J. Tenywa, Jean Bosco Ngarukiyimana, Alice Amonding Katushabe
{"title":"富拉尔醇对氮肥酸化效应的反应","authors":"J. Tenywa, Jean Bosco Ngarukiyimana, Alice Amonding Katushabe","doi":"10.4236/JACEN.2021.101005","DOIUrl":null,"url":null,"abstract":"Background: The objective of this study was to determine the short-term effect of urea fertiliser application on soil reactions in a Ferralsol, with particular thrust on P sorption. Methods: Two experiments were conducted for this purpose: 1) a screenhouse pot experiment; and 2) a laboratory P sorption component. The pot (10 litre capacity plastic pots) experiment was conducted at the Makerere University Agricultural Research, Kabanyolo in Uganda, using a Ferralsol. The study comprised of four urea N (46% N) fertiliser treatments, namely, 0, 40, 80 and 120 kg N·ha-1, equivalent to 0, 200, 400 and 600 mg N per pot. A completely randomised design was adopted with three replicates. Urea rates were applied in 50% split doses, one at planting and the other at 19 days after seedling emergence (to simulate farmer practice). This was followed by watering to field capacity using distilled water. Soil samples were taken at three daily intervals until day fourteen; thereafter, soil sampling was at an interval of seven days. The second urea split dose was applied at 21 days followed by soil sampling at an interval of three days till day fourteen. Thereafter, soil was sampled at seven day intervals until the end of experiment. Soil samples were analysed for exchangeable H+, Al3+, NH4+and NO3- ions. The reaction trends of the concentrations of these ions and Bray 1 P were used to structure different response curves representing the instantaneous reactions. As for the laboratory P-sorption study, treatments included the four rates of urea used in the pot experiment (0, 40, 80 and 120 kg N·ha-1) and seven levels of P (2.5, 5, 10, 20, 30, 40 and 50 ppm) as KH2PO4. The setup was incubated under laboratory conditions and soil samples were repeatedly taken at 10 days (after 4 days of urea incubation plus 6 days of P application). The P sorption data were fitted to Langmuir model. Results: The pot experiment revealed an abrupt drop in the concentrations of exchangeable Al3+ and H+ ions (p 0.05) within the first 6 days after urea application, accompanied by a positive surge in the concentration of NH4+ ions. This phase (6 days) was followed by a rise in the levels of exchangeable Al3+, H+ and NO3- ion concentration, which was inversely mirrored by a drop in the concentration of NH4+ ions. Consequently, the patterns displayed by the soil reactions were delineated into four phases, with Phase 1 (6 days) being characterised by urea hydrolysis reactions of deamination and ammonification, Phase 2 (10 days) being dominated by nitrification and its acidifying properties, Phase 3 being a repeat of Phase 1, both occurring immediately after urea application (within 6 days); and Phase 4 being a repeat of Phase 2. As for the P-sorption study, the effects of urea hydrolysis in a Ferralsol markedly increased soil pH and surprisingly P sorption. The contradictory P sorption behavior, despite the drop in exchange acidity was attributed to presence of divalent calcium in the extraction reagent used. Conclusion: The short term insights obtained in response to urea N application in the Ferralsol, are eye openers to future use of N fertilisers as well as strategic management of the associated acidification process which is often more costly and complicated to manage.","PeriodicalId":68148,"journal":{"name":"农业化学和环境(英文)","volume":"10 1","pages":"69-79"},"PeriodicalIF":0.0000,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Reaction of Ferralsol to Acidifying Effect of Nitrogen Fertilisation\",\"authors\":\"J. Tenywa, Jean Bosco Ngarukiyimana, Alice Amonding Katushabe\",\"doi\":\"10.4236/JACEN.2021.101005\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"Background: The objective of this study was to determine the short-term effect of urea fertiliser application on soil reactions in a Ferralsol, with particular thrust on P sorption. Methods: Two experiments were conducted for this purpose: 1) a screenhouse pot experiment; and 2) a laboratory P sorption component. The pot (10 litre capacity plastic pots) experiment was conducted at the Makerere University Agricultural Research, Kabanyolo in Uganda, using a Ferralsol. The study comprised of four urea N (46% N) fertiliser treatments, namely, 0, 40, 80 and 120 kg N·ha-1, equivalent to 0, 200, 400 and 600 mg N per pot. A completely randomised design was adopted with three replicates. Urea rates were applied in 50% split doses, one at planting and the other at 19 days after seedling emergence (to simulate farmer practice). This was followed by watering to field capacity using distilled water. Soil samples were taken at three daily intervals until day fourteen; thereafter, soil sampling was at an interval of seven days. The second urea split dose was applied at 21 days followed by soil sampling at an interval of three days till day fourteen. Thereafter, soil was sampled at seven day intervals until the end of experiment. Soil samples were analysed for exchangeable H+, Al3+, NH4+and NO3- ions. The reaction trends of the concentrations of these ions and Bray 1 P were used to structure different response curves representing the instantaneous reactions. As for the laboratory P-sorption study, treatments included the four rates of urea used in the pot experiment (0, 40, 80 and 120 kg N·ha-1) and seven levels of P (2.5, 5, 10, 20, 30, 40 and 50 ppm) as KH2PO4. The setup was incubated under laboratory conditions and soil samples were repeatedly taken at 10 days (after 4 days of urea incubation plus 6 days of P application). The P sorption data were fitted to Langmuir model. Results: The pot experiment revealed an abrupt drop in the concentrations of exchangeable Al3+ and H+ ions (p 0.05) within the first 6 days after urea application, accompanied by a positive surge in the concentration of NH4+ ions. This phase (6 days) was followed by a rise in the levels of exchangeable Al3+, H+ and NO3- ion concentration, which was inversely mirrored by a drop in the concentration of NH4+ ions. Consequently, the patterns displayed by the soil reactions were delineated into four phases, with Phase 1 (6 days) being characterised by urea hydrolysis reactions of deamination and ammonification, Phase 2 (10 days) being dominated by nitrification and its acidifying properties, Phase 3 being a repeat of Phase 1, both occurring immediately after urea application (within 6 days); and Phase 4 being a repeat of Phase 2. As for the P-sorption study, the effects of urea hydrolysis in a Ferralsol markedly increased soil pH and surprisingly P sorption. The contradictory P sorption behavior, despite the drop in exchange acidity was attributed to presence of divalent calcium in the extraction reagent used. Conclusion: The short term insights obtained in response to urea N application in the Ferralsol, are eye openers to future use of N fertilisers as well as strategic management of the associated acidification process which is often more costly and complicated to manage.\",\"PeriodicalId\":68148,\"journal\":{\"name\":\"农业化学和环境(英文)\",\"volume\":\"10 1\",\"pages\":\"69-79\"},\"PeriodicalIF\":0.0000,\"publicationDate\":\"2021-01-01\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"农业化学和环境(英文)\",\"FirstCategoryId\":\"1091\",\"ListUrlMain\":\"https://doi.org/10.4236/JACEN.2021.101005\",\"RegionNum\":0,\"RegionCategory\":null,\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"\",\"JCRName\":\"\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"农业化学和环境(英文)","FirstCategoryId":"1091","ListUrlMain":"https://doi.org/10.4236/JACEN.2021.101005","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
引用次数: 0
摘要
背景:本研究的目的是确定尿素施用对土壤反应的短期影响,特别是对磷吸收的影响。方法:进行2项试验:1)筛网盆栽试验;2)实验室P吸附组分。盆栽(容量为10升的塑料盆)试验在乌干达卡巴尼奥洛的Makerere大学农业研究中心进行,使用的是Ferralsol。试验采用完全随机设计,3个重复,分别为0、40、80和120 kg N·ha-1 4个尿素氮(46% N)处理,每罐施氮量分别为0、200、400和600 mg。尿素按50%分次施用,一剂在播种时施用,另一剂在幼苗出苗后19天施用(模拟农民做法)。然后用蒸馏水浇灌到田间容量。每隔3天采集土壤样本,直至第14天;此后每隔7天采样一次。第2次尿素分次施用于第21天,之后每隔3天至第14天取样一次土壤。此后,每隔7天采样一次,直至试验结束。分析了土壤样品的交换性H+、Al3+、NH4+和NO3-离子。利用这些离子浓度与Bray - 1p的反应趋势,构建了代表瞬时反应的不同响应曲线。在室内磷吸附研究中,盆栽试验采用4种尿素浓度(0、40、80和120 kg N·ha-1)和7种磷浓度(2.5、5、10、20、30、40和50 ppm)作为KH2PO4处理。在实验室条件下孵育,每隔10天(尿素孵育4天,施磷肥6天)重复取土样。P吸附数据符合Langmuir模型。结果:盆栽试验结果显示,施用尿素后6 d内,交换性Al3+和H+离子浓度急剧下降(p < 0.05), NH4+离子浓度急剧上升。在这一阶段(6天)之后,交换性Al3+、H+和NO3-离子浓度上升,NH4+离子浓度下降。因此,土壤反应模式被划分为4个阶段,第1阶段(6天)的特征是尿素的脱氨和氨化水解反应,第2阶段(10天)主要是硝化作用及其酸化特性,第3阶段是第1阶段的重复,两者都发生在尿素施用后(6天内);第四阶段是第二阶段的重复。在磷吸附研究方面,尿素在Ferralsol中的水解作用显著提高了土壤pH值,并显著提高了磷的吸附。尽管交换酸度下降,但矛盾的P吸附行为归因于所使用的萃取试剂中存在二价钙。结论:从feralsol中尿素N的施用中获得的短期见解,为未来氮肥的使用以及相关酸化过程的战略管理打开了眼界,这通常是更昂贵和复杂的管理。
Reaction of Ferralsol to Acidifying Effect of Nitrogen Fertilisation
Background: The objective of this study was to determine the short-term effect of urea fertiliser application on soil reactions in a Ferralsol, with particular thrust on P sorption. Methods: Two experiments were conducted for this purpose: 1) a screenhouse pot experiment; and 2) a laboratory P sorption component. The pot (10 litre capacity plastic pots) experiment was conducted at the Makerere University Agricultural Research, Kabanyolo in Uganda, using a Ferralsol. The study comprised of four urea N (46% N) fertiliser treatments, namely, 0, 40, 80 and 120 kg N·ha-1, equivalent to 0, 200, 400 and 600 mg N per pot. A completely randomised design was adopted with three replicates. Urea rates were applied in 50% split doses, one at planting and the other at 19 days after seedling emergence (to simulate farmer practice). This was followed by watering to field capacity using distilled water. Soil samples were taken at three daily intervals until day fourteen; thereafter, soil sampling was at an interval of seven days. The second urea split dose was applied at 21 days followed by soil sampling at an interval of three days till day fourteen. Thereafter, soil was sampled at seven day intervals until the end of experiment. Soil samples were analysed for exchangeable H+, Al3+, NH4+and NO3- ions. The reaction trends of the concentrations of these ions and Bray 1 P were used to structure different response curves representing the instantaneous reactions. As for the laboratory P-sorption study, treatments included the four rates of urea used in the pot experiment (0, 40, 80 and 120 kg N·ha-1) and seven levels of P (2.5, 5, 10, 20, 30, 40 and 50 ppm) as KH2PO4. The setup was incubated under laboratory conditions and soil samples were repeatedly taken at 10 days (after 4 days of urea incubation plus 6 days of P application). The P sorption data were fitted to Langmuir model. Results: The pot experiment revealed an abrupt drop in the concentrations of exchangeable Al3+ and H+ ions (p 0.05) within the first 6 days after urea application, accompanied by a positive surge in the concentration of NH4+ ions. This phase (6 days) was followed by a rise in the levels of exchangeable Al3+, H+ and NO3- ion concentration, which was inversely mirrored by a drop in the concentration of NH4+ ions. Consequently, the patterns displayed by the soil reactions were delineated into four phases, with Phase 1 (6 days) being characterised by urea hydrolysis reactions of deamination and ammonification, Phase 2 (10 days) being dominated by nitrification and its acidifying properties, Phase 3 being a repeat of Phase 1, both occurring immediately after urea application (within 6 days); and Phase 4 being a repeat of Phase 2. As for the P-sorption study, the effects of urea hydrolysis in a Ferralsol markedly increased soil pH and surprisingly P sorption. The contradictory P sorption behavior, despite the drop in exchange acidity was attributed to presence of divalent calcium in the extraction reagent used. Conclusion: The short term insights obtained in response to urea N application in the Ferralsol, are eye openers to future use of N fertilisers as well as strategic management of the associated acidification process which is often more costly and complicated to manage.