scholarly journals El control de la contaminación por nitratos en el regadío

2011 ◽  
Vol 2 (2) ◽  
pp. 115 ◽  
Author(s):  
Yolanda Martínez Martínez ◽  
Skender Uku Karaj ◽  
José Albiac Murillo

This paper analyzes the effects of some water management policies and irrigation systems on crop yields and water pollution, in an area located in the Flumen- Monegros irrigation district in Huesca (Spain). The analysis is performed using water and nitrogen crop response functions, which are estimated with the EPIC crop growth package. The estimation of response for the crop activities incorporates information on local climate, soils, crop management and irrigation systems. The relationship between yields and water and nitrogen input use is examined, in order to quantify the pollution reduction cost faced by farmers. The costs depend on the particular crop and the pollution abatement measure, and information on these costs is important to design efficient pollution abatement measures.

Water ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 538
Author(s):  
Zihao Guo ◽  
Jianen Gao ◽  
Pengcheng Sun ◽  
Shaohui Dou ◽  
Juan Li ◽  
...  

Gully Land Consolidation (GLC) is a proven method to create farmlands and increase crop yields in the Loess Hilly and Gully Region, China. However, GLC influences phreatic water transformation and might cause the farmlands water disasters, such as salinization and swamping. For exploring the influence of GLC on phreatic water transformation and mitigating disasters, a series of indoor experiments were conducted in the artificial rainfall hall. Then, we simulated the phreatic water transformation patterns under more conditions with HYDRUS-3D. Finally, an engineering demonstration in the field was performed to validate our research. The indoor experiments indicated that GLC could increase phreatic water outflow rate 4.39 times and phreatic water coefficient (PWC) 2.86 times with a considerable delay. After calibration and validation with experimental data, the HYDRUS-3D was used to simulate phreatic water transformation under more soil thickness and rainfall intensities. Accordingly, we summarized the relationship among PWC, rainfall intensities, and soil thickness, and therefore suggested a blind ditch system to alleviate farmlands disasters. Field application showed that a blind ditch system could avoid disasters with 3.2 times the phreatic water transformation rate compared to loess. Our research provides implications for sustainable land uses and management in the region with thick soil covers.


1980 ◽  
Vol 7 (1) ◽  
pp. 19-25 ◽  
Author(s):  
D. L. Hallock ◽  
A. H. Allison

Abstract The relative effectiveness of United States Gypsum granular 420 Landplaster Bulk (420-Bulk) and Texasgulf Gypsum (Tg Gypsum) were compared with finely ground anhydrite (Bagged-LP) as sources of supplemental Ca for Florigiant peanuts (Arachis hypogaea L.). Treatments included the above sources at rates of 605 kg/ha banded (61 cm) or 907 kg/ha broadcast (91-cm wide rows) of CaSO4 equivalent per unit area covered (double these rates of 420-Bulk and Bagged-LP also were applied in 1977). Times of application were planting, planting + ca 30 days, and early flowering stage. The experiments were located on Kenansville lfs (Arenic Hapludult) in 1977 and on Rumford lfs (Typic Hapludult) in 1978. The Ca treatments increased crop yields from 360 to 1,200 kg/ha and crop value (yield × price) from $343 to $889/ha over the check in 1977. Slightly lower yield increases were obtained in 1978 when dry conditions prevailed during fruit maturation. Kernel size grades were improved markedly by all Ca treatments in 1977. There was a definite trend both years (significant in 1978) toward higher productivity when the Ca sources were applied at the early flowering stage compared to earlier applications. No difference was noted between methods of application of Bagged-LP or Tg Gypsum in 1978. Double rates of Bagged-LP or 420-Bulk in 1977 did not increase productivity over the low rates. A single application of Bagged-LP was as effective as split applications in the 1978 test. Germinability of seed in 1977 averaged 85% or higher for all Ca treatments. Seed germination in 1978 averaged 75%, 69% and 74% in plots where Tg Gypsum, 420-Bulk or Bagged-LP was applied, respectively. Germination was lowest in the check plots both years. Germinability and seed-Ca contents were significantly higher in 1978 when the Ca sources were applied at the early flowering stage (ca July 1) than 15 days earlier. Seed-Ca contents both years and K contents in 1978 were significantly correlated with germinability. The correlation coefficients were only 0.4 in each case and the relationship was negative for K. In general, 420-Bulk, Tg Gypsum, or Bagged-LP were equally effective sources of supplemental Ca for peanuts. However, when fruit mature under very dry conditions 420-Bulk may be somewhat inferior to the other Ca sources especially when applied before early flowering.


2019 ◽  
Vol 4 (1) ◽  
pp. 2-14
Author(s):  
HANS BLEUMINK

Historical surface irrigation of pastures in the Dutch province of Noord-Brabant: visible traces of a failed experiment In the second half of the 19th century, some major changes occurred in the water management of the eastern and southern provinces of the Netherlands. Unlike the low-lying western parts of the Netherlands which were characterised by polders and had a long history of formal water boards, the higher eastern and southern parts of the Netherlands were characterized by brook systems and sandy soils, and had no centralised water boards until 1850. From the 1850s onward, water boards were introduced in these higher regions as well, and agronomical scientists and organisations like the Nederlandse Heidemaatschappij endeavoured for the modernisation of agricultural water management. One of their priorities was the introduction of modern forms of surface irrigation of pastures, in order to increase crop yields. In various places modern irrigation systems were constructed. From the 1900s onward, these systems were abandoned due to the introduction of new chemical fertilizers, among others. This article describes the construction and abandonment of one of these modern irrigation systems that was located in Liempde, in the province of Noord-Brabant. The local farmers were not interested in the new technique, and within a few years the system was transformed in a poplar plantation. Nowadays, the area is part of a nature reserve. Nonetheless, the global layout of the irrigation system is still visible.


2015 ◽  
Vol 19 (7) ◽  
pp. 3073-3091 ◽  
Author(s):  
J. Jägermeyr ◽  
D. Gerten ◽  
J. Heinke ◽  
S. Schaphoff ◽  
M. Kummu ◽  
...  

Abstract. Global agricultural production is heavily sustained by irrigation, but irrigation system efficiencies are often surprisingly low. However, our knowledge of irrigation efficiencies is mostly confined to rough indicative estimates for countries or regions that do not account for spatiotemporal heterogeneity due to climate and other biophysical dependencies. To allow for refined estimates of global agricultural water use, and of water saving and water productivity potentials constrained by biophysical processes and also non-trivial downstream effects, we incorporated a process-based representation of the three major irrigation systems (surface, sprinkler, and drip) into a bio- and agrosphere model, LPJmL. Based on this enhanced model we provide a gridded world map of irrigation efficiencies that are calculated in direct linkage to differences in system types, crop types, climatic and hydrologic conditions, and overall crop management. We find pronounced regional patterns in beneficial irrigation efficiency (a refined irrigation efficiency indicator accounting for crop-productive water consumption only), due to differences in these features, with the lowest values (< 30 %) in south Asia and sub-Saharan Africa and the highest values (> 60 %) in Europe and North America. We arrive at an estimate of global irrigation water withdrawal of 2469 km3 (2004–2009 average); irrigation water consumption is calculated to be 1257 km3, of which 608 km3 are non-beneficially consumed, i.e., lost through evaporation, interception, and conveyance. Replacing surface systems by sprinkler or drip systems could, on average across the world's river basins, reduce the non-beneficial consumption at river basin level by 54 and 76 %, respectively, while maintaining the current level of crop yields. Accordingly, crop water productivity would increase by 9 and 15 %, respectively, and by much more in specific regions such as in the Indus basin. This study significantly advances the global quantification of irrigation systems while providing a framework for assessing potential future transitions in these systems. In this paper, presented opportunities associated with irrigation improvements are significant and suggest that they should be considered an important means on the way to sustainable food security.


2021 ◽  
Vol 4 (2) ◽  
pp. 34-47
Author(s):  
Anastasiia Zymaroieva ◽  
Tetiana Fedoniuk ◽  
Svitlana Matkovska ◽  
Olena Andreieva ◽  
Victor Pazych

Global food security largely depends on the crop yield increase, so the study of the yield-limiting factors of potato (the second bread) is a pressing issue today. This study determines the contribution of the agroecological factors, namely, bioclimatic variables, soil indicators, and factors of landscape diversity, to the variation in potato yields. Conducted in Polissya and Forest-steppe zones of Ukraine during 1991–2017, this study has not only addressed the relationship between ecological determinants and potato yields, but also considered crop yields as a dynamic system. The dynamics of potato yields from the mid-1990s to the present is described by a log-logistic model. There are statistically significant regression dependencies between potato yield parameters and agroecological factors. Potato yield is dependent on the diversity of landscape cover. The relationship between yield parameters and landscape-ecological diversity is non-linear, which determines the presence of optimal landscape structure for the highest potato yields. Among climatic factors, the continental climate is of the greatest importance for potato yield. The high sensitivity of potato yield parameters to soil indices was found, and mostly the soil texture components (silt content), which largely determines the potato yield spatial variation.


2021 ◽  
Author(s):  
Romeu G. Jorge ◽  
Isabel P. de Lima ◽  
João L.M.P. de Lima

&lt;p&gt;In irrigated agricultural areas, where the availability of water for irrigation does not rely on any water storage, water management requires special attention, in particular under large annual and inter-annual variability in the hydrological regime and the uncertainty of climate change. The inherent increased vulnerability of the agro-ecosystem, makes the monitoring of crop conditions and water requirements a valuable tool for improving water use efficiency and, therefore, crop yields.&lt;/p&gt;&lt;p&gt;This presentation focus on one such agricultural area, located in the Lis Valley (Centre of Portugal), which is a rather vulnerable area also facing drainage and salinity problems. The study aims at contributing to better characterizing the temporal and spatial distribution of rice water requirements during the growing season. Irrigation water sources are the Lis River and its tributaries, which discharges depend directly from precipitation. The most important problems of water distribution in the Lis Valley irrigation district are water shortage and poor water quality in the dry summer period, aggravated by limitations of the irrigation and drainage systems that date back to the end of the 1950&amp;#8217;s.&lt;/p&gt;&lt;p&gt;We report preliminary results on using remote sensing data to better understand rice cropping local conditions, obtained within project GO Lis (PDR2020-101-030913) and project MEDWATERICE (PRIMA/0006/2018). Rice irrigation is traditionally conducted applying continuous flooding, which requires much more irrigation water than non-ponded crops, and therefore needs special attention. In particular, data obtained from satellite Sentinel-2A land surface imagery are compared with data obtained using an unmanned aerial vehicle (UAV). Data for rice cultivated areas during the 2020 cultivation season, together with weather and crop parameters, are used to calculate biophysical indicators and indices of water stress in the vegetation. Actual crop evapotranspiration was appraised with remote sensing based estimates of the crop coefficient (Kc) and used to assess rice water requirements. Procedures and methodologies to estimate Kc were tested, namely those based on vegetation indices such as the Normalized Difference Vegetation Index (NDVI). Results are discussed bearing in mind the usefulness of the diverse tools, based on different resolution data (Sentinel-2A and UAV), for improving the understanding of the impacts of irrigation practices on crop yield and main challenges of rice production and water management in the Lis Valley irrigation district.&lt;/p&gt;


2019 ◽  
Vol 64 ◽  
pp. 03013 ◽  
Author(s):  
Ilya V. Dunichkin ◽  
Emanuele Naboni ◽  
Anna E. Korobeinikova ◽  
Olga I. Poddaeva

Subject of research: visualization of the wind regime of residential buildings on the slope area in the Arctic. Goals: the purpose of the study is to identify the problems of visualization of the wind regime on the slopes and the analysis of patterns of airflow around the sloping territories, affecting the comfort of pedestrians. Materials and methods: airflow patterns of slope areas with different characteristics and comfort assessment for humans are analyzed in the course of work. Geotechnical methods are presented in solving the problems of wind erosion and the stability of hillsides and complex terrain within the city limits. Results: The importance and novelty of the research in studying the relationship of slope geometry and environmental quality, as a decrease in comfort inevitably leads to a decrease in the development of nearby urban areas in settlements on the coast of the Arctic Ocean, problems with climate and local climate, as well as a decrease in the quality of life of people. The article considers the relationship of plastic relief with the aeration regime of the territory, the dependence of aerodynamic roughness on their height, features of aeration of the slope and hilly terrain, factors affecting the direction and speed of the wind and methods for studying the aeration regime of slope areas. Findings: The possibilities of applying existing approaches to research and visualization for slope areas are demonstrated. The direction of development of the technique for visualization of slope areas has been determined.


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