ministry of agriculture, fisheries and...
TRANSCRIPT
MINISTRY OF AGRICULTURE, FISHERIES AND FOOD Date project completed:
Research and Development 30/06/1999
Final Project Report(Not to be used for LINK projects)
Section 1 : Identification sheet
1. (a) MAFF Project Code NT1423(b) Project Title “Good MANNERs” (MANure Nitrogen Evaluation Routines);
development of an improved manure nitrogen decision support system.
(c) MAFF Project Officer Dr P A Costigan
(d) Name and addressof contractor
ADAS Consulting Ltd,Woodthorne,Wergs Road,Wolverhampton Postcode WV6 8TQ
(e) Contractor’s Project Officer
(f) Project start date 01/10/1998 Project end date 30/06/1999
(g) Final year costs: approved expenditure
actual expenditure
(h) Total project costs / total staff input: approved project expenditure
actual project expenditure
*approved staff input
*actual staff input
(i) Date report sent to MAFF
(j) Is there any Intellectual Property arising from this project ?
*staff years of direct science effort
Section 2 : Scientific objectives / Milestones
CSG 13 (1/97) 1
2. Please list the scientific objectives as set out in CSG 7 (ROAME B). If necessary these can be expressed in an abbreviated form. Indicate where amendments have been agreed with the MAFF Project Officer, giving the date of amendment. Key scientific objectives in the development of an improved, user-friendly version of the manure nitrogen decision support system, MANNER:
DESSAC enabled Active-X control version. Validation testing of new version against existing MANNER version 2.1. Development of a simple, GIS (map) front end and integral drainage model for England & Wales. Capability to include operation with two or more manures per field. Improved graphics and display to promote user-friendliness. File saving option (to allow saving and retrieval of current run). Simple operation or programming to allow multiple, concurrent, runs (to allow wide ranging scenario testing). Option to allow direct keyed input of reported manure analytical results
3. List the primary milestones for the final year.It is the responsibility of the contractor to check fully that ALL primary milestones have
been met and to provide a detailed explanation if this has not proved possibleMilestones Target
dateMilestones met?
Number Title in full on time
If any milestones have not been met in the final year,an explanation should be included in Section 5.
Section 3 : Declaration
4. I declare that the information I have given in this report is correct to the best of my knowledge and belief. I understand that the information contained in this form may be held on a computer system.
Signature Date
Name
Position in Organistation
Section 4 : Executive summary
CSG 13 (1/97) 2
Improved utilisation of manure nitrogen (N) is essential if nitrate and ammonia emissions from agriculture are to be reduced; and making better use of the N content of farm manures could result in major cost savings for agriculture as well as reduced environmental pollution. However, uncertainty about N availability from manure applications makes it difficult for farmers to rely on manure N when planning their inorganic fertiliser applications. The overall objective of the project was the development of an improved, user-friendly version of the manure nitrogen decision support system, MANNER, accessible to easy updating and capable of interfacing with other software, in particular DESSAC.
Early industry experience in the practical application of MANNER Version 2.1, through both consultants and farmers directly, has been very encouraging. The model, however, in its previous programming language, lacked flexibility and a new version was needed that would enable DESSAC compliance and convenient interfacing with other software packages, e.g. an ACCESS database or installation in a web page. New developments of MANNER, completed within this project, include the following:
MANNER ActiveX Control, which now controls all data inputs, input validation, reporting of results and allows rapid interfacing with other software packages. A notable improvement over Version 2.1, is the way in which the user interacts with the MANNER ActiveX control; whilst changes to any of the input parameters are made in the same way, the results displayed at the bottom of the control interface remain visible at all times. The results are recalculated immediately and refreshed at the bottom of the form (allowing much quicker and easier operation), whereas in Version 2.1, users had to manually recompile the results in order to inspect the impact of any changes made to the inputs. A major advantage of the ActiveX control is the freedom it allows other programmers who may wish to develop software applications that include the MANNER model. The MANNER ActiveX control is fully compatible with the requirements of the DESSAC developers ‘toolbox’.
Validation of MANNER ActiveX Control. The same validation data as used for MANNER Version 2.1 (for a wide range of different manure application scenarios) were tested against the ActiveX version of the MANNER model and the results confirmed to be the same as in Version 2.1.
MANNER Consultancy Shell integrates the MANNER ActiveX control with a national database of long term mean climate variables (including monthly rainfall and temperatures), a simple soil drainage model (Mean Climate Drainage Model), and a telephone standard area code directory, to provide a system which allows the user to set up MANNER with weather data specific to a chosen location within England and Wales. This is a valuable extension to the MANNER Program and provides an improved system for the utilisation and management of manures. It is proposed that this will form the basis for MANNER Version 3.0 and will be available from September 1999. A number of data licensing issues (for the climate data included with the shell) remain unresolved, however an agreement with the UK Meteorological Office is under negotiation.
During the year, the opportunity has been taken to demonstrate MANNER Version 2.1 and latterly, the MANNER Consultancy Shell, to groups of farmers and consultants, at a number of meetings and at key national events. Response has almost always been positive and encouraging and numbers of enquiries/orders for MANNER Version 3.0, in advance of a projected September 1999 launch, have already been received.
CSG 13 (1/97) 3
Section 5 : Scientific report
5.1 Introduction
A decision support system (DSS) to predict the fate of nitrogen (N) following organic manure applications to land was developed by Chambers et. al., 1999, drawing together the latest UK research information on factors affecting manure availability. The ADAS MANure Nitrogen Evaluation Routine(MANNER) takes account of manure N analysis, ammonia volatilisation, nitrate leaching and mineralisation of organic N. Only a few simple inputs are required and the output provides predictions of N volatilised or leached, and fertiliser N value for the next crop grown. Studies in the UK have suggested that farmers will use organic manure models only where the required input information is easily available (Smith et al. 1997). Therefore MANNER was designed to be easy to use and to require only readily available input data. During validation of the MANNER output against a wide range of independently collected experimental data, using cattle, pig and poultry manures applied to arable crops, good agreement was found (r2=60-79%, p<0.001), confirming the potential for MANNER to provide reliable estimates of manure N value following application to arable land under a range of conditions (Chambers et. al., 1999). Further validation, using grassland data, is underway.
5.2 MANNER - Version 2.1
The initial MANNER DSS (Version 2.1, 1997) was developed by ADAS (in conjunction with software developers Salford Software) using the FORTRAN programming language. Industry experience in the practical application of this advisory tool by researchers, consultants, and individual farmer / growers, have been very encouraging. However Version 2.1 lacks flexibility, both in terms of extending the computer code to integrate future improvements and development of the scientific model, and building in modifications to the DSS interface.
Salford Software’s CLEARWIN development kit was used to construct the software interface. With the many changes currently driving the software development industry, products such as CLEARWIN are rapidly becoming obsolete. Whilst Version 2.1 of the MANNER DSS satisfactorily provides a tool which quickly estimates the manure N availability and losses for a range of agricultural practices, the DSS does not conform to the protocols that are now firmly established for software development under the Microsoft WindowsTM
operating environment. Problems that were identified with Version 2.1 include:
whist relatively easy to use, Version 2.1 does not conform to the commonly accepted standards employed by software packages under the WindowsTM operating environment.
an inability to integrate either the MANNER model code, or the interface, with other software packages, computer programs and decision support systems.
in order to determine the effect of an individual change to the model inputs, a report has to be generated. This makes it difficult for a user to rapidly assess the sensitivity of model parameters under different conditions.
Version 2.1 does not permit the rapid exploration of differing manure application scenarios, a pre-requisite for full exploitation of the MANNER model by researchers.
5.3 Development of the MANNER ActiveX Control
5.3.1 Background to ActiveX Controls
It is widely accepted that object-oriented computer programming languages have a marked effect on the ability of software developers to write re-usable, maintainable code. However, an object-oriented language is not sufficient for widespread re-use. Microsoft’s Object Linking and Embedding (OLE) / Component Objects Model (COM) protocols provide developers with the opportunity to develop components that may be used by
CSG 13 (1/97) 4
other developers in producing their own software applications. Software components developed to the Microsoft COM specification may be used in many different development environments (e.g. Visual BasicTM, C++TM , DelphiTM, and JavaTM), thus allowing programmers to choose the language most appropriate for their immediate task.
ActiveX controls are a type of software component that may be re-used by different application programs in the same computer or in a distributed network. ActiveX controls may be downloaded as small programs or animations for Web pages, but they can also be used for any commonly needed task by an application program under the WindowsTM operating environment. Such a re-usable component approach to application development reduces development time and improves program capability and quality.
The MANNER model along with the inputs required and outputs generated are relatively simple and straightforward. In addition the wide ranging applicability of the MANNER model makes it’s inclusion in other related software applications and DSS highly desirable. The development of MANNER as an ActiveX control was therefore proposed as the logical progression in developing MANNER Version 3.0. As DESSAC (Decision Support System for Arable Crops) conforms to the COM standards discussed above, a further benefit of developing MANNER as an ActiveX control would make it available for all developers working on the DESSAC programme.
5.3.2 Developing the MANNER ActiveX Control
The MANNER ActiveX control has been developed by ADAS using Microsoft’s Visual Basic 6TM
development environment. The inclusion of Microsoft’s (and other vendors) controls and components have been kept to a minimum, such that the resultant ActiveX control compiles to a total size of 2.2 Mb including all the necessary support files.
The first stage in developing the MANNER model as an ActiveX control was the analysis of functionality that must be provided by the software component. The key requirements are summarised below:
must be very simple and straightforward to use should install on a basic computer (i.e. not require advanced hardware or software) in as far as possible the MANNER interface should appear similar to Version 2.1, allowing existing
users to upgrade without the need to re-familiarise themselves with the software MANNER must support the use of both metric and imperial systems for entering application rates,
and reporting of results the ability to save and load scenario files is essential the ActiveX control must make available a wide range of relevant properties and methods by which
other programmers may develop software that will interact with MANNER the MANNER ActiveX control must be extensible such that future developments of the MANNER
model may be incorporated without the need for substantial rewrite of the software.
The ActiveX control that has been developed for MANNER provides the common interface that is required in the general operation of the MANNER model. Thus all data inputs, input validation, and reporting of results are controlled by the ActiveX control.
The control may be employed in many different ways, e.g. as a consultants tool usually analysing individual manure applications, as a researchers tool examining many different manure application scenarios, and on the Internet. In each of these different applications of the ActiveX control, further programming is required in order to provide an interface to the model that offers relevant extended functionality to the MANNER model. These application examples are discussed in further detail in later sections.
CSG 13 (1/97) 5
It was decided that the MANNER ActiveX control should provide an interface structure that is similar to Version 2.1 currently being used. Figure 1 shows the use of three tabs on the input form to separate the input requirements into logical categories.
(a) Manure specific parameters
(b) Field conditions
(c) Manure incorporation details
Figure 1. The MANNER ActiveX control interface. Three different input tabs are usedto categorise the input of (a) manure, (b) field, and (c) incorporation specific parameters.
CSG 13 (1/97) 6
Note that in Figure 1, whilst the input tabs change to reflect specific parameter sets (a - manure, b - field, and c - incorporation), the results section at the bottom of the form remains visible at all times. As a user interacts with the MANNER ActiveX control, and changes any of the input parameters, the results are recalculated immediately and refreshed at the bottom of the form. This is a noticeable improvement on Version 2.1 where users had to manually recompile the results in order to inspect the impact of any changes made to the inputs.
In addition to the drop down selection boxes used to select one of the seventeen manure types, and fourteen soil types available as MANNER inputs, the MANNER ActiveX control uses other controls such as sliders (to select application rates, dry matter content, total nitrogen, and ammonia / uric acid nitrogen contents), and a calendar control (Figure 2) to aid the user to select dates that are both legal, (e.g. 29 th February only in leap years) and appropriate to MANNER (e.g. end of soil drainage may not occur after 31st July).
Figure 2. The addition of a calendar control aids the user’s selection of manure application date and the date when end of soil drainage occurs.
The MANNER ActiveX control validates all user input as it is made. For example the text boxes for direct keying of application rates, dry matter content, total nitrogen content, ammonia / uric acid nitrogen content and total rain, will only accept numeric characters as input. Each of the manure types have different minimum and maximum limits for application rates, dry matter content, total nitrogen content, and ammonia / uric acid nitrogen content, and the ranges of the sliders provided for user input are updated to reflect these limits. MANNER provides the user with helpful message boxes (Figure 3) to indicate inputs that are in error. If it is not appropriate for such message boxes to be displayed then this is a feature that may be ‘turned off’ by a programmer who has included the MANNER ActiveX control in their application.
An important feature of the MANNER ActiveX control is for the user to input and receive results in both metric and imperial units. The application rate for solid manures may be input as tonnes/ha or tons/acre, and for slurries the inputs may be made as m3/ha or gallons/acre. Results are displayed as kg/ha or units/acre depending on whether the user is working in metric or imperial units mode. Figure 4 shows the use of a pop-up menu (accessed by clicking the right mouse button over the MANNER ActiveX control) to select the appropriate units in which to work.
The pop-up menu (Figure 4) may also be used to save and load manner scenario files. This feature allows the user to save the current MANNER inputs as either a formatted text file (with *.txt file extension, an example content of a *.txt file is included in appendix B), or a binary encrypted manner scenario file (with *.man file extension). A MANNER scenario file with *.man file extension may be loaded back into the MANNER ActiveX control. By doing this, all the input boxes and results section are updated to reflect the status of the MANNER ActiveX control when the file was created. A version number has been attributed to every MANNER scenario file that is created so that the ActiveX control into which the file is being loaded can determine which version was used to save the file, and handle the file contents accordingly. A benefit in doing
CSG 13 (1/97) 7
this is that future developments to the MANNER model and ActiveX control will be backwards compatible. This feature will be of particular value to farmers and consultants, allowing them to run MANNER first predictively in a “planning” mode and then, retrospectively using actual weather data, for fine-tuning purposes just before time for spring top-dressing.
Figure 3. Helpful error messages inform the user when incorrect inputs have been made. In this case an input of 54 kg / t of nitrogen is outside the legal range of
0.1 to 12 kg / t expected for Cattle FYM - fresh.
Figure 4. Clicking on the right mouse button whilst over the MANNER ActiveX control allowsthe user to change the units between metric and imperial, and
to save and load MANNER scenario files.
The MANNER ActiveX control fully supports the ‘dragging and dropping’ of the MANNER results into compatible software packages. If the user ‘clicks’ and ‘drags’ the mouse on the results section of the MANNER ActiveX control, the inputs and results from the MANNER model may be ‘dragged’ into standard Microsoft Office products such as Word and Excel. Figure 5 shows the effects of this operation in both Microsoft Word and Excel. Note that in both packages, the inputs and results are pre-formatted by the drag and drop operation.
CSG 13 (1/97) 8
Figure 5. Outputs from Microsoft Word and Microsoft Excel following a ‘drag and drop’operation from the MANNER ActiveX control.
The features of the MANNER ActiveX control discussed so far are all accessible via the visual interface that is only part of the control’s full capability. The major advantage of re-programming the MANNER model as an ActiveX control was the freedom it gives to other programmers who wish to develop software applications that include the MANNER model. In support of this capability the MANNER ActiveX control supports a wide range of public properties, methods, and events that give programmers the ability to write computer program code that allows interaction with the both the ActiveX control’s visual interface and the MANNER model.
The full list of public properties, methods, and events available to programmers using the MANNER ActiveX control are detailed in Appendix A. These properties, methods, and events give the programmer the ability to set and / or return the current state of any parameter that is used as input to the MANNER model. In addition a programmer may return the current results being displayed by the MANNER model. Events triggered by the ActiveX control notify the programmer when any change has been made to the control’s interface by direct user interaction.
CSG 13 (1/97) 9
A key property of the MANNER ActiveX control is the ability to set its presence to be ‘invisible’ within another software application. In this way, a computer programme may use the MANNER model engine without having any of the MANNER interface visible to a user. When the ActiveX control is being used in this way, the control still features all of the input validation and error handling in the same ways as previously discussed.
5.3.3 Validating the MANNER ActiveX control
The MANNER model code used in the ActiveX control is an exact replica of that code written for Version 2.1 of MANNER currently on general release. The model code was ported from its current format in FORTRAN to Microsoft Visual BasicTM and compiled as an integral part of the MANNER ActiveX control. In order to validate the model results and ensure that these were satisfactory, the same validation data as for MANNER Version 2.1 were used. A full list of the validation data, the results computed by the MANNER model for a wide range of different manure application scenarios, and the field experimentation results, are available should these be required. All validation data were tested against the ActiveX version of the MANNER model and the results were confirmed to be the same as in Version 2.1.
5.4 Implementations of the MANNER ActiveX control
In order to demonstrate the usefulness of programming the MANNER model as an ActiveX control, the control has been applied in a number of different ways. These are discussed below in more detail.
5.4.1 DESSAC
DESSAC (Decision Support System for Arable Crops) is being developed by IACR-Rothamsted with MAFF, HGCA, and BBSRC funding. It is an integrated suite of decision support systems to assist arable farmers and advisors with a whole range of crop husbandry decisions.
DESSAC is designed to run under Windows 95TM, and is being built using Microsoft Visual C++TM. The core of the system is an OLE container / server, as are the individual modules, allowing extensive communication between the different components. The system is being fully built using component architecture principles. This has involved the creation of a software ‘toolkit’ which is available to developers of DESSAC modules. The kit comprises common user interface components, decision modelling and data handling routines which developers can use quickly to construct new modules. The MANNER ActiveX control is fully compatible with the requirements to be a part of the DESSAC developers toolbox.
5.4.2 MANNER Lite
MANNER Lite is a software application that largely replicates, and offers the user the same functionality, as Version 2.1 of the MANNER program. The software makes full use of the MANNER ActiveX control, and simply adds menu driven shortcuts to some of the MANNER ActiveX control’s advanced functions (e.g. saving and loading scenarios files, and changing the units). Figure 6 gives a snapshot of the interface.
In addition to the MANNER ActiveX control the MANNER help system has been re-written to conform to those standards expected by users in the WindowsTM operating environment. Figure 7 shows an example snapshot of the MANNER help system. This help system will be included with software applications such as MANNER Lite, giving users advice on how to use the software, and background to the science and calculations involved in the MANNER model.
CSG 13 (1/97) 10
Figure 6. Snapshot of the MANNER Lite interface.Note the menu options that give user-friendly access to some of the
MANNER ActiveX control’s more advanced functions.
Figure 7. The help system that will be distributed with all copies of the MANNER ActiveX control.
5.4.3 MANNER Consultancy Shell
The MANNER Consultancy Shell was developed to demonstrate how the MANNER ActiveX control and MANNER model can be integrated with other environment data and models to provide an improved system for the management of manures. In addition to all the features offered by the MANNER Lite application, the MANNER Consultancy Shell integrates the MANNER ActiveX control with a national database of long term mean climate variables (including monthly rainfall and temperatures), a simple soil drainage model (Mean Climate Drainage Model), and a telephone standard area code directory, to provide a system which allows the
CSG 13 (1/97) 11
user to set up the MANNER ActiveX control with weather data specific to a chosen location within England and Wales.
By default, the MANNER ActiveX control calculates manure nitrogen losses by leaching using climate data for a site in middle England. Monthly rainfall (and the degree of seasonality) varies significantly across England and Wales, in the range 50 - 200 mm. As a result, calculations of nitrate leaching losses and hence plant available nitrogen made using the climate data for the default middle England location may significantly over or under-estimate losses at different locations. When used on-site, the consultant has the opportunity to update the default rainfall values using data provided by the farmer. However, there may be occasions when the farm owner does not have access to local rainfall data. Also, it was envisaged that the model might be used for a strategic review of the impact of, for example, changes in the timing of manure applications, on nitrate leaching throughout England and Wales; for which purpose, access to rainfall data for all possible sites within England and Wales, would be required. Therefore, it was decided that a valuable extension of the existing MANNER ActiveX control would be to integrate it with a climate database.
To achieve this, public methods were added to the MANNER ActiveX control that allow the updating of the monthly climate data ( rainfall and actual evapotranspiration ). The MANNER ActiveX control was then built into a new computer program, the MANNER Consultancy Shell, that allows users to interactively select a site of interest by clicking with the mouse on a map display, and calculates monthly rainfall and actual evapotranspiration rates for the site. The calculations are done using data held at a 10 km2 spatial resolution ( sourced from the Climate Research Unit, University of East Anglia ), and a simple soil drainage model ( Mean Climate Drainage Model ) - described in more detail below. The calculated climate data are then automatically passed to the MANNER ActiveX control so that any calculations of plant available nitrogen are done with climate data specific to the selected part of England and Wales. Furthermore, to aid the consultant in identifying the true location of a client farm, a telephone directory was added to the program so that the user can enter the client’s standard area code, and the program would automatically select the appropriate part of England and Wales.
Figures 8 and 9 illustrate the interface of the shell which was developed using Microsoft’s Visual Basic 6TM
development environment, and Environmental System’s Research Institute’s (ESRI) MapObjects Light ActiveX control. Tools are provided for the user to change the map display, including changing the map scale and panning the map, to focus upon a site of interest. A site may be selected by clicking on the Select Site Tool button, and then on the map display. The location of the selected site is marked by a red circle on the map display. Alternatively, sites may be selected by finding areas with specific standard area telephone codes. Clicking on the “Find Site” tool button reveals a dialog which asks the user to enter a standard area code. For example, enter ‘01902’ for Wolverhampton telephone numbers. Area codes are representative of large areas of the country. A site will be selected a the approximate centre of the standard area code region.
When a site is selected, the integrated drainage model ( see below ) accesses the climate database for the site and calculates monthly values of rainfall, potential and actual evapotranspiration, and soil drainage for the site. These figures are displayed as a table ( Figure 9 ), which serves to graphically illustrate the seasonal and spatial variability of soil drainage across England and Wales. The calculated monthly rainfall and actual evapotranspiration figures are passed automatically to the embedded MANNER ActiveX control ( Figure 8 ) which may then be used as described in the previous sections to calculate nitrogen losses by leaching and volatilisation, and the remaining plant available nitrogen following manure applications. The shell also provides functionality for the saving and retrieval of the current state of the MANNER ActiveX control, including the site specific climate data, and for exporting the results to either a printer or a text file.
CSG 13 (1/97) 12
Figure 8. Manner Consultancy Shell interface, showing MANNER ActiveX control and map display.
Figure 9. Manner Consultancy Shell interface, showing graphical display of monthly soil drainage data calculated for the selected Wolverhampton site ( Standard Area Code ‘01902’ ).
CSG 13 (1/97) 13
5.4.4 Development of the Mean Climate Drainage Model
The Mean Climate Drainage Model ( MCDM ) was developed as an aid to the implementation of the MANNER model ( Chambers et al., 1999 ). The MANNER model requires as input a monthly time series of actual evapotranspiration following application of manures to land. The MCDM calculates the required monthly evapotranspiration figures for a representative permanent grass sward under mean climate conditions for any location within England and Wales. The MCDM also estimates the date of the end of soil drainage which is also required by the MANNER model. The MCDM results are intended to replace the fixed values of evapotranspiration and end of soil drainage (for a site in middle England) that MANNER version 2.1 currently uses by default.
Climate DataThe Climatic Research Unit ( CRU ), University of East Anglia, has constructed a 10 by 10 km gridded mean monthly 1961-90 baseline climatology for Great Britain. Monthly mean minimum and maximum temperatures, rainfall, wind speed, sunshine hours, and vapour pressure were interpolated from observations at Meteorological Office synoptic stations to the mean altitude within each 10 by 10 km grid cell by the method of partial thin plate splines ( Barrow et al., 1993 ). The numbers of synoptic stations used in the interpolation varied from 60 for wind speed, 350 for temperatures, and 2400 for rainfall.
5.4.4.1 Methodology
Potential EvapotranspirationMonthly mean potential evapotranspiration rates are calculated for each 10 by 10 km grid cell using the Penman-Monteith equation ( Monteith, 1965 ). The evapotranspiration radiation parameters used are those specified by the FAO Expert Consultation on FAO Methodologies for Crop Water Requirements ( Allen et al., 1994a; Allen et al., 1994b ).
Monthly crop leaf areas and effective heights are those used by the MORECS model ( Hough, 1996 ). The bulk surface ( canopy ) resistance is also calculated according to the MORECS model, assuming that the surface resistance of bare soil is always 100 s m-1.
Actual EvapotranspirationActual evapotranspiration is calculated according to the monthly book-keeping methodology of Thornthwaite and Mather ( 1955 ). According to Alley ( 1984 ), monthly actual evapotranspiration ETm and soil moisture deficit Sm are calculated as :
If Rm > PETm then
Sm = Min [ ( Rm - PETm ) + Sm-1 , Smax ]
Etm = PETm
Else
Sm = Sm-1 Exp [ -1 ( PETm - Rm ) Smax ]
Etm = Rm + Sm-1 - Sm
End
Where Rm is the monthly rainfall, PETm is the monthly potential evapotranspiration rate, Sm is the monthly soil mositure deficit, and Smax is the plant available soil water capacity. The model is initialised with a soil moisture deficit of zero and run a large number of times ( 1000 ), stepping through the monthly climate data, until the
CSG 13 (1/97) 14
calculated monthly evapotranspiration and drainage rates are stable. The value of Smax is dependent upon soil texture. For example, values for a Loamy Sand and Clay Loam are 95 mm and 150 mm, respectively.
End of Soil DrainageThe end of soil drainage occurs in the first month of the year for which the MCDM calculates zero soil drainage. The day of the month D on which soil drainage ends is estimated by comparison of the soil moisture deficit Sm with the preceding month’s soil drainage HERm-1 :
D = Int [ Nm HERm-1 / ( HERm-1 + Sm ) ]
Where Nm is the number of days in the month in which MCDM calculates zero soil drainage.
5.4.4.2 Validation
Validation of the MCDM is not possible in the conventional sense as there are no national datasets of observed drainage from grass swards under long-term climate conditions. Instead, the MCDM results are compared with the output of the Meteorological Office’s MORECS model for the reference permanent grass sward ( Hough et al., 1996 ).
Potential EvapotranspirationMonthly values of long-term mean ( 1961 - 90 ) potential evapotranspiration under grass ( PETG ) have been calculated using the MORECS model for 40 by 40 km grid cells. The values were calculated using weather data interpolated from a varying number of weather stations. The MCDM was also used to calculate monthly values of PETG, using the 10 by 10 km climatology provided by CRU. The MCDM and MORECS monthly values of PETG are compared in Table 1. Compared to the MORECS model, the MCDM under-estimated PETG in the winter months, and over-estimated in the summer months. Overall, the MCDM estimated a higher annual total PETG.
Soil DrainageMORECS simulations of long-term soil drainage under climate conditions are not available. However, Barrie et al. ( 1994 ) have derived regression equations that predict the long-term output of the MORECS model as a simple function of mean annual rainfall and PETG. Long-term drainage HER under grassland is predicted as :
HER = ( 0.86 AAR ) - ( 0.60 AAPETG ) - 61.9 … HIGH AWC
HER = ( 0.83 AAR ) - ( 0.50 AAPETG ) - 67.4 … LOW AWC
for soils of high ( > 150 mm ) and low ( < 100 mm ) plant available water content. Where AAR is the long-term mean annual rainfall, and AAPETG is the long-term mean annual potential evapotranspiration under grass.
These regression equations were used to calculate mean drainage for each of the 10 by 10 km grid cells, using the MCDM estimate of AAPETG and the CRU database estimate of AAR for each cell. The results were compared against the MCDM estimates of mean drainage for a Clay ( High AWC ) and Loamy Sand ( Low AWC ) soil ( Figures 10 and 11 ). It is shown by Figures 10 and 11 that the MCDM tends to calculate a greater volume of soil drainage than the MORECS mimic regression model, for both heavy and light soils. This is most pronounced for areas of low drainage where the MORECS mimic regression model predicts zero drainage, whilst the MCDM predicts at least 50 mm of drainage. On average, the MCDM predicts an extra 30 mm of soil drainage in a year.
Table 1. Comparison of MORECS and MCDM simulated long-term ( 1961 - 90 ) mean monthly potential evapotranspiration under permanent grass ( mm ).
MORECS MCDM MCDM = ( SLOPE
CSG 13 (1/97) 15
( n = 105 ) ( n = 1700 ) MORECS ) + INTERCEPT( n = 1700 )
Month Min Max Min Max SLOPE INTERCEPT
JanFebMarAprMayJunJulAugSepOctNovDec
9.012.227.945.168.470.571.460.541.325.514.08.4
20.221.639.658.491.492.598.986.262.241.527.019.6
0.05.017.841.780.290.497.473.738.816.32.60.0
5.213.036.170.4121.5133.9146.5118.971.234.810.93.7
0.190.410.741.190.921.071.151.210.890.340.080.11
0.02.02.0-5.228.024.722.24.58.014.45.60.1
Annual Total
460 620 466 766 1.02 49.0
0
100
200
300
400
500
600
0 100 200 300 400 500 600
MCDM Simulated Mean Annual Soil Drainage ( mm )
MO
RECS
MIM
IC S
imul
ated
Mea
n An
nual
Soi
l Dra
inag
e ( m
m )
1 : 1 Line
Figure 10. Comparison of MCDM and MORECS mimic regression model simulations of mean annual soil drainage under permanent grass on a Clay soil.
CSG 13 (1/97) 16
0
100
200
300
400
500
600
0 100 200 300 400 500 600
MCDM Simulated Mean Annual Soil Drainage ( mm )
MO
RECS
MIM
IC S
imul
ated
Mea
n An
nual
Soi
l Dra
inag
e ( m
m )
1 : 1 Line
Figure 11. Comparison of MCDM and MORECS mimic regression model simulations of mean annual soil drainage under permanent grass on a Sandy Loam soil.
5.4.5 Running MANNER in a monte-carlo simulation
As discussed earlier in this report, the MANNER ActiveX control may be programmed to run ‘invisibly’ within an application, the inputs to the MANNER model being controlled by a software program rather than by direct user interaction with the MANNER ActiveX control.
The ability to run the MANNER model in this way, was used in support of MAFF project WA 0711 - Optimum Strategies for reducing Emissions of Ammonia and N Leaching Under IPPC. The key objective of this project was to use the MANNER model to assess the effects on nitrate leaching of measures to reduce ammonia emissions following the spreading of manures and slurries.
The MANNER model was run for each of 6 manure / slurry types, in each of 5 locations (thus requiring the input of different rainfall and drainage assessments), on each of 5 different soil types, each run being calculated for 3 different delays in incorporation. For each simulation the date of application was incremented at fortnightly intervals from August through to April. In total therefore, over 8000 runs of the MANNER model were required each with different inputs. To perform this exercise using the current MANNER, Version 2.1 would not have been feasible due the amount of time required. However by programming the inputs to the MANNER model as a series of nested loops, running the MANNER model in invisible mode, and outputting the results directly into an Microsoft AccessTM database, the 8000 simulations were processed in less than 10 minutes. The results were then available for interpretation and reporting.
The use of the MANNER ActiveX control in this latter project has clearly demonstrated the applicability of programming scientific models such as MANNER as software components rather than as full software applications. The ability to interact with the model via public properties, methods and events is particularly valuable in support of research projects where researchers are interested in the effects of new policy options across many differing scenarios.
In the same way as using the MANNER ActiveX control in monte carlo simulations, an interface to the model may be programmed using the public properties, methods and events that will accept the direct keying of laboratory analyses of manures and / or slurries. This option would be particularly useful for farmers and consultants who often fail to correctly interpret the results of laboratory analysis reports, reducing also the risk of calculation or data entry errors during this phase of on-farm manure planning.
5.4.6 MANNER ActiveX control’s Internet compatibility
CSG 13 (1/97) 17
Microsoft’s ActiveX technology is fully supported by the majority of Internet browsers that are available for the personal computer. The MANNER ActiveX control is fully compatible with the Internet and may be included as part of an Internet page. This offers many advantages in promoting the usefulness of the MANNER model, whilst offering users the opportunity to use the interface and model as if it were on their own computer.
There are significant advantages on releasing scientific models using the Internet as a dissemination platform. Perhaps most beneficial is that there is only one copy of the model released at any one time. As the model evolves with scientific and technical developments, earlier versions may be replaced with the minimum of effort and the entire user community will receive the update at the same time.
5.5 Recommendations for further work
It is suggested that MAFF may wish to explore further the opportunity that the Internet offers as a dissemination point for the MANNER program, and Figure 12 demonstrates a simple example of deploying the MANNER ActiveX control in this way. Clearly with the development of software tools using languages and protocols suitable for use on the Internet (e.g. VB ScriptTM, Java ScriptTM) the MANNER ActiveX control could be supported by buttons and menus, and a help system, that will enhance usability and encourage wider dissemination of the MANNER model. The MANNER model, with associated help screens and scientific background, could form the basis of several Web pages that could be hosted on a number of host Internet sites (e.g. MAFF, ADAS, Rural Business Network) in order to fully promote the MANNER model and its scientific application.
Figure12. The deployment of the MANNER ActiveX control in an Internet environment.
5.6 Outputs arising from the project
5.6.1 Software
CSG 13 (1/97) 18
There are three main software outputs from this project and these are as listed:
The MANNER ActiveX control. This control (with help system) will be made available to the DESSAC development team, and incorporated as part of the DESSAC developers toolbox.
MANNER Lite with functionality similar to MANNER Version 2.1 is available as a software product from ADAS.
The MANNER Consultancy Shell has been developed as a prototype for an improved MANNER decision support system. It is proposed that this will form the basis for MANNER Version 3.0 and will be available from September 1999. A number of data licensing issues (for the climate data included with the shell) remain unresolved, however an agreement with the UK Meteorological Office is under negotiation.
5.6.2 Scientific and technical papers
Chambers B.J., Lord, E.I., Nicholson, F.A., Smith, K.A. (1999) Predicting Nitrogen Availability and Losses Following Land Applications of Manures : MANNER. Soil Use & Management (in press).
Henderson, D. and Anthony, S. (1999) Component Technologies for Support of Agricultural Consultancy and Research. A Case Study : MANNER. Proceedings from Association of Applied Biologists Conference : Information Technology for Crop Protection, 23 September 1999 (in publication).
In addition, MANNER development and application received prominent focus in the following technical articles published during the course of the current project:
Chambers, B. J. and Smith, K. A. (1998). Nitrogen: some practical solutions for the poultry industry. World’s Poultry Science Journal, 54, December 1998, pp 353-357. (Paper presented at the WPSA UK branch spring meeting, 26-27 March 1998).
Williams, J.R., Chambers, B.J., Smith, K.A. & Ellis, S. (1999) Farm manure application strategies to conserve nitrogen within farming systems. In “Agriculture and waste management for a sustainable future”. SAC/SEPA Conference: 31 March -2 April 1999.
Chambers, B.J., Smith, K.A. & Pain, B.F. (1999) Strategies to encourage better use of nitrogen in animal manures. In “Tackling Nitrate from Agriculture” Strategy from Science. Proceedings of MAFF Conference, London, June 24, 1999. MAFF Publications PB4401.
Chambers, B. J. and Smith, K. A. (1999). Utilising Organic Manures with minimum risk to Sugar Beet Quality. British Sugar Review, 67, (2), Summer 1999, pp25-28.
5.6.3 Technology Transfer
MANNER Version 2.1 and, latterly, MANNER Consultancy Shell were demonstrated at a large number of promotional events and farmer/consultancy meetings organised during the year. Many of these came within the MAFF Nutrient Demonstration Farms Project, under the banner, “Making the Most of Manures”. MANNER Consultancy Shell was featured at the following national events:
MUCK’99, Driffield, E Yorks, 28-29 April, 1999.
MAFF Nitrate Conference, “Tackling Nitrate from Agriculture” Strategy from Science. London, June 24, 1999.
CSG 13 (1/97) 19
MANNER was also featured strongly within the recently published series of booklets on “Managing Livestock Manures”, published by IGER, ADAS and SRI; in particular within Booklet 1 “Making better use of livestock manures on arable land.
6.0 References
Alley, W. M. ( 1984 ) On the treatment of evapotranspiration, soil moisture accounting, and aquifer recharge in monthly water balance models. Water Resources Research, 20, pp. 1137 - 1149.
Allen, R. G., Smith, M., Perrier, A., and Pereira, L. S. ( 1994a ) An update for the definition of reference evapotranspiration. ICID Bulletin, 43, 2, pp. 1 - 34.
Allen, R. G., Smith, M., Pereira, L. S., and Perrier, A. ( 1994b ) An update for the calculation of reference evapotranspiration. ICID Bulletin, 43, 2, pp. 35 - 92.
Barrie, I., Lord, E., and Hough, M. (1994) Derivation and Application of a Method to Estimate Area Values of Mean Annual Hydrologically Effective Rainfall. Unpublished ADAS Report.
Barrow, E., Hulme, M. and Jing, T. (1993 ) A 1961-90 Baseline Climatology and Future Climate Change Scenarios for Great Britain and Europe. Part 1 : 1961-90 Great Britain Baseline Climatology. Climatic Research Unit, School of Environmental Sciences, University of East Anglia.
Chambers B.J., Lord, E.I., Nicholson, F.A., Smith, K.A. (1999) Predicting Nitrogen Availability and Losses Following Land Applications of Manures : MANNER. Soil Use & Management (in publication).
Hough, M., Palmer, S., Weir, A., Lee, M., and Barrie, I. ( 1996 ) The Meteorological Office Rainfall and Evaporation Calculation System : MORECS Version 2.0 ( 1995 ). Meteorological Office, Bracknell, Update to Hydrological Memorandum No. 45.
Monteith, J. L. ( 1965 ) Evaporation and environment. Proceedings of the 19th Symposium of the Society for Experimental Biology, New York NY, Cambridge University Press, pp. 205 - 233.
Smith, J.U., Dailey, A.G., Glendinning, M.J., Bradbury, N.J., Addiscott, T.M., Smith, P., Bide, A., Boothroyd, D., Brown, E., Cartwright, R., Chorley R., Cook, S., Cousins, S., Draper, S., Dunn, M., Fisher, A., Griffith, P., Hayes, C., Lock, A., Lord, S., Mackay, J., Malone, C., Mitchell, D., Nettleton, D., Nicholls, D., Overman, H., Purslow, J., Scholey, A., Senior, S., Sim, L. and Taylor, P. (1997). Constructing a nitrogen fertiliser recommendation system using a dynamic model : what do farmers think? Soil Use and Management, 13, 225-228.
Thornthwaite, C. W. and Mather, J. R. ( 1955 ) The Water Balance. Philadelphia PA, Drexel Institute of Technology, Climatological Laboratory, Publication No. 8.
CSG 13 (1/97) 20
Appendix A
MANNER ActiveX ControlPublic Properties, Methods, and Events
Manures
Properties
ManureName Returns the currently selected manure ManureIndex Returns the index position of the currently selected
manure in the drop-down listManureList(index) Returns the manure at position index in the drop-down
listManureType Returns the manure type (FYM, slurry etc) of the
currently select manureManureListCount Returns the number of manures in the drop-down list
ManureAppRate Returns the current manure application rateManureDM Returns the dry matter content of the currently selected
manureManureTotalNitrogen Returns the total nitrogen content of the
currently selected manureManureAmmoniaUricAcidN Returns the total ammonia / uric acid N
content of the currently selected manure
Methods
SetManureName(name) Sets the currently selected manure to be nameSetManureIndex(index) Sets the currently selected manure to be the manure at
position index in the drop-down list
SetManureAppRate(value) Sets the current application rate to equal valueSetManureDM(value) Sets the current dry matter content to equal valueSetManureTotalNitrogen(value) Sets the current total nitrogen content to
equal value SetManureAmmoniaUricAcidN(value) Sets the current ammonia / uric acid
content to equal value
CSG 13 (1/97) 21
Soils
Properties
TopSoilName Returns the name of the currently selected top soilTopSoilIndex Returns the index position of the currently selected top
soil in the drop-down listTopSoilList(index) Returns the top soil at position index in the drop-down
list TopSoilListCount Returns the number of top soils in the drop-down listTopSoilFC Returns the field capacity of the selected top soilTopSoilAWC Returns the available water content of the selected top
soil
SubSoilName As with top soil PropertiesSubSoilIndex “ “SubSoilList(index) “ “SubSoilListCount “ “SubSoilFC “ “SubSoilAWC “ “
Methods
SetTopSoilName(name) Sets the currently selected top soil to be nameSetTopSoilIndex(index) Sets the currently selected top soil to be the top soil at
position index in the drop-down list
SetSubSoilName As with top soil PropertiesSetSubSoilIndex “ “
CSG 13 (1/97) 22
Incorporation Delay
Properties
IncorporationDelayName Returns the currently selected incorporation delay
IncorporationDelayIndex Returns the index position of the currently selected incorporation delay in the drop-down list
IncorporationDelayList(index)Returns the incorporation delay at position index in the drop-down list
IncorporationDelayListCount Returns the number of incorporation delays in the drop-down list
PloughedDown Returns the current status of the check box, indicating whether a manure was ploughed down or not
Methods
SetIncorporationDelayName(name) Sets the currently selected incorporation delay to be name
SetIncorporationDelayIndex(index) Sets the currently selected incorporation delay to the incorporation delay at position index in the drop-down list
SetIncorporationDelayHours(hours) Sets the currently selected incorporation delay to the incorporation delay that includes a delay of hours
SetPloughedDown(Boolean) Sets the status of the check box indicating whether or not a manure has been ploughed down.
CSG 13 (1/97) 23
Weather
Properties
AE(index) Returns the actual evapotranspiration value for the month index, where January is 1 and December is 12
Rainfall (index) Returns the rainfall value for the month index
TotalRain Returns the current value for the total rainfall from date of application until the end of soil drainage
Methods
SetAE(value,..,..,…..) Sets the 12 monthly actual evapotranspiration ratesSetRainfall(value,..,..,….) Sets the 12 monthly rainfall values
SetTotalRain Sets the total amount of rain between the date of application and the end of soil drainage
DATES
Properties
ApplicationDate Returns the currently selected manure application dateEndOfDrainageDate Returns the currently selected end of soil drainage date
Methods
SetApplicationDate(date) Sets the current application date to dateSetEndOfSoilDrianageDate(date) Sets the current end of soil drainage date to date
CSG 13 (1/97) 24
Results
Properties
TotalNitrogenApplied Returns the current value of total nitrogen applied
PotentiallyAvailableNitrogen Returns the current value of potentially available nitrogen
VolatilisedNitrogen Returns the current value of volatilised nitrogen
LeachedNitrogen Returns the current value of leached nitrogen
ActualAvailableNitrogen Returns the current value of plant available nitrogen
Miscellaneous
Properties
Filename Returns the name of the current manner scenario file
Easting Returns the Easting of the currently selected locationNorthing Returns the Northing of the currently selected location
RunSilent Returns or Sets the current status of whether MANNER is running in silent mode (i.e. without message boxes)
Units Returns or Sets the current units in which MANNER is running (i.e. metric or imperial)
Methods
Reset Resets the MANNER ActiveX control to reflect the default settings
SaveFile Saves the current settings to the MANNER scenario file that is currently loaded. If none is present defaults to the SaveFileAs method
SaveFileAs Displays the SaveAs dialog box, allowing the user to save the current settings to a MANNER scenario file
SaveFileTo(afilename) Saves the current settings to the MANNER scenario file called afilename
OpenFile Displays the OpenFile dialog box, allowing the user to select a MANNER scenario file to open
LoadFile(afilename) Loads the MANNER scenario file afilename, and adjust current settings accordingly
SetLocation(X,Y) Sets the current MANNER location to Easting X, and Northing Y
CSG 13 (1/97) 25
Events
ManureChange Returns the newly selected manureAppRateChange Returns the newly selected application rateDMChange Returns the newly selected dry matter contentTotalNChange Returns the newly selected total nitrogen valueAmmUricAcidNChange Returns the newly selected ammonia / uric acid N
content
TopSoilChange Returns the newly selected top soilSubSoilChange Returns the newly selected sub soil
AppDateChange Returns the newly selected application dateEndDrainageDateChange Returns the newly selected end of soil drainage dateTotalRainChange Returns the newly selected total rainfall
IncorporationDelayChange Returns the newly selected incorporation delayPloughedDownChange Returns the newly selected state of the ploughed down
check box
FilenameChange Returns the newly selected filename that is currently loaded
LocationChange Returns the newly selected location
MannerError Returns an error description of the error that has been trapped by the MANNER ActiveX control
CSG 13 (1/97) 26
Appendix B
Contents of a standard (*.txt) MANNER Scenario File
MANNER Report
Manure Analysis
Manure Type : Layer Manure
Application Rate : 25 t/haDry Matter Content : 36 %Total Nitrogen : 14.5 kg/tUric Acid N Content : 9.9 kg/t
Incorporation Details
Application Date : 11/11/98Date of End of Soil Drainage : 06/04/99
Total Rainfall : 289Delay to Incorporation : 12-24 hours
Ploughed Down within One Month ? : No
MANNER Results
Total Nitrogen Applied : 362.5 kg N/ha
Potentially Plant Available Nitrogen : 259 kg N/haVolatilised Nitrogen : 24.6 kg N/haLeached Nitrogen : 182.5 kg N/ha
Resultant Plant Available Nitrogen : 51.9 kg N/ha
CSG 13 (1/97) 27