scholarly journals Quantifying the Spatial Distribution of Soil Nitrogen Under Long-Term Drip Fertigation

2021 ◽  
Author(s):  
Yaran Bi ◽  
Linlin Wang ◽  
Wenyong Wu ◽  
Renkuan Liao ◽  
xiangshuai Bi ◽  
...  
Keyword(s):  
Spatial Distribution ◽  
Spatial Heterogeneity ◽  
Drip Irrigation ◽  
Multifractal Analysis ◽  
Soil Depth ◽  
Soil Samples ◽  
Nitrate N ◽  
Ammonium N ◽  
Drip Fertigation

Abstract Quantifying the spatial distribution of nitrogen (N) in the soil under long-term drip fertigation events is essential for the optimal regulation of drip fertigation systems. In this study, a greenhouse soil that has been under drip irrigation for 20 years was selected as the research object, and soil samples were collected from 0-50 cm soil depth. The concentrations of N in soil samples were measured and their spatial distribution characteristics were quantified by classical statistical analysis and multifractal analysis. The results showed that long-term drip fertigation and the influence of natural factors resulted in the nitrate N mainly accumulating in the shallow layer of the soil and within a distance from the drip irrigation belt, and the spatial heterogeneity gradually decreased with increasing depth. The content of ammonium N was low and its distribution was observed in the whole section. Multifractal analysis indicated that the Δα value of nitrate N and inorganic N gradually increased with the increase of research scale, i.e., the spatial heterogeneity gradually increased, and it did not appreciably change for ammonium N. Meanwhile, the local high value region was the main factor leading to the spatial heterogeneity of N, and this dominant effect gradually increased with increasing depth. Multifractal analysis can effectively reflect the local information of N spatial distribution in the soil and provide a more detailed description of the spatial heterogeneity of soil properties.

scholarly journals Spatial Distribution of Salinity and Sodicity in Arid Climate Following Long Term Brackish Water Drip Irrigated Olive Orchard

Water ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 2556 ◽  
Author(s):  
John Rohit Katuri ◽  
Pavel Trifonov ◽  
Gilboa Arye
Keyword(s):  
Spatial Distribution ◽  
Irrigation Water ◽  
Brackish Water ◽  
Drip Irrigation ◽  
Arid Regions ◽  
Drip Line ◽  
Negev Desert ◽  
Soil Reclamation ◽  
Olive Orchard

The availability of brackish groundwater in the Negev Desert, Israel has motivated the cultivation of various salinity tolerant crops, such as olives trees. The long term suitability of surface drip irrigation (DI) or subsurface drip irrigation (SDI) in arid regions is questionable, due to salinity concerns, in particular, when brackish irrigation water is employed. Nevertheless, DI and SDI have been adopted as the main irrigation methods in olive orchards, located in the Negev Desert. Reports on continued reduction in olive yields and, essentially, olive orchard uprooting are the motivation for this study. Specifically, the main objective is to quantify the spatial distribution of salinity and sodicity in the active root-zone of olive orchards, irrigated with brackish water (electrical conductivity; EC = 4.4 dS m−1) for two decades using DI and subsequently SDI. Sum 246 soil samples, representing 2 m2 area and depths of 60 cm, in line and perpendicular to the drip line, were analyzed for salinity and sodicity quantities. A relatively small leaching-zone was observed below the emitters depth (20 cm), with EC values similar to the irrigation water. However, high to extreme EC values were observed between nearby emitters, above and below the dripline. Specifically, in line with the dripline, EC values ranged from 10 to 40 dS m−1 and perpendicular to it, from 40 to 120 dS m−1. The spatial distribution of sodicity quantities, namely, the sodium adsorption ratio (SAR, (meq L−1)0.5) and exchangeable sodium percentage (ESP) resembled the one obtained for the EC. In line with the dripline, from 15 to 30 (meq L−1)0.5 and up to 27%, in perpendicular to the drip line from 30 to 60 (meq L−l)0.5 and up to 33%. This study demonstrates the importance of long terms sustainable irrigation regime in arid regions in particular under DI or SDI. Reclamation of these soils with gypsum, for example, is essential. Any alternative practices, such as replacing olive trees and the further introduction of even high salinity tolerant plants (e.g., jojoba) in this region will intensify the salt buildup without leaving any option for soil reclamation in the future.

CHANGES IN NATURAL 15N ABUNDANCE ASSOCIATED WITH PEDOGENIC PROCESSES IN SOIL. II. CHANGES ON DIFFERENT SLOPE POSITIONS

1980 ◽  
Vol 60 (2) ◽  
pp. 365-372 ◽  
Author(s):  
R. E. KARAMANOS ◽  
D. A. RENNIE
Keyword(s):  
Total Nitrogen ◽  
Organic N ◽  
Total N ◽  
Nitrate N ◽  
Ammonium N ◽  
Soil Forming Processes ◽  
Pedogenic Processes ◽  
15N Abundance ◽  
Upper Slope

Rather marked variations in δa15N values were obtained in a study carried out on samples taken from four soils belonging to the Weyburn soil association. The δa15N of the total N of well-drained depressional profiles dropped sharply with depth and, in contrast, for upper slope positions was relatively constant to a depth of approximately 5 m. This characteristic enrichment in the heavier isotope of total nitrogen of surface horizons may represent long-term immobilization of partially oxidized ammonium N into the organic N fraction; δa15N of the total N more closely represents past soil-forming processes while that of the nitrate N appears to reflect, in addition, recent N cycle stresses.

scholarly journals Drip Irrigation Affects the Morphology and Distribution of Olive Roots

HortScience ◽  
2017 ◽  
Vol 52 (9) ◽  
pp. 1298-1306 ◽  
Author(s):  
Shixin Deng ◽  
Qun Yin ◽  
Shanshan Zhang ◽  
Kankan Shi ◽  
Zhongkui Jia ◽  
...  
Keyword(s):  
Spatial Distribution ◽  
Root Morphology ◽  
Drip Irrigation ◽  
Soil Depth ◽  
Soil Layer ◽  
Radial Distance ◽  
Vertical Direction ◽  
Root Surface Area ◽  
Scanning System ◽  
Irrigation Amount

Under field conditions, this study investigated the influence of the irrigation amount on olive root morphology and spatial distribution. Soil samples were taken with an auger at distances of 30, 60, and 90 cm from the tree trunks in four directions. The roots were analyzed using an Epson Twain Pro root scanning system. The results indicated that under different irrigation treatments, the indicators of root morphology of different varieties showed different responses to the irrigation amount. The root length density (RLD), root surface area (RSA), and root volume (RV) of Arbosana first increased with increasing irrigation amount but then decreased; however, those of Arbequina monotonically increased with increasing irrigation amount. The root average diameter of the two varieties was inversely proportional to the irrigation amount. In the vertical dimension, the RLD and RSA of each treatment decreased with increasing soil depth and were mainly distributed in the surface soil (0–20 cm in depth). The RLD and RSA in the vertical direction (VD) of the drip irrigation belt were higher than those of the belt in the parallel direction (PD), and the range was 12% to 86%. Compared with the roots of the 0- to 20-cm soil layer, the roots of the 20- to 40-cm and 40- to 60-cm soil layers were more influenced by the irrigation amount. Horizontally, the RLD and RSA decreased with increasing radial distance. The 30-cm radial area contained most roots, the proportion of roots in this region increased with increasing irrigation capacity. The influence of irrigation quantity in the PD of the drip irrigation belt was greater than that in the VD. The results suggest that irrigation does not change the root spatial distribution pattern but does promote root growth. The two varieties had different responses to irrigation. In terms of soil moisture levels after irrigation, 75% of field capacity is appropriate for ‘Arbosana’, whereas 100% is advisable for ‘Arbequina’. To improve water use efficiency, moisture should be irrigated within the 30-cm radial distance from the trunk, and irrigation depth is not easy to more than 20 cm. This study provides a scientific basis for the efficient water management of olive trees.

scholarly journals Nitrogen mineralization in soils cultivated with plantain (Musa AAB Subgroup plátano cv. Hartón), Zulia state, Venezuela

2021 ◽  
Vol 38 (3) ◽  
pp. 525-547
Author(s):  
Ana González-Pedraza ◽  
Juan Escalante
Keyword(s):  
Multiple Comparisons ◽  
Soil Characteristics ◽  
Soil Samples ◽  
Mineralization Rate ◽  
Total N ◽  
Available N ◽  
Tukey Test ◽  
Nitrate N ◽  
Ammonium N ◽  
Potentially Mineralizable N

The main source of N in the soil is organic matter; therefore, its availability depends on its quantity and quality, microbial activity, soil characteristics and management. An efficient way to quantify available N is by mineralizing it as ammonium (N-NH ) and nitrate (N-NO ). Therefore, in this study, the total and available N was determined in soil samples 0-20 cm deep from two plots with plantain plants (Musa AAB plantain subgroup cv. Hartón) with high and low vigor (AV and BV, respectively), in the South of Lake Maracaibo. Total N was determined by the Kjeldalh method and the mineralization of available N by incubation under laboratory conditions for 10 weeks. The accumulated mineralized N (Nm), the constant mineralization rate of (k) and the potentially mineralizable N (N0) were calculated. A one-way analysis of variance was applied, when it was significant (p<0.05), a Tukey test was applied for multiple comparisons of means. Total N was low (<0.025 %) and did not present statistical differences (p<0.05) between AV and BV. The accumulated mineralized N-NO was statistically (p<0.05) higher (524.47 mg.kg-1) in BV, while the N-NH did not present differences between AV and BV. Only k was statistically higher (0.07 ± 0.03; p<0.05) in BV. Nitrification was the process that prevailed especially in BV where organic carbon was higher and presented a higher percentage of sand.

scholarly journals Soil inorganic nitrogen in spatially distinct areas within a commercial dairy farm in Canterbury, New Zealand

2017 ◽  
Vol 79 ◽  
pp. 83-88
Author(s):  
D.C. Ekanayake ◽  
J.L. Owens ◽  
S. Hodge ◽  
J.A.K. Trethewey ◽  
R.L. Roten ◽  
...  
Keyword(s):  
New Zealand ◽  
Surface Soil ◽  
Inorganic Nitrogen ◽  
Dairy Farm ◽  
Soil Samples ◽  
Inorganic N ◽  
N Distribution ◽  
Nitrate N ◽  
Ammonium N ◽  
Grazing Behaviour

For precision nitrogen (N) fertilisation of grazed dairy paddocks, soil N distribution needs to be quantified. It is expected that farm infrastructure will affect inorganic-N distribution due to its influence on cow grazing behaviour. Surface soil from four spatially distinct areas (main gate, water troughs, non-irrigated and the remaining pasture) was analysed for soil ammonium-N (NH4 +-N) and nitrate-N (NO3 --N) from three paddocks (180 soil samples) on an irrigated commercial dairy farm in Canterbury, New Zealand. Variation between paddocks was higher for NO3 - (P

Soil nutrient stratification and uptake by wheat after seven years of conventional and zero tillage in the Northern Grain belt of Canada

2006 ◽  
Vol 86 (5) ◽  
pp. 767-778 ◽  
Author(s):  
N Z Lupwayi ◽  
G W Clayton ◽  
J T O’Donovan ◽  
K N Harker ◽  
T K Turkington ◽  
...  
Keyword(s):  
Nutrient Uptake ◽  
Soil Depth ◽  
Soil Layer ◽  
Conventional Tillage ◽  
Wheat Crop ◽  
Zero Tillage ◽  
Tillage Systems ◽  
Nitrate N ◽  
Ammonium N ◽  
Nutrient Stratification

The distribution of NaHCO3-extractable nitrate-N, ammonium-N, phosphorus (P) and potassium (K) with soil depth (0 to 20 cm in 5-cm increments) at Fort Vermilion (58°23′N 116°02′ W), Alberta, was described in the 7th and 8th years of conventional and zero tillage following placement of red clover (Trifolium pratense) green manure (GM), field pea (Pisum sativum), canola (Brassica rapa) and monoculture wheat (Triticum aestivum) residues. Soil nitrate-N concentrations under zero tillage were greater than those under conventional tillage in the 0–5 cm soil layer, below which the concentrations were similar. Ammonium-N and K concentrations followed a similar pattern. However, soil P concentrations were usually not different between tillage systems in the 0–5 cm soil layer, but the concentrations decreased more under zero tillage than under conventional tillage at lower depths. A notable exception for soil phosphate was under canola residues, where the concentration was greater under zero tillage than under conventional tillage at all depths. Uptake of N, P or K by a subsequent wheat crop was usually greater (though not always significantly) under zero tillage than under conventional tillage, and there were no interactions between tillage and crop residue. Therefore, differences in nutrient stratification between the two tillage systems did not translate into differences in wheat nutrient uptake. Key words: Conservation tillage, crop rotation, nutrient uptake, soil nitrogen, soil phosphorus, soil potassium

scholarly journals Effects of Short-term Tillage of a Long-term No-Till Land on Available N and P in Two Contrasting Soil Types

2015 ◽  
Vol 4 (4) ◽  
pp. 27 ◽  
Author(s):  
Miles Dyck ◽  
Sukhdev. S. Malhi ◽  
Marvin Nyborg ◽  
Dick Puurveen
Keyword(s):  
N Fertilizer ◽  
Short Term ◽  
Available N ◽  
Straw Management ◽  
Nitrate N ◽  
No Till ◽  
Ammonium N ◽  
Extractable P ◽  
Fertilizer Rates

The effects of short-term (4 years) tillage (hereafter called reverse tillage [RT]) of land previously under long-term (29 or 30 years) no-till (NT), with straw management (straw removed [SRem] and straw retained [SRet]) and N fertilizer rate (0, 50 and 100 kg N ha-1 in SRet, and 0 kg N ha-1 in SRem plots) were determined in autumn 2011 on ammonium-N, nitrate-N and extractable P in the 0-7.5, 7.5-15 and 15-20 cm soil layers at Breton (Gray Luvisol [Typic Cryoboralf] loam) and Ellerslie (Black Chernozem [Albic Argicryoll] loam), Alberta, Canada. There was no significant effect of RT and straw on ammonium-N, nitrate-N and extractable P in soil. Ammonium-N in soil increased significantly (but small) with N rate in many cases at both sites. Nitrate-N in soil increased with increasing N rate from 0 to 100 kg N ha-1 rate at Ellerslie, and up to 50 kg N ha-1 rate at Breton. Etractable P in soil decreased markedly with increasing N rate up to 100 kg N ha-1 at Breton and up to 50 kg N ha-1 at Ellerslie. In summary, increased N fertilizer rates were usually associated with decreased extractable P and increased nitrate-N in soil, but RT and straw had no effect on these nutrients in soil.

Salinity and nutrient distribution in soil profiles of long-term crop rotations

1994 ◽  
Vol 74 (2) ◽  
pp. 229-234
Author(s):  
G. J. Beke ◽  
H. H. Janzen ◽  
T. Entz
Keyword(s):  
Root Zone ◽  
Soil Depth ◽  
Crop Rotations ◽  
Research Station ◽  
Nitrate N ◽  
Cropping Sequence ◽  
Extractable P ◽  
The Impact ◽  
Semi Arid

The effect of cropping systems on salt and nutrient movement in soil has been studied mainly at relatively short-term (< 20 yr) experimental sites or at commercial sites without documented history. This study investigated the impact of two similar, unfertilized, long-term crop rotation experiments, differing in duration and experimental design, on soil EC (salinity), sodium adsorption ratio (SAR), nitrate-N, and extractable-P distributions in semi-arid southern Alberta. The experiments, established in 1911 and 1951 at the Lethbridge Research Station on moderately well drained soils, included continuous spring wheat (Triticum aestivum L.) fallow-wheat-wheat and fallow-wheat cropping sequences. Regardless of length of experiment or cropping sequence, the salinity and SAR values increased with soil depth. Leaching of salts had occurred to a minimum depth of 150 cm, depending on the nature of the parent material and soil-drainage volumes. Within the 90- to 150-cm depth, most salt leaching had taken place under the fallow-wheat rotation and least under the continuous-wheat cropping sequence. Downward movement of nitrate-N generally peaked in the lower root zone, regardless of cropping system or duration of the experiment. Deep leaching of nitrate-N had occurred in the fallow-wheat soil. Movement of extractable P was restricted to the 0- to 30-cm depth. Significant deep leaching of salts had taken place over the 35-yr period of the 1951 experiment whereas the longer, 75-yr period of the 1911 experiment was required to cause significant deep leaching of nitrate-N and of extractable P movement in the 0- to 30-cm depth. Key words: Dryland crop rotations, summerfallow, semi-arid region, soil salinity, soil nitrate and phosphate

Spatial Distribution of HTO Activity in Unsaturated Soil Depth in the Vicinity of Long-term Release Source

2015 ◽  
Vol 67 (2) ◽  
pp. 353-356 ◽  
Author(s):  
Alexey Golubev ◽  
Valentina Golubeva ◽  
Sergey Mavrin
Keyword(s):  
Spatial Distribution ◽  
Unsaturated Soil ◽  
Soil Depth

scholarly journals POPULATION DYNAMICS, AGGLOMERATION ECONOMIES AND MUNICIPAL SIZE: A LONG-TERM ANALYSIS

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Maria Teresa CIOMMI ◽  
laria ZAMBON ◽  
Luca SALVATI
Keyword(s):  
Population Dynamics ◽  
Spatial Distribution ◽  
Population Density ◽  
Spatial Heterogeneity ◽  
Goodness Of Fit ◽  
Basic Knowledge ◽  
Optimal Size ◽  
Administrative Units ◽  
Over Time

Under the hypothesis that modifications in municipal boundaries and creation (or suppression) of new administrative units reflect a progressive adjustment toward a more balanced distribution of population over space, the present study investigates the long-term relationship (1928-2012) between urban expansion, population dynamics and municipal area in a growing metropolitan region (Athens, Greece). In expanding regions, municipal size is a key variable outlining the amount and spatial concentration of services and infrastructures, resulting to be functionally related to population density, agglomeration factors, land availability to building and characteristic socioeconomic profiles of local communities. A statistical analysis of the relationship between population density and municipal area provides basic knowledge to policy and planning adjustments toward a more balanced spatial distribution of population and land among the local government units. Descriptive statistics, mapping, correlation analysis and linear regressions were used to assess the evolution of such relationship over a sufficiently long time period. The average municipal area in Athens decreased moderately over time, with a slight increase in spatial heterogeneity. Conversely, the average population density per municipality increased more rapidly, with a considerable reduction in spatial heterogeneity. The observed goodness-of-fit of the linear relationship between population density and municipal area increased significantly over time. The empirical results of our study indicate that municipal size has progressively adjusted to population density across metropolitan areas, determining a more balanced spatial distribution of the resident population, which was consolidated by the recent administrative reform of the local authorities in Greece (the so called ‘Kallikratis’ law). Such conditions represent a base for the informed analysis of the spatial structure of local administrative units and they contribute to the debate on the optimal size of municipalities and other administrative districts with relevant impact on both urban and metropolitan scales of governance.

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