Nitrate leaching affected by management options with respect to urine-affected areas and groundwater levels for grazed grassland

1997 ◽  
Vol 66 (3) ◽  
pp. 197-210 ◽  
Author(s):  
M.J.D.Hack-ten Broeke ◽  
A.H.J. van der Putten
Keyword(s):  
Nitrate Leaching ◽  
Management Options ◽  
Groundwater Levels ◽  
Grazed Grassland

Management options to limit nitrate leaching from grassland

1995 ◽  
Vol 20 (3-4) ◽  
pp. 299-312 ◽  
Author(s):  
S.P. Cuttle ◽  
D. Scholefield
Keyword(s):  
Nitrate Leaching ◽  
Management Options

scholarly journals A Comprehensive Modelling Approach to Assess Water Use Efficiencies of Different Irrigation Management Options in Rice Irrigation Districts of Northern Italy

Water ◽  
2019 ◽  
Vol 11 (9) ◽  
pp. 1833 ◽  
Author(s):  
Alice Mayer ◽  
Michele Rienzner ◽  
Sandra Cesari de Maria ◽  
Marco Romani ◽  
Alberto Lasagna ◽  
...  
Keyword(s):  
Irrigation Management ◽  
Northern Italy ◽  
Irrigation District ◽  
Total Production ◽  
Management Options ◽  
Channel Network ◽  
Groundwater Levels ◽  
Rice Irrigation ◽  
Winter Flooding ◽  
Irrigation Drainage

European rice production is concentrated in limited areas of a small number of countries. Italy is the largest European producer with over half of the total production grown on an area of 220,000 hectares, predominantly located in northern Italy. The traditional irrigation management (wet seeding and continuous flooding until few weeks before harvest—WFL) requires copious volumes of water. In order to propose effective ‘water-saving’ irrigation alternatives, there is the need to collect site-specific observational data and, at the same time, to develop agro-hydrological models to upscale field/farm experimental data to a spatial scale of interest to support water management decisions and policies. The semi-distributed modelling system developed in this work, composed of three sub-models (agricultural area, groundwater zone, and channel network), allows us to describe water fluxes dynamics in rice areas at the irrigation district scale. Once calibrated for a 1000 ha district located in northern Italy using meteorological, hydrological and land-use data of a recent four-year period (2013–2016), the model was used to provide indications on the effects of different irrigation management options on district irrigation requirements, groundwater levels and irrigation/drainage network efficiency. Four scenarios considering a complete conversion of rice irrigation management over the district were implemented: WFL; DFL—dry seeding and delayed flooding; WDA—alternate wetting and drying; WFL-W—WFL followed by post-harvest winter flooding from 15 November to 15 January. Average results for the period 2013–2016 showed that DFL and WDA would lead to a reduction in summer irrigation needs compared to WFL, but also to a postponement of the peak irrigation month to June, already characterized by a strong water demand from other crops. Finally, summer irrigation consumption for WFL-W would correspond to WFL, suggesting that the considered winter flooding period ended too early to influence summer crop water needs.

Groundwater flow modelling to assist dryland salinity management of a coastal plain of southern Australia

Soil Research ◽  
1997 ◽  
Vol 35 (4) ◽  
pp. 669 ◽  
Author(s):  
Paul Pavelic ◽  
Kumar A. Narayan ◽  
Peter J. Dillon
Keyword(s):  
Groundwater Flow ◽  
Groundwater Recharge ◽  
Coastal Plain ◽  
Small Scale ◽  
Management Options ◽  
Aquifer System ◽  
Groundwater Levels ◽  
Flow Modelling ◽  
Groundwater Flow Modelling ◽  
The Impact

Groundwater flow modelling has been undertaken for an area of 10 500 ha within the regional unconfined aquifer system of a coastal plain of southern Australia, in the vicinity of the town of Cooke Plains, to predict the impact of various land management options (including recharge reduction and discharge enhancement) on the extent of land salinisation caused by shallow saline watertables. The model was calibrated against field data collected over 6 years. Sensitivity analysis was performed to assess the influence of mesh size, boundary conditions, and aquifer parameters, and particularly rates of recharge and evaporative discharge, on groundwater levels. These were varied until the model was shown to be capable of simulating seasonal trends and regional and local flow patterns. The model was then used to predict the impact of the management options on groundwater levels. The results showed that continuing current annual crop–pasture rotations will result in watertable rises of approximately 0·2 m in 20 years (significant in this setting), with a further 50 ha of land salinised. A reduction in the rates of groundwater recharge through the establishment of high water-use perennial pastures (e.g. lucerne) showed the most promise for controlling groundwater levels. For example, a reduction in recharge by 90% would result in watertable declines of 0·6–1·0 m within 5–10 years, with the return to productivity of 180 ha of saline land. Small-scale (say <100 ha) efforts to reduce recharge were found to have no significant impact on groundwater levels. Enhanced groundwater discharge such as pumping from a windmill was found to be non-viable due to the relatively high aquifer transmissivity and specific yield. The modelling approach has enabled a relatively small area within a regional aquifer system to be modelled for a finite time (20 years) and has shown that extension of the boundaries of the model would not have altered the predicted outcomes. Furthermore, the analysis of sensitivity to cell size in an undulating landscape where net recharge areas can become net discharge areas with only small increases in groundwater level is novel, and has helped to build confidence in the model. Modelling has demonstrated that dryland salinisation can be controlled by reducing groundwater recharge over substantial tracts of land, and is not dependent on recharge reduction over an extensive area upgradient, at least over the next 20 years.

The relation between fertilizer nitrogen applications and nitrate leaching from grazed grassland

1992 ◽  
Vol 8 (2) ◽  
pp. 51-55 ◽  
Author(s):  
D. Barraclough ◽  
S. C. Jarvis ◽  
G. P. Davies ◽  
J. Williams
Keyword(s):  
Nitrate Leaching ◽  
Fertilizer Nitrogen ◽  
Grazed Grassland

scholarly journals Application of the nutrient budgeting model OVERSEER™ to assess management options and Regional Council consent requirements on a Hawke's Bay dairy farm

1999 ◽  
pp. 227-231
Author(s):  
S.F. Ledgard ◽  
G.A. Edgecombe ◽  
A.H.C. Roberts
Keyword(s):  
Nitrate Leaching ◽  
N2 Fixation ◽  
Management Practices ◽  
Dairy Farm ◽  
Main Role ◽  
Fruit And Vegetable ◽  
Management Options ◽  
Total N ◽  
Regional Council ◽  
N Removal

OVERSEER™ is a nutrient budgeting model which estimates the inputs, outputs and balances of N, P, K and S for different farming systems. Its main role is as an index of the sustainability of farm systems and to provide information on the potential environmental impacts through estimates of nutrient leaching. OVERSEER was used to assess the N flows and balances associated with different management practices on the farm of Hawke's Bay Dairies Ltd. The 210 ha farm includes a feed-pad for feeding cows with fruit and vegetable processing wastes and pasture which is cut and carried from a 41 ha effluent area (the latter is a requirement of the Regional Council consent). Outputs from OVERSEER for the effluent area revealed that N removal in cut pasture was 1.4 × total N inputs in effluent and clover N2 fixation and the total N balance was -117 kg N/ha/year. This could lead to significant pasture deterioration and would be unsustainable in its current state. Current N inputs for the whole farm system were estimated at 80, 147 and 87 kg N/ha/year in fertiliser, brought-in feed and clover N2 fixation. Outputs of N in milk and nitrate leaching were estimated at 154 and 66 kg N/ha/year, respectively. Hawke's Bay Dairies propose changes in management to exclude the cut-and-carry operation. The effects of these changes on N flows and balances are presented and compared with those from the long-term farmlet trial at the Dairying Research Corporation Number 2 Dairy farm. In the Hawke's Bay Dairies farm, high milk production (2200 kg milksolids/ ha) is being achieved through utilisation of locallyavailable fruit and vegetable wastes which are high in energy and low in protein. This results in very efficient conversion of total N inputs into milk (49%) and lower leaching losses than those measured in farmlet systems based on high (400 kg N/ ha/year) inputs of N fertiliser. Keywords: dairy farm, feed-pad, nitrate leaching, nitrogen model, OVERSEER™

scholarly journals Reducing nitrate leaching losses from a Taupo pumice soil using a nitrification inhibitor eco-n

2007 ◽  
pp. 131-135 ◽  
Author(s):  
K.C. Cameron ◽  
H.J. Di ◽  
J.L. Moir ◽  
A.H.C. Roberts
Keyword(s):  
Water Quality ◽  
Nitrate Leaching ◽  
Nitrification Inhibitor ◽  
N Leaching ◽  
N Transfer ◽  
Management Options ◽  
N Losses ◽  
Leaching Losses ◽  
Significant Contributor ◽  
Annual Loss

The decline in water quality in Lake Taupo has been attributed to nitrogen (N) leaching from surrounding land areas. Pastoral agriculture has been identified as a significant contributor to this N transfer to the lake through animal urine deposition. There is therefore an immediate need for new management options to reduce N losses. The objective of this study was to measure the effectiveness of using a nitrification inhibitor (eco-n) to reduce nitrate leaching losses from a pasture soil of the Taupo region. A 3-year study was conducted using 20 lysimeters on Landcorp's 'Waihora' sheep and beef farm, within 10 km of Lake Taupo. The results show that animal urine patches were the main source of nitrate leaching (>95% of the total annual loss) and that eco-n significantly (P

Wetter, but not wet enough – limited greenhouse gas mitigation effects of submerged drains and blocked ditches in an intensively used grassland on fen peat

2021 ◽  
Author(s):  
Sebastian Heller ◽  
Peter Gatersleben ◽  
Sebastian Oehmke ◽  
Ullrich Dettmann ◽  
Melanie Bräuer ◽  
...  
Keyword(s):  
Water Management ◽  
Ghg Emissions ◽  
Water Levels ◽  
Greenhouse Gas Mitigation ◽  
First Year ◽  
Management Options ◽  
Groundwater Levels ◽  
The North ◽  
Fodder Quality ◽  
Additional Release

&lt;p&gt;The vast majority of peatlands in the North German Plain are cultivated as grassland. Intensive drainage measures are a prerequisite for conventional agricultural use of peatlands, but this practice causes high emissions of greenhouse gases (GHG), mainly carbon dioxide (CO&lt;sub&gt;2&lt;/sub&gt;). Thus, raising the water levels is necessary to reduce or stop CO&lt;sub&gt;2&lt;/sub&gt; emissions. Water management options such as submerged drains (SD) and ditch blocking (DB) are discussed as a potential compromise between maintaining the trafficability for intensive grassland use and reducing the GHG emissions. Furthermore, grassland renewal is regularly practiced to improve the fodder quality for dairy farming; however, this might cause additional release of GHGs, especially nitrous oxide (N&lt;sub&gt;2&lt;/sub&gt;O). Here, we present results of a four-year study on the GHG emissions from an intensively used grassland on fen peat equipped with SD and DB. Additionally, the effect of grassland renewal by shallow ploughing and direct sowing was evaluated.&lt;/p&gt;&lt;p&gt;The target groundwater levels were set to -0.30 m below ground. In the first year, the water management system was optimized. In the following years, mean annual water levels at the parcels with SD were -0.23 m and at the parcels with DB -0.37 m. The groundwater level at the SD parcels was around 0.18 m higher than at the conventionally drained control parcels. Thus, water management by SD enabled us to even surpass the target water levels. However, year two and three of the study were dryer than usual, the differences between the SD parcels and the control parcels are expected to be lower in wet years. DB, in contrast, raised the water levels only marginally.&lt;/p&gt;&lt;p&gt;During the first three years, control parcels with ditch drainage emitted 27-49 t CO&lt;sub&gt;2&lt;/sub&gt;-eq. ha&lt;sup&gt;-1&lt;/sup&gt; a&lt;sup&gt;-1&lt;/sup&gt;. This is within the typical range of emissions from grasslands on fen peat in Germany. On average, the parcels with SD showed slightly lower emissions than the drained control parcels, but these were highly variable (16-60 t CO&lt;sub&gt;2&lt;/sub&gt;-eq. ha&lt;sup&gt;-1&lt;/sup&gt; a&lt;sup&gt;-1&lt;/sup&gt;). Due to similar groundwater levels the emissions from the parcel with DB (23-43 t CO&lt;sub&gt;2&lt;/sub&gt;-eq. ha&lt;sup&gt;-1&lt;/sup&gt; a&lt;sup&gt;-1&lt;/sup&gt;) were comparable to the drained control parcels. Reasons for the high CO&lt;sub&gt;2&lt;/sub&gt; emissions despite increased groundwater levels by SD remain so far unclear. Both types of grassland renewal lead to higher N&lt;sub&gt;2&lt;/sub&gt;O emissions during the first year after renewal. Afterwards, effects became ambiguous.&amp;#160;&amp;#160;&lt;/p&gt;&lt;p&gt;Results from the fourth measurement year (2020) will be presented as well. So far, the data seems to support the results of the previous years.&lt;/p&gt;

Nitrogen supply to no-tillage crops, as influenced by mulch type, soil type and season, following pasture leys in the semi-arid tropics

1996 ◽  
Vol 36 (8) ◽  
pp. 937 ◽  
Author(s):  
JP Dimes ◽  
RL McCown ◽  
PG Saffigna
Keyword(s):  
Nitrate Leaching ◽  
Soil Texture ◽  
C:N Ratio ◽  
Field Studies ◽  
Experimental Results ◽  
Research Approach ◽  
No Tillage ◽  
Management Options ◽  
Bare Fallow ◽  
Semi Arid

Past cropping research in the semi-arid tropics of northern Australia has shown that in this climate and on the predominantly sesquioxidic soils, recovery of fertiliser nitrogen (N) by crops is often low. Conceptually, no-tillage, legume ley farming offers features for coping better with the constraints of climate, soil and high fertiliser transport costs to this remote region. This paper summarises the N cycle in a system in which pastures provide N for successive crops, and mulch at the time of crop establishment is provided by the killing of new pasture growth. The aim was further to provide a sound foundation for managing N supply in relation to demand in a climate that causes high variation and uncertainty for pasture N2 fixation and sequestering, the amount of early season re-growth (mulch), rate of mulch decomposition, nitrate leaching losses, and crop growth and N demand. The research approach combined field studies with simulation modelling. A series of field studies that included bare fallow and grass and legume pasture leys on clay loam and sandy loam soils, were conducted at Katherine over 4 wet seasons to study subsequent mineralisation of N. Experimental results were used to test the performance of a simulation model for predicting the observed variations consequent upon the various management options. Experimental results showed that the carbon (C) : N ratio of the residue and soil texture were important factors in determining N mineralisation, immobifisation, and nitrate leaching following chemical kill of pasture leys. However, the greatest variation was between seasons. A modified version of the CERES-Maize N model was able to simulate the accumulation of nitrate following a bare fallow and following pasture leys with high levels (above and below ground) of freshly killed residues with widely differing C:N ratio, the downward movement of nitrate-N in the soil and the interaction of these processes with seasonal rainfall. Despite a capability for simulation of the soil N dynamics in a cropping phase following pasture leys, ex~erimental results indicated how nitrate distribution following leys is influenced by pasture growth during the ley, and how this varied greatly with season and soil texture. The simulation capability reported here has been incorporated elsewhere into the development of a full system model, embracing both the ley phase and the crop phase.

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