scholarly journals The extent of soil loss across the US Corn Belt

2021 ◽  
Vol 118 (8) ◽  
pp. e1922375118
Author(s):  
Evan A. Thaler ◽  
Isaac J. Larsen ◽  
Qian Yu

Soil erosion in agricultural landscapes reduces crop yields, leads to loss of ecosystem services, and influences the global carbon cycle. Despite decades of soil erosion research, the magnitude of historical soil loss remains poorly quantified across large agricultural regions because preagricultural soil data are rare, and it is challenging to extrapolate local-scale erosion observations across time and space. Here we focus on the Corn Belt of the midwestern United States and use a remote-sensing method to map areas in agricultural fields that have no remaining organic carbon-rich A-horizon. We use satellite and LiDAR data to develop a relationship between A-horizon loss and topographic curvature and then use topographic data to scale-up soil loss predictions across 3.9 × 105 km2 of the Corn Belt. Our results indicate that 35 ± 11% of the cultivated area has lost A-horizon soil and that prior estimates of soil degradation from soil survey-based methods have significantly underestimated A-horizon soil loss. Convex hilltops throughout the region are often completely denuded of A-horizon soil. The association between soil loss and convex topography indicates that tillage-induced erosion is an important driver of soil loss, yet tillage erosion is not simulated in models used to assess nationwide soil loss trends in the United States. We estimate that A-horizon loss decreases crop yields by 6 ± 2%, causing $2.8 ± $0.9 billion in annual economic losses. Regionally, we estimate 1.4 ± 0.5 Pg of carbon have been removed from hillslopes by erosion of the A-horizon, much of which likely remains buried in depositional areas within the fields.

2020 ◽  
Author(s):  
Isaac Larsen ◽  
Evan Thaler ◽  
Qian Yu

<p>Soil erosion in agricultural landscapes reduces crop yields and influences the global carbon cycle. However, the magnitude of historical topsoil loss remains poorly quantified at large, regional spatial scales, hindering predictions of economic losses to farmers and quantification of the role soil erosion plays in the carbon cycle. We focus on one of the world’s most productive agricultural regions, the Corn Belt of the Midwestern United States and use a novel spectral remote sensing method to map areas of complete topsoil loss in agricultural fields. Using high-resolution satellite images and the association between topsoil loss and topographic curvature, we use high resolution LiDAR topographic data to scale-up soil loss predictions to 3.7x10<sup>5</sup> km<sup>2</sup> of the Corn Belt. Our results indicate 34±12% of the region has completely lost topsoil as a result of agriculturally-accelerated erosion. Soil loss is most prevalent on convex slopes, and hilltops throughout the region are often completely denuded of topsoil indicating that tillage is a major driver of erosion, yet tillage erosion is not simulated in models used to assess soil loss trends in the U.S. We estimate that soil regenerative farming practices could restore 16±4.4 Pg of carbon to the exposed subsoil in the region. Soil regeneration would offset at least $2.5±0.3 billion in annual economic losses to farmers while generating a carbon sink equivalent to 8±3 years of U.S. CO<sub>2</sub> emissions, or ~14% of the global soil carbon lost since the advent of agriculture.  </p>


1998 ◽  
Vol 12 (4) ◽  
pp. 752-760 ◽  
Author(s):  
G. F. Warren

About 15 years ago, I heard several speakers saying that our crop yields were “leveling off.” This stimulated me to assemble data on the subject. The result is shown in Table 1, which gives the U.S. average yields for 10-yr periods during this century for nine crops. The increases are spectacular, varying from two- to sevenfold. Factors contributing to these increases differ from crop to crop. To obtain information on this subject, several experts on each crop were consulted, and their conclusions are summarized in the following text. Only those factors contributing to increased yields are covered. However, great improvements in efficiency of production, product quality, and reduction in soil erosion also have occurred as cultivars and production practices have changed. For most of the crops, increases in yields started in the 1940s and have increased dramatically during the rest of the century. We have not attempted to predict the future at this time, but the rate at which yields are increasing does not appear to be slowing.


2020 ◽  
Vol 119 (820) ◽  
pp. 303-309
Author(s):  
J. Nicholas Ziegler

Comparing the virus responses in Germany, the United Kingdom, and the United States shows that in order for scientific expertise to result in effective policy, rational political leadership is required. Each of these three countries is known for advanced biomedical research, yet their experiences in the COVID-19 pandemic diverged widely. Germany’s political leadership carefully followed scientific advice and organized public–private partnerships to scale up testing, resulting in relatively low infection levels. The UK and US political responses were far more erratic and less informed by scientific advice—and proved much less effective.


Author(s):  
Gilles Duruflé ◽  
Thomas Hellmann ◽  
Karen Wilson

This chapter examines the challenge for entrepreneurial companies of going beyond the start-up phase and growing into large successful companies. We examine the long-term financing of these so-called scale-up companies, focusing on the United States, Europe, and Canada. The chapter first provides a conceptual framework for understanding the challenges of financing scale-ups. It emphasizes the need for investors with deep pockets, for smart money, for investor networks, and for patient money. It then shows some data about the various aspects of financing scale-ups in the United States, Europe, and Canada, showing how Europe and Canada are lagging behind the US relatively more at the scale-up than the start-up stage. Finally, the chapter raises the question of long-term public policies for supporting the creation of a better scale-up environment.


Author(s):  
Andrew Schmitz ◽  
Charles B. Moss ◽  
Troy G. Schmitz

AbstractThe COVID-19 crisis created large economic losses for corn, ethanol, gasoline, and oil producers and refineries both in the United States and worldwide. We extend the theory used by Schmitz, A., C. B. Moss, and T. G. Schmitz. 2007. “Ethanol: No Free Lunch.” Journal of Agricultural & Food Industrial Organization 5 (2): 1–28 as a basis for empirical estimation of the effect of COVID-19. We estimate, within a welfare economic cost-benefit framework that, at a minimum, the producer cost in the United States for these four sectors totals $176.8 billion for 2020. For U.S. oil producers alone, the cost was $151 billion. When world oil is added, the costs are much higher, at $1055.8 billion. The total oil producer cost is $1.03 trillion, which is roughly 40 times the effect on U.S. corn, ethanol, and gasoline producers, and refineries. If the assumed unemployment effects from COVID-19 are taken into account, the total effect, including both producers and unemployed workers, is $212.2 billion, bringing the world total to $1266.9 billion.


2012 ◽  
Vol 102 (7) ◽  
pp. 652-655 ◽  
Author(s):  
K. L. Everts ◽  
L. Osborne ◽  
A. J. Gevens ◽  
S. J. Vasquez ◽  
B. K. Gugino ◽  
...  

Extension plant pathologists deliver science-based information that protects the economic value of agricultural and horticultural crops in the United States by educating growers and the general public about plant diseases. Extension plant pathologists diagnose plant diseases and disorders, provide advice, and conduct applied research on local and regional plant disease problems. During the last century, extension plant pathology programs have adjusted to demographic shifts in the U.S. population and to changes in program funding. Extension programs are now more collaborative and more specialized in response to a highly educated clientele. Changes in federal and state budgets and policies have also reduced funding and shifted the source of funding of extension plant pathologists from formula funds towards specialized competitive grants. These competitive grants often favor national over local and regional plant disease issues and typically require a long lead time to secure funding. These changes coupled with a reduction in personnel pose a threat to extension plant pathology programs. Increasing demand for high-quality, unbiased information and the continued reduction in local, state, and federal funds is unsustainable and, if not abated, will lead to a delay in response to emerging diseases, reduce crop yields, increase economic losses, and place U.S. agriculture at a global competitive disadvantage. In this letter, we outline four recommendations to strengthen the role and resources of extension plant pathologists as they guide our nation's food, feed, fuel, fiber, and ornamental producers into an era of increasing technological complexity and global competitiveness.


Plant Disease ◽  
2014 ◽  
Vol 98 (5) ◽  
pp. 696-696 ◽  
Author(s):  
J. A. Crouch ◽  
M. P. Ko ◽  
J. M. McKemy

Downy mildew of impatiens (Impatiens walleriana Hook.f.) was first reported from the continental United States in 2004. In 2011 to 2012, severe and widespread outbreaks were documented across the United States mainland, resulting in considerable economic losses. On May 5, 2013, downy mildew disease symptoms were observed from I. walleriana ‘Super Elfin’ at a retail nursery in Mililani, on the Hawai'ian island of Oahu. Throughout May and June 2013, additional sightings of the disease were documented from the islands of Oahu, Kauai, Maui, and Hawai'i from nurseries, home gardens, and botanical park and landscape plantings. Symptoms of infected plants initially showed downward leaf curl, followed by a stippled chlorotic appearance on the adaxial leaf surfaces. Abaxial leaf surfaces were covered with a layer of white mycelia. Affected plants exhibited defoliation, flower drop, and stem rot as the disease progressed. Based on morphological and molecular data, the organism was identified as Plasmopara obducens (J. Schröt.) J. Schröt. Microscopic observation disclosed coenocytic mycelium and hyaline, thin-walled, tree-like (monopodial branches), straight, 94.0 to 300.0 × 3.2 to 10.8 μm sporangiophores. Ovoid, hyaline sporangia measuring 11.0 to 14.6 × 12.2 to 16.2 (average 13.2 × 14.7) μm were borne on sterigma tips of rigid branchlets (8.0 to 15.0 μm) at right angle to the main axis of the sporangiophores (1,3). Molecular identification of the pathogen was conducted by removing hyphae from the surface of three heavily infected leaves using sterile tweezers, then extracting DNA using the QIAGEN Plant DNA kit (QIAGEN, Gaithersburg, MD). The nuclear rDNA internal transcribed spacer was sequenced from each of the three samples bidirectionally from Illustra EXOStar (GE Healthcare, Piscataway, NJ) purified amplicon generated from primers ITS1-O and LR-0R (4). Resultant sequences (GenBank KF366378 to 80) shared 99 to 100% nucleotide identity with P. obducens accession DQ665666 (4). A voucher specimen (BPI892676) was deposited in the U.S. National Fungus Collections, Beltsville, MD. Pathogenicity tests were performed by spraying 6-week-old impatiens plants (I. walleriana var. Super Elfin) grown singly in 4-inch pots with a suspension of 1 × 104 P. obducens sporangia/ml until runoff using a handheld atomizer. Control plants were sprayed with distilled water. The plants were kept in high humidity by covering with black plastic bags for 48 h at 20°C, and then maintained in the greenhouse (night/day temperature of 20/24°C). The first symptoms (downward curling and chlorotic stippling of leaves) and sporulation of the pathogen on under-leaf surfaces of the inoculated plants appeared at 10 days and 21 days after inoculation, respectively. Control plants remained healthy. Morphological features and measurements matched those of the original inoculum, thus fulfilling Koch's postulates. To our knowledge, this is the first report of downy mildew on I. walleriana in Hawai'i (2). The disease appears to be widespread throughout the islands and is likely to cause considerable losses in Hawai'ian landscapes and production settings. References: (1) O. Constantinescu. Mycologia 83:473, 1991. (2) D. F. Farr and A. Y. Rossman. Systematic Mycology and Microbiology Laboratory, ARS, USDA. Retrieved from http://nt.ars-grin.gov/fungaldatabases/ July 16, 2013. (3) P. A. Saccardo. Syllogue Fungorum 7:242, 1888. (4) M. Thines. Fungal Genet Biol 44:199, 2007.


Plant Disease ◽  
2010 ◽  
Vol 94 (7) ◽  
pp. 924-924 ◽  
Author(s):  
C. Hernandez-Zepeda ◽  
T. Isakeit ◽  
A. Scott ◽  
J. K. Brown

During the okra growing season from August to November of 2009, symptoms reminiscent of geminivirus infection were observed on 75% of ‘Green Emerald’ Abelmoschus esculentus (L.) Moench, plants in a 0.2-km2 field in Hidalgo County, TX. Visible symptoms consisted of irregular yellow patches on leaves, distinctive yellow borders on leaf edges, and chlorosis of subsequently developing leaves. The whitefly vector of begomoviruses, Bemisia tabaci (Genn.), infested okra plants in the early growth stages during late July 2009. Total DNA was isolated from the leaves of three symptomatic okra plant samples (1) and used as the PCR template to amplify a 575-bp fragment of the coat protein gene (CP) using the universal begomovirus primers AV494 and AC1048 (2). PCR products of the expected size were cloned into the pGEM-T Easy (Promega, Madison, WI) and sequenced using the universal M13F and M13 R primers. ClustalV alignment indicated 99 to 100% shared nucleotide (nt) identity, and BLAST analysis revealed that the closest relative was Okra yellow mosaic Mexico virus - Tetekalitla (OkYMMV) (GenBank Accession No. EF591631) at 98%. To amplify the full-length DNA-A and a possible cognate DNA-B component, one plant that was positive by CP-PCR and DNA sequencing was selected for further analysis. Total DNA from this plant was used as template for a second detection method that consisted of rolling circle amplification (RCA) using the TempliPhi 100 Amplification System (GE Healthcare). RCA is a non-sequence-specific approach that permits amplification of circular DNA. The RCA products were linearized to release unit length ~2.6 kb DNA-A and DNA-B components using BamHI, and EcoRI, respectively. These products were cloned into pGEM3zf+ (Promega) and sequenced using M13F and M13 R primers and then by primer walking (>300 base overlap). Full-length DNA-A and DNA-B components were obtained, respectively, at 2,613 bp (GenBank Accession No. HM035059) and 2,594 bp (GenBank Accession No HM035060). Alignment of the DNA-A component using ClustalV (MegAlign, DNASTAR, Madison, WI) with begomoviral sequences available in GenBank indicated that it was 99% identical to OkYMMV DNA-A (GenBank Accession No. DQ022611). The closest relative to the DNA-B component (ClustalV) was Sida golden mosaic virus (SiGMV) (GenBank Accession No. AJ250731) at 73%. The nt identity of the 172-nt ‘common region’ present in the DNA-A and DNA-B components was 99%, and the iterons (predicted Rep binding motif) were identical for the two components, indicating that they are a cognate pair. The genome organization was typical of other New World bipartite begomoviruses. The economic losses due to infection by this virus could not be determined because an early freeze killed the plants. Hidalgo County is adjacent to Tamaulipas, Mexico, where ~50 km2 of okra are grown and the whitefly vector is also present. The identification of OkYMMV based on two independent detection methods, and the presence of begomovirus-like symptoms together with the whitefly vector, provide robust evidence for the association of OkYMMV-TX with diseased okra plants. To our knowledge, this is the first report of OkYMMV-TX infecting okra crops in Texas and in the continental United States. References: (1) J. J. Doyle and J. L. Doyle. Focus 12:13, 1990. (2) S. Wyatt and J. K. Brown. Phytopathology 86:1288, 1996.


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