[PDF] Cover Crop Effects On The Carbon Cycle eBook

Author : Anna Marie Cates
Publisher :
Page : 128 pages
File Size : 36,8 MB
Release : 2018
Category :
ISBN :

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Cover crops, or the practice of adding an unharvested crop to an annual crop rotation, are increasing in popularity and widely recommended to help retain soil, water, and nutrients on agricultural land. However, the ability of cover crops to improve soil health and sequester soil C remains unknown. Cover crops are thought likely to increase soil C because they add diversity in C inputs and increase the total growing season, but the magnitude and probability of this effect in different systems is critical for informing our understanding of cover crop efficacy and making recommendations to growers. In addition, cover crops may impact biogeochemical cycling and soil processes via changing the abiotic environment. Motivated by the need for detailed evidence of cover crop efficacy at multiple scales, I combined field-based evaluation of cover crop effects on the C cycle with an investigation into mechanisms of C storage under varying abiotic conditions. In Chapter 1, I review establishment constraints and variability in production to argue that cover cropping in northern climates requires specific agronomic systems and "buy-in" from farmers and government agencies. In Chapter 2, I used a biometric approach to the net ecosystem C balanced (NECB) of maize-cover crop and found that grain maize's NECB hovered near zero, suggesting that with or without cover crops the systems had marginal ability to increase soil C. Silage maize's NECB was always negative, despite greater rye biomass. In Chapter 3, I carried out a litterbag experiment on maize residue decomposition, soil or litter microbial decomposer community and analyzed particulate organic matter (POM) and potentially mineralizable C (PMC) as indices of active C. We found that cover crops did not alter microbial composition or maize residue decomposition rate. We observed increases in PMC and POM-C with cover crops, which were correlated with total NPP. In Chapter 4, we report on a laboratory incubation evaluating whether temperature and moisture effect on physical protection of decomposing plant litter C. We found that higher temperatures increased C mineralization, shifted bacterial composition, and decreased efficiency of conversion of litter C to soil C, but dry conditions increased soil aggregation.

Author : Andy Clark
Publisher : DIANE Publishing
Page : 248 pages
File Size : 15,66 MB
Release : 2008-07
Category : Technology & Engineering
ISBN : 1437903797

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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.

Author : Joshua Smith
Publisher :
Page : 0 pages
File Size : 10,26 MB
Release : 2014
Category :
ISBN :

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In the United States, there is renewed interest in incorporating cover crops into agricultural systems to provide a variety of potential benefits related to soil quality, water quality, and greenhouse gas emissions. This study focused on assessing whether cover crops influence N 2 O and CO2 emissions in a central Illinois agricultural research field over two years (2011-2013) of cover crop growing seasons. Three winter cover crop systems, annual ryegrass (Lolium multiflorum), cereal rye (Secale cereale), and a cereal rye (2011)/ hairy vetch (Vicia villosa) (2012) rotation were planted after fall 2011 and 2012 harvests. The field included a total of eight main plots, two of each treatment, and two no cover crop control plots. Soil carbon dioxide (CO 2) and nitrous oxide (N2 O) fluxes were measured from the plots in a single corn (Zea mays) - soybean (Glycine max) system for two cover crop growing seasons. Fluxes of CO 2 and CO2 were measured in March 2012, August 2012, and February 2013. The CO2 flux measurements were performed by using an infrared gas analyzer. The N2 O fluxes were analyzed from samples collected at 0, 10, 20, 30 min intervals from the same closed dynamic chamber system. Both CO2 and N2 O fluxes were computed from respective gas concentrations over time. Data were analyzed with a repeated measures mixed model procedure. N2 O fluxes from the cereal rye/hairy vetch plots were greater than the no cover control and annual ryegrass plots, suggesting that cover crops may not decrease N2 O fluxes immediately after being incorporated into a cropping system. In contrast, CO2 fluxes did not significantly differ among the treatments, but the cereal rye/hairy vetch plot sequestered ~100 kg C ha-1 of soil organic carbon (SOC). Overall, it was observed that some cover crop plots can have higher N2 O fluxes than plots without cover crops, but cover crops have the long-term potential to sequester C in croplands demonstrating that their use should still be considered a sustainable agriculture practice.

Author : Jerry L. Hatfield
Publisher : John Wiley & Sons
Page : 432 pages
File Size : 48,26 MB
Release : 2020-01-22
Category : Technology & Engineering
ISBN : 0891188533

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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.

Author : Chuck A. Ingels
Publisher : University of California, Agriculture and Natural Resources
Page : 172 pages
File Size : 16,49 MB
Release : 1998
Category : Technology & Engineering
ISBN : 9781879906358

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This guide features cutting-edge methods for using cover crops to enhance vineyard performance. Based on extensive research, this guide details technical and theoretical information on how cover crops affect vineyards and promote ecological stability. With how-to instructions for activities such as field application, this practical reference is a must-have for vineyard owners, managers, consultants, and pest control advisers.

Author : Fred Magdoff
Publisher : Sare
Page : 294 pages
File Size : 47,26 MB
Release : 2009
Category : Humus
ISBN : 9781888626131

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"'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."

Author : Jonathan Vick
Publisher :
Page : pages
File Size : 44,44 MB
Release : 2017
Category :
ISBN : 9781369795554

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Nitrous oxide (N2O) is a potent greenhouse gas (GHG) with a global warming potential (GWP) 298 times greater than CO2. Cover crops, those crops grown other than the cash crop, offer a range of benefits for growers. However, cover crops also serve as inputs of carbon (C) and nitrogen (N), that can stimulate microbial N2O emissions. Vineyard agroecosystems represent a unique case for studying the effects of cover crops on N2O emissions as vineyard cover crops are generally non-fertilized and rain-fed. A two-year field study and accompanying laboratory incubation was conducted to examine the effects of three cover crop treatments (a legume mix, a ‘soil builder’ mix, and perennial ryegrass) and a fallow control on soil GHG emissions and soil N-dynamics. N2O emissions over the course of the study period did not show significant differences, with emissions ranging from 550 ± 202 g N2O-N ha−1 from the fallow soil to 951 ± 135 g N2O-N ha−1 from the ryegrass planted soil. Precipitation patterns were an important driver of N2O emissions. The laboratory incubation results showed N2O emissions from the legume mix planted soil to be an order of magnitude higher than the other treatments, with denitrification as the pathway responsible for the observed differences in gaseous N production rates. Additionally, patterns of N-transformations exhibited treatment differences, suggesting that two years of cover cropping influenced soil microbial community behavior.