Potential and Observed Release of Phosphorus from Crop Residue and Cover Crops Over the Non-growing Season in a Cool Temperate Region

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Book Synopsis Potential and Observed Release of Phosphorus from Crop Residue and Cover Crops Over the Non-growing Season in a Cool Temperate Region by : Tatianna Lozier

Download or read book Potential and Observed Release of Phosphorus from Crop Residue and Cover Crops Over the Non-growing Season in a Cool Temperate Region written by Tatianna Lozier and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Maintaining crop residue or cover crops on fields during winter is a recommended Best Management Practice (BMP) in temperate regions. However, losses of phosphorus (P) to runoff have been attributed to vegetation following freeze-thaw cycles (FTC). Much of the existing knowledge on P loss from vegetation following FTC has been obtained under severe frost conditions (either simulated or natural). In cool temperate climates, such as Southwestern Ontario, air temperatures are more moderate. Consequently, crop residue and cover crops may be less severely impacted by FTC. An improved understanding of the role of surface vegetation in P losses during the non-growing season (NGS) in cool temperate climate zones is needed to determine if the use of cover crops is suitable for these regions. This thesis addresses two major objectives: (1) to better understand the potential role of hydroclimatic conditions (FTC and hydrological event type) in mobilizing P from crop residue, Triticum aestivum L. (winter wheat), as well as Trifolium pretense L. (red clover) and Avena sativa L. (oat) as cover crops, using laboratory experimentation; and (2) to quantify the release of P from vegetation and soil over the NGS in a field setting, and, determine if changes in water extractable phosphorus (WEP) in vegetation or soil were reflected in loads of dissolved reactive phosphorus (DRP) or total phosphorus (TP) in surface runoff and tile drain effluent. Results from this study revealed that the patterns observed in the laboratory were reflected in the field, where cover crops released more P than winter wheat residue. Oat cover crop was impacted by FTC whereas red clover was not, likely because it had been terminated in early fall using a herbicide. The laboratory and field experiments also demonstrated that potential losses of P from cover crops do not necessarily translate to losses of P in runoff because the mobilization of P in runoff is impacted by both supply and transport processes. Phosphorus leaching and loss from fields are hampered if crops are not inundated/flooded or if surface runoff is limited, but enhanced when vegetation is subjected to prolonged contact with runoff water. The field study demonstrated that although P appeared to have been mobilized from both vegetation and soil pools during the NGS, loads of DRP P and TP leaving the fields were small in comparison, suggesting that much of the P released was retained within the field rather than lost in runoff. This study provides insight into the timing and magnitude of P release from vegetation throughout the NGS in regions with a cool temperate climate and provides an improved understanding of the contribution of cover crops to winter P losses.

Release of Phosphorus from Crop Residue and Cover Crops to Runoff Over the Nongrowing Season in Southwestern Ontario

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ISBN 13 :
Total Pages : 122 pages
Book Rating : 4.:/5 (988 download)

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Book Synopsis Release of Phosphorus from Crop Residue and Cover Crops to Runoff Over the Nongrowing Season in Southwestern Ontario by : Tatianna M. Lozier

Download or read book Release of Phosphorus from Crop Residue and Cover Crops to Runoff Over the Nongrowing Season in Southwestern Ontario written by Tatianna M. Lozier and published by . This book was released on 2016 with total page 122 pages. Available in PDF, EPUB and Kindle. Book excerpt: Maintaining crop residue or cover crops on fields during winter is a recommended Best Management Practice (BMP) in temperate regions. However, losses of phosphorus (P) to runoff have been attributed to vegetation following freeze-thaw cycles (FTC). Much of the existing knowledge on P loss from vegetation following FTC has been obtained under severe frost conditions (either simulated or natural). In cool temperate climates, such as Southwestern Ontario, air temperatures are more moderate. Consequently, crop residue and cover crops may be less severely impacted by FTC. An improved understanding of the role of surface vegetation in P losses during the non-growing season (NGS) in cool temperate climate zones is needed to determine if the use of cover crops is suitable for these regions. This thesis addresses two major objectives: (1) to better understand the potential role of hydroclimatic conditions (FTC and hydrological event type) in mobilizing P from crop residue, Triticum aestivum L. (winter wheat), as well as Trifolium pretense L. (red clover) and Avena sativa L. (oat) as cover crops, using laboratory experimentation; and (2) to quantify the release of P from vegetation and soil over the NGS in a field setting, and, determine if changes in water extractable phosphorus (WEP) in vegetation or soil were reflected in loads of dissolved reactive phosphorus (DRP) or total phosphorus (TP) in surface runoff and tile drain effluent. Results from this study revealed that the patterns observed in the laboratory were reflected in the field, where cover crops released more P than winter wheat residue. Oat cover crop was impacted by FTC whereas red clover was not, likely because it had been terminated in early fall using a herbicide. The laboratory and field experiments also demonstrated that potential losses of P from cover crops do not necessarily translate to losses of P in runoff because the mobilization of P in runoff is impacted by both supply and transport processes. Phosphorus leaching and loss from fields are hampered if crops are not inundated/flooded or if surface runoff is limited, but enhanced when vegetation is subjected to prolonged contact with runoff water. The field study demonstrated that although P appeared to have been mobilized from both vegetation and soil pools during the NGS, loads of DRP P and TP leaving the fields were small in comparison, suggesting that much of the P released was retained within the field rather than lost in runoff. This study provides insight into the timing and magnitude of P release from vegetation throughout the NGS in regions with a cool temperate climate and provides an improved understanding of the contribution of cover crops to winter P losses.

Impacts of Freeze-thaw Processes on Phosphorus Release from a Variety of Cover Crop Species in a Temperate Climate

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ISBN 13 :
Total Pages : 86 pages
Book Rating : 4.:/5 (18 download)

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Book Synopsis Impacts of Freeze-thaw Processes on Phosphorus Release from a Variety of Cover Crop Species in a Temperate Climate by : James Cober

Download or read book Impacts of Freeze-thaw Processes on Phosphorus Release from a Variety of Cover Crop Species in a Temperate Climate written by James Cober and published by . This book was released on 2018 with total page 86 pages. Available in PDF, EPUB and Kindle. Book excerpt: Cover crops (CC) are grown by farmers as an agricultural best management practice (BMP) to improve soil health during the non-growing season (NGS), and potentially reduce soil erosion. Some managers have cautioned against the use of CC due to their potential to act as sources of phosphorus (P) following exposure to freeze-thaw cycles (FTC), given that P has been strongly linked to eutrophication and algal blooms in freshwater systems. Existing literature on the effects of FTC on CC has indicated that the degree of P leaching may be influenced by multiple factors, including the number and/or magnitude of FTC, CC species, and the duration, intensity, and type of leaching event. However, much of the research has been done in laboratory studies, using conditions that are not representative of temperate climates or practices used in Southern Ontario. The objectives of this thesis were to evaluate the effects of FTC intensity and CC species on P release, using conditions and CC species commonly used in Ontario. These objectives were addressed in two separate experiments. The first experiment was done in the laboratory, where clippings of five CC species were exposed to five FTC at varying intensities (4 °C, -4 to 4 °C, -18 to 4 °C, and -18 to 10 °C), prior to extraction of P and nitrogen (N). The impact of termination was evaluated by comparing living CC samples to CC which were terminated with glyphosate. The second experiment was done in the field, and included seven plots of different CC species and mixtures. Plant and soil samples were analysed for P content throughout the NGS, and runoff and shallow groundwater were sampled on an event basis to evaluate the timing of P release from CC and the pathways through which the P moved. This thesis showed that CC species ranged greatly in P released after FTC, but N leaching was unaffected. Heavy frost ( -18 °C) increased P release, particularly from frost-intolerant species, whereas minimal FTC ( -4 °C) did not. Termination resulted in increased P and ammonium-N release from all species, but did not have an additive effect in combination with FTC. In a field setting, P release from CC was smaller in magnitude than was observed in the lab, consistent with the more moderate air temperatures that occurred. However, P release from CC was not related to P concentrations in surface soils and shallow groundwater, and, the pool of water extractable P was much smaller in the CC than in surface soil (5 cm). This thesis has shown that the tested CC species did not present risk for increased edge of field P loss, which is predicted to be consistent with other CC species grown in temperate climates. Planting CC should continue to be promoted as a BMP in Southern Ontario; however, in regions with colder climates, frost-tolerant CC species are recommended.

Cover Crop and Phosphorus Fertilizer Management Implications for Water Quality in a No-till Corn-soybean Rotation

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ISBN 13 :
Total Pages : 0 pages
Book Rating : 4.:/5 (139 download)

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Book Synopsis Cover Crop and Phosphorus Fertilizer Management Implications for Water Quality in a No-till Corn-soybean Rotation by : Robert Elliott Carver

Download or read book Cover Crop and Phosphorus Fertilizer Management Implications for Water Quality in a No-till Corn-soybean Rotation written by Robert Elliott Carver and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Phosphorus (P) is an essential nutrient required for crop growth with finite global reserves. Although naturally occurring concentrations of total P in soils may greatly exceed crop demand, quantities of readily plant-available P in soil solution are typically very low. As such, agricultural producers regularly apply P-containing fertilizers to help optimize crop yields. While applications of P fertilizers may improve crop performance, losses of P from non-point agricultural sources are a known contributor to the degradation of surface water quality with excessive P inputs leading to eutrophication, harmful algal blooms, and increased water treatment costs. Acknowledging the importance of P in production agriculture and the role it plays in water quality it is imperative to develop agricultural management systems designed to promote crop yields while protecting water quality. This study explores the interplay between winter grown cover crops and P fertilizer management practice in relation to annual concentrations and loads of total suspended solids, total P, and dissolved reactive P in surface runoff generated by natural precipitation events for a no-till corn (Zea mays)-soybean (Glycine max) rotation located in the Central Great Plains. To explain the mechanisms behind the potential implications of altering cover crop and/or P fertilizer management practice in relation to water quality, this study examined temporal/seasonal variability in surface runoff water quality, changes in soil fertility status, and the impact of winter cereal cover crop species on potential P release and nutrient cycling. The majority of this research was conducted at the Kansas Agricultural Watershed (KAW) field laboratory located near Manhattan, KS, USA, from September 2015 through September 2019. This study utilized three methods of P fertilizer management (no P, fall broadcast P, and spring injected P) each expressed with and without a winter grown cover crop. The spring injected method of P fertilizer application consistently lost less total P and DRP compared to the fall broadcast method of applying P fertilizer highlighting the importance of using P fertilizer placement to protect water quality. Findings from this study show that the addition of a cover crop during a normally fallow period increased dissolved reactive P loss in 3 of 4 years representing an unintended consequence of a traditionally recognized conservation practice. Cover crops also decreased sediment loss with greater reductions in sediment loss coming from the P fertilized cover crop treatments. Soil test data for samples collected from KAW field lab found that spring subsurface placement of P fertilizer did not result in lesser concentrations of either Mehlich-III not total P in the top 0-5 cm compared to fall broadcast P. The spring injected P fertilizer without a cover crop treatment had lesser concentrations of water-extractable P (WEP) in the top 0-2.5 cm compared to the fall broadcast with and without cover crop treatments; however, when a cover crop was added to the spring injected treatment, WEP was found to be equal to the two fall broadcast treatments The final portion of this research was conducted from fall 2019 through fall 2021 at locations near both Manhattan, KS, USA and Leonardville, KS, US, and examined the impact of six choices in winter cereal cover crops [included winter barley (Hordeum vulgare), winter oat (Avena sterilis), cereal rye (Secale cereale), triticale (X Tritico-secale), winter wheat (Triticum aestivum), and Cereal Killer Blend (1:1:1:1 of barley:oat:rye:triticale)] on P release from cover crop tissue, residue persistence, and the effect of cover crop choice on nutrient cycling throughout the cash crop growing season. This study found winter wheat to have the greatest potential for P release immediately following termination; however, after one week post termination, P concentrations in winter wheat residues were similar to other observed cover crops. Oats were observed to have lowest residue persistence and also to release assimilated nutrients faster than the remaining species. Marginal differences between winter barley, cereal rye, and triticale were observed with regards to P concentration, residue persistence, and nutrient cycling; however, these differences were not biologically significant. Results from this and the aforementioned studies highlight the importance and implications of management decisions when developing agricultural management practices to protect surface water quality.

Managing Cover Crops Profitably (3rd Ed. )

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Publisher : DIANE Publishing
ISBN 13 : 1437903797
Total Pages : 248 pages
Book Rating : 4.4/5 (379 download)

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Book Synopsis Managing Cover Crops Profitably (3rd Ed. ) by : Andy Clark

Download or read book Managing Cover Crops Profitably (3rd Ed. ) written by Andy Clark and published by DIANE Publishing. This book was released on 2008-07 with total page 248 pages. Available in PDF, EPUB and Kindle. Book excerpt: Cover crops slow erosion, improve soil, smother weeds, enhance nutrient and moisture availability, help control many pests and bring a host of other benefits to your farm. At the same time, they can reduce costs, increase profits and even create new sources of income. You¿ll reap dividends on your cover crop investments for years, since their benefits accumulate over the long term. This book will help you find which ones are right for you. Captures farmer and other research results from the past ten years. The authors verified the info. from the 2nd ed., added new results and updated farmer profiles and research data, and added 2 chap. Includes maps and charts, detailed narratives about individual cover crop species, and chap. about aspects of cover cropping.

Cover Crop and Phosphorus Fertilizer Management Effects on Phosphorus Loss and Nutrient Cycling

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ISBN 13 :
Total Pages : pages
Book Rating : 4.:/5 (16 download)

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Book Synopsis Cover Crop and Phosphorus Fertilizer Management Effects on Phosphorus Loss and Nutrient Cycling by : Robert Elliott Carver

Download or read book Cover Crop and Phosphorus Fertilizer Management Effects on Phosphorus Loss and Nutrient Cycling written by Robert Elliott Carver and published by . This book was released on 2018 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Phosphorus (P) loss from non-point agricultural sources has been identified as a main contributor to degraded surface water quality throughout the United States. Excessive P inputs to surface waters can lead to eutrophication, increased water treatment costs, and negative health impacts. Therefore, agricultural best management practices (BMP) that promote water quality, through minimizing P loss, must be identified. Studies outlined in this thesis aim to determine the impacts of cover crops and P fertilizer placement on P loss in surface runoff and nutrient cycling in a no-till corn (Zea mays)-soybean (Glycine max) rotation and provide insight into how cover crop species selection and termination method affects potential P loss from crop tissue. The first study examined combined effects of cover crop and P fertilizer placement on total P, dissolved reactive P (DRP) and sediment losses in surface runoff from natural precipitation events. This large-scale field study was conducted near Manhattan, Kansas, at the Kansas Agricultural Watershed (KAW) Field Laboratory during the 2016 and 2017 cropping years. Two levels of cover crop [no cover crop (NC) and cover crop (CC)] and three levels of P fertilizer management [no P (CN), fall broadcast P (FB), and spring injected P (SI)] were used. Flow-weighted composite water samples were collected from precipitation events generating greater than 2.0 mm of surface runoff. Results from this study found the CC treatment increased DRP losses compared to NC in both cropping years; however, CC reduced sediment loss by over 50% compared to NC. Application of P fertilizer increased DRP losses compared CN in both cropping years, although SI resulted in lower quantities of DRP loss compared to FB. In addition, this study found that CC reduced biomass and yield of corn compared to NC and therefore decreased nutrient uptake, removal, and deposition during the 2017 cropping year. However, no negative impacts of CC on biomass or yield were observed during the 2015 (corn) and 2016 (soybean) cropping years. Application of P fertilizer increased the concentration of Melich-3 P and total P in the top 0-5 cm of soil compared to CN; however, no differences between P fertilizer management practice were observed for concentrations of Melich-3 P at 5-15 cm. A greenhouse-based study determined the impacts of cover crop species (brassica, grass, and legume), termination method (clipping, freezing, and herbicide), and time after termination (1, 7, and 14 days after termination) on total P and water-extractable P (WEP) release from cover crop biomass. Freezing increased WEP concentration of crop tissue by more than 140% compared to clipping and herbicide. Additionally, at 7 and 14 days after termination, both concentration of WEP and fraction of WEP compared total P increased compared to 1 DAT. Findings from these studies suggest the use of cover crops may unintentionally result in greater DRP losses in surface runoff. However, addition of a cover crop can dramatically reduce erosion losses. In addition, cover crop species selection can directly impact the quantity of P being taken up and released by crop tissue. Understanding the impact of crop species selection may help create new BMPs which aim to reduce P loss.

Infiltration of Water Into the Soil

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ISBN 13 :
Total Pages : 90 pages
Book Rating : 4.3/5 (91 download)

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Book Synopsis Infiltration of Water Into the Soil by :

Download or read book Infiltration of Water Into the Soil written by and published by . This book was released on 1940 with total page 90 pages. Available in PDF, EPUB and Kindle. Book excerpt:

The Effects of Cover Crops on Phosphorus Cycling in Agricultural Soils of California

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ISBN 13 :
Total Pages : pages
Book Rating : 4.:/5 (95 download)

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Book Synopsis The Effects of Cover Crops on Phosphorus Cycling in Agricultural Soils of California by : Gabriel Maltais-Landry

Download or read book The Effects of Cover Crops on Phosphorus Cycling in Agricultural Soils of California written by Gabriel Maltais-Landry and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Phosphorus (P) limits agricultural productivity because most soil P is found in pools of low plant-availability and external inputs that are used to increase plant-available P are only partially recovered in crops, resulting in low P use efficiency (PUE). Cover crops could reduce external P input requirements, increase PUE and stimulate soil P cycling by mobilizing soil P and by retaining soil P via plant uptake, especially in low-input agricultural systems. This dissertation seeks to determine if cover crops have similar effects on soil P cycling in intensive agricultural systems with relatively high soil P, using two long-term experiments in California, greenhouse experiments and nutrient budgets. In both field and laboratory conditions, legume cover crops had a greater potential to mobilize soil P than other cover crops, although in practice they did not mobilize soil P. In contrast, cereals had the strongest effect on soil P availability and P cycling by taking up more soil P than other cover crops. Regardless of cover crop type, P taken up in cover crop biomass was recycled rapidly in these systems: cover crop residues and mineral fertilizer contributed similarly to soil pools and wheat P uptake, with a greater contribution at lower soil P availability. However, cover crops had relatively small effects on long-term soil P dynamics relative to compost addition that was the main factor driving differences in P budgets computed at the farm-scale. Overall, cover crops have the potential to affect soil P cycling in these systems with relatively high soil P, although to a lesser degree than do composts.

Crop Physiology Case Histories for Major Crops

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Publisher : Academic Press
ISBN 13 : 0128191953
Total Pages : 780 pages
Book Rating : 4.1/5 (281 download)

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Book Synopsis Crop Physiology Case Histories for Major Crops by : Victor Sadras

Download or read book Crop Physiology Case Histories for Major Crops written by Victor Sadras and published by Academic Press. This book was released on 2020-12-05 with total page 780 pages. Available in PDF, EPUB and Kindle. Book excerpt: Crop Physiology: Case Histories of Major Crops updates the physiology of broad-acre crops with a focus on the genetic, environmental and management drivers of development, capture and efficiency in the use of radiation, water and nutrients, the formation of yield and aspects of quality. These physiological process are presented in a double context of challenges and solutions. The challenges to increase plant-based food, fodder, fiber and energy against the backdrop of population increase, climate change, dietary choices and declining public funding for research and development in agriculture are unprecedented and urgent. The proximal technological solutions to these challenges are genetic improvement and agronomy. Hence, the premise of the book is that crop physiology is most valuable when it engages meaningfully with breeding and agronomy. With contributions from 92 leading scientists from around the world, each chapter deals with a crop: maize, rice, wheat, barley, sorghum and oat; quinoa; soybean, field pea, chickpea, peanut, common bean, lentil, lupin and faba bean; sunflower and canola; potato, cassava, sugar beet and sugarcane; and cotton. A crop-based approach to crop physiology in a G x E x M context Captures the perspectives of global experts on 22 crops

Soil Management

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Publisher : John Wiley & Sons
ISBN 13 : 0891188533
Total Pages : 432 pages
Book Rating : 4.8/5 (911 download)

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Book Synopsis Soil Management by : Jerry L. Hatfield

Download or read book Soil Management written by Jerry L. Hatfield and published by John Wiley & Sons. This book was released on 2020-01-22 with total page 432 pages. Available in PDF, EPUB and Kindle. Book excerpt: Degradation of soils continues at a pace that will eventually create a local, regional, or even global crisis when diminished soil resources collide with increasing climate variation. It's not too late to restore our soils to a more productive state by rediscovering the value of soil management, building on our well-established and ever-expanding scientific understanding of soils. Soil management concepts have been in place since the cultivation of crops, but we need to rediscover the principles that are linked together in effective soil management. This book is unique because of its treatment of soil management based on principles—the physical, chemical, and biological processes and how together they form the foundation for soil management processes that range from tillage to nutrient management. Whether new to soil science or needing a concise reference, readers will benefit from this book's ability to integrate the science of soils with management issues and long-term conservation efforts.

Building Soils for Better Crops

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Publisher : Sare
ISBN 13 : 9781888626131
Total Pages : 294 pages
Book Rating : 4.6/5 (261 download)

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Book Synopsis Building Soils for Better Crops by : Fred Magdoff

Download or read book Building Soils for Better Crops written by Fred Magdoff and published by Sare. This book was released on 2009 with total page 294 pages. Available in PDF, EPUB and Kindle. Book excerpt: "'Published by the Sustainable Agriculture Research and Education (SARE) program, with funding from the National Institute of Food and Agriculture, U.S. Department of Agriculture."

Cover Crops in West Africa

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Publisher : IDRC
ISBN 13 : 088936852X
Total Pages : 319 pages
Book Rating : 4.8/5 (893 download)

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Book Synopsis Cover Crops in West Africa by : International Development Research Centre (Canada)

Download or read book Cover Crops in West Africa written by International Development Research Centre (Canada) and published by IDRC. This book was released on 1998 with total page 319 pages. Available in PDF, EPUB and Kindle. Book excerpt: Cover Crops in West Africa Contributing to Sustainable Agriculture

Mitigating Phosphorus Loss in Runoff from Agricultural Soils

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Publisher :
ISBN 13 :
Total Pages : pages
Book Rating : 4.:/5 (132 download)

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Book Synopsis Mitigating Phosphorus Loss in Runoff from Agricultural Soils by : Francis Opoku

Download or read book Mitigating Phosphorus Loss in Runoff from Agricultural Soils written by Francis Opoku and published by . This book was released on 2021 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Eutrophication of surface waters caused by excessive phosphorus (P) loading is of water quality concern because of its promotion of algal blooms. Cover crops reduce total P (TP) loads in runoff and erosion but have been reported as potential source of dissolved reactive P (DRP) to runoff during winter due to lysis of cover crop cells by freeze-thaw cycles (FTC). However, the effects of cover crops on runoff P could be influenced by other factors such as species and age of cover crop, herbicide termination of cover crop, and soil test P (STP). Experiments were conducted to assess P release from cover crops -- oat (Avena sativa), cereal rye (Secale cereale), annual ryegrass (Lolium multiflorum), red clover (Trifolium pratense) and mustard (Brassica nigra) to runoff DRP. Freeze-thaw cycles elevated P release from cover crops but their impact was reduced when mature cover crops acclimatized at cooler temperatures in the field prior to laboratory extractions. The amounts of DRP contributing to runoff by cover crops was low relative to their tissue P pools and water extractable P (WEP) release under laboratory FTC conditions. Since red clover and mustard typically had less biomass than oat and cereal rye, they contributed minimally or to no detectable DRP amounts to runoff P. Particulate P (PP) and Total (TP) in runoff differed by cover crop species while herbicide application increased runoff DRP contribution by some species of cover crops. Runoff DRP and TP were higher in fall than spring whether cover crops were killed with herbicide or left to grow over winter. Generally, the STP range of these studies, 11 to 32 mg Olsen P kg-1 soil, did not impact cover crop biomass size nor their contribution to runoff DRP despite the high levels (45 to 63 mg kg-1) of WEP released from cover crops. The results of this study suggest that cover crop species selection, management of cover crop biomass and termination of cover crop, either by cutting late in the fall or by leaving it on the field over winter, are essential practices that should be adopted to minimize environmental P risk management.

Management of Biological Nitrogen Fixation for the Development of More Productive and Sustainable Agricultural Systems

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Publisher : Int. Rice Res. Inst.
ISBN 13 : 0792334132
Total Pages : 300 pages
Book Rating : 4.7/5 (923 download)

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Book Synopsis Management of Biological Nitrogen Fixation for the Development of More Productive and Sustainable Agricultural Systems by : J.K. Ladha

Download or read book Management of Biological Nitrogen Fixation for the Development of More Productive and Sustainable Agricultural Systems written by J.K. Ladha and published by Int. Rice Res. Inst.. This book was released on 1995-09-30 with total page 300 pages. Available in PDF, EPUB and Kindle. Book excerpt: Reprinted from Plant and Soil, v.174, nos.1-2 (1995), this volume is devoted to discussions on the role of biological nitrogen fixation (BNF) in agricultural sustainability. Papers presented on BNF in crop forage and tree legumes are augmented with discussion of integrated farming systems involving BNF, soil and N management, and recycling of legume residues. BNF by non-legumes is discussed and attempts to transform cereals into nodulating plants are critically reviewed. Also described are advances in the development of new methodologies to understand symbiotic interactions and to assess N-2 fixation in the field; means of enhancing BNF through plant and soil management; breeding and selection; problems encountered in exploiting BNF under farmers' field conditions; and promising approaches to improve BNF exploitation. Lacks a subject index. Annotation copyright by Book News, Inc., Portland, OR

Linkages Between Cover Crops, Phosphorus Fertilizer Management, Soil Health, and Phosphorus Bioavailability in Replicated Research Watersheds

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ISBN 13 :
Total Pages : 0 pages
Book Rating : 4.:/5 (134 download)

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Book Synopsis Linkages Between Cover Crops, Phosphorus Fertilizer Management, Soil Health, and Phosphorus Bioavailability in Replicated Research Watersheds by : Laura Marie Starr

Download or read book Linkages Between Cover Crops, Phosphorus Fertilizer Management, Soil Health, and Phosphorus Bioavailability in Replicated Research Watersheds written by Laura Marie Starr and published by . This book was released on 2021 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Phosphorus (P) pollution from agricultural remains a persistent and complex problem that negatively affects freshwater quality, causing harmful algal blooms and eutrophication. Phosphorus can be lost from fields as sediment bound solids and dissolved in leachate or runoff. Phosphorus is cycled through the soil ecosystem via biotic and abiotic interactions as organic or inorganic compounds. Conservation practices such as no-till and cover cropping have been promoted as ways to promote soil health and reduce sediment loss from cropping systems. A growing body of research has documented increased dissolved reactive P in runoff from cover crops. It is not clear how conservation management interacts with P fertilizer management, nor what their impact is on the biogeochemical cycling of P and its potential for loss. The objective of this study was to document the impact of cover crops and P fertilizer management on P bioavailability and stratification, as well as investigate changing nutrient status on microbial biomass P (MB-P) and the activity of P cycling enzymes. In 2014, a field scale experiment was established in a no-till, corn-soybean cropping system, at the Kansas Agricultural Watershed in NE Kansas. The experiment was organized as a 2*3 full factorial with eighteen, 0.5 ha watersheds, in a randomized complete block design. A cover crop treatment consisted of cover crop (CC) or no cover crop (NC), was implemented with three P fertilizer management treatments; fall surface broadcast diammonium phosphate (FB), spring subsurface injected ammonium polyphosphate (SI), or no P fertilizer (NP). The first objective was accomplished by measuring the gross P pools such as total P (P[subscript]T), and total organic P (P[subscript]O), as well as bioavailable P pools such as water extractable P (P[subscript]W), and 2 mM citric acid extractable P (P[subscript]C), at the 0-5 cm depth (spring/fall 2018 and 2019), and 5-10/10-15 cm depths (fall 2018, and spring/fall 2019). Additionally, we used diffusive gradient thin films (P[subscript]DGT) to measured total soil-water available P, and Mehlich-III (P[subscript]M) to measure the agronomically relevant P, at the 0-5 cm depth (spring/fall 2018 and 2019). The second objective was addressed by measuring MB-P, and P cycling enzyme activity (acid and alkaline phosphatase, and phosphodiesterase) at the 0-5 cm depth, in fall 2018 and spring/fall 2019. We documented P stratification of P[subscript]T in all treatments in fall 2018 and spring 2019, but reduced stratification in NP, and increased stratification in FB and SI by fall 2019. Total organic P was highest in the 5-10 cm depth in FB and SI in spring/fall 2019. While NP treatments almost always had less P than the fertilized treatments, it had either the same or more P[subscript]O than FB and SI. The labile pools of P, P[subscript]W and P[subscript]C, were stratified in FB*CC, FB*NC, SI*CC treatments but not in SI*NC, NP*NC, NP*CC in spring 2019 (P[subscript]W) and fall 2018 and spring 2019 (P[subscript]C). There were cover crop*P fertilizer interactions in the 0-5 cm depth where a SI*CC increased the amount of P compared to SI*NC in P[subscript]W (spring 2019), P[subscript]C (fall 2018 and spring 2019), and P[subscript]DGT (spring 2019). Cover crops did not affect the amount of P[subscript]W, P[subscript]C, P[subscript]DGT, or P[subscript]M in the 0-5 cm depth of NP or FB fertilizer management at any time. Cover crops reduced the amount of P[subscript]C at 5-10 cm (fall 2018 and spring 2019) and P[subscript]DGT at 10-15 cm (fall 2019). Almost identical P fertilizer * cover crop interactions from P[subscript]C and P[subscript]DGT was detected in MB-P in spring/fall 2019. Cover crops consistently increased P cycling enzyme activity compared to NC treatments. The MB-P was higher in fertilized plots compared to NP treatments in all seasons. Low MB-C:P in NP treatments suggest conditions for P immobilization by microorganisms, possibly contributing to organic P pools. These results suggest that cover crops could be translocating P in spring subsurface applied ammonium polyphosphate, that was then being stored in labile P pools, such as MB-P. At the same time, cover crops may be increasing the potential for organic P mineralization in all fertilizer management treatments. This body of research demonstrates that cover cropping and P fertilizer management in no-till corn-soybean cropping systems interact, changing where and how P is stored and cycled. Further research will be necessary to develop more nuanced management recommendations to optimize soil fertility and reduce P loss to runoff.

Estimation of Available Phosphorus in Soils by Extraction with Sodium Bicarbonate

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ISBN 13 :
Total Pages : 20 pages
Book Rating : 4.:/5 (31 download)

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Book Synopsis Estimation of Available Phosphorus in Soils by Extraction with Sodium Bicarbonate by : Sterling Robertson Olsen

Download or read book Estimation of Available Phosphorus in Soils by Extraction with Sodium Bicarbonate written by Sterling Robertson Olsen and published by . This book was released on 1954 with total page 20 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Exploring the Opportunities for Agroforestry in Changing Rural Landscapes

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ISBN 13 :
Total Pages : 270 pages
Book Rating : 4.:/5 (319 download)

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Book Synopsis Exploring the Opportunities for Agroforestry in Changing Rural Landscapes by :

Download or read book Exploring the Opportunities for Agroforestry in Changing Rural Landscapes written by and published by . This book was released on 1999 with total page 270 pages. Available in PDF, EPUB and Kindle. Book excerpt: