scholarly journals Nitrogen Fertilizer Efficiency Determined by the 15N Dilution Technique in Maize Followed or Not by a Cover Crop in Mediterranean Chile

Agriculture ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 721
Author(s):  
Osvaldo Salazar ◽  
Renato Diaz ◽  
Adriana Nario ◽  
Ximena Videla ◽  
María Alonso-Ayuso ◽  
...  
Keyword(s):  
Cover Crops ◽  
Negative Impact ◽  
Optimal Dose ◽  
Mediterranean Area ◽  
Mitigation Strategies ◽  
Fertilizer Efficiency ◽  
Agricultural System ◽  
N Leaching ◽  
Maize Crop ◽  
N Dose

Nitrogen (N) in a maize crop is a determining yield factor, but its negative impact on the environment is also known. Therefore, it is necessary to propose mitigation strategies that allow an improvement in the N fertilizer efficiency (NFE), such as the use of cover crops (CC) and the adjustment of the fertilizer dose. The objective of the study was to determine NFE using 15N isotopic techniques and nitrate (NO3−) leaching in a maize–fallow versus a maize–CC rotation with optimal and excessive doses of N in the Mediterranean area of Chile. The treatments were a combination of crop rotation (maize–fallow versus maize–CC of Lolium multiflorum) with the optimal dose of N (250 kg ha−1) or excessive dose (400 kg ha−1). We found that the optimal dose of maize–CC rotation contributed to reducing the losses of N by leaching and improving the NFE. Using the optimal dose decreased the dissolved inorganic N (DIN) emission intensity by 50% compared to the excessive doses. Even if grain yield was higher (19 t ha−1) when applying the excessive N dose, the NFE (28%) was lower than when applying the optimal dose (40%). In the maize–CC rotation with optimal dose, yield was 17 Mg ha−1. The excessive N dose generated higher DIN content at the end of the maize season (177 kg N ha−1). In conclusion, replacing the traditional autumn–winter fallow in the maize monoculture with a CC with optimal N dose contributed to improving NFE and reducing N leaching in a Mediterranean agricultural system. Consequently, it is a strategy to consider as it has positive advantages in soil and N management, helping to reduce diffuse pollution of surface and groundwater bodies.

NLEAP Computer Model and Multiple Linear Regression Prediction of Nitrate Leaching in Vegetable Systems

2002 ◽  
Vol 12 (2) ◽  
pp. 250-256 ◽  
Author(s):  
Hudson Minshew ◽  
John Selker ◽  
Delbert Hemphill ◽  
Richard P. Dick
Keyword(s):  
Linear Regression ◽  
Multiple Linear Regression ◽  
Nitrate Leaching ◽  
Cover Crops ◽  
N Uptake ◽  
N Leaching ◽  
Residual Soil ◽  
Vegetable Crops ◽  
Crop N Uptake ◽  
Mlr Model

Predicting leaching of residual soil nitrate-nitrogen (NO3-N) in wet climates is important for reducing risks of groundwater contamination and conserving soil N. The goal of this research was to determine the potential to use easily measurable or readily available soilclimatic-plant data that could be put into simple computer models and used to predict NO3 leaching under various management systems. Two computer programs were compared for their potential to predict monthly NO3-N leaching losses in western Oregon vegetable systems with or without cover crops. The models were a statistical multiple linear regression (MLR) model and the commercially available Nitrate Leaching and Economical Analysis Package model (NLEAP 1.13). The best MLR model found using stepwise regression to predict annual leachate NO3-N had four independent variables (log transformed fall soil NO3-N, leachate volume, summer crop N uptake, and N fertilizer rate) (P < 0.001, R2 = 0.57). Comparisons were made between NLEAP and field data for mass of NO3-N leached between the months of September and May from 1992 to 1997. Predictions with NLEAP showed greater correlation to observed data during high-rainfall years compared to dry or averagerainfall years. The model was found to be sensitive to yield estimates, but vegetation management choices were limiting for vegetable crops and for systems that included a cover crop.

scholarly journals 307 A systems approach to understanding biosecurity decision-making

2020 ◽  
Vol 98 (Supplement_4) ◽  
pp. 43-43
Author(s):  
Scott C Merrill ◽  
Christopher Koliba ◽  
Gabriela Bucini ◽  
Eric Clark ◽  
Luke Trinity ◽  
...  
Keyword(s):  
Decision Making ◽  
Negative Impact ◽  
Risk Mitigation ◽  
African Swine Fever Virus ◽  
The United States ◽  
Mitigation Strategies ◽  
Communication Strategy ◽  
Livestock Industry ◽  
Diarrhea Virus ◽  
Operational Level

Abstract Disease and its consequences result in social and economic impacts to the US animal livestock industry, ranging from losses in human capital to economic costs in excess of a billion dollars annually. Impacts would dramatically escalate if a devastating disease like Foot and Mouth Disease or African Swine Fever virus were to emerge in the United States. Investing in preventative biosecurity can reduce the likelihood of disease incursions and their negative impact on our livestock industry, yet uncertainty persists with regards to developing an effective biosecurity structure and culture. Here we show the implications of human behavior and decision making for biosecurity effectiveness, from the operational level to the owner/managerial level and finally to the systems level. For example, adjustments to risk messaging strategies could double worker compliance with biosecurity practices at the operational level. The improvement of our risk communication strategy may increase willingness to invest in biosecurity. Furthermore, the adaptation of policies could nudge behavior so that we observe a short disease outbreak followed by a quick eradication instead of a pandemic. Our research shows how the emergence of now-endemic diseases, such as Porcine Epidemic Diarrhea virus, cannot be adequately modeled without the use of a human behavioral component. Focusing solely on any one sector or level of the livestock system is not sufficient to predict emergent disease patterns and their social and economic impact on livestock industries. These results provide insight toward developing more effective risk mitigation strategies and ways to nudge behavior toward more disease resilient systems.

scholarly journals A 3-year field study to assess winter cover crops as nitrogen sources for an organic maize crop in Mediterranean Portugal

2021 ◽  
Vol 128 ◽  
pp. 126302
Author(s):  
Adelaide Perdigão ◽  
José L.S. Pereira ◽  
Nuno Moreira ◽  
Henrique Trindade ◽  
João Coutinho
Keyword(s):  
Field Study ◽  
Cover Crops ◽  
Nitrogen Sources ◽  
Maize Crop ◽  
Winter Cover ◽  
Winter Cover Crops

Sources of variability in the effectiveness of winter cover crops for mitigating N leaching

2016 ◽  
Vol 220 ◽  
pp. 226-235 ◽  
Author(s):  
Edmar I. Teixeira ◽  
Paul Johnstone ◽  
Emmanuel Chakwizira ◽  
John de Ruiter ◽  
Brendon Malcolm ◽  
...  
Keyword(s):  
Cover Crops ◽  
N Leaching ◽  
Winter Cover ◽  
Winter Cover Crops

scholarly journals Effect of Winter Cover Crops on Soil Nitrogen Availability, Corn Yield, and Nitrate Leaching

2001 ◽  
Vol 1 ◽  
pp. 22-29 ◽  
Author(s):  
S. Kuo ◽  
B. Huang ◽  
R. Bembenek
Keyword(s):  
Cover Crops ◽  
Cover Crop ◽  
N Fertilizer ◽  
N Leaching ◽  
Corn Yield ◽  
N Availability ◽  
Soil N ◽  
Soil N Availability ◽  
N Concentration ◽  
Fertilizer Rates

Biculture of nonlegumes and legumes could serve as cover crops for increasing main crop yield, while reducing NO3leaching. This study, conducted from 1994 to 1999, determined the effect of monocultured cereal rye (Secale cereale L.), annual ryegrass (Lolium multiflorum), and hairy vetch (Vicia villosa), and bicultured rye/vetch and ryegrass/vetch on N availability in soil, corn (Zea mays L.) yield, and NO3-N leaching in a silt loam soil. The field had been in corn and cover crop rotation since 1987. In addition to the cover crop treatments, there were four N fertilizer rates (0, 67, 134, and 201 kg N ha-1, referred to as N0, N1, N2, and N3, respectively) applied to corn. The experiment was a randomized split-block design with three replications for each treatment. Lysimeters were installed in 1987 at 0.75 m below the soil surface for leachate collection for the N0, N2, and N3treatments. The result showed that vetch monoculture had the most influence on soil N availability and corn yield, followed by the bicultures. Rye or ryegrass monoculture had either no effect or an adverse effect on corn yield and soil N availability. Leachate NO3-N concentration was highest where vetch cover crop was planted regardless of N rates, which suggests that N mineralization of vetch N continued well into the fall and winter. Leachate NO3-N concentration increased with increasing N fertilizer rates and exceeded the U.S. Environmental Protection Agency’s drinking water standard of 10 mg N l�1 even at recommended N rate for corn in this region (coastal Pacific Northwest). In comparisons of the average NO3-N concentration during the period of high N leaching, monocultured rye and ryegrass or bicultured rye/vetch and ryegrass/vetch very effectively decreased N leaching in 1998 with dry fall weather. The amount of N available for leaching (determined based on the presidedress nitrate test, the amount of N fertilizer applied, and N uptake) correlated well with average NO3-N during the high N leaching period for vetch cover crop treatment and for the control without the cover crops. The correlation, however, failed for other cover crops largely because of variable effectiveness of the cover crops in reducing NO3leaching during the 5 years of this study. Further research is needed to determine if relay cover crops planted into standing summer crops is a more appropriate approach than fall seeding in this region to gain sufficient growth of the cover crop by fall. Testing with other main crops that have earlier harvest dates than corn is also needed to further validate the effectiveness of the bicultures to increase soil N availability while protecting the water quality.

scholarly journals Climate Smart Agriculture: A New Approach for Sustainable Intensification

2020 ◽  
pp. 138-147
Author(s):  
Gayatri Sahu ◽  
Pragyan Paramita Rout ◽  
Suchismita Mohapatra ◽  
Sai Parasar Das ◽  
Poonam Preeti Pradhan
Keyword(s):  
Climate Change ◽  
Food Security ◽  
Agricultural Practices ◽  
Sustainable Intensification ◽  
Mitigation Strategies ◽  
Agricultural System ◽  
World Population ◽  
Resource Degradation ◽  
Security Challenge ◽  
Smart Agriculture

World population is increasing day by day and at the same time agriculture is threatened due to natural resource degradation and climate change. A growing global population and changing diets are driving up the demand for food. The food security challenge will only become more difficult, as the world will need to produce about 70 percent more food by 2050 to feed an estimated 9 billion people. Production stability, agricultural productivity, income and food security is negatively affected by changing climate. Therefore, agriculture must change according to present situation for meeting the need of food security and also withstanding under changing climatic situation. Agriculture is a prominent source as well as a sink of greenhouse gases (GHGs). So, there is a need to modify agricultural practices in a sustainable way to overcome these problems. Developing climate smart agriculture is thus crucial to achieving future food security and climate change goals. It helps the agricultural system to resist damage and recover quickly by adaptation and mitigation strategies. Sustainable Intensification is an essential means of adapting to climate change, also resulting in lower emissions per unit of output. With its emphasis on improving risk management, information flows and local institutions to support adaptive capacity, CSA provides the foundations for incentivizing and enabling intensification. Since climate smart agriculture is defined along three pillars (productivity increases, building resilience and adapting, and GHG emission reduction), key concepts such as productivity, resilience, vulnerability and carbon sequestration provide indicators for future empirical measurements of the climate smart agriculture concept.

Cover crop species affect mycorrhizae-mediated nutrient uptake and pest resistance in maize

2019 ◽  
Vol 35 (5) ◽  
pp. 467-474 ◽  
Author(s):  
Ebony G. Murrell ◽  
Swayamjit Ray ◽  
Mary E. Lemmon ◽  
Dawn S. Luthe ◽  
Jason P. Kaye
Keyword(s):  
Nutrient Uptake ◽  
Cover Crops ◽  
Cover Crop ◽  
European Corn Borer ◽  
Pest Resistance ◽  
Plant Nutrient ◽  
Crop Species ◽  
Maize Crop ◽  
Corn Borer ◽  
Maize Growth

AbstractArbuscular mycorrhizal fungi (AMF) can increase plant nutrient uptake and chemical defense production, both of which can improve plants’ ability to resist insect herbivory. Cover crops—non-commercial species planted in between cash crops in a crop rotation—can naturally alter both soil nutrients and AMF. We tested whether different cover crop species alter AMF colonization, plant nutrient status and plant–insect interactions in a subsequent maize crop. Cover crop species were either non-mycorrhizal, non-leguminous (canola, forage radish), mycorrhizal non-leguminous (cereal rye, oats), mycorrhizal leguminous (clover, pea) or absent (fallow). We measured the cascading consequences of cover crop treatment on maize root AMF colonization, maize growth and performance of an herbivorous insect (European corn borer) feeding on the maize. Maize AMF colonization was greater in plots previously planted with mycorrhizal (rye, oats) than non-mycorrhizal (canola, radish) cover crops or no cover crop (fallow). AMF colonization was linked to increased plant phosphorous and nitrogen, and maize growth increased with low plant N:P. Induced jasmonic acid pathway plant defenses increased with increasing maize growth and AMF colonization. European corn borer survivorship decreased with lower plant N:P, and insect development rate decreased with increased induced plant defenses. Our data describe a cascade in which cover crop species selection can increase or decrease mycorrhizal colonization of subsequent maize crop roots, which in turn impacts phosphorus uptake and may affect herbivory resistance in the maize. These results suggest that farmers could select cover crop species to manage nutrient uptake and pest resistance, in order to amend or limit fertilizer and pesticide use.

scholarly journals The Prediction and Assessment of the Impacts of Soil Sealing on Agricultural Land in the North Nile Delta (Egypt) Using Satellite Data and GIS Modeling

2019 ◽  
Vol 11 (17) ◽  
pp. 4662 ◽  
Author(s):  
Ehab Hendawy ◽  
A. A. Belal ◽  
E. S. Mohamed ◽  
Abdelaziz Elfadaly ◽  
Beniamino Murgante ◽  
...  
Keyword(s):  
Agricultural Land ◽  
Land Reclamation ◽  
Nile Delta ◽  
Negative Impact ◽  
Mitigation Strategies ◽  
Support Vector ◽  
Class Iii ◽  
Gis Modeling ◽  
Soil Sealing ◽  
The North

Soil sealing is currently one of the most critical barriers to sustainable development, particularly in developing countries such as Egypt. Agriculture is a major component of the Egyptian economy and the country’s main source of food security. Urbanization is devouring vast areas of agricultural land, and therefore, in the present study, urbanization was used to determine the degree of soil sealing in a region of Kafr El Sheikh Governorate, Egypt. In this work, remote sensing data were used to monitor changes in land use and land cover (LULC) between 1984 and 2016. A field survey and population data were also used in the analysis. Support vector machine (SVM) classification was used to produce LULC maps of the study area. An accuracy assessment was performed by calculating overall accuracy and individual kappa coefficients. Additionally, soil sealing was assessed using data from 1984 to 2016, and the potential expansion of soil sealing until 2048 was simulated using the cellular automata (CA)–Markov model. Our analysis showed that in the study area (i) about 90% of the soils had soil capability degrees between class II and class III; (ii) soil sealing was not uniformly distributed in the study area; (iii) between 1984 and 2016, the area of soil sealing in fertile soils due to urbanization increased by 19,500 hectares; and (iv) between 1984 and 2000, the urban area increased by around 29%, whereas between 2000 and 2010 it increased by around 43.6%. The results suggest that the magnitude of soil sealing is a good indicator of the soil loss rate and the potential for agricultural development in the Nile Delta. The model predicted that by 2048 an area of 32,290 hectares of agricultural soil will be lost to urbanization. This study indicates that the change of LULC has a negative impact on soil sealing. Between 2000 and 2010, the area of agricultural land decreased by 4%, despite an increase in land reclamation in the north of the study area. The amount of soil sealing was found to increase towards the southeast and northeast of the study area, except for the northern parts, where the amount of soil sealing increased towards the east. Our analyses and forecasts are useful for decision-makers responsible for soil-sealing mitigation strategies and soil-sealing protection plans in the Kafr El Sheikh Governorate, Egypt.

scholarly journals Chronological trends in maximum and minimum water flows of the Teesta River, Bangladesh, and its implications

2017 ◽  
Vol 9 (1) ◽  
Author(s):  
Md. Sanaul H. Mondal ◽  
Md. Serajul Islam
Keyword(s):  
Negative Impact ◽  
Risk Mitigation ◽  
Flow Characteristics ◽  
Sharp Decrease ◽  
Water Levels ◽  
Mitigation Strategies ◽  
Low Flow ◽  
Risk Mitigation Strategies ◽  
Major River ◽  
Water Justice

Bangladesh shares a common border with India in the west, north and east and with Myanmar in the southeast. These borders cut across 57 rivers that discharge through Bangladesh into the Bay of Bengal in the south. The upstream courses of these rivers traverse India, China, Nepal and Bhutan. Transboundary flows are the important sources of water resources in Bangladesh. Among the 57 transboundary rivers, the Teesta is the fourth major river in Bangladesh after the Ganges, the Brahmaputra and the Meghna and Bangladesh occupies about 2071 km2 . The Teesta River floodplain in Bangladesh accounts for 14% of the total cropped area and 9.15 million people of the country. The objective of this study was to investigate trends in both maximum and minimum water flow at Kaunia and Dalia stations for the Teesta River and the coping strategies developed by the communities to adjust with uncertain flood situations. The flow characteristics of the Teesta were analysed by calculating monthly maximum and minimum water levels and discharges from 1985 to 2006. Discharge of the Teesta over the last 22 years has been decreasing. Extreme low-flow conditions were likely to occur more frequently after the implementation of the Gozoldoba Barrage by India. However, a very sharp decrease in peak flows was also observed albeit unexpected high discharge in 1988, 1989, 1991, 1997, 1999 and 2004 with some in between April and October. Onrush of water causes frequent flash floods, whereas decreasing flow leaves the areas dependent on the Teesta vulnerable to droughts. Both these extreme situations had a negative impact on the lives and livelihoods of people dependent on the Teesta. Over the years, people have developed several risk mitigation strategies to adjust with both natural and anthropogenic flood situations. This article proposed the concept of ‘MAXIN (maximum and minimum) flows’ for river water justice for riparian land.

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