几种包膜缓控释肥粒养分释放特征的研究

采用水浸泡法对国内外4种包膜控释肥料的养分释放特性进行了系统的研究。结果表明,4种缓控释肥料的初期溶出率均小于12%,微分溶出率在0.4%～1.5%之间,这符合国际上公认的缓/控释肥的评价标准,初期溶出率小于15%、微分溶出率在0.25%～2.5%之间。采用水浸泡法测定包膜控释肥料养分释放特征,简便快速,检测时间短,重复次数少,养分浓度变化直接反映出包膜控释肥料的释放速率特性,还可以定量的测定其供肥性能,控释肥料有控制养分释放、延长供应时间的作用;其中腐殖酸和炭基有利于提高肥料颗粒的水稳定性,减缓养分的释放速率。     

包膜控释肥料养分释放率快速测定方法的研究

包膜控释肥料养分释放率的快速测定是控释肥质量检测和制定评价标准的关键。快速测定方法可以在较短时间内,推测和评价控释肥料的养分释放速率的快慢及释放期的长短。本研究对4种不同包膜控释肥料在25℃温度条件下的静水释放过程进行了测定,并应用100℃快速浸提化学实测法的测定结果与之拟合,找出两者相同养分释放量的时间对应关系方程,并对方程进行了检验和评价;同时,还对100℃温度条件下快速浸提液进行了电导率法(简便方法)的测定。结果表明,4种不同包膜控释肥料的相同养分释放量与时间对应关系方程的拟合度均达到极显著水平;在100℃温度条件下,快速浸提测定法能在较短的时间内准确测定包膜控释肥料的养分释放率,释放期为36～个月的包膜控释肥,在104～8.h就可初步测定出养分释放期;在25℃释放期为6个月的控释肥,100℃快速浸提测定的养分释放期的最大误差为10.d(5.6%);100℃快速浸提电导率法亦可简便快速的测定出包膜控释肥的养分释放率,其对养分释放期为6个月的包膜控释肥料预测值的最大误差为15.d(8.3%)。     

聚烯烃包膜控释肥膜层孔径测定方法研究

【目的】物理包覆法制备的聚合物控释膜层结构直接决定了其养分的释放,控释膜层存在的微孔和裂缝是肥芯养分进出的最主要通道。因此,控释膜层结构特征是决定包膜肥料释放性能的关键因素。泡点法能够准确测定膜的有效孔径及其分布,是一种重要的膜层孔径测试方法。本研究根据包膜肥控释膜层的特点,研究适用于测定聚烯烃包膜控释肥膜层最大孔径的泡点法,并建立测定包膜肥料最大孔径的标准方法。【方法】以泡点法为基础,建立测定膜层最大孔径的装置,确定膜层最大孔径的位置,并利用扫描电镜对膜层的孔隙结构进行观察,确定其形貌结构特征;通过对浸润剂种类、 浸润时间、 浸润温度等测定因素的比较分析,确定适合测定膜层最大孔径的最佳条件;并以释放期分别为1、 3、 5、 6月的聚烯烃包膜肥料为研究对象,研究释放期与最大孔径之间的相关关系。【结果】 1)将4种肥料放入水中浸泡,随浸泡时间的增长,膜层表面有尿素结晶的白色点位的颗粒逐渐增多,浸泡10天,80%以上颗粒均能检测到泡点,其白色点位可被认为是肥芯养分的溶出通道,以颗粒的白色点位作为膜层最大孔径的测定位置;这与扫描电镜观察到的孔隙或孔洞的特征相吻合 ;2)通过对浸润条件研究,认为在25℃,以Q-16为浸润剂,浸润5 min能够使用自制的压泡法装置直接测定控释膜层最大孔径; 3)释放期为46、 105、 160、 198天的包膜肥料的膜层平均孔径分别为1.93、 0.58、 0.45和0.41 m,最大孔径随着释放期的缩短而增大,随着微分溶出率的增加而增大,最大孔径与释放性能存在密切联系。【结论】综上所述,采用塑料管端封装浸泡10天的膜层,以Q-16作为浸润剂,在室温下浸润5 min的条件下可以测定最大孔隙结构,泡点法可作为一种标准方法用于控释膜层最大孔径的测定,其测定的最大孔径与释放期存在相关关系,对包膜控释肥控释性能和养分释放机理的深入认识有重要作用。     

包膜控释肥养分释放特性评价方法的研究进展

控释肥已成为国内外肥料研究的热点 ,但是评价控释肥养分释放特性的方法研究相对滞后 ,至今没有较为完善的方法和统一的测试标准。本文综述了包膜控释肥养分释放特性的现有评价方法 :水中 (或溶液 )溶出率法、土壤溶出率法、扩散率法、渗透率法、电超滤法和同位素示踪法等 ;评述了各种方法的优缺点及改进途径 ;并展望了今后评价方法的研究方向     

膜材料及其构成对调节控释肥料养分释放特性的影响

试验采用水溶出率实测法研究了自行研制的控释肥料养分释放的特性。以养分释放速率和释放期为主要指标评价了膜材料及其构成对调节控释肥养分释放特性的影响。结果表明,膜材料M2的控释性能优于膜材料M1;用膜材料M1包膜肥料的养分累积释放曲线呈对数曲线,而用膜材料M2包膜肥料的养分累积释放曲线呈直线型。在膜的比面重(单位肥料面积上所含膜材料的重量)为20～80g/m2范围内,随着比面重的增加,包膜肥的初期溶出率降低,释放期延长;通过调节膜材料组成与比面重可以研制出释放期不同的控释肥料。     

桐油包膜尿素养分释放机理的研究

以桐油为包膜材料,采用土壤盆栽试验和水中静置试验,对控释肥料养分释放动态进行了研究。结果表明,以桐油为包膜材料的包膜尿素,在土壤中养分初期溶出率为12.6%,在水中养分初期溶出率为20.1%,是比较理想的包膜材料。在水中与土壤中养分释放期为1∶1.2;N素的释放可用LOGISTIC动力学方程描述,释放常数k值可用来判断控释尿素的N素释放速率大小。     

醋酸酯淀粉包膜尿素水中养分溶出特征

以研制的4种醋酸酯淀粉包膜尿素肥料为研究对象,日本70 d聚烯烃包膜尿素肥料为对照,研究醋酸酯淀粉包膜尿素在水中尿素态氮溶出特征,以确定醋酸酯淀粉包膜尿素的控释性能.结果表明.醋酸酯淀粉包膜肥料尿素累积溶出曲线呈倒"L"型.在水中7～13 d达到最大溶出量.尿素态氮累积溶出80%的时间为2～3 d,初期溶出率65.71%～75.79%;养分累积释放率不超过75%的时间为1～2 d;第7 d微分溶出率都显著大于2.5%.聚烯烃包膜肥料尿素态氮累积溶出80%的时间超过40 d.初期溶出率为2.05%;聚烯烃养分累积释放率36 d为73.32%,37 d为75.01%;第7 d微分溶出率1.68%.醋酸酯淀粉包膜尿素缓/控释效果较差,对养分的控释能力明显低于聚烯烃包膜尿素,但对尿素态氮起到了一定的缓/控释作用.醋酸酯淀粉包膜尿素及聚烯烃包膜尿素肥料在水中尿素态氮累积溶出特征曲线符合一元二次方程模型.     

控释复合肥田间养分释放特征及对土壤硝态氮和铵态氮累积的影响

通过水中溶出率法和田间玉米根下土埋法,研究聚合物包膜控释复合肥的养分释放特征及其对土壤中NO3^--N和NH4^＋-N累积的影响。结果表明,浸提温度越低,控释复合肥的养分释放速率越慢,CRF1和CRF2在15℃的释放期分别是25℃的1.5,1.67倍,5℃的释放期皆为25℃的2倍;夏季CRF3田间养分释放速率稍慢于水中溶出速率,从第7天到第84天二者累积养分释放率平均变幅为3.12%;春季CRF4田间养分释放明显慢于水中溶出速率,最大变幅达31.8%;与CCF处理相比,施用控释复合肥能够显著提高玉米生长期耕层的NH4^＋-N含量和0-20 cm土层的NO3^--N含量,显著减少20-40 cm土层的NO3^--N的累积,且CRF3-H处理与CCF处理比较,在第14天和第84天时20-40 cm土层的NO3--N含量仍然表现为差异显著。因此,应根据不同地域的气候条件和作物需求,选用养分释放特征适宜的控释肥料,达到增效、节肥、安全、环保的目的。     

粒径和包膜厚度对控释肥氮素释放特性的影响

通过静水溶出率试验探讨粒径和包膜厚度对控释肥料初期溶出率、微分溶出率以及氮素累积溶出率的影响,筛选出适宜的粒径和包膜厚度的控释肥料,以此达到节省包膜材料用量、降低包膜控释肥生产成本的目的。试验结果表明,小粒径(2.5~3 mm)处理的包膜效果优于中粒径(3~4 mm)和大粒径(4~5 mm)处理的包膜效果。当包膜厚度在60~70 g/m2范围内时,中粒径处理的释放速度平缓,释放期长,控释效果优于小粒径和大粒径处理的控释效果;随着厚度的增大,初期、微分溶出率以及氮素累积溶出率都有显著减小的趋势。其中,包膜厚度对中粒径处理的影响最为显著,而对大粒径处理的影响相对较小。     

缓控释肥料养分释放特性评价及快速测定方法研究

采用水中浸提释放法和土壤恒温培养法,按照缓控释肥料行业标准(HG/T3931-2007)和欧洲标准化委员会(CEN)推荐的控释肥料评价标准,对5种缓控释肥料的氮素释放特性进行了评价。结果表明:采用25℃常温浸提法测定与100℃快速浸提法测定,后者的养分释放率加快。用100℃快速浸提法建立预测预报缓控释肥料在常温下(25℃)的释放期的回归方程(一元二次方程,相关系数大于0.98),预测值与实测值相差1～3 d。对于25℃常温浸提法测定释放期分别为66 d和84 d的塑料包膜控释复合肥(CRF)和树脂包膜控释复合肥(CRF3),用100℃电导率法预测的养分释放期分别为65 d和81 d,相对误差小于3.5%,可见电导率法也可以准确快速地预测包膜控释复合肥料的养分释放率和释放期。用初期养分释放率、平均释放率和养分释放期等参数,可用于缓控释肥料的综合评价。     

缓控释肥料缓释期的快速测定研究

采用25℃水浸提法和高温快速浸提法,研究了3种不同类型的缓控释肥料缓释期快速测定的最佳温度,测定三者在25℃下的缓释期,并对其在缓释期最佳测定温度和25℃下达到相同氮素累积释放率所需时间进行相关分析.结果表明:微溶性二价金属磷酸铵钾盐为包裹层的多层包裹粒状水溶性肥料(1#)肥料缓释期最佳预测温度为40℃,热塑性树脂包膜...     

脲酶—硝化抑制剂缓释肥对不同土壤氮素释放特性及黄瓜NPK吸收利用的影响

为了提高黄瓜氮素利用率,减少氮肥对环境污染,采用恒温培养和土培试验研究了专用脲酶硝化双抑制剂缓释肥(CSRF1和CSRF2)在酸、碱、中性土壤中的氮素释放特性以及对黄瓜生长、NPK吸收利用的影响,其中缓释肥中包含抑制剂N-丁基硫代磷酰三胺(nBPT)、氢醌(HQ)、双氰胺(DCD)。结果表明:在酸、碱、中性3种不同土壤中,氮素释放累积量均表现为普通复合肥(OCF)商品缓释肥(MSRF)自制专用肥(CCF)自制专用脲酶硝化双抑制剂缓释肥1(CSRF1)自制专用脲酶硝化双抑制剂缓释肥2(CSRF2);不同施肥处理对于3种土壤类型影响下的氮素累积释放量顺序为碱性土最大,中性土次之,酸性土最小。铵态氮、硝态氮的累积量大小顺序也为碱性土最大,中性土次之,酸性土最小。不同形态氮在3种土壤中的累积释放量动态以应用一级动力学方程拟合最好(r=0.952**~0.993**)。通过一级动力学方程,反映了3种形态氮素的最大释放量N0值大小顺序:总N最大,NH_4~+-N次之,NO_3~--N最小,此结果与土壤中不同形态的氮素累积释放特性变化规律相一致。2种专用脲酶硝化双抑制剂缓释肥(CSRF1和CSRF2)显著提高了黄瓜产量(果实干物质量),较OCF、MSRF和CCF处理分别增加了59.1%,30.3%,33.8%(CSRF1)和46.2%,19.7%,22.9%(CSRF2)。与普通复合肥相比,2种专用脲酶硝化双抑制剂缓释肥处理的NPK相对养分利用效率增加了18.52%~24.20%(N),19.27%~20.02%(P),28.54%~35.69%(K)。相较于普通复合肥,黄瓜专用脲酶—硝化抑制剂缓释肥的施用能够延缓肥料中的氮素释放,提高黄瓜NPK养分利用率和黄瓜产量。     

Nitrogen Release from Coated Urea Fertilizers in Different Soils

The nitrogen (N) release from coated urea fertilizers (Arborite and ESN), traditional N fertilizers [urea, (NH₂)₂CO], and urea ammonium nitrate (UAN) [(NH₂)₂CO, NH₄NO₃] in three North Carolina (USA) soils was measured throughout a 12-week laboratory incubation. Treatments were N source and moisture level (60% and 80% of field capacity). In both the Candor and Cecil soils, 40% of the Arborite N had released by day 2 after addition to the soil. Maximum Arborite N release was achieved by week 6 for both soils. The ESN N release began between weeks 1 and 2, and maximum release was attained by week 6 for the Candor and by week 8 for the Cecil soil. The ESN reached 70% release on Portsmouth by week 8 and Arborite had an immediate release. Field studies of these coated ureas would be needed to determine if they are economically viable over more traditional N fertilizers in North Carolina.     

脲酶硝化双抑制剂缓释肥提高番茄产量及NPK养分吸收

为提高番茄肥料的利用效率,该文采用恒温培养和土培试验研究了自制番茄专用缓释肥（special slow-realease fertilizer for tomato,TSRF1和TSRF2）在酸、中、碱性土中的氮素释放特性以及对番茄产量、NPK养分吸收利用的影响。结果表明,在3种不同土壤中,氮素释放累积量均表现为普通复合肥（ordinary compound fertilizer,OCF）>商品缓释肥（commercial slow-release fertilizer,MSRF）>自制专用肥（special compound fertilizer for tomato,TCF）>自制专用缓释肥1（TSRF1）>自制专用缓释肥2（TSRF2）,且各施肥处理在3种不同土壤类型上的氮素累积释放量大小表现为碱性土>中性土>酸性土。在整个培养期,各施肥处理在3种不同土壤中氮素相对累积释放率大小总体表现为碱性土>中性土>酸性土,且土壤中不同形态氮素累积量均是铵态氮大于硝态氮。铵态氮、硝态氮的累积量大小也表现为碱性土>中性土>酸性土。不同形态氮在3种土壤中的累积释放量动态释放以一级动力学方程拟合最好（r=0.963～0.998）。采用一级动力学方程,不同形态氮素的最大释放量表现为总N>NH4+-N>NO3--N,这与土壤中各形态氮素养分的累积释放特性变化规律表现一致。在土培试验中,两种专用缓释肥（TSRF2和TSRF1）显著提高了番茄果实干物质量,较TCF、MSRF和OCF处理分别增加了18.18%、7.24%、31.40%和13.45%、2.96%、26.15%,且番茄产量在各处理之间的差异达到显著水平。各处理对氮素的积累量大小顺序为TSRF2>TSRF1>MSRF>TCF>OCF,对磷的吸收上表现为TSRF1>TSRF2>MSRF>TCF> OCF,钾素吸收积累量的趋势与氮素基本相同。与普通复合肥相比,两种专用缓释肥处理的N、P、K利用率分别增加了10.66%、20.53%和18.62%（TSRF1）,14.94%、18.48%和21.95%（TSRF2）。两种专用缓释肥（TSRF2和TSRF1）在抑制剂的作用下,能够延缓肥料中N素养分的释放,增加番茄植株对氮磷钾养分的吸收,从而提高了NPK养分利用率和番茄产量。     

施用控释肥提高直播水稻氮的利用率

Field trials on a silt-loamy paddy soil derived from shallow-sea deposit in direct seeding rice fields were conducted in Zhejing ,China,in 1996 to compare N efficiency of controlled release fertilizers (LP fertilizers) with the conventional urea.Six treatments including CK (no N fertilizer),conventional urea and different types of LP fertilizers at different rates were designed for two succeeding crops of early and late rice.A blend of different types of LP fertilizers as a single preplant “co-situs“ application released n in a rate and amount synchronizing with uptake pattern of direct seeding rice.A single preplant application of the LP fertilizers could meet the N requirement of rice for the whole growth period without need of topdressing,Using LP fertilizer blends ,equivalent grain yields could be maintained even if the N fertilization rates were reduced by 25%-50% compared with the conventional urea .Agronomi efficiency of the LP fertilizers was 13.6%-86.4% higher than that of the conventional urea in early rice and 100%-164.1% in late rice,depending on the amounts of the LP fertilizers applied.N fertilizer recovery rate incereased from 27.4% for the conventional application of urea to 41.7%-54.1%,for the single preplant “co-situs“ application of the LP fertilizers,Use of the LP fertilizers was promising if the increse in production costs due to the hihg LP fertilizer prices could be compensated by increase in yield and N efficiency,reduction in labor costs and improvement in environment.     

Nitrogen release from plant‐derived and industrially processed organic fertilizers used in organic horticulture

As a consequence of the BSE crisis, alternatives for fertilizers derived from animal residues are being sought for use in organic horticulture. Grain legumes (milled seeds of pea, yellow lupine, and faba bean) and organic fertilizers of industrially processed plant and microbial residues (Maltaflor®‐spezial, Phytoperls®, Agrobiosol®, Rizi‐Korn) were investigated as to their suitability as a replacement fertilizer. With four soils, incubation studies were conducted to determine net N mineralization of the organic fertilizers, and pot experiments were used to measure the apparent N utilization by perennial ryegrass. The objectives of this study were (1) to determine simple fertilizer characteristics that describe their N release and (2) to compare the suitability of both experimental setups to predict fertilizer N release. At the end of all experiments, net N mineralization and apparent N utilization from Rizi‐Korn was highest compared to all the other organic fertilizers, while pea performed relatively poor. This differentiation between the fertilizers developed during the first 2 weeks. Nitrogen release from the organic fertilizers as described by net N mineralization or apparent N utilization was significantly related to the N content of the fertilizers. Different soils modified this relationship. Two industrially processed fertilizers (Phytoperls®, Agrobiosol®) could not be included into a generalized relationship because N release from these fertilizers was low compared to their N content. It is discussed that the quality of fertilizer C and N affected the N release from the fertilizers. Both experimental setups, incubation and pot experiments, were suitable to describe the release of plant‐available N from the organic fertilizers. However, N release of fertilizers with a low net N mineralization in the incubation experiments was underestimated compared to plant N uptake of ryegrass in the pot experiments. It is concluded that the N content of organic fertilizers indicates, but not predicts their N release.     

Biomass and nutrient concentration of lettuce grown with organic fertilizers

The responses of lettuce (Lactuca sativa L. ‘Arroyo’) to organic nitrogen (N) fertilizers were investigated in a greenhouse. Fertilizers were blood meal (BLO), feather meal (FM), cottonseed meal, alfalfa meal, sewage sludge, compost, cow manure, a chemical fertilizer, and a treatment without fertilizer. Amounts of N from fertilizers were 100, 200, 400, or 800?mg per pot. Lettuce yield was higher for plants receiving fertilizers than with no fertilizer and increased with increased N applications, but high applications of BLO or FM suppressed yields. Nitrogen and nitrate increased in leaves as N supply increased with all fertilizers. Small changes in leaf nutrient contents other than N occurred among or with increased application of the various fertilizers. The soil carbon dioxide release and ammonia volatilization were high from fertilizers with high N concentrations. Organic fertilizers with high N increased lettuce growth at lower applications than those with low N content.     

丙烯酸树脂包膜尿素肥料研制及其控释效果

采用丙烯酸树脂为包膜材料,以NBPT（N-丁基硫代磷酰三胺）和DCD（双氰胺）为生化抑制剂,利用流化床对尿素进行涂层生化抑制剂及包膜,制备4种包膜肥料,对这些包膜肥料在水中的控释效果进行了研究。结果表明,采用此技术制备的包膜肥料,表面成膜完整,包膜物质在成膜时分布均匀、与尿素肥心接合紧密,表面光滑。NBPT和DCD与肥心结合严密,包膜层紧覆于抑制剂的外表。包膜可有效控制尿素的溶出,在水中的控释时间为19～30d。初期溶出率远远小于15％,微分溶出率基本上在0．25％～2．5％之间;在水中尿素累积溶出特征符合一元二次方程模型,尿素释放曲线呈“S”形。