Agro-environmental analysis and modelling

A.Y. 2019/2020
Overall hours
Learning objectives
The objective of the course is that the student:
- Know the structure and the function of cropping systems simulation models, with respect to crop production and environmental impact.
- Know the difference between empirical and mechanistic models.
- Know the meaning of simplifications used in all models presented in the lectures.
- Know how to calibrate and evaluate simulation models.
The knowledge and the skills acquired here, together with those of other courses ("Modeling and simulation" and "Statistical methodology for agricultural research" in particular), make the student and the future practitioner able to analyse, monitor and design agro-environmental systems with a quantitative and systemic approach.
Expected learning outcomes
At the end of the course, the student will be able to:
- Know the models for the simulation of crop potential production, of nitrogen and carbon balance in the soil-crop system, and of nitrogen-limited crop production.
- Implement simple models using a spreadsheet.
- Implement the effects of crop and soil management in simulations, and understand their interactions with soil and atmosphere.
- Calibrate and validate simulation models.
- Communicate this knowledge in writing and orally.
- Acquire autonomously new knowledge in this domain (e.g. know, understand, implement and use a simulation model for agro-environmental processes not dealt with in this course).
Course syllabus and organization

Single session

Lesson period
First semester
Course syllabus
1. Introduction to agronomic modelling: utility of models; systems theory; models classification; examples of models used in agriculture.

2. Simulation of crop development (thermal time, photoperiod, vernalization).

3. Simulation of crop growth (light interception, gross and net photosynthesis, respiration).

4. Simulation of soil carbon and nitrogen dynamics (soil organic matter decomposition, nitrogen mineralisation, main transformations of soil mineral nitrogen, crop nitrogen uptake).

5. Calibration and evaluation of simulation models.
Prerequisites for admission
The concepts of some basic disciplines - already used in the BSc to learn agronomy - are needed in this course:

- Mathematics, chemistry, physics
- Botany
- Plant physiology
- Soil science: texture and structure; soil water retention; biogeochemical cycles

With respect to agrometeorology, these concepts must be reviewed before starting the lectures:
- global radiation; solar constant; Sun-Earth geometry; cosine law; atmospheric transmissivity
- radiative balance and net radiation
- air temperature
- air humidity and vapour pressure deficit (VPD)
- surface energy balance
- evapotranspiration
- crop development: thermal units, photoperiod, vernalisation

From agronomy, you also need to remember the concept of growth analysis (LAI, crop growth rate), the phenological phases and the management techniques for the main arable crops (at least maize and wheat). Finally, a basic knowledge of a spreadsheet is needed (e.g. Microsoft Excel).

All the agronomic concepts can be reviewed using this book (in Italian), available in the Faculty Library:

Ceccon, P., Fagnano, M., Grignani, C., Monti, A., Orlandini, S., 2017. Agronomia, Prima edizione, EdiSES, Napoli, 620 pp.

Alternatively, this book in English is also available:

Loomis, R.S., Connor, D.J., 1992. Crop ecology: Productivity and management in agricultural systems. Cambridge University Press, Cambridge, UK
Teaching methods
There will be:

(a) Lectures to present all topics of the programme
(b) Computer practicals to apply - using a spreadsheet - all the concepts learnt during the lectures. Simple dynamic models will be implemented during the practicals, either using normal Excel formulas, or - only for students interested to learn the basics of a programming language - with Visual Basic for Applications (VBA). Students interested in VBA shall take an introductory seminar.

The practicals are very important. They consist in a practical application of the concepts presented during the lectures and therefore allow a better assimilation of all the concepts. Moreover, the orders of magnitude of variables and parameters can be easily grasped.

You are strongly invited not to study the concepts by heart. This will allow in the future to extend what you have learnt to other cases that are similar to those presented in this course, and to obtain a critical view. One way to do so is to read not only the lecture notes but also the articles and books that are suggested. Moreover, doing various exercises allows to verify that all the concepts are clear.
Teaching Resources
A textbook for this course does not exist. An accurate selection of book chapters, articles and web pages, together with the slides, is available on ARIEL. Most material is in English.

This is a list of the most important sources:

* Donatelli, M., 1995. Sistemi nella gestione integrata delle colture, Appunti dalle lezioni. Pubblicazione speciale dell'Istituto Sperimentale Agronomico, ISA-Sezione di Modena, Modena, 133 pag., Progetto finalizzato PANDA, Serie Generale, Pubblicazione no. 3.
* Vries, F.P. de, 1989. Simulation of ecophysiological processes of growth in several annual crops. Int. Rice Res. Inst.
* Loomis, R.S., Connor, D.J., 1992. Crop ecology: productivity and management in agricultural systems. * Cambridge, Cambridge University Press, pp. 538.
* Campbell, G.S., Norman, J.M., 1998. An introduction to environmental biophysics, Springer, New York, 286 pp.
* Stöckle, C.O., M. Donatelli, R. Nelson, 2003. CropSyst, a cropping systems simulation model. European Journal of Agronomy, 18, 289-307.
* Manzoni, S., Porporato, A., 2009. Soil carbon and nitrogen mineralization: Theory and models across scales. Soil Biology and Biochemistry 41, 1355-1379. doi:10.1016/j.soilbio.2009.02.031: Solo paragrafo "3. Modeling decomposition and N mineralization"
* Mackay, D., Di Guardo, A., Paterson, S., Kicsi, G., Cowan, C.E., 1996. Assessing the fate of new and existing chemicals: A five-stage process. Environmental Toxicology and Chemistry 15, 1618-1626. doi:10.1002/etc.5620150928
* Mackay, D., Di Guardo, A., Paterson, S., Cowan, C.E., 1996. Evaluating the environmental fate of a variety of types of chemicals using the EQC model. Environmental Toxicology and Chemistry 15, 1627-1637. doi:10.1002/etc.5620150929
* Mackay, D., Di Guardo, A., Paterson, S., Kicsi, G., Cowan, C.E., Kane, D.M., 1996. Assessment of chemical fate in the environment using evaluative, regional and local-scale models: Illustrative application to chlorobenzene and linear alkylbenzene sulfonates. Environmental Toxicology and Chemistry 15, 1638-1648. doi:10.1002/etc.5620150930
* Bellocchi, G., Rivington, M., Donatelli, M., Matthews, K., 2010. Validation of biophysical models: issues and methodologies. A review. Agronomy for Sustainable Development 30, 109-130.
Assessment methods and Criteria
The exam is written. It is made of 10-12 questions, more or less equally divided in theoretical questions and short exercises on the whole programme. The optimal length of an answer ranges from a few lines to a whole page written by hand, depending on the question or exercise. The exam lasts two hours. The mark is assigned by averaging the marks of each answer.

The evaluation considers: a) the use of adequate language; b) the correctness of the contents; c) the completeness of the answers. Missing contents reduce the mark. Excess contents are not evaluated. In the exercises it is important to use the proper order of magnitude for the variables and the parameters. Units must always be specified.

A pocket calculator can be used for the exercises.

An oral exam is not planned.

There will:
- Two exam dates at the end of each semester (Jun-Jul, Jan-Feb)
- An exam date during the intermediat exams period (Apr, Nov)
- An exam date in September

How to study: a) participate to the lectures and the practicals; b) study your lecture notes, the slides, the papers and the books; c) revise the exercises done during the practicals; d) use the models in conditions other than those proposed during the practicals.
AGR/02 - AGRONOMY AND FIELD CROPS - University credits: 6
Practicals: 32 hours
Lessons: 32 hours
Professor: Bechini Luca
By making an appointment.
In my office (Via Celoria 2, Dipartimento di Scienze Agrarie e Ambientali - Agronomia, 1st floor above "Aula 1")