Kathleen Delate

Dr. Kathleen Delate

Departments of Agronomy and Horticulture, Iowa State University, Ames, IA 50011, USA

Research Focus & Metrics

Academic Career Length

26Years (2001-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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1 September 2004 in Agronomy Journal
Verified
Journal Article
Closed access
PDF file
KDKathleen Delate
Kathleen Delate
CCCynthia A. Cambardella
Cynthia A. Cambardella

1 June 2003 in American Journal of Alternative Agriculture
Verified
Journal Article
Closed access
PDF file
KDKathleen Delate
Kathleen Delate
MDMichael Duffy
Michael Duffy
CCCraig Chase
Craig Chase
AHAnn Holste
Ann Holste
HFHeather Friedrich
Heather Friedrich
NWNoreen Wantate
Noreen Wantate
Based on the interest of organic and conventional farmers in Iowa in long-term analysis of organic systems, the Neely-Kinyon Long-Term Agroecological Research (LTAR) site was established in 1998 to examine the agronomic and economic performance of conventional and organic systems, using certified organic production practices. We report the results of the economic analysis from 3 years of production (1999–2001). Using organic price premiums for organic crops, returns for corn within the organic corn-soybean-oat and corn-soybean-oat-alfalfa rotations were significantly greater than conventional corn-soybean rotation returns (US$126 ha−1). Com returns were not significantly different between the two organic rotations, at US$655 ha−1 and US$674 ha−1, respectively. Returns for soybean within the organic corn-soybean-oat and com-soybean-oat-alfalfa rotations were not significantly different, at US$1233 ha−1 and US$1326 ha−1, respectively. Organic soybean returns were significantly greater than conventional soybean crop returns (US$235 ha−1) in the corn-soybean rotation. Rotational 3-year average returns were US$180 ha−1 for the conventional corn-soybean rotation, compared to US$734 ha−1 for the organic corn-soybean-oat and US$739 ha−1 for the organic com-soybean-oat-alfalfa rotation.

19 December 2011 in Renewable Agriculture and Food Systems
Verified
Journal Article
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KDKathleen Delate
Kathleen Delate
DCDaniel Cwach
Daniel Cwach
CCCraig Chase
Craig Chase
Novel technologies to reduce tillage in organic systems include a no-tillage roller/crimper for terminating cover crops prior to commercial crop planting. The objective of this experiment was to compare: (1) weed management and yield effects of organic tilled and no-tillage systems for corn (Zea maysL.), soybean [Glycine max(L.) Merr.] and irrigated tomato (Lycopersicon esculentumMill.), using a roller/crimper and two cover crop combinations [hairy vetch/rye (Vicia villosaRoth/Secale cerealeL.) and winter wheat/Austrian winter pea (Triticum vulgareL./Pisum sativumL. ssp.arvense(L.) Poir.)]; and (2) the economic performance of each system. Weed management ranged from fair to excellent in the organic no-tillage system for soybean and tomato crops, with the rye/hairy vetch mulch generally providing the most weed suppression. Corn suffered from low rainfall, competition from weeds and hairy vetch re-growth and, potentially, low soil nitrogen (N) from lack of supplemental fertilization and N immobilization during cover crop decomposition. No-tillage corn yields averaged 5618 and 634 kg ha−1in 2006 and 2007, respectively, which was 42–92% lower than tilled corn. No-tillage soybeans in 2007 averaged 2793 kg ha−1compared to 3170 kg ha−1for tilled soybeans, although no-tillage yields were 48% of tilled yields in the dry year of 2006. Irrigated tomato yields averaged 40 t ha−1in 2006 and 63 t ha−1in 2007, with no statistical differences among tillage treatments. Economic analysis for the three crops revealed additional cover crop seed and management costs in the no-tillage system. Average organic corn returns to management were US$1028 and US$2466 ha−1greater in the tilled system compared to the no-tillage system in 2006 and 2007, respectively, which resulted mainly from the dramatically lower no-tillage yields. No-tillage soybean returns to management were negative in 2006, averaging US$ −14 ha−1, compared to US$742 ha−1for tilled soybeans. However, in 2007, no-tillage soybean returns averaged US$1096 ha−1. The 2007 no-tillage irrigated tomato returns to management averaged US$53,515 compared to US$55,515 in the tilled system. Overall, the organic no-tillage soybean and irrigated tomato system demonstrated some promise for reducing tillage in organic systems, but until economic benefits from soil carbon enhancement can be included for no-tillage systems, soil improvements probably cannot offset the economic losses in no-tillage systems. Irrigation could improve the performance of the no-tillage system in dry years, especially if grain crops are rotated with a high-value irrigated tomato crop.

27 November 2020 in Renewable Agriculture and Food Systems
Verified
Journal Article
Open access
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KDKathleen Delate
Kathleen Delate
BHBen Heller
Ben Heller
JSJessica Shade
Jessica Shade
Conventional cotton production has been associated with the extensive use of agricultural chemicals, leading to environmental and health problems, decreased effectiveness of pesticides and higher costs of production. Organic bans the use of most pesticides while providing premiums for growers, and therefore may be a beneficial alternative for growers. Unfortunately, there has been a paucity of research examining the specific practices used by organic cotton growers and the environmental aspects of those practices. This study surveyed organic cotton producers and processors to document specific approaches and techniques used in organic cotton production and processing, the environmental impacts of those techniques and challenges facing organic cotton growers. We discuss the environmental impacts of organic management techniques and methods for conserving water and reducing dependence on irrigation. We also highlight the challenges to organic production identified in the survey, including management for weeds, insects and diseases, genetic contamination of organic crops from genetically modified cotton, organic seed availability, climate change, chemical drift and marketing of organic cotton. Finally, we suggest that investing in research to produce higher-yielding organic varieties, improved methods for organic weed management, and supporting carbon-sequestering practices will improve conversion to organic production.

1 May 2004 in Crop Science
Verified
Journal Article
Closed access
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LDL. M. Duppong
L. M. Duppong
KDKathleen Delate
Kathleen Delate
MLM. Liebman
M. Liebman
RHR. Horton
R. Horton
FRF. Romero
F. Romero
PCP. K. Chowdbury
P. K. Chowdbury

7 May 2017 in Agriculture
Verified
Journal Article
Open access
PDF file
ESErin Silva
Erin Silva
KDKathleen Delate
Kathleen Delate
The organic industry continues to expand in the United States (U.S.), with 14,093 organic farms in 2014. The upper Midwestern U.S. has emerged as a hub for organic row crop production; however, the management of these organic row crop hectares heavily relies on tillage and cultivation for weed control. Faced with the soil quality challenges related to these practices, and cognizant of the benefits of conventional no-till practices, organic farmers have shown significant interest in the development of Cover Crop-Based Reduced Tillage (CCBRT) techniques to lessen soil disturbance while achieving successful weed management. To serve this farmer interest, significant research efforts have been conducted in the upper Midwestern U.S., focused on systems-based practices to ensure adequate suppression of weeds, through a combination of agronomic and cover crop species and variety selection. Within this review article, we discuss the agronomic successes that have been achieved in CCBRT using a combination of cereal rye and soybeans, resulting in consistent suppression of weeds while providing fuel and labor savings for farmers, as well as the continued challenges that have persisted with its implementation. Continued investment in research focused on cover crop breeding and management, optimization of CCBRT equipment and fertility management, and a greater understanding of rotation effects will contribute to the further expansion of this technique across organic farms.