Jorge A. Delgado

United States Department of Agriculture

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A. R. Mosier

University of Melbourne

R. F. Follett

Agricultural Research Service

Merlin A. Dillon

Colorado State University

Daniel K. Manter

Agricultural Research Service - Plains Area

K. A. Barbarick

Colorado State University

Richard T. Sparks

Agricultural Research Service

Marvin J. Shaffer

Agricultural Research Service

Catherine E. Stewart

Agricultural Research Service - Plains Area

Michael C. Amacher

Rocky Mountain Research (United States)

M. J. Shaffer

United States Department of Agriculture

Cooperative Institutions

Agricultural Research Service

Colorado State University

United States Department of Agriculture

Agricultural Research Service - Plains Area

Instituto Nacional de Investigaciones Forestales Agrícolas y Pecuarias

University of Florida

Center for Agricultural Resources Research

Natural Resources Conservation Service

Oregon State University

Chinese Academy of Sciences

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USE OF BEST MANAGEMENT PRACTICES TO INCREASE NITROGEN USE EFFICIENCY AND PROTECT ENVIRONMENTAL QUALITY IN A BROCCOLI-CORN ROTATION OF CENTRAL MEXICO

Communications in Soil Science and Plant Analysis (2001)

J. Z. Castellanos Salvador Villalobos Jorge A. Delgado J.J. Muñoz-Ramos Anacleto Sosa

Underground water reserves in Central Mexico have been declining and NO3 − -N concentrations of some irrigation wells have been found to exceed 10 ppm. There is the need to develop best management practices (BMPs) that can increase N and water use efficiency by vegetables such as broccoli (Brassica oleracea L. Italica Group) in this region. Three field experiments were conducted during 1996 through 1998 at the Experimental Station of INIFAP in Celaya, Gto., Mexico to develop BMPs for the region. To determine the N sufficiency levels in the most recently fully expanded leaf (MRFEL), dry midrib and press sap were analyzed for total N and NO3 − -N. Maximum marketable yields of 24.5 to 27.0 ton ha−1 were attained with rates of 400 to 425 kg N ha−1. Sufficiency levels for N in the MRFEL were in the range of 5.5 to 6.5% at the beginning of the season, and then it was reduced to 5.5 to 6.0% at heading and then to 4.0–5.0% during the preharvest stage. The critical NO3 − -N concentration in the midrib ranged from 15,000 to 20,000 mg kg−1 at the beginning of the season to 3,500–5,000 mg kg−1 for the pre-harvest stage of development. The adequate levels of NO3 − -N in press sap ranged from 1,600–2,000 mg L−1 at the beginning of the season to 500–800 mg L−1 during pre-harvest growth stage. Broccoli fertilized with 400 kg N ha−1 provided residual effects in the following crop of maize (Zea mays L.), equivalent to 60% of that produced with N fertilizer. This study shows that drip irrigation, spoon feeding of N, monitoring of N status during the growing season and crop rotations with grains has the potential to increase the N fertilizer use efficiency for vegetables grain cropping systems and contribute to protecting environmental quality in Central Mexico.

Preharvest

Growing season

Dry season

10.1081/css-100104112

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Citations (9)

The Nanchang Communication about the potential for implementation of conservation practices for climate change mitigation and adaptation to achieve food security in the 21st century

International Soil and Water Conservation Research (2016)

Jorge A. Delgado Rui Li

There is a large number of peer-reviewed publications reporting that a changing climate is one of the biggest challenges humanity will have during the 21st century. With population growth and the need to significantly increase agricultural production per unit of area during the 21st century, a changing climate will put additional stress on soil resources. Soil and water conservation will be key for the future of humanity. Professional societies in the area of agriculture and soil and water conservation have recognized the importance that soil resources will have for humanity during this century and have made calls for implementation of worldwide soil and water conservation. For example, in 2010 the Soil and Water Conservation Society (SWCS) invited a group of scientists to review the literature about the potential to use conservation practices for climate change adaptation and mitigation. The Delgado et al. (2011) paper was used by the SWCS to develop and adopt a position statement about the importance of using soil and water conservation practices to mitigate and adapt to climate change. The International Soil Conservation Organization (ISCO) invited the lead author to present the paper as a keynote presentation at the ISCO 2013 conference. The European Society of Soil Conservation (ESSC) published a short communication about this paper in one of their newsletters in 2014. The World Association of Soil and Water Conservation (WASWAC) also invited the lead author to present a keynote presentation on this topic at the 2015 WASWAC annual meeting in Nanchang. This paper (the Nanchang Communication) is a summary of the Delgado et al. (2011) paper that was used by the SWCS to develop the SWCS position statement related to soil and water conservation and climate change. The Nanchang Communication (this paper) was used by WASWAC to develop a position statement about the immediate need for implementation of conservation practices for mitigation of and adaptation to climate change to achieve food security in the 21st century. These papers (Delgado et al., 2011, Nanchang Communication), and the SWCS and WASWAC position statements, support the conclusions from the worldwide literature that without implementation of soil and water conservation practices for climate change mitigation and adaptation, the survival of life, including our own species, will be in jeopardy, since soils will be key to meeting the higher demands for food during the 21st century.

10.1016/j.iswcr.2016.05.002

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Long-term N fertilization and conservation tillage practices conserve surface but not profile SOC stocks under semi-arid irrigated corn

Soil and Tillage Research (2017)

Catherine E. Stewart Ardell D. Halvorson Jorge A. Delgado

Stover

Conventional tillage

Crop Residue

10.1016/j.still.2017.04.003

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Citations (36)

Precision Conservation

CRC Press eBooks (2007)

Jorge A. Delgado Joseph Berry

10.1201/noe0849396274.ch223

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Citations (11)

Assessment of mineral nitrogen dynamic and its concentration in the soil profile with the updated NLEAP V.2 model: A case study in South Central Bulgaria

Gueorgui Anguelov Jorge A. Delgado Marvin J. Shaffer

Source

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USE OF CONTROLLED RELEASE FERTILIZERS AND NITRIFICATION INHIBITORS TO INCREASE NITROGEN USE EFFICIENCY AND TO CONSERVE AIR ANDWATER QUALITY

Communications in Soil Science and Plant Analysis (2001)

Sadao Shoji Jorge A. Delgado A. R. Mosier Yusuke Miura

Field trials on controlled release fertilizers (CRF) and a nitrification inhibitor (NI) were conducted in order to show their potential to increase N use efficiency (NUE) and to conserve air and water quality. For this purpose, flood irrigated barley grown on a clay soil (Colorado, USA), center-pivot irrigated potato grown in a sandy field (Colorado, USA), and corn grown on a loamy soil at a large scale lysimeter (Fukushima, Japan) were selected. NI (dicyandiamide) and CRF (polyolefin coated urea) were capable of reducing N2O emissions from urea applied to the barley field by 81 % and 35 %, respectively. Total N fertilizer losses averaged 15 and 10 % in the NI and urea treatments, respectively. On the other hand, those from the CRF treatment averaged only 1.9 %, indicating that CRF showed the highest potential to increase N use efficiency. The trials in the potato field demonstrated that CRF could markedly increase NUE and tuber yields. A single basal application of CRF at planting (N rate, 112 kg ha−1) produced tuber yields comparable with those of traditional fertilizer applications (112 kg N ha−1)by basal dressing, 90 kg N ha−1 by topdressing and 67 kg N ha−1 by 8 fertilizations). The urea and CRF plots in the corn fields showed similar N2O emission patterns, having two high emission periods following the basal and topdressed N applications in the urea plots and the enhanced N release from a short linear formulation and a long sigmoidal formulation in the CRF plots, respectively. However, the total N2O emission value of the CRF plots was almost one third of that of the urea plots. The plant recovery of CRF N was almost two times of that of urea N. Finally, the authors discussed that contributions of CRF and NI to conserve air and water quality are basically due to maximizing NUE and reducing the N fertilization rate.

Coated urea

Lysimeter

10.1081/css-100104103

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Citations (296)

Best Nitrogen Management Practices Can Reduce the Potential Flux of Nitrogen Out of the Arkansas Delta

Soil Science (2011)

Cal Shumway Jorge A. Delgado Theodis Bunch LeRoy Hansen Marc Ribaudo

Some studies have reported that nitrogen losses in the Arkansas Delta can contribute to the flux of nitrogen into the Mississippi River Basin, which can in turn contribute to the nitrate load that the hypoxia problem in the Gulf of Mexico has been attributed to. The need to reduce nitrogen losses in this region can be addressed with the development and validation of robust, new assessment tools that can be used to quickly evaluate management practices and their effects on the environment in terms of potential nitrogen losses and other factors. The recently developed concept of trading nitrogen in air and water quality markets can be used in conjunction with field studies to assess the potential benefits of nitrogen management. In 2008 and 2009, field studies were conducted to collect data to test the new Nitrogen Loss and Environmental Assessment Package (NLEAP) and its ability to simulate nitrate dynamics for different cropping systems grown in three different locations in the Arkansas Delta. Simulation by the NLEAP conducted for cotton, soybean, and corn grown in the Arkansas Delta showed that the model was able to simulate the effects of management on residual soil nitrate (P < 0.01). The simulation showed that residual nitrate can range from about 10 to 240 kg NO3-N ha−1 in the top 1.5 m of soil, in agreement with measured values. In addition, long-term NLEAP simulation analysis showed that rotations of soybeans into corn systems significantly reduced emissions of N2O across this region and reduced NO3-N leaching losses at the field level.

Reactive nitrogen

Nitrogen Cycle

Nutrient pollution

10.1097/ss.0b013e31823fd4ae

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Citations (6)

A nitrogen index for improving nutrient management within commercial Mexican dairy operations

International Soil and Water Conservation Research (2016)

Uriel Figueroa Viramontes Jorge A. Delgado Juan Isidro Sánchez Duarte Esmeralda Ochoa Martínez Gregorio Núñez-Hernández

Some intensive dairy operations in Mexico are contributing to large, negative environmental impacts, especially in regions dominated by high concentrations of animals. Excessive manure inputs plus additional nitrogen (N) fertilizer has, in some cases, resulted in background nitrate–nitrogen (NO3–N) levels in irrigation water that are so high, it is not safe for human consumption. One reason is that commercial farmers in this region are currently not using any method to rapidly calculate N budgets based on their practices, N inputs and/or crop N uptake. The Nitrogen Index, a quick tool that can be used to conduct an assessment within a few minutes, was developed for Mexico, but needed further testing under commercial field operations. We conducted studies in 2010 and 2011 and collected soil and crop information from several commercial farming operations to test the tool. The index accurately assessed (P<0.0001) residual soil nitrate after harvesting corn (Zea mays L.) and oats (Avena sativa L.); and also accurately assessed the N uptake of these crops (P<0.01). The Mexico N Index is a tool that can be used to quickly conduct N balances, show when N is being over-applied, and help reduce over-application, thus reducing N losses to the environment and improving management of dairy forage systems in Mexico.

Nutrient Management

Avena

10.1016/j.iswcr.2016.02.005

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Citations (5)

Rhizosphere bacteriome assemblage following initial fluctuations is delayed with nitrogen additions in tomato seedlings

Biology and Fertility of Soils (2024)

Mary Dixon Carley R. Rohrbaugh Daniel K. Manter Jorge A. Delgado Jorge M. Vivanco

Assemblage (archaeology)

10.1007/s00374-024-01882-1

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Evaluation of Nitrate‐Nitrogen Transport in a Potato–Barley Rotation

Soil Science Society of America Journal (2001)

Jorge A. Delgado Ronald R. Riggenbach Richard T. Sparks Merlin A. Dillon Lawrence M. Kawanabe

Well water NO − 3 –N concentrations have been found to exceed 10 mg L −1 of NO − 3 –N for some areas of the San Luis Valley (SLV) of South‐Central Colorado. The region's predominant soils are sandy soils, with a dominant potato ( Solanum tuberosum L.) followed by malting barley ( Hordeum vulgare L.) crop rotation. There is limited knowledge about how much NO − 3 –N is lost by leaching from these systems, and protocols need to be developed to evaluate the NO − 3 –N transport out of these coarse textured soils from these arid and semiarid irrigated cropping systems. Management information, N content at harvest, initial and final NO − 3 –N in the soil profile, and other supportive data were collected at 14 commercial fields and used as inputs for the Nitrate Leaching and Economic Analysis Package (NLEAP) model, version 1.20. NLEAP simulated available soil water for the root zone as well as the transport of NO − 3 –N in the soil profile, and can be used as part of the protocol to evaluate the NO − 3 –N transport of these systems. Best recommended practices in this region, such as application of N fertilizer rates on the basis of soil test analysis and split applications of N fertilizers, kept the net transport of NO − 3 –N out of the potato–barley systems to a minimum. Our approach of applying simulation models to assess management scenarios showed that barley served as a scavenger for the NO − 3 –N that was added with irrigation water and the residual soil nitrate from the potato growing period.

Crop Rotation

DNS root zone

Cropping system

10.2136/sssaj2001.653878x

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Citations (72)