Understanding and predicting dissolved phosphorus release from soils is critical to proper land management for maximizing P uptake by agronomic crops and minimizing losses to surface waters. In this study, we investigate the amount and rate of P release for 22 diverse soils using flow cells operating at low and high velocity. P release data were fit to a one-dimensional advection-dispersion equation assuming two P pools (Q1 and Q2) each with their own kinetic desorption rate. The model provided exceptionally good fits to the P release data at both flow velocities. The high-flow velocity desorbed P at a higher rate, while the slow-flow velocity released more P and at higher concentrations; although when normalized for residence time, the rate of P desorption was greater in the slow-flow velocity columns. Fitted values of the readily available P pool (Q1) for the two flow velocities were well correlated, with Q1 values for the slow flow velocity being consistently greater than the high flow velocity. Conversely, kinetic desorption parameters between the two flow velocities were not as well correlated. Fitted Q1 values were strongly correlated with oxalate-extractable P (POx), Mehlich-3 P (PM3), and water-extractable P (PW). Q1 values were much lower than POx and PM3 but similar to PW. We only found weak correlations between the kinetic desorption rates and measured soil properties. Our results show that the use of flow-through cells can provide useful information on P release from soils, but results will be dependent on flow velocity.
了解和预测土壤中溶解磷的释放对于适当的土地管理,最大限度地提高农作物对磷的吸收,最大限度地减少地表水的损失至关重要。在这项研究中,我们研究了22种不同土壤中磷的释放量和速率,使用流动池在低速和高速下工作。假设两个P池(Q1和Q2)各有自己的动力学解吸速率,P释放数据拟合为一维平流-色散方程。该模型在两种流速下都能很好地拟合P释放数据。高流速对磷的解吸速率较高,慢流速对磷的解吸速率和浓度较高;虽然当将停留时间归一化时,在慢流速柱中P的解吸速率更大。两种流速的可得P池(Q1)拟合值具有较好的相关性,慢流速的Q1值始终大于高流速。相反,两种流速之间的动力学解吸参数相关性不强。拟合Q1值与草酸盐可提取P (POx)、Mehlich-3 P (PM3)和水提取P (PW)密切相关。Q1值远低于POx和PM3,但与PW相似。我们只发现动力学解吸速率和测量土壤性质之间的弱相关性。我们的研究结果表明,使用流动细胞可以提供有用的信息从土壤中释放磷,但结果将取决于流速。
{"title":"Estimating soil P pools and desorption rates using flow-through cells","authors":"Carl H. Bolster, Chad J. Penn","doi":"10.1002/jeq2.70090","DOIUrl":"10.1002/jeq2.70090","url":null,"abstract":"<p>Understanding and predicting dissolved phosphorus release from soils is critical to proper land management for maximizing P uptake by agronomic crops and minimizing losses to surface waters. In this study, we investigate the amount and rate of P release for 22 diverse soils using flow cells operating at low and high velocity. P release data were fit to a one-dimensional advection-dispersion equation assuming two P pools (<i>Q</i><sub>1</sub> and <i>Q</i><sub>2</sub>) each with their own kinetic desorption rate. The model provided exceptionally good fits to the P release data at both flow velocities. The high-flow velocity desorbed P at a higher rate, while the slow-flow velocity released more P and at higher concentrations; although when normalized for residence time, the rate of P desorption was greater in the slow-flow velocity columns. Fitted values of the readily available P pool (<i>Q</i><sub>1</sub>) for the two flow velocities were well correlated, with <i>Q</i><sub>1</sub> values for the slow flow velocity being consistently greater than the high flow velocity. Conversely, kinetic desorption parameters between the two flow velocities were not as well correlated. Fitted <i>Q</i><sub>1</sub> values were strongly correlated with oxalate-extractable P (P<sub>Ox</sub>), Mehlich-3 P (P<sub>M3</sub>), and water-extractable P (P<sub>W</sub>). <i>Q</i><sub>1</sub> values were much lower than P<sub>Ox</sub> and P<sub>M3</sub> but similar to P<sub>W</sub>. We only found weak correlations between the kinetic desorption rates and measured soil properties. Our results show that the use of flow-through cells can provide useful information on P release from soils, but results will be dependent on flow velocity.</p>","PeriodicalId":15732,"journal":{"name":"Journal of environmental quality","volume":"54 6","pages":"2025-2036"},"PeriodicalIF":2.3,"publicationDate":"2025-10-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145238611","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The development of phytoplankton communities in hypereutrophic shallow lakes, often used for aquaculture, is not fully understood and can sometimes be unpredictable. Focusing on the abiotic factors that regulate their succession, we recorded short-term mixing events in a shallow lake and examined their relationship with nutrient release from sediments in the lab. In situ measurements reveal a dynamic cycle of mixing and stratification during summer, when the lake mostly stratifies during the day and mixes at night, depending on wind conditions. The studied lake was stratified 45% of the time and, on average, mixed every 1.5 days. In terms of hydrodynamics, the velocities of surface and bottom waters are similar in magnitude, regardless of whether conditions are calm or windy. Stirred-core experiments recreated both lake hydrodynamic regimes and the observed patterns of destratification at the study site. Temporal destratification experiments show that the sediment releases more solutes during complete mixing than during partial destratification, due to an increase in sediment/water concentration gradients. This results in more phosphorus and ammonia being released, and more nitrate being consumed by sediments, when the water column is fully mixed compared to when a bottom layer remains unmixed. The effect of dissolved oxygen did not directly influence nutrient release by Fe-P compounds dissolution, as oxygen above the sediment did not fall below 50% saturation, but mixing enhanced the transport of electron acceptors to the sediment. The cycle of stratification and mixing appears to be a key factor in internal loading under oxic conditions.
{"title":"Shallow-lake sediments release nutrients by complete destratification events","authors":"Jiří Jan, Felipe Breton, Jakub Borovec","doi":"10.1002/jeq2.70092","DOIUrl":"10.1002/jeq2.70092","url":null,"abstract":"<p>The development of phytoplankton communities in hypereutrophic shallow lakes, often used for aquaculture, is not fully understood and can sometimes be unpredictable. Focusing on the abiotic factors that regulate their succession, we recorded short-term mixing events in a shallow lake and examined their relationship with nutrient release from sediments in the lab. In situ measurements reveal a dynamic cycle of mixing and stratification during summer, when the lake mostly stratifies during the day and mixes at night, depending on wind conditions. The studied lake was stratified 45% of the time and, on average, mixed every 1.5 days. In terms of hydrodynamics, the velocities of surface and bottom waters are similar in magnitude, regardless of whether conditions are calm or windy. Stirred-core experiments recreated both lake hydrodynamic regimes and the observed patterns of destratification at the study site. Temporal destratification experiments show that the sediment releases more solutes during complete mixing than during partial destratification, due to an increase in sediment/water concentration gradients. This results in more phosphorus and ammonia being released, and more nitrate being consumed by sediments, when the water column is fully mixed compared to when a bottom layer remains unmixed. The effect of dissolved oxygen did not directly influence nutrient release by Fe-P compounds dissolution, as oxygen above the sediment did not fall below 50% saturation, but mixing enhanced the transport of electron acceptors to the sediment. The cycle of stratification and mixing appears to be a key factor in internal loading under oxic conditions.</p>","PeriodicalId":15732,"journal":{"name":"Journal of environmental quality","volume":"54 6","pages":"2061-2073"},"PeriodicalIF":2.3,"publicationDate":"2025-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://acsess.onlinelibrary.wiley.com/doi/epdf/10.1002/jeq2.70092","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145199535","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Laura Naslund, Lily Kirk, Jana E. Compton, Anne Neale
Excess nitrogen and phosphorus export from agricultural lands is a primary contributor to water quality degradation in the United States. To improve water quality, significant investments have been made to implement conservation practices on agricultural lands, including through mandated spending in the Farm Bill and the Inflation Reduction Act. Effectively guiding conservation implementation requires assessment of practice efficacy at regional and national scales, consistent with the scales of water quality goals. To evaluate whether existing resources are sufficient for such conservation efficacy assessments, we review prior efforts and publicly available data and tools to evaluate the effects of agricultural conservation on water quality outcomes. We find that practice records from programs that fund agricultural conservation have a unique and substantial potential for secondary use to generate insights about conservation effects from local to national scales, but modifications would help maximize the potential of these data for assessing conservation efficacy. Such assessments would benefit from improved consistency in reporting units and geographic scales across program datasets; quantification of the duration of water quality benefits from conservation practices; publication of practice data aggregated across programs, to increase the spatial resolution of conservation insights while maintaining legal protections of producer privacy; and collection of water quality and conservation practice data at similar temporal and spatial scales. Enhancing existing and future datasets could deliver high return on effort by generating valuable insights to improve the use of conservation practices for water quality management.
{"title":"Linking agricultural conservation to water quality outcomes in the United States at multiple scales: Do we have the information we need?","authors":"Laura Naslund, Lily Kirk, Jana E. Compton, Anne Neale","doi":"10.1002/jeq2.70086","DOIUrl":"10.1002/jeq2.70086","url":null,"abstract":"<p>Excess nitrogen and phosphorus export from agricultural lands is a primary contributor to water quality degradation in the United States. To improve water quality, significant investments have been made to implement conservation practices on agricultural lands, including through mandated spending in the Farm Bill and the Inflation Reduction Act. Effectively guiding conservation implementation requires assessment of practice efficacy at regional and national scales, consistent with the scales of water quality goals. To evaluate whether existing resources are sufficient for such conservation efficacy assessments, we review prior efforts and publicly available data and tools to evaluate the effects of agricultural conservation on water quality outcomes. We find that practice records from programs that fund agricultural conservation have a unique and substantial potential for secondary use to generate insights about conservation effects from local to national scales, but modifications would help maximize the potential of these data for assessing conservation efficacy. Such assessments would benefit from improved consistency in reporting units and geographic scales across program datasets; quantification of the duration of water quality benefits from conservation practices; publication of practice data aggregated across programs, to increase the spatial resolution of conservation insights while maintaining legal protections of producer privacy; and collection of water quality and conservation practice data at similar temporal and spatial scales. Enhancing existing and future datasets could deliver high return on effort by generating valuable insights to improve the use of conservation practices for water quality management.</p>","PeriodicalId":15732,"journal":{"name":"Journal of environmental quality","volume":"54 6","pages":"1653-1673"},"PeriodicalIF":2.3,"publicationDate":"2025-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145191856","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Helen C. S. Amorim, Amanda J. Ashworth, Thomas F. Ducey, Valerie B. Brewer-Gunsaulis, Gerson L. Drescher, Phillip R. Owens, Alana H. Patterson, Giovanna De Blasis, Iris van Straaten
Frass—the main by-product of insect rearing for animal feed—is emerging as a promising soil amendment and plant growth promoter. However, basic agronomic information is lacking and prevents frass’ widespread use as a biofertilizer. This study assessed impacts of black soldier fly (Hermetia illucens L. [Diptera: Stratiomyidae]) frass on soil fertility, crop growth, and quality compared to poultry litter (PL). Irrigated and non-irrigated soybean (Glycine max L. Merr.) and non-irrigated switchgrass (Panicum virgatum L.) plots received either PL (5.6 Mg ha−1), low frass rate (LF; 5.6 Mg ha−1), high frass rate (HF; 11.2 Mg ha−1), besides the unamended control (CT). In general, soil nutrients and enzymes at the soil surface (0–15 cm) were unaffected by soil amendments. Irrigated-HF soybean had 7% higher grain P concentration than non-irrigated-HF, and 13% greater P concentration than the non-irrigated CT. Additionally, HF increased K concentration in switchgrass by 25% relative to the CT. HF reduced soybean leaf damage by 35% and 48% relative to the non-irrigated CT and PL-irrigated plots, illustrating for the first time frass’ potential to enhance plant resistance to herbivory, likely owing to the presence of chitin. LF had 2–4 times greater nutrient use efficiency than HF and PL in organic soybean and switchgrass systems, reflective of similar yields despite lower nutrient inputs. These findings provide foundational knowledge for frass utilization as an organic fertilizer and biostimulant, closing nutrient loops through waste recovery during insect rearing, and supporting the development of an emerging sustainable industry.
作为动物饲料用昆虫饲养的主要副产品,黄酮作为一种很有前途的土壤改良剂和植物生长促进剂正在出现。然而,由于缺乏基本的农艺信息,这阻碍了草作为生物肥料的广泛使用。本研究评估了黑兵蝇(Hermetia illucens L.[双翅目:层蝇科])草对土壤肥力、作物生长和品质的影响。灌溉和不灌溉的大豆(Glycine max L. Merr.)和不灌溉的柳枝稷(Panicum virgatum L.)除未经改良的对照(CT)外,分别给予PL (5.6 Mg ha-1)、低草率(LF; 5.6 Mg ha-1)、高草率(HF; 11.2 Mg ha-1)处理。总体而言,土壤表层(0 ~ 15 cm)土壤养分和酶不受土壤改型的影响。灌水hf大豆籽粒磷浓度比未灌水hf高7%,比未灌水CT高13%。此外,与CT相比,HF使柳枝稷中钾的浓度增加了25%。与不灌溉的CT和pl灌溉相比,HF减少了35%和48%的大豆叶片伤害,首次说明了草具有增强植物抗草食性的潜力,这可能是由于几丁质的存在。在有机大豆和柳枝稷体系中,LF的养分利用效率是HF和PL的2-4倍,反映了在养分投入较低的情况下产量相近。这些发现为利用草籽作为有机肥料和生物刺激素、在昆虫饲养过程中通过废物回收实现营养循环以及支持新兴可持续产业的发展提供了基础知识。
{"title":"Recycling waste via insect agriculture: Frass impacts on soil and plant health","authors":"Helen C. S. Amorim, Amanda J. Ashworth, Thomas F. Ducey, Valerie B. Brewer-Gunsaulis, Gerson L. Drescher, Phillip R. Owens, Alana H. Patterson, Giovanna De Blasis, Iris van Straaten","doi":"10.1002/jeq2.70089","DOIUrl":"10.1002/jeq2.70089","url":null,"abstract":"<p>Frass—the main by-product of insect rearing for animal feed—is emerging as a promising soil amendment and plant growth promoter. However, basic agronomic information is lacking and prevents frass’ widespread use as a biofertilizer. This study assessed impacts of black soldier fly (<i>Hermetia illucens</i> L. [Diptera: Stratiomyidae]) frass on soil fertility, crop growth, and quality compared to poultry litter (PL). Irrigated and non-irrigated soybean (<i>Glycine max</i> L. Merr.) and non-irrigated switchgrass (<i>Panicum virgatum</i> L.) plots received either PL (5.6 Mg ha<sup>−1</sup>), low frass rate (LF; 5.6 Mg ha<sup>−1</sup>), high frass rate (HF; 11.2 Mg ha<sup>−1</sup>), besides the unamended control (CT). In general, soil nutrients and enzymes at the soil surface (0–15 cm) were unaffected by soil amendments. Irrigated-HF soybean had 7% higher grain P concentration than non-irrigated-HF, and 13% greater P concentration than the non-irrigated CT. Additionally, HF increased K concentration in switchgrass by 25% relative to the CT. HF reduced soybean leaf damage by 35% and 48% relative to the non-irrigated CT and PL-irrigated plots, illustrating for the first time frass’ potential to enhance plant resistance to herbivory, likely owing to the presence of chitin. LF had 2–4 times greater nutrient use efficiency than HF and PL in organic soybean and switchgrass systems, reflective of similar yields despite lower nutrient inputs. These findings provide foundational knowledge for frass utilization as an organic fertilizer and biostimulant, closing nutrient loops through waste recovery during insect rearing, and supporting the development of an emerging sustainable industry.</p>","PeriodicalId":15732,"journal":{"name":"Journal of environmental quality","volume":"54 6","pages":"1457-1469"},"PeriodicalIF":2.3,"publicationDate":"2025-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://acsess.onlinelibrary.wiley.com/doi/epdf/10.1002/jeq2.70089","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145149240","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Natalia Rogovska, Sabrina J. Ruis, Derek B. Carney, Kathleen Delate, Ken M. Wacha, John L. Kovar, Peter L. O'Brien, Cynthia A. Cambardella
Organic production aims to diversify crop rotation and use organic fertilizer sources to build soil fertility and improve soil health indicators. The impact of organic farming on water quality in artificially drained midwestern Mollisols has received limited attention. This 7-year study compares tile nitrate loss and yields under three cropping systems: (1) conventional corn (Zea mays L)-soybean (Glycine max L.), (2) organic corn–soybean–oat (Avena sativa L.)/alfalfa (Medicago sativa L)–alfalfa, and (3) organic perennial pasture. Nitrogen (N) fertilization consisted of sidedress urea ammonium nitrate for conventional corn (168 kg N ha−1) and spring-applied composted manure for organic corn (168 kg N ha−1) and oats (56 kg N ha−1). Overall, the 4-year organic rotation reduced N loads by 50% and pasture reduced loads by 93% compared with the conventional 2-year corn–soybean rotation. Reductions in N loads were related to the diversified cropping system as no difference in N losses was detected when only corn–soybean phases of the organic rotation were compared with the conventional system. Annual variations in N loads were explained by precipitation and varied by crop. Soil health indicators sampled in the fall showed minimal influence on N losses. Organic corn (4 of 7 years) and soybean (6 of 7 years) yields were equivalent to or higher than conventional in most years. Results of this study suggest that organic farming practices that combine use of animal manure and inclusion of small grains, forage legumes, and green manures can improve water quality in artificially drained landscapes while maintaining crop yields.
有机生产旨在使作物轮作多样化,利用有机肥来源,建立土壤肥力,改善土壤健康指标。有机农业对人工排水的中西部Mollisols水质的影响受到的关注有限。本研究历时7年,比较了3种种植制度下硝态氮的损失和产量:(1)传统玉米(Zea mays L)-大豆(Glycine max L.),(2)有机玉米-大豆-燕麦(Avena sativa L.)/苜蓿(Medicago sativa L.) -苜蓿,(3)有机多年生牧草。常规玉米施侧施尿素硝铵(168 kg N ha-1),有机玉米施堆肥肥(168 kg N ha-1),燕麦施堆肥肥(56 kg N ha-1)。总体而言,与常规的2年玉米-大豆轮作相比,4年有机轮作减少了50%的氮负荷,牧场减少了93%的氮负荷。氮素负荷的减少与多样化耕作制度有关,仅有机轮作的玉米-大豆阶段与常规轮作相比,氮素损失没有差异。氮负荷的年变化可以用降水来解释,也可以用作物来解释。秋季取样的土壤健康指标对氮损失的影响最小。有机玉米(7年中的4年)和大豆(7年中的6年)的产量在大多数年份相当于或高于常规产量。这项研究的结果表明,有机农业的做法,结合使用动物粪便,包括小谷物,饲草豆科植物和绿色肥料,可以改善人工排水景观的水质,同时保持作物产量。
{"title":"Organic production reduces subsurface nitrate leaching and maintains crop yields in a US Mollisol","authors":"Natalia Rogovska, Sabrina J. Ruis, Derek B. Carney, Kathleen Delate, Ken M. Wacha, John L. Kovar, Peter L. O'Brien, Cynthia A. Cambardella","doi":"10.1002/jeq2.70085","DOIUrl":"10.1002/jeq2.70085","url":null,"abstract":"<p>Organic production aims to diversify crop rotation and use organic fertilizer sources to build soil fertility and improve soil health indicators. The impact of organic farming on water quality in artificially drained midwestern Mollisols has received limited attention. This 7-year study compares tile nitrate loss and yields under three cropping systems: (1) conventional corn (<i>Zea mays</i> L)-soybean (<i>Glycine max</i> L.), (2) organic corn–soybean–oat (<i>Avena sativa</i> L.)/alfalfa (<i>Medicago sativa</i> L)–alfalfa, and (3) organic perennial pasture. Nitrogen (N) fertilization consisted of sidedress urea ammonium nitrate for conventional corn (168 kg N ha<sup>−1</sup>) and spring-applied composted manure for organic corn (168 kg N ha<sup>−1</sup>) and oats (56 kg N ha<sup>−1</sup>). Overall, the 4-year organic rotation reduced N loads by 50% and pasture reduced loads by 93% compared with the conventional 2-year corn–soybean rotation. Reductions in N loads were related to the diversified cropping system as no difference in N losses was detected when only corn–soybean phases of the organic rotation were compared with the conventional system. Annual variations in N loads were explained by precipitation and varied by crop. Soil health indicators sampled in the fall showed minimal influence on N losses. Organic corn (4 of 7 years) and soybean (6 of 7 years) yields were equivalent to or higher than conventional in most years. Results of this study suggest that organic farming practices that combine use of animal manure and inclusion of small grains, forage legumes, and green manures can improve water quality in artificially drained landscapes while maintaining crop yields.</p>","PeriodicalId":15732,"journal":{"name":"Journal of environmental quality","volume":"54 6","pages":"1875-1887"},"PeriodicalIF":2.3,"publicationDate":"2025-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145149293","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Xue Bai, Samuel J. Smidt, Young Gu Her, Yuncong Li, Donghyeon Kim, Noel Manirakiza, Lisa Duriancik, Jehangir H. Bhadha
Agricultural practices in the Everglades Agricultural Area (EAA) of South Florida have focused on managing accelerated organic matter (OM) decomposition in Histosols, which leads to soil subsidence. Rotating flooded rice (Oryza sativa L., variety Diamond) during the summer fallow period of sugarcane (Saccharum officinarum L.) has been proposed to reduce soil oxidation and loss by creating anaerobic conditions. However, limited research exists on the oxidation–reduction (redox) dynamics of these unique organic soils under rice cultivation and the associated OM decomposition, hindering the development of effective water management practices. This study aimed to understand the effects of flooded rice cropping on OM decomposition and loss by unraveling the intricacies of the redox conditions and their relationship with irrigation practices. Soil redox indicators, including dissolved oxygen (DO) and redox potential (Eh), along with flood depth, soil temperature, and acidity level (pH) were monitored in two rice fields. Soil samples were collected before planting and after harvest and their OM and active carbon concentrations were compared to quantify the effects of rice cultivation. Results showed that prolonged flooding shifted the soil from aerobic to moderately reduced conditions. Increased flood depth, elevated soil temperatures, and higher pH from alkaline limestone mixing contributed to lower DO and Eh. The observed reduction in active carbon suggests that flooded rice cultivation can slow the rate of OM decomposition and loss. Improved water management practices, including extended irrigation periods, consistent water levels, and optimized field conditions, are recommended to further mitigate soil loss and support sustainable farming in the EAA.
{"title":"Sensitivity of redox conditions to irrigation practice and organic matter decomposition in a rotational flooded rice (Oryza sativa) cropping system","authors":"Xue Bai, Samuel J. Smidt, Young Gu Her, Yuncong Li, Donghyeon Kim, Noel Manirakiza, Lisa Duriancik, Jehangir H. Bhadha","doi":"10.1002/jeq2.70087","DOIUrl":"10.1002/jeq2.70087","url":null,"abstract":"<p>Agricultural practices in the Everglades Agricultural Area (EAA) of South Florida have focused on managing accelerated organic matter (OM) decomposition in Histosols, which leads to soil subsidence. Rotating flooded rice (<i>Oryza sativa</i> L., variety Diamond) during the summer fallow period of sugarcane (<i>Saccharum officinarum</i> L.) has been proposed to reduce soil oxidation and loss by creating anaerobic conditions. However, limited research exists on the oxidation–reduction (redox) dynamics of these unique organic soils under rice cultivation and the associated OM decomposition, hindering the development of effective water management practices. This study aimed to understand the effects of flooded rice cropping on OM decomposition and loss by unraveling the intricacies of the redox conditions and their relationship with irrigation practices. Soil redox indicators, including dissolved oxygen (DO) and redox potential (<i>E<sub>h</sub></i>), along with flood depth, soil temperature, and acidity level (pH) were monitored in two rice fields. Soil samples were collected before planting and after harvest and their OM and active carbon concentrations were compared to quantify the effects of rice cultivation. Results showed that prolonged flooding shifted the soil from aerobic to moderately reduced conditions. Increased flood depth, elevated soil temperatures, and higher pH from alkaline limestone mixing contributed to lower DO and <i>E<sub>h</sub></i>. The observed reduction in active carbon suggests that flooded rice cultivation can slow the rate of OM decomposition and loss. Improved water management practices, including extended irrigation periods, consistent water levels, and optimized field conditions, are recommended to further mitigate soil loss and support sustainable farming in the EAA.</p>","PeriodicalId":15732,"journal":{"name":"Journal of environmental quality","volume":"54 6","pages":"1804-1816"},"PeriodicalIF":2.3,"publicationDate":"2025-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://acsess.onlinelibrary.wiley.com/doi/epdf/10.1002/jeq2.70087","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145149311","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Plant-available soil extractable P is used for making P fertilizer recommendations and can be helpful in assessing P loss potential in surface runoff water. Current efforts to relate soil test P (STP) to soluble P concentration in snowmelt surface runoff in the Canadian Prairie Pothole Region do not account for the relative solubility of the P source used nor crop productivity as influenced by the properties of the receiving soil. These factors also potentially influence the utility of STP as an indicator of runoff P losses. In this study, the relationship between STP (modified Kelowna extraction) and P concentration in simulated snowmelt runoff was evaluated across eight inorganic P fertilizer sources applied for 3 years at three sites of variable topography and soil properties in south-central Saskatchewan, Canada. Over 3 years, lower solubility P fertilizer sources had lower P concentrations in runoff that were predicted by assessment of soil residual P level in the fall. Phosphorus fertilizer applications, landscape positions, and crops grown that gave rise to higher crop P uptake and removal over time tended to lead to lower P losses in snowmelt runoff. In contrast, soil conditions that limited crop P uptake, including elevated salinity and low soil moisture, promoted P losses in surface runoff. These influences were also predicted by STP content, demonstrating the utility of the STP measure.
{"title":"Fertilizer source and soil properties affect soil test phosphorus and relationships with phosphorus losses in snowmelt runoff","authors":"B. Weiseth, J. J. Schoenau, J. A. Elliott","doi":"10.1002/jeq2.70083","DOIUrl":"10.1002/jeq2.70083","url":null,"abstract":"<p>Plant-available soil extractable P is used for making P fertilizer recommendations and can be helpful in assessing P loss potential in surface runoff water. Current efforts to relate soil test P (STP) to soluble P concentration in snowmelt surface runoff in the Canadian Prairie Pothole Region do not account for the relative solubility of the P source used nor crop productivity as influenced by the properties of the receiving soil. These factors also potentially influence the utility of STP as an indicator of runoff P losses. In this study, the relationship between STP (modified Kelowna extraction) and P concentration in simulated snowmelt runoff was evaluated across eight inorganic P fertilizer sources applied for 3 years at three sites of variable topography and soil properties in south-central Saskatchewan, Canada. Over 3 years, lower solubility P fertilizer sources had lower P concentrations in runoff that were predicted by assessment of soil residual P level in the fall. Phosphorus fertilizer applications, landscape positions, and crops grown that gave rise to higher crop P uptake and removal over time tended to lead to lower P losses in snowmelt runoff. In contrast, soil conditions that limited crop P uptake, including elevated salinity and low soil moisture, promoted P losses in surface runoff. These influences were also predicted by STP content, demonstrating the utility of the STP measure.</p>","PeriodicalId":15732,"journal":{"name":"Journal of environmental quality","volume":"54 6","pages":"1470-1483"},"PeriodicalIF":2.3,"publicationDate":"2025-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://acsess.onlinelibrary.wiley.com/doi/epdf/10.1002/jeq2.70083","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145137687","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ashim Datta, Brook Wilke, Christine Charles, Marc Hasenick, Tayler Ulbrich, Maninder Singh, Molly Sears, G. Philip Robertson
The transition from conventional to more regenerative cropping systems can be economically risky due to variable transition period yields and unforeseen costs. We compared yields and economic returns for the first 3 years of the transition from a business as usual (BAU) conventional corn (Zea mays)–soybean (Glycine max) rotation to an aspirational (ASP) five-crop (corn-soybean-winter wheat [Triticum aestivum]–winter canola [Brassica napus]-forage) rotation in the Upper Midwest United States. Regenerative ASP cropping practices included the more diverse crop rotation, continuous no-till, cover crops, precision inputs, and livestock (compost) integration. For the first two transition years, BAU corn yields were 8%–12% higher than ASP while in the third transition year, BAU corn yields were 5% lower. Soybean yields were similar for the first 2 years but higher in BAU in the third year due to an ASP pest outbreak. Equivalent yields for other ASP crops were lower than BAU in the first 2 years but similar in the third year except for canola, which suffered from slug damage. Whole-system economic returns narrowed across years; by year three, whole system comparisons for the ASP corn and soybean entry points (corn-soybean-wheat and soybean-wheat-canola, respectively) showed equivalent economic returns for BAU and ASP, despite yield differences, owing largely to the ASP system's reduced operational costs. Overall findings suggest that early regenerative systems can be as profitable as conventional systems with careful attention to rotation entry points and inputs.
{"title":"Crop performance and profitability for the initial transition years of a regenerative cropping system in the Upper Midwest United States","authors":"Ashim Datta, Brook Wilke, Christine Charles, Marc Hasenick, Tayler Ulbrich, Maninder Singh, Molly Sears, G. Philip Robertson","doi":"10.1002/jeq2.70084","DOIUrl":"10.1002/jeq2.70084","url":null,"abstract":"<p>The transition from conventional to more regenerative cropping systems can be economically risky due to variable transition period yields and unforeseen costs. We compared yields and economic returns for the first 3 years of the transition from a business as usual (BAU) conventional corn (<i>Zea mays</i>)–soybean (<i>Glycine max</i>) rotation to an aspirational (ASP) five-crop (corn-soybean-winter wheat [<i>Triticum aestivum</i>]–winter canola [<i>Brassica napus</i>]-forage) rotation in the Upper Midwest United States. Regenerative ASP cropping practices included the more diverse crop rotation, continuous no-till, cover crops, precision inputs, and livestock (compost) integration. For the first two transition years, BAU corn yields were 8%–12% higher than ASP while in the third transition year, BAU corn yields were 5% lower. Soybean yields were similar for the first 2 years but higher in BAU in the third year due to an ASP pest outbreak. Equivalent yields for other ASP crops were lower than BAU in the first 2 years but similar in the third year except for canola, which suffered from slug damage. Whole-system economic returns narrowed across years; by year three, whole system comparisons for the ASP corn and soybean entry points (corn-soybean-wheat and soybean-wheat-canola, respectively) showed equivalent economic returns for BAU and ASP, despite yield differences, owing largely to the ASP system's reduced operational costs. Overall findings suggest that early regenerative systems can be as profitable as conventional systems with careful attention to rotation entry points and inputs.</p>","PeriodicalId":15732,"journal":{"name":"Journal of environmental quality","volume":"54 6","pages":"1572-1585"},"PeriodicalIF":2.3,"publicationDate":"2025-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://acsess.onlinelibrary.wiley.com/doi/epdf/10.1002/jeq2.70084","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145130964","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Hannah L. Ampe, William G. Crumpton, Greg A. Stenback, David I. S. Green
Although wetland restoration is a promising strategy to reduce nonpoint source nitrogen (N) loads, there is some concern over the potential for increased nitrous oxide (N2O) emissions. We examined the production and emission of N2O and methane (CH4) from wetlands designed to intercept and reduce elevated, nonpoint source nitrate (NO3−) loads. We measured N2O and CH4 flux rates at three wetlands subject to a wide range of NO3− loading rates. Nitrate, dissolved N2O, and dissolved CH4 associated with inflows and outflows were estimated using measured flows and concentrations, and N2O and CH4 emissions were estimated using floating chambers. Nitrate removal, N2O production, and CH4 production were estimated by mass balance analyses. Methane emission rates averaged 1,010 mg m−2 day−1, similar to rates for restored depressional wetlands, and N2O emission rates averaged 4.49 mg m−2 day−1, similar to rates from cropland. Inflows and outflows contributed little to CH4 fluxes but were significant components of N2O budgets. Dissolved N2O loads to the wetlands from inflow streams ranged from 8.1% to 70% of the total N2O inputs, and dissolved N2O export from the wetlands through outflow to streams ranged from 7.3% to 63% of the total N2O outputs. Nitrous oxide production and emission increased with NO3− loading; however, these wetlands also exhibited very high NO3− conversion efficiencies, with N2O-N production and emission averaging approximately 0.5% of NO3− removal. The fraction of N loading that would be transformed to N2O in these wetlands is much lower than in cropland or downstream riverine systems.
{"title":"Nitrous oxide and methane production and emission in wetlands receiving nonpoint source nitrate loads","authors":"Hannah L. Ampe, William G. Crumpton, Greg A. Stenback, David I. S. Green","doi":"10.1002/jeq2.70081","DOIUrl":"10.1002/jeq2.70081","url":null,"abstract":"<p>Although wetland restoration is a promising strategy to reduce nonpoint source nitrogen (N) loads, there is some concern over the potential for increased nitrous oxide (N<sub>2</sub>O) emissions. We examined the production and emission of N<sub>2</sub>O and methane (CH<sub>4</sub>) from wetlands designed to intercept and reduce elevated, nonpoint source nitrate (NO<sub>3</sub><sup>−</sup>) loads. We measured N<sub>2</sub>O and CH<sub>4</sub> flux rates at three wetlands subject to a wide range of NO<sub>3</sub><sup>−</sup> loading rates. Nitrate, dissolved N<sub>2</sub>O, and dissolved CH<sub>4</sub> associated with inflows and outflows were estimated using measured flows and concentrations, and N<sub>2</sub>O and CH<sub>4</sub> emissions were estimated using floating chambers. Nitrate removal, N<sub>2</sub>O production, and CH<sub>4</sub> production were estimated by mass balance analyses. Methane emission rates averaged 1,010 mg m<sup>−2</sup> day<sup>−1</sup>, similar to rates for restored depressional wetlands, and N<sub>2</sub>O emission rates averaged 4.49 mg m<sup>−2</sup> day<sup>−1</sup>, similar to rates from cropland. Inflows and outflows contributed little to CH<sub>4</sub> fluxes but were significant components of N<sub>2</sub>O budgets. Dissolved N<sub>2</sub>O loads to the wetlands from inflow streams ranged from 8.1% to 70% of the total N<sub>2</sub>O inputs, and dissolved N<sub>2</sub>O export from the wetlands through outflow to streams ranged from 7.3% to 63% of the total N<sub>2</sub>O outputs. Nitrous oxide production and emission increased with NO<sub>3</sub><sup>−</sup> loading; however, these wetlands also exhibited very high NO<sub>3</sub><sup>−</sup> conversion efficiencies, with N<sub>2</sub>O-N production and emission averaging approximately 0.5% of NO<sub>3</sub><sup>−</sup> removal. The fraction of N loading that would be transformed to N<sub>2</sub>O in these wetlands is much lower than in cropland or downstream riverine systems.</p>","PeriodicalId":15732,"journal":{"name":"Journal of environmental quality","volume":"54 6","pages":"2048-2060"},"PeriodicalIF":2.3,"publicationDate":"2025-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://acsess.onlinelibrary.wiley.com/doi/epdf/10.1002/jeq2.70081","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145069659","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Walter K. Dodds, Leon A. Barmuta, Susana Bernal, Jessica Corman, Tamara K. Harms, Sherri L. Johnson, Li Li, Davi Gasparini Fernandes Cunha, Julian D. Olden, Tenna Riis, Lucas C. R. Silva, John C. Stella, Pamela Sullivan, Ellen Wohl
Riparian zones are a critical terrestrial-aquatic ecotone. They play important roles in ecosystems including (1) harboring biodiversity, (2) influencing light and carbon fluxes to aquatic food webs, (3) maintaining water quality and streamflow, (4) enhancing aquatic habitat, (5) influencing greenhouse gas production, and (6) sequestering carbon. Defining what qualifies as a riparian zone is a first step to delineation. Many definitions of riparian boundaries focus on static attributes or a subset of potential functions without recognizing that they are spatially continuous, temporally dynamic, and multi-dimensional. We emphasize that definitions should consider multiple ecological and biogeochemical functions and physical gradients, and explore how this approach influences spatial characterization of riparian zones. One or more of the following properties can guide riparian delineation: (1) distinct species, elevated biodiversity, or species with specific adaptations to flooding and inundation near streams relative to nearby upland areas; (2) unique vegetation structure directly influencing irradiance or organic material inputs to aquatic ecosystems; (3) hydrologic and geomorphic features or processes maintaining floodplains; (4) hydric soil properties that differ from the uplands; and/or (5) elevated retention of dissolved and suspended materials relative to adjacent uplands. Considering these properties for an operational and dynamic definition of riparian zones recognizes that riparian boundaries vary in space (e.g., variation of riparian corridor widths within or among watersheds) and time (e.g., responses to hydrological variance and climate change). Inclusive definitions addressing multiple riparian functions could facilitate attainment of research and management goals by linking properties of interest to specific outcomes.
{"title":"Defining stream riparian zones across multidimensional environmental gradients","authors":"Walter K. Dodds, Leon A. Barmuta, Susana Bernal, Jessica Corman, Tamara K. Harms, Sherri L. Johnson, Li Li, Davi Gasparini Fernandes Cunha, Julian D. Olden, Tenna Riis, Lucas C. R. Silva, John C. Stella, Pamela Sullivan, Ellen Wohl","doi":"10.1002/jeq2.70080","DOIUrl":"10.1002/jeq2.70080","url":null,"abstract":"<p>Riparian zones are a critical terrestrial-aquatic ecotone. They play important roles in ecosystems including (1) harboring biodiversity, (2) influencing light and carbon fluxes to aquatic food webs, (3) maintaining water quality and streamflow, (4) enhancing aquatic habitat, (5) influencing greenhouse gas production, and (6) sequestering carbon. Defining what qualifies as a riparian zone is a first step to delineation. Many definitions of riparian boundaries focus on static attributes or a subset of potential functions without recognizing that they are spatially continuous, temporally dynamic, and multi-dimensional. We emphasize that definitions should consider multiple ecological and biogeochemical functions and physical gradients, and explore how this approach influences spatial characterization of riparian zones. One or more of the following properties can guide riparian delineation: (1) distinct species, elevated biodiversity, or species with specific adaptations to flooding and inundation near streams relative to nearby upland areas; (2) unique vegetation structure directly influencing irradiance or organic material inputs to aquatic ecosystems; (3) hydrologic and geomorphic features or processes maintaining floodplains; (4) hydric soil properties that differ from the uplands; and/or (5) elevated retention of dissolved and suspended materials relative to adjacent uplands. Considering these properties for an operational and dynamic definition of riparian zones recognizes that riparian boundaries vary in space (e.g., variation of riparian corridor widths within or among watersheds) and time (e.g., responses to hydrological variance and climate change). Inclusive definitions addressing multiple riparian functions could facilitate attainment of research and management goals by linking properties of interest to specific outcomes.</p>","PeriodicalId":15732,"journal":{"name":"Journal of environmental quality","volume":"54 6","pages":"1674-1697"},"PeriodicalIF":2.3,"publicationDate":"2025-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://acsess.onlinelibrary.wiley.com/doi/epdf/10.1002/jeq2.70080","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145064746","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}