Minimising off-site movement of contaminants in furrow irrigation using polyacrylamide (PAM). II. Phosphorus, nitrogen, carbon, and sediment

Soil Research ◽  
2006 ◽  
Vol 44 (6) ◽  
pp. 561 ◽  
Author(s):  
Danielle P. Oliver ◽  
Rai S. Kookana

Off-site movement of nutrients and sediment from furrow-irrigated agriculture has been a concern in the Ord River Irrigation Area, Western Australia. After consultation with growers, a range of management strategies were tested to assess the effectiveness of various practices to minimise off-site movement of nutrients during irrigation. This paper reports on the effectiveness of the additions of high molecular weight, anionic, polyacrylamide (PAM) to irrigation water to minimise off-site movement of phosphorus, nitrogen, carbon, and sediment. Surface runoff water quantity and quality from 4 separate irrigation bays, which contained 25 furrows per irrigation bay, was monitored over time for a single irrigation 35 days after sowing. Addition of PAM as a puck (cylindrical disc 55 mm diameter by 23 mm height) to the head of each irrigation furrow significantly (P < 0.001) decreased the average volume of surface runoff water leaving the irrigation bays by 54%, from 599 kL for the control irrigation bays to 277 kL for the PAM-treated irrigation bays. The addition of PAM also significantly (P < 0.001) decreased the average total suspended sediment load for the duration of the irrigation from 94.9 kg/ha for the control bays to 13.4 kg/ha for the PAM-treated irrigation bays. The concentrations of the different forms of N, P, and C measured in the runoff water were not significantly different between the 2 treatments. The amounts (g) of particulate (>0.45 µm) P and dissolved organic C were significantly (P < 0.01) less from the PAM-treated bays than from the control bays. There was a consistent trend for the addition of PAM to decrease the cumulative mass loss of all nutrients (N, P, and C) measured. However, significant decreases were only seen for particulate (>0.45 µm) P (by 94%), unfiltered (or total) N (by 56%), and unfiltered (or total) C (by 60%). This experiment demonstrated that the addition of PAM to irrigation waters has the potential to decrease the off-site movement of nutrients bound to colloidal material. However, in this study off-site movement of contaminants present in the ‘soluble’ (<0.45 µm) fraction is unlikely to be mitigated by the addition of PAM to irrigation water. The mode of application of PAM, however, may affect water infiltration and hence vertical movement of ‘soluble’ contaminants and requires further investigation to ensure that while off-site surface transport is being minimised, contamination of groundwater is not being increased. Other strategies to minimise off-site movement for contaminants in the dissolved phase also need investigation.

Soil Research ◽  
2006 ◽  
Vol 44 (6) ◽  
pp. 551 ◽  
Author(s):  
Danielle P. Oliver ◽  
Rai S. Kookana

Off-site movement of pesticides from furrow-irrigated agriculture has been a concern in the Ord River Irrigation Area, Western Australia. After consultation with growers a range of management strategies were tested to assess the effectiveness of various practices to minimise off-site movement of pesticides during irrigation. This paper reports on the effectiveness of the additions of high molecular weight, anionic, polyacrylamide (PAM) to irrigation water to minimise off-site movement of endosulfan, chlorothalonil, bupirimate, and atrazine. Water leaving from 4 separate irrigation bays, which consisted of 25 furrows per irrigation bay (Expt 1) or 39 furrows per irrigation bay (Expt 2), was monitored over time. The average concentration of endosulfan α and β and bupirimate leaving the irrigation bays for the duration of the single irrigation event was generally always less for the PAM-treated irrigation bays than the control (control treatment). The addition of PAM to the irrigation water significantly decreased the cumulative runoff losses (g) of total endosulfan by 54% from 11.41 to 5.19 g/ha (P < 0.05), and of chlorothalonil by 49% from 53.65 to 27.32 g/ha (P < 0.001). There was no statistical difference in the load of atrazine or bupirimate leaving either treatment. Although the addition of PAM to irrigation water effectively decreased the off-site movement of 2 fairly strongly sorbed pesticides, endosulfan and chlorothalonil, it did not decrease the total load moving off-site of the more weakly sorbed pesticides, bupirimate and atrazine. The addition of PAM as a liquid to irrigation water was not found to increase the infiltration of a soluble pesticide, atrazine, into the soil profile. The mode of application of PAM, however, may affect water infiltration and hence vertical movement of soluble pesticides and requires further investigation.


2005 ◽  
Vol 51 (3-4) ◽  
pp. 107-115 ◽  
Author(s):  
R.E. Sojka ◽  
J.A. Entry ◽  
W.J. Orts ◽  
D.W. Morishita ◽  
C.W. Ross ◽  
...  

Low concentrations of synthetic- or bio-polymers in irrigation water can nearly eliminate sediment, N, ortho- and total-P, DOM, pesticides, micro-organisms, and weed seed from runoff. These environmentally safe polymers are employed in various sensitive uses including food processing, animal feeds, and potable water purification. The most common synthetic polymer is anionic, high purity polyacrylamide (PAM), which typically provides 70–90% contaminant elimination. Excellent results are achieved adding only 10 ppm PAM to irrigation water, applying 1–2 kg ha−1 per irrigation, costing $4–$12 kg−1. Biopolymers are less effective. Using twice or higher concentrations, existing biopolymers are ≈60% effective as PAM, at 2–3 times the cost. A half million ha of US irrigated land use PAM for erosion control and runoff protection. The practice is spreading rapidly in the US and worldwide. Interest in development of biopolymer surrogates for PAM is high. If the supply of cheap natural gas (raw material for PAM synthesis) diminishes, industries may seek alternative polymers. Also “green” perceptions and preferences favor biopolymers for certain applications.


Soil Research ◽  
2013 ◽  
Vol 51 (2) ◽  
pp. 124 ◽  
Author(s):  
Xiaojun Li ◽  
Jinggang Zheng ◽  
Xinrong Li ◽  
Huijuan Tan ◽  
Yanxia Pan ◽  
...  

Runoff and nutrient loss in drylands are closely related to vegetation cover. Simulated rainfall experiments with an intensity of 80 mm/h were conducted in sandy grassland and shrubland in the Tengger Desert, China, to investigate the responses of runoff and associated carbon (C) and nitrogen (N) losses to the replacement of grassland by shrubland. Times to ponding and to generate runoff, and the amount of rainfall for runoff commencement in bare, inter-shrub plots were significantly smaller than in shrub (ST) and grassland (GT) plots; no statistical differences were found for these parameters between ST and GT. Overall, this indicated a higher soil water infiltration rate in grassland than in shrubland. The volume-weighted concentrations of organic C (OC) and total N (TN) in runoff from shrubland (0.083 and 0.011 g/L, respectively) were lower than those from grassland (0.103 and 0.012 g/L, respectively). The cover-weighted runoff coefficients, and sediment, OC, and TN losses from shrubland (34.46%, and 44.95 1.72, and 0.23 g/m2, respectively) were greater than from grassland (15.22%, and 15.91, 0.94, and 0.11 g/m2). Vegetation degradation was accompanied by reduced nutrient retention capacity; both soil OC and TN of grassland (8.97 and 0.62 g/kg, respectively) were greater than those weighted values for shrubland (4.18 and 0.26 g/kg). Understanding of these processes suggests that decline or loss of vegetation cover, with the appearance of biological soil crust patches, inevitably leads to increases in runoff and induced soil loss, further accelerating desertification.


2017 ◽  
pp. 31-43
Author(s):  
Berta Ratilla ◽  
Loreme Cagande ◽  
Othello Capuno

Organic farming is one of the management strategies that improve productivity of marginal uplands. The study aimed to: (1) evaluate effects of various organic-based fertilizers on the growth and yield of corn; (2) determine the appropriate combination for optimum yield; and (3) assess changes on the soil physical and chemical properties. Experiment was laid out in Randomized Complete Block Design, with 3 replications and 7 treatments, namely; T0=(0-0-0); T1=1t ha-1 Evans + 45-30-30kg N, P2O5, K2O ha-1; T2=t ha-1 Wellgrow + 45-30-30kg N, P2O5, K2O ha-1; T3=15t ha-1 chicken dung; T4=10t ha-1 chicken dung + 45-30-30kg N, P2O5, K2O ha-1; T5=15t ha-1 Vermicast; and T6=10t ha-1 Vermicast + 45-30-30kg N, P2O5, K2O ha-1. Application of organic-based fertilizers with or without inorganic fertilizers promoted growth of corn than the control. But due to high infestation of corn silk beetle(Monolepta bifasciata Horns), its grain yield was greatly affected. In the second cropping, except for Evans, any of these fertilizers applied alone or combined with 45-30-30kg N, P2O5, K2O ha-1 appeared appropriate in increasing corn earyield. Soil physical and chemical properties changed with addition of organic fertilizers. While bulk density decreased irrespective of treatments, pH, total N, available P and exchangeable K generally increased more with chicken dung application.


Author(s):  
Valery Yashin

Представлены материалы исследований формирования режима влажности и динамики грунтовых вод орошаемых солонцовых комплексных почв при различных способах полива, проведенные в Волгоградском Заволжье. Установлена значительная неравномерность распределения влажности почвы при поливах дождеванием. Отмечается поверхностный сток по микрорельефу до 30% от поливной нормы, что приводит к недостаточности увлажнения корневой зоны на солонцах и переувлажнению почв в понижениях микрорельефа и потере оросительной воды на инфильтрационное питание грунтовых вод.The article presents the materials of research on the formation of the humidity regime and dynamics of ground water of irrigated saline complex soils under various irrigation methods, conducted in the Volgograd Zavolzhye. A significant unevenness in the distribution of soil moisture during irrigation with sprinkling has been established. There is a surface runoff on the microrelief of up to 30% of the irrigation norm, which leads to insufficient moisture of the root zone on the salt flats and waterlogging of the soil in the microrelief depressions and loss of irrigation water for infiltration feed of ground water.


1987 ◽  
Vol 19 (8) ◽  
pp. 75-86 ◽  
Author(s):  
S. P. Amaral

The technology of treatment through landfarming for oily wastes has been more and more often utilized in Brazil, always successfully. The definition, the processes which occur, as well as the factors which affect its performance are herein presented. Design parameters, such as location, ground characterization, dimensioning of the area of application, groundwater protection, drainage, treatment of surface runoff water and percolated liquid, among others, are presented. Operational procedures and quality monitoring of effluents and environment are also described. PETROBRÁS is already operating two landfarming systems and has several others in the design stage. We present data from these projects and report that oily waste degradation has been achieved in around six months. Finally, we expect to be contributing to the affirmation and development of this technology in our Country.


1992 ◽  
Vol 26 (7-8) ◽  
pp. 1851-1856 ◽  
Author(s):  
J. L. Lai ◽  
K. S. L. Lo

A mixing-based model for describing solute transfer to overland flow was developed. This model included a time-dependent mixing depth of the top layer and a complete-mixed surface runoff zone. In a series of laboratory experiments, runoff was passed at various velocities and depths over a medium bed. The media were saturated with uniform concentration of potassium chloride solution. Runoff water was sampled at the beginning and end of the flume and the potassium chloride concentration analyzed. Using this model, dimensionless ultimate mixing depth and dimensionless change rate of mixing depth from experimental data were investigated and implemented. The results showed that the Reynolds number and relative roughness are two important factors.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ningguang Dong ◽  
Guanglong Hu ◽  
Yunqi Zhang ◽  
Jianxun Qi ◽  
Yonghao Chen ◽  
...  

AbstractThis study characterized the effect of green manures (February orchid, hairy vetch, rattail fescue and a no-green-manure control) and the termination method (flail or disk) on nutrient contents, enzyme activities, microbial biomass, microbial community structure of rhizosphere soil and vegetative growth of walnut tree. All three selected green manures significantly enhanced the water content, organic C, total N and available P. The rattail fescue significantly decreased the mineral N. Total organic C, total N, mineral N and available P were significantly greater under flail than under disk. Hairy vetch and February orchid significantly improved levels of soil β-glucosidase, N-acetyl-glucosaminidase and acid phosphatase activity, whereas rattail fescue improved only β-glucosidase activity. All of the green manures significantly decreased phenoloxidase activity. β-glucosidase, N-acetyl-glucosaminidase and acid phosphatase activities were significantly greater under flail relative to disk. The termination method had no significant effect on phenoloxidase activity. The different types of green manures and termination methods significantly altered the soil microbial biomass and microbial community structure. The green-manure treatments were characterized by a significantly greater abundance of Gram-positive (Gram +) bacteria, total bacteria and saprophytic fungi compared to the control. Hairy vetch significantly decreased the abundance of arbuscular mycorrhizal fungi (AMF) while February orchid and rattail fescue increased their abundance compared to the no-green-manure treatment. The abundance rates of Gram+ bacteria, actinomycetes, saprophytic fungi and AMF were significantly greater in soils under flail than under disk. In terms of vegetative growth of walnut tree, hairy vetch showed the greatest positive effects. The growth of walnut tree was significantly greater under flail relative to disk. Our results indicate that green-manure application benefits the rhizosphere soil micro-ecology, rhizosphere soil nutrient contents and tree growth. Overall, the hairy vetch and flail combined treatment is recommended for walnut orchards in northern China.


2021 ◽  
Vol 13 (4) ◽  
pp. 1991
Author(s):  
Silvia Stanchi ◽  
Odoardo Zecca ◽  
Csilla Hudek ◽  
Emanuele Pintaldi ◽  
Davide Viglietti ◽  
...  

We studied the effects of three soil management approaches (permanent grassing, chemical weeding, and buffer strips), and the additional impact of tractor passage on soil erosion in a sloping vineyard located in the inner part of Aosta Valley (N-W Italian Alps). The vineyard rows were equipped with a sediment collection system with channels and barrel tanks. A total of 12 events with sediment production were observed across 6 years, and the collected sediments were weighted and analyzed. Average erosion rates ranged from negligible (mainly in grassed rows) to 1.1 t ha−1 per event (after weeding). The most erosive event occurred in July 2015, with a total rainfall of 32.2 mm, of which 20.1 were recorded in 1 h. Despite the limited number of erosive events observed, and the low measured erosion rates, permanent grassing reduced soil erosion considerably with respect to weeding; buffering had a comparable effect to grassing. The tractor passage, independent of the soil management approaches adopted, visibly accelerated the erosion process. The collected sediments were highly enriched in organic C, total N, and fine size fractions, indicating a potential loss of fertility over time. Despite the measured erosion rates being low over the experiment’s duration, more severe events are well documented in the recent past, and the number of intense storms is likely to increase due to climate change. Thus, the potential effects of erosion in the medium and long term need to be limited to a minimum rate of soil loss. Our experiment helped to compare soil losses by erosion under different soil management practices, including permanent grassing, i.e., a nature-based erosion mitigation measure. The results of the research can provide useful indications for planners and practitioners in similar regions, for sustainable, cross-sectoral soil management, and the enhancement of soil ecosystem services.


2011 ◽  
Vol 347-353 ◽  
pp. 2302-2307 ◽  
Author(s):  
Hong Xiang Wang ◽  
Yi Shi ◽  
Jian Ma ◽  
Cai Yan Lu ◽  
Xin Chen

A field experiment was conducted to study the characteristics of non-point source nitrogen (N) in the surface runoff from sloping croplands and the influences of rainfall and cropland slope gradient. The results showed that dissolved total N (DTN) was the major form of N in the runoff, and the proportion occupied by dissolved inorganic nitrogen (DIN) ranged from 45% to 85%. The level of NH4+-N was generally higher than the level of NO3--N, and averaged at 2.50 mg·L-1and 1.07 mg·L-1respectively. DIN was positively correlated with DTN (R2=0.962). Dissolved organic N (DON) presented a moderate seasonal change and averaged at 1.40 mg·L-1. Rainfall amount and rainfall intensity significantly affected the components of DTN in the runoff. With the increase of rainfall amount and rainfall intensity, the concentrations of DTN, NH4+-N and NO3--N presented a decreased trend, while the concentration of DON showed an increased trend. N loss went up with an increase in the gradient of sloping cropland, and was less when the duration was longer from the time of N fertilization.fertilization.


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