Using enriched zeolite as a slow release iron fertilizer for soilless greenhouse cultivation of cucumber

Two studies were conducted to find the effects of zeolite in soilless cucumber culture. Zeolite was enriched by essential cations (Z_cat) for some treatments and with essential cations plus iron sulfate (Z_fe) in others. In 2010, various Z_Fe levels were compared with various amounts of iron in irrigation water and various zeolite levels in two enrichment methods were studied. In 2011, various Z_Fe levels mixed with Peatlite and also perlite were compared with various amounts of iron in irrigation water. The effects of treatments on iron concentration of leaves were not significant, which could be because iron was supplied by releasing it from zeolite. Using ZFe as iron resource increased the yield and vigor of plants in proportion to iron chelates. Enrichment methods did not have significant effect on measured traits. Z_Fe had provided iron requirement of plant. Perlite in comparison to Peatlite did not affect iron absorption.     

Development of slow release Zn fertilizer using nano-zeolite as carrier

Zinc (Zn) use efficiency hardly exceeds 2–3% and major portion of added Zn gets fixed in the soil. In order to improve the Zn use efficiency by crops, a laboratory study was undertaken at the Department of Nano Science and Technology, Tamil Nadu Agricultural University, Coimbatore, India, to develop Zn fertilizer using nano-zeolite as a substrate. The natural zeolite (clinoptilolite) was ball milled to achieve nano-dimension (90–110 nm) and fortified with Zn by loading Zinc sulphate (ZnSO₄). The zeolite was characterized before and after loading of Zn using particle size analyzer, Fourier Transform Infrared Spectroscopy, Raman Spectroscopy, X-ray Diffraction, Scanning Electron Microscope and Transmission Electron Microscope. The data clearly indicated that the nano-zeolite was loaded successfully loaded with Zn to the tune of 14% and Zn presence in the substrate was confirmed by Energy dispersive X-ray spectroscopy and Atomic Force Microscopy. After the synthesis, sorption and desorption pattern of Zn of the nano-zeolite was examined using a percolation reactor. The results showed that Zn release from the nano-zeolite substrate has prolonged for a period of 1,176 hrs, while the Zn release from the ordinary ZnSO₄ ceased to exist within 216 hrs. The data suggest that the nano-sized zeolite is capable of retaining Zn and slowly release into the soil solution, which may be served as a slow release Zn fertilizer and improve use efficiency by crops.     

脲醛缓释肥料棒氮素缓释特性研究

以脲醛缓释肥料棒为研究对象,测定了其密度、压缩比以及抗压强度,并通过室内间歇式土柱淋溶试验,研究了脲醛缓释肥料棒氮素淋出特性及其氮素累积淋出率曲线方程拟合。结果表明,随着脲甲醛用量增加,缓释肥料棒密度、压缩比及抗压强度逐渐减小;脲醛缓释肥料棒可明显减少氮素淋失,随着脲甲醛用量增加,氮素累积淋出率减小,并且一级动力学方程对脲醛缓释肥料棒的氮素累积淋出率曲线拟合效果最佳(r=0.967**~0.998**,SE=0.94%~3.85%),可用于表征氮素累积淋出率与时间的关系。第42 d淋溶时,脲甲醛氮量占缓释肥料棒总氮0、25%、50%、75%的脲醛缓释肥料棒FR、UFR1、UFR2、UFR3的氮素累积淋出率分别较普通肥料减少了21.93%、49.46%、61.34%、82.90%。表明脲醛缓释肥料对氮素具有较好的缓释效果,且随着脲甲醛用量增加,缓释作用增强。     

亚磷酸盐作缓释磷肥对黄瓜体内养分吸收和光合特性的影响

本文以黄瓜为材料,采用营养液培养方法,研究了不同亚磷酸盐浓度对黄瓜植株各部位氮、 磷养分含量, 干重及根冠比, 植株氮、 磷总量以及叶片光合特性的影响。结果表明,黄瓜果实、 叶片和根部氮含量随亚磷酸盐浓度的增加而增加,茎部氮含量没有显著差异; 果实和茎部磷含量随亚磷酸盐浓度的增加呈增加趋势,根部磷含量呈降低趋势,叶片磷含量没有显著差异; 亚磷酸盐浓度增加到一定浓度时,各部位干重显著降低,根冠比没有显著差异; 植株氮、 磷总量随亚磷酸盐浓度的增加有下降的趋势; 黄瓜叶片净光合速率（Pn）随亚磷酸盐浓度的增加呈下降趋势。本研究结果显示,随着亚磷酸盐浓度的增加,植株表现出缺磷效应,对植株养分元素的吸收及光合作用产生了不利影响。该文讨论了亚磷酸盐作为缓释磷肥的可行性。     

Soil phosphorus sorption and availability as a function of high phosphorus fertilizer additions

Abstract

After a 3‐months equilibration of soil with phosphorus (P) (up to four times the respective P sorption capacity), equilibrium P concentration (EPCo), standard P requirement (SPR), P sorption index (SI), and P availability by Bray I, Olsen, water and iron‐oxide paper strip methods were determined on three soils of the Latium region of Italy, widely ranging in their affinity for P. Soil P addition increased EPCo and availability P content and decreased SPR and SI values for all soils with differences between soil types a ffinction of P sorption maximum. The tractional increase of available NaHCO₃‐P with added P, i.e. P availability index (F) was 0.486 for the soil with the lowest P sorption maximum, 0.217 for the soil with the highest P sorption maximum, and 0.369 for the third soil presenting an intermediate P sorption (r = 0.997; P<0.01). The results indicate that soil type, in addition to the amount of P added, will determine the potential for a soil to release P to runoff.     

Grape response to phosphorus fertilizer: Petiole to blade P ratio as a guide for fertilizer application

Abstract

A two‐year fertilizer study on a mature vineyard of grapes (Vitis vinifera L., cv. ‘Cabernet Sauvignon’ and ‘Sauvignon blanc') was conducted on a White House sandy loam (fine, mixed, thermic Ustollic Haplargid) soil at the University of Arizona Oracle Agricultural Center. Two cultivars were grown and treated with different levels of N and P fertilizer and tested for total P and NO₃‐N content of plant tissues.

Available P was evaluated with two extracting methods (Olsen and Bray P₁). Relationships between soil pH, extractable Al, Fe, Mn, and Zn with the availability indexes of soil P were also examined. Furthermore, the effects of P rates and placement on the P content of plant tissue, grape yield, and petiole to blade P ratios were investigated. Three fertilizer placements (0, 25, and 50 cm depths) at rates of 88 g P and 80 g N per vine were used for both cultivars in 1987, whereas, in 1988, three P rates (0, 88, and 176 g P per vine) and 207 g of N per vine were applied.

The results of this investigation indicated that fertilizer placement did not have a significant effect on grape yield nor the P content of petioles or leaf blades. Nevertheless, P fertilization of grapes resulted in a significant increase in plant P content and grape yield. Petiole to blade P ratio proved to be a suitable indicator for diagnosis of P status of grape plants.     

液态缓释复配肥在日光温室蔬菜上的应用研究

节能日光温室蔬菜生产中,在农民自己施肥的基础上,于茄子、黄瓜采收前距离植株10 cm处,打直径为5~7 cm的孔,茄子地适宜孔深为40 cm,黄瓜地适宜孔深为20 cm,灌施液态缓释复配肥,间隔20 d时间灌施1次,连续灌施3次,茄子以每次每株灌施800 mL为宜,其增产率为35.8%。黄瓜每次每株灌施500 mL为宜,增产率为17.2%。茄子高效益期的产量占总计产时段产量的58.3%,而产值占总计产时段产值的71.5%。黄瓜高效益期的产量占总计产时段产量的64.3%,产值占总计产时段产值的86.5%。     

缓释肥在水稻抛秧栽培中的应用效果

近年来,随着人民生活水平的提高和种植业结构的调整,广大农民迫切需求省工增产高效的技术.     

改性聚丙烯酸酯制备包膜缓释肥性能研究

为制备一种可以用于水稻种肥同播的缓控释肥料,试验以甲基丙烯酸甲酯(MMA)、丙烯酸丁酯(BA)为主要材料,并使用少量的羧甲基纤维素(CMC)和纳米SiO₂改性材料,制备改性聚丙烯酸酯乳液包裹肥料以达到缓释效果。选用25℃静水溶出率法,结合红外、电子显微镜等分析技术,探索了不同的原料配比和3种包膜量(10%、15%、20%)制备的改性聚丙烯酸酯缓释肥在水中的养分释放规律。结果表明：在CMC质量占固含量(BA+MMA)的5%且包膜量为20%时缓释效果最好,其在第1和28 d的累积养分释放率分别为0.5%和63.8%,低于15%和80%的限值。使用此规格的自制缓释肥进行了盆栽试验,比较了在不同施肥量和施肥方式下盆面水中全氮、全磷的含量以及水稻生长状况的差异。研究表明,缓释肥施用量为传统施肥量的70%时,相较于传统施肥方式,分别降低56.4%和88.9%的全氮和全磷流失的同时也保证了水稻的产量。     

粘土包膜缓释尿素的养分释放特征及其增产效应

以尿素为缓释肥料核心,两种粘土矿物为包膜材料,聚乙烯醇为粘结剂,研制出两种包膜缓释肥料,并探讨了两种包膜肥料在土壤、石英砂等介质条件下的氮素释放特征及形态转化规律,还通过盆栽试验进一步研究了包膜尿素的增产效应。试验结果表明,与普通尿素相比,两种粘土矿物肥料均具有较好的缓释性能,在以石英砂为介质时表现的尤为明显;包膜后的尿素具有较明显的生物增产效应,两种包膜肥料在株高、鲜重、干重等主要产量性状方面与普通尿素均存在显著差异。     

植物幼苗生长对缓释肥种类和施肥水平的反应

选用刺槐、白榆和大叶猪屎豆3种播种苗为试验植物,研究不同类型缓释肥以及施肥量对植物生长和地上部干质量的影响。结果表明：3种缓释肥类型对白榆的株高、地径以及地上部干质量生长有显著的促进作用,对刺槐的各项生长指标的促进作用有所减弱,而猪屎豆的生长指标则有随着缓释肥施用量的增加而减小的趋势;缓释肥中,总N量对3种植物地上部干质量的影响具有相似趋势,总P量对3种植物地上部干质量无显著影响。在播种造林技术中,为了促进苗木高生长,增强与周围杂草的竞争能力,要尽可能选用豆科植物,在选用无固氮能力的植物进行播种造林时,施用缓释肥料是促进植物幼苗生长的重要手段。     

基质肥料缓释基质的筛选及其氮素释放规律

为提高基质肥料的缓释性能,该文选用10种有机和无机基质制备基质肥料,通过砂柱间歇淋洗的方法研究了基质肥料的氮素释放规律,并根据Logistic方程的参数和氮素释放拐点的UPGMA聚类分析评价了10种基质的缓释效果,结果表明：基质肥料氮素累积释放率随时间的动态变化可用一级动力学方程、Elovich方程、抛物线扩散方程和Logistic方程表征,其中以Logistic方程拟合效果最好,这说明定量描述氮素养分释放规律的方程中以Logistic方程评价更具有实效性,而有机基质中氧化淀粉和木质素的缓释效果较好,无机基质中膨润土的缓释效果最好。     

我国缓／控释肥料的现状和发展方向

总结了我国缓/控释肥料的几大类型,对主要类型缓/控释肥料工艺设备的优缺点予以评述,指出了发展中存在的问题和解决对策,提出了发展方向。     

华北小麦-玉米轮作区缓控释肥应用效果分析

田间试验以常规施肥为对照,分析了华北平原北部小麦-玉米轮作区缓控释肥不同配比和用量土壤硝态氮含量和产量性状的变化。结果表明,常规用量分次施肥（100%UD）处理,土壤中NO-3-N含量在小麦生育后期仍然维持较高的水平,并且穗数、千粒重以及产量相对较高; 缓控释肥处理土壤中硝态氮（NO-3-N）含量与100%UD相比处于较低的水平,但产量无显著差异。玉米生长季缓控释肥表现出了明显优势,肥料利用率提高,玉米穗秃尖长度减小; 其中减少20%用量的缓控释肥处理（80%SCR）产量显著高于常规施肥处理,增产达到18.3 %。缓控释肥缓慢释放的特性有利于被作物及时充分吸收,减少了在土壤中因淋失而造成浪费的机会,从而使得肥料利用率提高。从小麦、玉米两季的变化情况来看,还需要进一步优化肥料在不同生长季之间的配置,使缓控释肥料发挥其最大潜力,实现小麦玉米产量双高产和经济效益、环境效益同步提高。     

Effects of polymeric slow release fertilizer on Chinese cabbage growth and soil nutrients

One pot experiment was conducted to study the effects of a new polymeric slow release fertilizer (PRF) on Chinese cabbage growth and soil nutrients. The experiment comprised three kinds of fertilizer (common compound fertilizer, 21% and 45% solubility of PRF in 25°C water, all fertilizers with N:P₂O₅:K₂O = 10:5.7:20) and three fertilizer levels (0, 21.6 and 43.2 g m^?2). Results showed that the high water-soluble PRFs (PRFHH and PRFHL) fit nutrient requirements of Chinese cabbage, and the high fertilization level significantly increased yield and improved quality of Chinese cabbage. Although the PRFHL treatment at 21.6 g fertilizer m^?2 had one-half less supplied nutrient than that of common compound fertilizer treatment (43.2 g fertilizer m^?2), the yield of Chinese cabbage with PRFHH and PRFHL was 8.0% more. The soluble sugar, vitamin C and leaf chlorophyll contents of Chinese cabbage can be effectively improved with PRFHH (43.2 g m^?2), PRFHL (21.6 g m^?2) and PRFLH (low water-soluble PRF, 43.2 g m^?2). The PRF treatment reduced the nitrate content and improved soil capacity of supplying nutrient effectively, and there were no changes in values of pH and electrical conductivity of soil.     

缓释复合肥养分释放特性和黄连生物效应研究

采用连续恒温培养和大田试验研究了4种缓释复合肥在种植黄连的土壤(森林黄棕壤)中的养分释放特性及其对黄连产量和药用品质的效应。结果表明,20℃恒温模拟条件下缓释复合肥氮、磷、钾养分缓释性能较佳,3种养分释放的动力学过程可用Elovich方程St=a+blnt、双常数方程lnSt=a+blnt和抛物线扩散方程St=a+bt0.5表征,各方程参数b值均可用于描述缓释复合肥氮、磷、钾养分释放速率。在田间试验中4种缓释复合肥极显著提高3～5年生黄连产量,大幅度提高黄连小檗碱和生物碱产量,并以SRF3、SRF2和SRF13种缓释复合肥的效应大。     

炭肥比和膨润土粘结剂对炭基肥颗粒理化及缓释特性的影响

为探究炭肥比和膨润土粘结剂对生物炭基肥理化及缓释特性的影响,以生物炭为基底,分别制备了炭肥比1:4,膨润土粘结剂质量分数为20%、15%、10%、5%和粘结剂质量分数10%,炭肥比为1:6、1:5、1:4、1:3的柱状尿素和氯化钾生物炭基肥颗粒,分析了生物炭基肥颗粒的理化及缓释特性。结果表明,在炭肥比为1:4条件下,膨润土粘结剂质量分数越高,生物炭基肥微观结构越紧密,力学和缓释特性越好,质量分数为20%时,氯化钾和尿素生物炭基肥平均抗压强度分别为286.78和281.27 N,前3天养分淋出率分别为45.53%和36.87%。在膨润土粘结剂质量分数为10%条件下,炭肥比越高,生物炭基肥缓释性能越好,炭肥比为1:3时,氯化钾和尿素生物炭基肥前3天养分淋出率分别为42.06%和40.32%。同时,氯化钾生物炭基肥表面孔隙先增后减,炭肥比为1:6和1:3的平均抗压强度分别为271.25和282.42 N。尿素生物炭基肥内部结构中孔隙变多,炭肥比为1:6时,平均抗压强度为最大值267.84 N。综合考虑,满足中等肥料浓度要求时,膨润土粘结剂质量分数为20%、炭肥比为1:4或膨润土粘结剂质量分数为10%、炭肥比为1:3的生物炭基肥成型配方较优。     

保水缓释氮肥水分状态与吸持特征研究

保水肥料的水分有效性不但取决于保水肥料的吸水倍率,还取决于水分在保水肥料中的存在状态及吸持特征。首次用差示扫描量热仪(DSC)和水分特征曲线方法对实验合成的保水缓释氮肥水分状态及吸持特征进行了研究。发现保水缓释氮肥的自由水+束缚水含量随着平衡含水量增大而提高,保水缓释氮肥平衡含水量中94％以上为自由水＋束缚水,其与普通水具有相同或相近的热力学性质,其相当于土壤重力水,毛管水和薄膜水之和,保水缓释氮肥所持水分90％以上是植物有效水。保水缓释氮肥的结合水占5％以下,其相当于土壤吸湿水,是植物难利用水。DSC测定的有效水(94％)和水分特征曲线测定的有效水(91％)十分接近,因此,DSC可作为评价吸水保水缓释肥料有效性快速方法。保水缓释肥料可增加土壤持水量,降低土壤水分蒸发,提高土壤保水和释水量。保水缓释氮肥合成过程中待聚液保温时间是一个重要工艺参数。     

Review of phosphorus acid and its salts as fertilizer materials

This is a review of the literature, recent unpublished research, and other information pertaining to the use of phosphorus acid (H₃PO₃) and its salts as fertilizer materials. Early studies on the potential of H₃PO₃ and its salts as alternative phosphate fertilizers showed that these phosphorus (P)‐containing materials were not as effective as phosphoric acids (H₃PO₄) and its derivatives on growth of the first crop in successive cropping trials. However, a definite growth response to phosphite was seen when compared to the zero‐P control, proving that these materials provided nutritional support. Beneficial effects from the phosphite and H₃PO₃ treatments were observed in the subsequent crops, and were presumed attributable to the probable conversion of phosphite to phosphate in the soil. Studies done more than thirty years later on plant responses to the phosphite anion focused on plant disease control, rather than on the nutrient qualities of such materials. Nevertheless, many plant physiological phenomena caused by the phosphite‐active ingredient were discovered as its chemical dynamics were documented. Effects important to plant growth were shown to occur when plants were treated with H₃PO₃ or its salts even in the absence of plant pathogens. Whereas a certain amount of observed nutritional responses to phosphite is correlated with its conversion to orthophosphate by microbial action and other mechanisms, other nutritional responses were also observed, leading to commercialization of specially formulated H₃PO₃ derivatives as fertilizers. For example, higher yields in oranges were directly attributable to increased flowering and fruit set after winter pre‐bloom foliar applications of commercial phosphite fertilizer formulations. Many horticultural and agronomic crops have exhibited positive growth responses under field conditions to the nutritional support available in fertilizers derived from H₃PO₃.     

Layered double hydroxides as supports for the slow release of acid herbicides

A Mg/Al layered double hydroxide (LDH) was intercalated with the anionic herbicides 2,4-D, MCPA, and picloram by using three different methodologies: (i) direct synthesis (DS), (ii) regeneration (RE), and (iii) ion exchange (IE). The resulting complexes were characterized and assayed by batch release and column leaching tests, aiming at the controlled release of these herbicides. All the tested LDH-herbicide complexes displayed similar slow herbicide release properties in water, although the IE method seemed to result in complexes with a greater fraction of herbicide in a readily available form. Apparently, the LDH-herbicide complexes released most of the active ingredient present in the complexes at the end of the batch release experiment. This was attributed to the replacement of the intercalated herbicide by carbonate and hydroxyl anions from the aqueous solution. Compared to the free herbicides, the application of the three LDH-herbicide complexes (RE) to soil columns resulted in reduction in the maximum herbicide concentration in leachates and led to the retardation of herbicide leaching through the soil. All LDH-herbicide complexes presented an herbicidal efficacy similar to that of the free (technical) herbicides. Our results indicated the potential applicability of LDHs as supports for the preparation of slow release formulations of acid herbicides such as 2,4-D, MCPA, or picloram.