect and reduce environmental pollution.In this research,we formulated a new double-coated controlled-release fertilizer(CRF)by using food-grade microcrystalline wax(MW)and marine polysaccharide derivatives(calcium alginate and chitosan-glutaraldehyde copolymer).The pellets of water-soluble nitrogen fertilizer were coated with the marine polysaccharide derivatives and MW.A convenient and eco-friendly method was used to prepare the CRF.Scanning electron microscopy(SEM)and Fourier transform infrared spectroscopy(FTIR)were used to characterize the morphology and composition of the products.The nitrogen-release properties were determined in water using UV-Vis spectrophotometry.The controlled-release properties of the fertilizer were improved dramatically after coating with MW and the marine polysaccharide derivatives.The results show that the double-coated CRFs can release nitrogen in a controlled manner,have excellent controlled-release features,and meet the European Standard for CRFs.

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.

Development and Application of Coated Fertilizer in Japan

The fertilizer industry faces a continuing challenge to improve its products to increase the fertilizer use efficiency and to minimize any possible adverse environmental impact.For this purpose,studies on the development of coated fertilizers have been done all over the world.In this paper,we are to introduce our coated urea“MEISTER”as the sophisticated fertilizer,with explaining the features and applications in actual fields.“MEISTER”is the coated urea with a mixture of polyolefin and silicate mineral.“MEISTER”has two releasing types.One is the linear type.Another is the sigmoidal type.Release of nitrogen from“MEISTER”mainly depends on temperature which allows precise prediction of nutrient release.Application experiments for rice,Chinese cabbage and long onion are introduced in this paper.Every experiment shows single basal application is possible by using“MEISTER”with keeping yield and high nitrogen recovery.Coated fertilizers show accurate release control of nutrients.The use of coated fertilizers brings:(a)efficient use of fertilizer resources,(b)reduction of environmental load by fertilizer,(c)labor saving.Thus applying coated fertilizers is definitely smart fertilization technology in agriculture.Coated fertilizers seem to closely meet the requirements of an ideal fertilizer.The problem is its high price compared to the normal rapid soluble fertilizer.Unit price of coated fertilizer is expensive on the surface,though total application cost of coated fertilizers is often cheaper than the cost of rapid soluble fertilizers.This sometime disturbs the spread of coated fertilizers.So,we have been trying to make an effort to reduce production cost and doing application enlargement trials of coated fertilizers for becoming more widespread.Through those studies and development,we believe coated fertilizers will contribute to agriculture more in the world.

吉林省复混肥料“产—销—用”现状调研与产业发展建议

采用抽样调查方法,2021—2022年对吉林省复混肥企业、不同地区的乡/镇肥料经销商和玉米种植户开展问卷调查,分别收到有效问卷20、85和255份,分析了“产—销—用”环节的产品类型、养分含量及群体特征,为区域化肥产业发展、农田减肥增效提供参考。结果表明,40年来吉林省农业生产中复混肥投入量持续增加,目前肥料复合化率达70%,远超全国平均水平。总体上,吉林省复混肥企业的复合肥、掺混肥产品占比平均分别为46.1%和53.9%,具有缓/控释功能产品占比平均为51.6%。不同规模企业的产品类型差异明显,大中型企业以复合肥为主(占比分别为75.4%和58.9%),小型企业以掺混肥为主(占比85.5%),大、中、小型企业生产缓/控释肥的平均比例分别为21.7%、50.6%和74.8%。乡/镇肥料经销商销售的复混肥品牌大多在3~4个(占比55%),吉林省内肥料企业产品平均占比46.7%。复合肥、掺混肥平均销售比例分别为47.9%和52.1%,缓/控释肥平均销售比例为37.4%。玉米种植户采用一次性施肥方式的平均比例达76%,复合肥、掺混肥平均施用比例分别为43.6%和56.4%,缓/控释肥平均施用比例为42.7%。相比西部地区,中东部地区掺混肥、缓/控释肥的销售与使用比例明显更高。总养分含量45%~50%、含氮量≥25%的复混肥是吉林省生产、销售及施用的主要产品,小型企业的高氮肥产品占比更高,中东部地区总养分含量≥50%、含氮量≥25%的肥料售用比例也明显高于西部地区。肥料经销商和玉米种植户年龄主体分别为40~50和50~60岁,受教育程度分别以高中和初中学历为主,部分有较高学历的中青年经销商(38.8%)和农户(19.6%)认为控释肥材料可能存在环境污染风险。不同地区农户选购肥料首要的考虑因素均为肥料价格(占比24.9%),而后为肥料效果、肥料品牌和经销商宣传等。可见,目前掺混肥及高浓度、高含氮量肥料成为吉林省复混肥“产—销—用”主流产品,缓/控释产品比例大幅增加,建议未来从肥料立法、产品创新、优化营销和强化服务等方面进一步推进肥料行业转型、促进农业绿色发展。

植物油包膜控释氮肥在间作玉米-大豆上的施用效果研究

为考察新型植物油包膜控释氮肥对间作玉米-大豆的产量、经济效益、肥料利用率等方面的影响,开展了田间小区试验。试验以不施氮肥(CK)、施用普通尿素(PU)处理为对照;植物油包膜控释氮肥施肥量为全量、减量20%、减量30%等3种,控释氮占总氮量为60%、40%等2种,共设置4个处理。结果表明,在玉米试验中,与PU处理相比,控释氮占总氮量60%的全量、减量20%处理的产量分别显著增产14.70%、7.49%,纯收入分别显著增加3192.80、2680.02元/hm2;控释氮肥处理的氮素利用率为50.14%~53.43%,差异显著。在大豆试验中,与PU处理相比,控释氮占总氮量60%的全量处理显著增产16.67%,纯收入显著增加2725.80元/hm2;控释氮肥处理的氮素利用率为54.12%~57.98%,差异显著。对于玉米-大豆间作栽培,建议全量或减量20%施用控释氮占总氮量60%的植物油包膜控释氮肥。

聚乙烯醇/壳聚糖膜制备及其包膜尿素特性

为解决传统肥料养分利用率低,以及一般聚合物包膜肥料的膜材料难以降解、养分释放速率不可控等问题,该研究以聚乙烯醇(PVA)为膜基材,通过与壳聚糖(CS)共混、使用戊二醛(GA)交联、添加纳米SiO_(2)3种不同的方式,制备了3种膜:PVA/CS膜、PVA/CS/GA膜、PVA/CS/GA/纳米SiO_(2)膜,此外,制备了纯PVA膜作为对比。对4种膜进行了吸水率(Q)、生物降解性(De)、养分渗透系数(Ps)等表征,结果表明:CS的添加提升了膜的生物降解率,GA交联可以延缓膜在土壤中的生物降解速率,而纳米SiO_(2)的添加对膜的生物降解性影响不大,总体来说4种膜都显示出良好的生物降解性(77 d内的生物降解率在30%~60%);相比于PVA膜,PVA/CS、PVA/CS/GA和PVA/CS/GA/纳米SiO_(2)膜的吸水率分别降低43.00%、68.79%和82.73%;相比于PVA/CS膜,PVA/CS/GA和PVA/CS/GA/纳米SiO_(2)膜的养分渗透系数分别降低48.51%和57.59%,说明CS的添加、GA的交联和纳米SiO_(2)的添加都增强了PVA膜的疏水性。将4种膜液通过转鼓包衣机包覆在尿素颗粒表面制得了4种包膜尿素(PCU)颗粒(PCU-PVA、PCU-PVA/CS、PCUPVA/CS/GA和PCU-PVA/CS/GA/纳米SiO_(2)),分别使用土埋法测定和数学模型拟合了氮素释放行为,结果显示4种PCU的氮释放量达到90%时所需的时间分别为5、11、23、28 d;氮素释放行为符合一级动力学模型,释放速率常数(k)依次减小,分别为0.3654、0.2333、0.1127、0.0926,且与膜的养分渗透系数(Ps)呈线性关系,相关系数(R2)为0.9991。该研究提供了系列生物降解性能良好、养分释放速率可控的聚乙烯醇/壳聚糖膜材料,并成功地应用于包膜尿素颗粒的制备,更方便和有效地指导PCU的施用。

控释肥一次性基施对黑豆谷子带状复合种植产量及经济效益的影响

为选择带状复合种植中高效施肥模式,通过3年田间定位试验研究不同施肥模式对带状复合种植中黑豆和谷子产量及经济效益的影响。黑豆谷子各设置4个施肥模式,分别为不施氮肥设对照(CK),农户施肥习惯设常规施肥,控释肥设追肥处理,控释肥一次性基施,黑豆选用低氮控释肥,谷子选用高氮控释肥。结果表明,施用控释肥追肥及控释肥基施处理显著增加了带状复合种植中黑豆谷子产量及其构成因素,较常规施肥产量增加了11.77%~19.39%、9.77%~12.63%,控释氮肥一次性基施的效果与控释肥追肥处理无显著差异。控释肥一次性基施产投比最高为1.86,黑豆谷子带状复合种植中宜推广省工高效的控释肥一次性基施。

控释复合肥对坡耕地花生产量及氮素流失的影响

【目的】坡耕地氮素易于流失,加重面源污染风险,也制约作物产量。试验研究了坡耕地一次性基施不同量控释复合肥的氮素径流损失,为提高坡耕地花生产量和效益,降低氮素损失提供理论依据。【方法】田间试验在山东临沂进行,供试花生品种为“‘花育25号’,供试控释复合肥(CRF)和普通复合肥(CF)N-P_(2)O_(5)-K_(2)O比例均为15-15-15。不施肥为对照处理(CK),控释复合肥和普通复合肥均设置800 kg/hm^(2)(100%CRF、100%CF)、560 kg/hm^(2)(70%CRF、70%CF)两个水平,共5个处理。于花生主要生育期采集肥料、植株和径流样品,测定肥料释放量、植株生物量和氮含量、径流水中硝态氮和铵态氮含量,成熟期花生测产。【结果】100%CRF处理籽仁产量较100%CF处理增加13.8%,70%CRF较70%CF处理增加12.4%,且70%CRF与100%CF处理籽仁产量差异不显著。70%CF处理花生出仁率与100%CF差异不显著,但显著低于两个CRF处理。100%CRF、70%CRF处理较100%CF、70%CF处理的氮素吸收量分别增加5.9%和6.0%。成熟期同等施肥量下,控释复合肥处理较普通复合肥处理干物质累积量增加7.1%~8.3%;不同施肥量下,70%CRF与100%CF处理无显著差异。控释复合肥降低了苗期和开花下针期径流水中硝态氮和铵态氮含量,之后的生育期施肥处理间硝态氮和铵态氮流失量之和差异不明显。100%CRF处理肥料对产量的贡献率为19.45%,较100%CF处理高102.6%,70%CRF处理的肥料贡献率为14.65%,较70%CF处理高74.4%。【结论】在坡面农田上,控释复合肥氮素缓慢释放,满足花生各生育期氮素需求,一次性基施显著提高花生氮素吸收量和花生产量,有效减少硝态氮和铵态氮地表径流损失,减少30%的肥料用量依然可以保证花生稳产。

聚氨酯微塑料和秸秆添加对滨海脱盐潮土有机碳矿化及其组分的影响

为模拟研究聚氨酯包膜控释肥微塑料残膜对土壤有机碳矿化及秸秆降解的影响,采集江苏省滨海地区脱盐潮土,进行为期35 d的室内培养试验。设置未添加物料(CK)、添加0.1%(质量分数w,下同)微塑料(T1)、0.3%微塑料(T2)、1%微塑料(T3)、1%秸秆(S)、0.1%微塑料+1%秸秆混施(T1+S)、0.3%微塑料+1%秸秆混施(T2+S)、1%微塑料+1%秸秆混施(T3+S)共8个处理,分析微塑料及其与秸秆混施条件下土壤有机碳矿化速率、有机碳组分和酶活性的变化特征。结果表明,T3、T1+S、T2+S、T3+S处理可显著促进土壤有机碳矿化,T1、T2处理对有机碳矿化无显著影响。与对照相比,T1、T2、T3处理显著提高了土壤累积矿化量,增幅为72.77%~80.00%。微塑料和秸秆添加处理均增加了土壤可溶性有机碳(DOC)、微生物量碳(MBC)、易氧化有机碳(ROC)含量。与对照相比,微塑料处理的DOC、MBC、ROC含量分别增加5.70%~57.43%、9.14%~41.92%和2.87%~57.34%;与单施秸秆相比,微塑料+秸秆处理的DOC、MBC、ROC含量在培养期间分别增加13.74%~75.82%、10.38%~60.19%和2.21%~34.76%。微塑料和秸秆添加处理均显著提高了土壤β-葡萄糖苷酶和过氧化氢酶活性。微塑料添加条件下土壤有机碳矿化速率与DOC、MBC、ROC含量及β-葡萄糖苷酶活性均呈显著正相关,而与土壤过氧化氢酶活性无显著相关性。结果表明,聚氨酯微塑料短期内可以增加土壤活性碳组分,促进土壤有机碳矿化,聚氨酯微塑料和秸秆对有机碳矿化和酶活性的影响具有交互作用。

不同复合肥对小麦生长和土壤养分特征的影响

采用田间试验方法,以镇麦12为研究对象,研究不同配方的常规复合肥和控释肥对土壤肥力和小麦产量及其构成因子的影响,为泰州地区培肥地力和提高粮食产量提供理论依据。结果表明,常规复合肥和控释肥均能提高土壤有机质、全氮、有效磷和速效钾含量,其中控释肥(28-15-6)培肥效果最好;施肥可促进小麦生长发育,提高有效穗数、穗粒数和千粒重等,小麦产量增幅72.3%~89.0%,控释肥增产效果优于复合肥。综上,兴化地区小麦施肥推荐一次性施用控释肥(28-15-6)525 kg/hm^(2)。

控释肥施用对带状复合种植黑豆和谷子农艺性状及产量的影响

为筛选出带状复合种植中的高效施肥模式,通过3 a田间定位试验研究了不同施肥模式对带状复合种植中黑豆和谷子的农艺性状及产量的影响。试验将黑豆与谷子各设置4个施肥模式,分别为不施氮肥处理(CK),常规施肥处理(CF),控释肥设追肥处理(DN+/GN+),控释肥一次性基施处理(DN/GN),黑豆选用低氮控释肥,谷子选用高氮控释肥。结果表明:(1)苗期各黑豆与拔节期谷子处理的干物重差异不显著,其他生育时期控释追肥和控释一次性基施处理的干物重显著增加,且两者之间差异不显著。(2)成熟期时,与常规施肥处理相比,控释肥基施处理与控释肥追肥处理的黑豆和谷子干物重分别提高了3.53%~11.76%、14.10%~30.42%。控释肥追肥处理与控释肥基施处理显著提高了带状复合种植中黑豆与谷子的产量及其构成因素,产量较常规施肥分别提高了11.77%~19.39%、9.77%~12.63%,控释氮肥一次性基施的效果与控释肥追肥处理之间无显著差异。因此,黑豆与谷子带状复合种植中宜推广省工高效的控释肥一次性基施。

控释复合肥对高蛋白大豆农艺性状·产量及效益的影响

以国家黄淮海区域对照品种冀豆12为供试材料,研究了控释复合肥对高蛋白大豆农艺性状、干物质积累、产量及效益的影响。结果表明,与常规复合肥(CK)相比,不同用量控释复合肥施用后植株各性状均得到改善。相比CK,300和375 kg/hm^(2)控释肥处理下,植株株高、根长和有效荚数显著增加;植株总干重增加幅度分别为24.84%、26.28%,豆荚干重增幅最大,分别为30.96%、32.63%;产量增幅分别为20.40%、18.65%,主要体现在单株荚数和粒数上;经济效益分别增收3325.83、2777.36元/hm^(2)。表明控释复合肥在大豆上的施用可行有效。鉴于300和375 kg/hm^(2)处理间无显著差异,考虑到降低肥料成本,300 kg/hm^(2)控释肥处理可作为相似生态条件下大豆生产中的推荐施肥方式。

包膜控释肥料研究进展

控释肥被认为是一种环境友好型肥料,不仅能控制养分释放速率与植物生长相匹配,而且能减少因肥料养分流失带来的农业面源污染。综述了国内外控释肥包膜材料研究的新进展,介绍了控释肥养分释放机制,分析了控释肥在农业生产中的应用效果和存在的问题,并对控释肥在农业上的应用前景进行了展望。

“墨翠”腐殖酸钾复合肥在水稻上的应用效果研究

为明确腐殖酸钾复合肥(腐殖酸螯合长效型)在华南地区双季稻上的应用效果以及为水稻高效施肥提供技术支撑,在广东省台山市海宴镇仑定村开展了腐殖酸钾复合肥在水稻上的应用效果试验,共设3个处理,试验过程中对水稻农艺性状、产量及土壤养分含量进行监测和分析。结果表明,“墨翠”腐殖酸钾复合肥(24-10-16)处理在推荐施肥用量范围内,水稻分蘖数高于其他2个处理,株高、有效穗、平均产量均高于农户习惯施肥即彩虹包膜双控控释肥(23-6-21)和不施肥处理,差异达显著水平(P<0.05)。水稻经济效益和经济系数依次为“墨翠”腐殖酸钾复合肥(24-10-16)处理>不施肥处理>农户习惯施肥即彩虹包膜双控控释肥(23-6-21)处理,但各处理之间未达到显著差异水平。与农户习惯施肥即彩虹包膜双控控释肥(23-6-21)处理相比,“墨翠”腐殖酸钾复合肥(24-10-16)处理水稻增产11.54%,产值增加1717.1元/hm2。“墨翠”腐殖酸钾复合肥(24-10-16)处理对减缓土壤p H值下降、调节和稳定土壤p H值有一定效果。腐殖酸钾分解后释放植物所需的营养元素对水稻生长具有积极作用。腐殖酸钾复合肥在华南地区可实现水稻的一次性施肥。

有机高聚物包膜控释肥氮释放特性的测定与农业评价

采用水浸泡法对 3种有机高聚物包膜控释肥Osmocote 、MEISTER 和山东农业大学包膜肥试样的养分溶出特征进行了系统比较测定 ,研究了 3种控释肥初期溶出率、微分溶出率和养分释放期的特征与差异 ;研究了温度对3种包膜控释肥氮素释放率与释放期的影响 ;通过土壤施用包膜控释肥的盆栽试验 ,测定水稻全生育期的吸氮量和产量。并将 2种测定方法综合分析 ,用于评价不同控释肥的作用适应性 。